BRPI0809244B1 - USE OF A PDE7 INHIBITOR COMPOUND - Google Patents

Abstract

PDE7 INHIBITOR COMPOUND, METHOD FOR IDENTIFYING AN AGENT THAT INHIBITS PDE7 ACTIVITY, AND USES OF A PDE7 INHIBITOR COMPOUND, AND A DOPAMINE RECEPTOR AGONIST OR PRECURSOR THEREOF A method of treating a movement abnormality associated with the pathology of a neurological movement disorder, such as Parkinson's disease or restless legs syndrome, by administering a therapeutically effective amount of a PDE7 inhibitory agent. One aspect of the invention provides for the administration of a PDE7 inhibiting agent in conjunction with a dopamine agonist or precursor, such as levodopa. In another aspect of the invention, the PDE7 inhibitory agent may be selected by targeting PDE7 relative to other molecular targets (i) known to be involved in the pathology of Parkinson's disease or (ii) in which other drugs that are therapeutically effective for treating Parkinson's disease.

Description

CROSS-REFERENCE TO RELATED ORDERS

This application claims the benefit of U.S. Conditional Application No. 60/920,496, filed March 27, 2007, under 35 U.S.C. § 119(e), the discovery of which is incorporated herein by reference.

FIELD OF INVENTION

The present invention relates to methods of treating a movement abnormality associated with the pathology of a movement disorder comprising administering to a patient in need thereof an amount of a PDE7 inhibitory agent effective to inhibit PDE7 enzymatic activity.

BASIS

Parkinson's disease ("PD") is a progressive disorder that affects a small group of neurons (called the substantia nigra) in the midbrain. PD is associated with the depletion of dopamine, which is important for maintaining movement control through interaction with cells in the striatum. Approximately one in 1,000 people develop the disease, and about 1% of the population over the age of 65 suffers from PD. Common symptoms of PD include resting tremor, muscle stiffness (or rigidity), slow movement, and loss of balance (postural dysfunction).

Parkinson's disease is one of three distinct conditions that can be categorized as Parkinsonism. Parkinson's disease, or shaking paralysis, is the most common form of Parkinsonism, affecting approximately 75% of cases and is of unknown origin or cause. A second type of Parkinsonism is caused by medications and toxins, including carbon monoxide, manganese, and a chemical compound known as MPTP (methylphenyltetrahydropyridine). A third form of Parkinsonism, referred to as vascular Parkinsonism, can be caused by multiple small strokes that damage the brain cells that produce dopamine.

Many treatments have been tried since James Parkinson named and described the condition in 1817. Most treatments are symptomatic therapies, such as using pharmacokinetic therapy (e.g., levodopa, dopamine receptor agonists, MAO-B inhibitors, COMT inhibitors), or deep brain stimulation therapy to alleviate symptoms of the disease. Recently, neuroprotective therapies have been the subject of intense research and development efforts.

The combination therapy of levodopa (L-dopa), a dopamine precursor, and a dopa decarboxylase inhibitor (carbidopa), is considered one of the most effective treatments for the symptoms of Parkinson's disease (The Medical Letter 35:31-34, 1993). However, certain limitations of the combination become apparent within two to five years of initiating combination therapy. As the disease progresses, the benefit of each dosage becomes shorter (the "wear-off effect"), and some patients fluctuate unpredictably between mobility and immobility (the "on-off effect"). "On" periods are usually associated with high plasma levodopa concentrations and frequently include abnormal involuntary movements (i.e., dyskinesias). "Off" periods have been correlated with low plasma levodopa concentrations and episodes of bradykinetics. Therefore, there is a need for additional effective treatments for Parkinson's disease.

The salient pathological feature of Parkinson's disease is the degeneration of dopaminergic neurons in the substantia nigra compacta (SNc) that project to the striatum. Fomo L.S., J. Neuropathol Exp Neurol 55:259-272, 1996. It is thought that relatively selective dopamine depletion in the striatum and other basal ganglia results in disordered and increased discharge and synchronization in motor areas of the basal ganglia-thalamocortical motor arcs. Wichmann and Delong, Neuropsychopharmacology: The Fifth Generation of Progress, Chapter 122, "Neurocircuitry of Parkinson's Disease," 2002. In addition to Parkinson's disease, abnormal basal ganglia function has also been implicated in a variety of neurological disorders with movement abnormalities. Such neurological disorders include restless legs syndrome (Hening, W. et al., Sleep 22:970–999, 1999) and Huntington's disease (Vonsattel, J. P. et al., J. Neuropathol. Exp. Neurol. 44:559–577, 1985). The study of the consequences of pathophysiological changes in the basal ganglia that result from the loss of dopaminergic transmission in the basal ganglia was facilitated by the discovery that primates and rodents treated with MPTP developed anatomical and behavioral changes that closely mimic the features of Parkinson's disease in humans. See, for example, Bankiewicz, K. S. et al., Life Sci. 39:7–16, 1986, Bums, R. S. et al., PNAS 80:4546–4550, 1983.

Cyclic nucleotide phosphodiesterases (PDEs) represent a family of enzymes that hydrolyze the intracellular oblique second messengers, 3',5'-adenosine monophosphate (cAMP) and 3',5'-guanosine monophosphate (cGMP), to their corresponding inactive metabolites 5'-monophosphate. At least 11 distinct classes of PDE isozymes (PD11-11) are believed to exist, each possessing unique kinetic and physical characteristics and representing single gene families. Within each of the distinct PDE classes, there may be up to four distinct subtypes. (Crocker, I. et al., Drugs Today 35(7):519-535, 1999; Fawcett, L. et al., PNAS 97(7):3702-3703, 2000; and Yuasa, K. et al., J. Biol. Chem. 275(40):31496-31479, 2000).

Virtually all phosphodiesterases are expressed in the central nervous system ("CNS"), making this gene family a particularly attractive source of novel targets for the treatment of neurodegenerative and psychiatric disorders. However, all neurons express multiple phosphodiesterases, which differ in nucleotide specificity, affinity, regulatory control, and subcellular compartmentalization, linking the target to a specific disease with the treatment of the disease's difficulty. Therefore, there is a need to identify a target from the phosphodiesterase family for the treatment of a specific CNS disease, such as Parkinson's disease and other neurological disorders with movement abnormalities.

Despite the advantages in the detection and treatment of Parkinson's disease, there is a need for new treatments for this disease and other neurological disorders with movement abnormalities. The present invention seeks to fulfill this need and provide related advantages.

SUMMARY

In accordance with the foregoing, in one aspect, the invention provides a method of treating a movement abnormality associated with the pathology of a neurological movement disorder. The method according to this aspect of the invention comprises administering to a patient in need thereof an amount of a PDE7 inhibitor effective to inhibit PDE7 enzymatic activity, wherein such inhibition of PDE7 enzymatic activity is the primary therapeutic mode of action of the PDE7 inhibitor in treating the movement abnormality.

In accordance with the foregoing, in one aspect, the invention provides a method of treating a movement abnormality associated with the pathology of a neurological disorder. The method according to this aspect of the invention comprises administering to a patient in need thereof an amount of a PDE7 inhibitor effective to inhibit PDE7 enzymatic activity, wherein such inhibition of PDE7 enzymatic activity is the primary therapeutic mode of action of the PDE7 inhibitor in treating the movement abnormality.

In another aspect, the invention provides a method for identifying an agent that inhibits PDE7 activity useful for treating the movement abnormality associated with the pathology of a neurological movement disorder in a mammalian patient in need thereof. The method of this aspect of the invention comprises (a) determining the IC50 for inhibition of PDE7A and/or PDE7B activity of each of the plurality of agents; (b) selecting agents from the plurality of agents having an IC50 for inhibition of PDE7A and/or PDE7B activity of less than about 1 μM; (c) determining the IC50 for inhibition of PDE4 activity of the agents having an IC50 for inhibition of PDE7 activity of less than about 1 μM; (d) identifying agents useful for treating a movement disorder by screening compounds having an IC50 for inhibition of PDE4 activity greater than 10 times the lower of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity; and (e) evaluating the activity of the identified compounds in a neurological movement disorder model assay wherein an agent that has an IC50 for inhibition of PDE7A and/or PDE7B activity of less than about 1 μM and an IC50 for inhibition of PDE4 activity greater than 10 times the lower of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity and is determined to be effective for treating at least one movement abnormality in a model assay in a model assay, is indicative of a PDE7 inhibitory agent useful for treating the movement abnormality associated with the pathology of a neurological movement disorder in a mammalian patient.

In another aspect, the invention provides a method of treating a movement abnormality associated with the pathology of a neurological movement disorder. The method according to this aspect of the invention comprises administering to a patient in need thereof a therapeutically effective amount of a chemical compound that is a PDE7 inhibitor, the chemical compound characterized in that: (i) the chemical compound has an IC50 for the inhibition of PDE7A and/or PDE7B activity of less than about 1 μM; and (ii) the chemical compound has an IC50 for the inhibition of PDE 3 greater than 10 times the lower of the IC50 for the inhibition of PDE7A activity and the IC50 for the inhibition of PDE7B activity.

The methods of various aspects of the invention are useful for treating a movement abnormality associated with a neurological disorder. The methods of various aspects of the invention are also useful for treating a neurological movement disorder. The methods of various aspects of the invention are further useful for treating a movement abnormality associated with a neurological movement disorder.

In some embodiments of various aspects of the invention, the methods are useful for treating a neurological movement disorder, the movement abnormality associated with a neurological disorder, and/or the movement abnormality associated with a neurological movement disorder that is treatable with a dopamine receptor agonist or precursor of a dopamine receptor agonist. In some embodiments, the methods are useful for treating a neurological movement disorder selected from the group of Parkinson's disease, post-encephalitic parkinsonism, dopamine-responsive dystonia, Shy-Drager syndrome, periodic limb movement disorder (PLMD), periodic limb movements in sleep (PLMS), Tourette's syndrome, and restless legs syndrome (RLS).

In some embodiments of various aspects of the invention, the methods are useful for treating the movement abnormality associated with the pathology of a neurological movement disorder and/or the pathology of a neurological disorder. In some embodiments of various aspects of the invention, the methods are useful for treating the movement abnormality associated with the pathology of a neurological movement disorder that is treatable with a dopamine receptor agonist or precursor of a dopamine receptor agonist. In some embodiments, the methods are useful for treating the movement abnormality associated with the pathology of a neurological movement disorder selected from the group of Parkinson's disease, post-encephalitic parkinsonism, dopamine-responsive dystonia, Shy-Drager syndrome, periodic limb movement disorder (PLMD), periodic limb movements in sleep (PLMS), Tourette's syndrome, and restless legs syndrome (RLS).

DESCRIPTION OF DRAWINGS

The foregoing aspects and many of the continuing advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawing. In certain of these figures, statistical significance is indicated by the marking "+" refers to a p-value of less than 0.05, "**" refers to a p-value of less than 0.01, and "***" refers to a p-value of less than 0.005. In the figures: FIGURE 1 is a flowchart illustrating the neurotransmission pathway in the basal ganglia in a midbrain of a healthy mammalian patient, with excitatory pathways labeled "+" with hatched arrows and with inhibitory pathways labeled with open arrows; FIGURE 2A illustrates a proposed model of the dopamine receptor-activated pathway in a healthy patient, illustrating the new finding that the dopamine receptor-activated intracellular signaling pathway is downregulated or antagonized by PDE7, which hydrolyzes cAMP to this 5'monophosphate (5'AMP); FIGURE 2B illustrates a model proposed by the present inventors of the dopamine receptor-activated pathway in an untreated patient with Parkinson's disease (PD), showing that the reduced amount of the dopamine receptor-activated intracellular signaling pathway is still downregulated or antagonized by PDE7, which hydrolyzes cAMP to this 5'monophosphate (5'AMP), leading to low levels of activated PKA and reduced neuronal activation as compared to a healthy patient; FIGURE 2C illustrates a model proposed by the present inventors of the dopamine receptor-activated pathway in a Parkinson's disease (PD) patient treated with a PDE7 inhibitory agent, showing that the presence of a PDE7 inhibitory agent that is effective at inhibiting PDE7 enzymatic activity by blocking cAMP hydrolysis effectively increases intracellular cAMP levels, activating protein kinase A ("PKA"), which modulates the phosphorylation of downstream elements in intracellular signaling pathways, leading to an increase in neuronal activation in accordance with various embodiments of the methods of the invention; FIGURE 3A is a graph illustrating the PDE7A inhibitory activity (IC50), expressed as counts per minute ("CPM"), of a representative PDE7 inhibitory agent (OM69) useful in the methods of the invention; FIGURE 3B is a graph illustrating the PDE7B inhibitory activity (IC50), expressed as CPM, of a representative PDE7 inhibitory agent (OM69) useful in the methods of the invention; FIGURE 4A is a graph illustrating the PDE7A inhibitory activity (IC50), expressed as CPM, of a representative PDE7 inhibitory agent (OM955) useful in the methods of the invention; FIGURE 4B is a graph illustrating the PDE7B inhibitory activity (IC50), expressed as CPM, of a representative PDE7 inhibitory agent (OM955) useful in the methods of the invention; FIGURE 5A is a graph illustrating the PDE7A inhibitory activity (IC50), expressed as CPM, of a representative PDE7 inhibitory agent (OM956) useful in the methods of the invention; FIGURE. 5B is a graph illustrating the PDE7B inhibitory activity (IC50), expressed as CPM, of a representative PDE7 inhibitory agent (OM956) useful in the methods of the invention; FIGURE 6A is a graph illustrating the PDE7A inhibitory activity (IC50), expressed as CPM, of a representative PDE7 inhibitory agent (OM056) useful in the methods of the invention; FIGURE 68 is a graph illustrating the PDE7B inhibitory activity (IC50), expressed as CPM, of a representative PDE7 inhibitory agent (OM056) useful in the methods of the invention; FIGURE 69 is a graph comparing the concentration (ng/g) in brain tissue and plasma over time of a representative PDE7 inhibitor (OM69) useful in the method of the invention; FIGURE 70 is a flowchart illustrating an experiment performed in a methylphenyltetrahydropyridine (“MPTP”) mouse model of Parkinson’s disease to initially evaluate a representative PDE7 inhibitory agent (OM69) useful in the methods of the invention, administered alone or in combination with L-dopa, compared to the effect of L-dopa alone, as described in Example 5; FIGURE 71 is a bar graph illustrating the painted paw lunge length test in the MPTP mouse model following the protocol illustrated in FIGURE 8, demonstrating that a representative PDE7 inhibitory agent (OM69) useful in the method of the invention increases lunge length in MPTP-treated mice when administered alone or in combination with L-dopa, and comparing the effectiveness of this inhibitor by L-dopa alone to a saline control, as described in Example 5; FIGURE 72 is a bar graph illustrating a subset of the data shown in FIGURE 9 comparing the effect on stride length in the MPTP mouse model of various dosages of a representative PDE7 inhibitory agent (OM69 (Compound 1)) useful in the method of the invention, various dosages of L-dopa, and combinations of OM69 and L-dopa, as described in Example 5; FIGURE 73 is a bar graph illustrating a subset of the data shown in FIGURE 9 comparing the effect on stride length in the MPTP mouse model of a representative PDE7 inhibitor (OM69) useful in the method of the invention, L-dopa, and combinations thereof, compared to saline control (i.e., not treated by MPTP) mice, as described in Example 5; FIGURE 74 is a flowchart illustrating an experiment performed in the MPTP mouse model of Parkinson's disease to confirm that the representative PDE7 inhibitor (OM69) increases lunge length in MPTP-treated mice as described in Example 6; FIGURE 13A is a bar graph illustrating that the vehicle control dimethylacetamide:polyethylene glycol:methanesulfonic acid (DMA:PEG:MSA) does not alter lunge length in MPTP-treated mice when administered alone as described in Example 7; FIGURE 138 is a bar graph illustrating that the vehicle control tartaric acid (TA) does not alter lunge length in MPTP-treated mice when administered alone as described in Example 7; FIGURE 139 is a bar graph illustrating the spotted paw lunge length test in the MPTP mouse model demonstrating that the representative PDE7 inhibitory agent OM955 (Compound 2) increases lunge length in MPTP mice, with full recovery to baseline lunge length at 20 minutes after dosing at 0.5 mg/kg, as described in Example 7; FIGURE 15A is a bar graph illustrating the spotted paw lunge length test in the MPTP mouse model demonstrating that 1 mg/kg L-dopa does not increase lunge length in MPTP mice to a significant level at 20 minutes after dosing, as described in Example 7; FIGURE 15B is a bar graph illustrating the spotted paw lunge length test in the MPTP mouse model, demonstrating that 0.1 mg/kg OM955 (compound 2) does not increase lunge length in MPTP mice to a significant extent at 20 minutes post-administration, as described in Example 7; FIGURE 15C is a bar graph illustrating the spotted paw lunge length test in the MPTP mouse model, demonstrating mice administered the combination of 0.1 mg/kg OM955 (compound 2) and 1 mg/kg L-dopa show full recovery of lunge length in MPTP-treated mice to a significant extent at 20 minutes post-administration, thereby demonstrating synergistic results of the combination, as described in Example 7; FIGURE 16 is a bar graph illustrating the spotted paw lunge length test in the MPTP mouse model, demonstrating that the representative PDE7 inhibitory agent OM956 (compound 3) increases lunge length in MPTP-treated mice, with full recovery of lunge length to baseline at 20 minutes after dosing at 0.5 mg/kg, as described in Example 7; FIGURE 17 is a bar graph illustrating the spotted paw lunge length test in the MPTP mouse model, demonstrating that the representative PDE7 inhibitory agent OM056 (compound 4) increases lunge length in MPTP-treated mice, with full recovery of lunge length to baseline at 20 minutes after dosing at 0.05 mg/kg, as described in Example 7; and FIGURE 18 is a bar graph illustrating the painted paw lunge length test in the MPTP mouse model, demonstrating that the representative PDE7 inhibitory agent OM69 (compound 1) increases lunge length in MPTP-treated mice in a dose-dependent manner and further demonstrating that the combination of OM69 and L-dopa provides greater than additive (i.e., synergistic) increases in lunge length in MPTP-treated mice, as described in Example 6.

DETAILED DESCRIPTION

The present invention is based on the surprising discovery by the present inventors that selective inhibitors of cyclic nucleotide phosphodiesterase type 7 (PDE7) cause a striking improvement in motor function in the 1-methyl, 4-phenyl, 1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease (PD). Through the use of the MPTP animal model, the present inventors have shown that administration of selective PDE7 inhibitors to MPTP-lesioned mice is effective in restoring stride length in these animals in a manner comparable to treatment with L-dopa, but at a surprisingly low dosage compared to the dosage of L-dopa required to achieve an equivalent level of response. Furthermore, the inventors have demonstrated that the combination of suboptimal dosages of L-dopa and a selective PDE7 inhibitor, when administered together, provides a greater than additive (i.e., synergistic) effect, again restoring stroke length in MPTP-lesioned mice to normal values.

I. Definitions

Unless specifically defined herein, all terms used herein have the same meaning as would be understood by those of ordinary skill in the art of the present invention. The following definitions are provided in order to provide clarity with respect to the terms as they are used in the specification and claims to describe the present invention.

As used herein, the term "neurological movement disorder" refers to a movement disorder characterized by a deficiency or defect in dopamine signaling that is clinically manifested by one or more movement abnormalities associated with the pathology of the movement disorder, such as abnormal involuntary movements, resting tremor, changes in muscle tone, difficulty in initiating movement (slow movement), and/or disturbances in postural stability.

As used herein, the term "Parkinson's disease" refers to a clinical syndrome marked by four cardinal signs: (1) resting tremor; (2) rigidity; (3) slow movement; and (4) impaired postural reflexes.

As used herein, the term "post-encephalitic Parkinsonism" refers to Parkinsonism that occurs after and presumably as a result of encephalitis.

As used herein, the term "Parkinsonism" refers to any of a group of neurological disorders similar to Parkinson's disease, marked by four cardinal signs of Parkinson's disease: resting tremor, muscular rigidity, bradykinesia, and impaired postural reflexes.

As used herein, the term "slow movement" or "akinesia" refers to an impairment of spontaneous or automatic movement.

As used herein, the term "hyperkinesia" or "dyskinesia" refers to abnormal or excessive involuntary movement.

As used herein, the term "tremor" refers to relatively rhythmic, oscillating movements that may, for example, result from alternating contractions of opposing muscle groups (e.g., Parkinson's tremor).

As used herein, the term "dystonia" refers to involuntary movements with sustained contractions at the end of the movement.

As used herein, the term "dopamine-responsive dystonia" refers to a neurological movement disorder in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures, and which can be alleviated by agents that increase dopamine levels or enhance signaling through dopaminergic pathways. Such a disorder may be associated with Parkinson's disease, juvenile parkinsonism, progressive supranuclear palsy, cortical basal ganglionic degeneration, certain types of multiple system atrophy, or DYT3 X-linked recessive parkinsonism-dystonia.

As used herein, the term "periodic limb movement of sleep" (PLMS) refers to a condition in which patients' legs move or twitch involuntarily during sleep. If these movements result in sleep disturbance, this syndrome is referred to as periodic limb movement disorder (PLMD).

As used herein, the term "restless legs syndrome" (RLS) refers to a neurological disorder of uncertain pathophysiology that is characterized by sensations of pain, burning, tingling, or crawling in the legs that occur especially at night, usually when lying down (as before sleep), and cause a strong urge to move the legs that is often accompanied by difficulty falling and staying asleep and by involuntary twitching of the legs during sleep.

As used herein, the term "Shy-Drager syndrome" refers to a degenerative neurological disorder characterized by orthostatic hypotension, autonomic dysfunction, bladder dysfunction, and Parkinson's-like deficits in movement.

As used herein, the term "dopaminergic agent" refers to an agent that has functions to enhance or replace dopamine-mediated effects in the central nervous system, including dopamine (if a clinically effective method of delivery is to be developed), dopamine precursors such as L-dopa, dopamine cofactors, dopamine metabolizing enzyme inhibitors, other dopamine receptor agonists and precursor compounds that are metabolically converted to a dopamine receptor agonist, as well as dopamine uptake inhibitors.

As used herein, the term "dopamine receptor agonist" refers to any molecule that causes activation of one or more of the subtypes of the dopamine receptor protein family.

As used herein, the term "molecular target known to be involved in Parkinson's disease pathology" includes cachechol-O-methyltransferase (COMT), monamine oxidase B (MAO-B), dopamine transporters (DAT), tyrosine hydroxylase, dopamine receptors, adenosine A2A receptors, and gabapentin receptors.

As used herein, the term "molecular target known to be associated with the dopamine signaling pathway" includes cachechol-O-methyltransferase (COMT), monamine oxidase B (MAO-B), dopamine transporters (DAT), tyrosine hydroxylase, dopa decarboxylase, dopamine receptors, N-methyl D-aspartate (NMDA) receptors, muscarinic acetylcholine receptors, gamma amino butyric acid (GABA) receptors, adenylyl cyclase, protein kinase A (PKA), dopamine and cyclic AMP-regulated phosphoprotein of molecular weight 32,000 (DARPP32), and protein phosphatase-1.

As used herein, the term "treatment" includes symptomatic therapy to reduce, alleviate, or mask the symptoms of the disease or disorder, as well as therapy to prevent, mitigate, halt, or reverse the progression of the severity of the condition or symptoms being treated. As such, the term "treatment" includes both medical therapeutic treatment of an established condition or symptoms and/or prophylactic administration, as appropriate.

As used herein, the term "treatment of a movement abnormality associated with the pathology of a neurological movement disorder" refers to the reversal, alleviation, amelioration, or inhibition of one or more movement abnormalities associated with the neurological movement disorder.

As used herein, the term "treating a neurological movement disorder" includes: (1) treating the movement abnormality associated with the pathology of a neurological movement disorder; and/or (2) treating a neurological movement disorder.

As used herein, the term "treating a neurological disorder" includes: (1) treating the movement abnormality associated with the pathology of a neurological disorder; and/or (2) treating a neurological disorder.

As used herein, the term "treatment" also encompasses, depending on the condition of the patient in need thereof, preventing the neurological movement disorder or preventing the movement abnormality associated with the pathology of the neurological movement disorder or preventing the neurological disorder or preventing the movement abnormality associated with the pathology of the neurological disorder, including the onset of the movement abnormality or any symptoms associated therewith, as well as reducing the severity of the movement abnormality, or preventing a recurrence of the movement abnormality.

As used herein the term "PDE7" is used generically to refer to all translation products encoded by transcripts of one or both of these two genes (PDE7A and/or PDE7B).

As used herein, the term "PDE7 inhibitory agent" refers to an agent, such as a chemical compound, a peptide, or a nucleic acid molecule, that directly or indirectly inhibits or blocks the phosphodiesterase activity of PDE7A, PDE7B, or both PDE7A and PDE7B. In some cases, the agent may bind to or interact directly with the PDE7 protein. An agent that binds to PDE7 may act to inhibit or block PDE7 activation by any suitable means, such as by inhibiting cAMP binding or by binding the substrate to PDE7. In other cases, the PDE7 inhibitory agent may inhibit PDE7 activity indirectly, such as by decreasing PDE7 protein expression.

As used herein, the term "mammalian subject" includes all mammals, including without limitation humans, non-human primates, dogs, cats, horses, sheep, goats, cows, rabbits, pigs, and rodents.

II. Use of PDE7 inhibitor agents to treat movement abnormality associated with the pathology of a neurological movement disorder

The dopaminergic system is strongly implicated in the regulation of locomotor activity and movement in general. See, for example, Tran, A.H. et al., PNAS 102:2117–2122, 2005; Tran, A.H. et al., PNAS 99:8986–8991, 2002. For example, evidence shows that dopaminergic dysfunction plays a critical role in Parkinson's disease, parkinsonism, restless legs syndrome (RLS), periodic limb movement disorder (PLMD), periodic limb movement in sleep ("PLMS"), and other movement disorders. In Parkinson's disease, there is a dopamine deficiency in the striatum, which results from a loss of pigmented neurons in the substantia nigra and locus coeruleus with corresponding loss of their neurotransmitters dopamine and norepinephrine. In postencephalic parkinsonism, the midbrain is affected, with loss of substantia nigra neurons. Wyngaarden and Smith, Cecil Textbook of Medicine, 17th Ed. "Neurological and Behavioral Disease: Section 5: The Extrapyramidal Disorders: Parkinsonism," 1985.

Relatively selective dopamine depletion in the striatum and other basal ganglia is thought to result in disordered and increased discharge and synchronization in motor areas of the basal ganglia-thalamocortical motor arcs. Wichmann and Delong, Neuropsychopharmacology: The Fifth Generation of Progress, Chapter 122, "Neurocircuitry of Parkinson’s Disease," 2002.

The basal ganglia serves as a major input to the motor system of the pyramidal tract. The basal ganglia comprises five pairs of neurons, including the caudate nucleus, putamen nucleus, pallidum, subthalamic nucleus, and substantia nigra. The subthalamic nucleus is in the diencephalon. The substantia nigra is located in the midbrain. The caudate nucleus, putamen, and pallidum reside within the cerebral hemispheres and are collectively referred to as the striatum. The caudate and putamen are collectively considered the striatum, which serves as the primary site of neural input to the basal ganglia. The striatum receives afferents from all parts of the cerebral cortex and the median central nucleus of the thalamus. The striatum's major output is the pallidum and the substantia nigra reticularis. The dorsal part of the substantia nigra sends efferents to the striatum (from the nigrostriatal dopaminergic pathway) and the ventral part of the substantia nigra receives fibers from the striatum.

FIGURE 1 illustrates the neurotransmission pathway in the basal ganglia in the midbrain of a healthy mammalian patient, with excitatory pathways labeled "+" with hatched arrows and inhibitory pathways labeled "-" with open arrows. As shown in FIGURE 1, the neural pathways connect the output pathways of the basal ganglia, a functionally related subcortical nucleus that includes the external globulus pallidus ("GPe"), the internal globulus pallidus ("GPi"), the substantia nigra pars compacta ("SNc"), and the substantia nigra para reticulata ("SNr"), to the striatum. FIGURE 1 also illustrates the pathways connecting the subthalamic nuclei ("STN") to the GPe, GPi, and SNr. As shown in FIGURE 1, in a healthy patient, dopamine ("DA") from dopamine-producing cells in the SNc sends an excitatory signal to dopamine D1 ("D1") receptors, which, once activated, send an inhibitory signal to the SNr and an inhibitory signal to the GPi. As further shown in FIGURE 1, DA from dopamine-producing cells in the SNc also sends an inhibitory signal to dopamine D2 ("D2") receptors, which inhibits the D2 receptors from sending an inhibitory signal to the GPe.

The prominent pathological feature of Parkinson's disease ("PD") is the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc) that project to the striatum. Forno, L.S., J. Neuropathol Exp Neurol 55:259-272, 1996. In the early stages of Parkinson's disease, dopamine depletion has been determined to be greatest in the sensorimotor territory of the striatum, consistent with the early manifestation of motor dysfunction. Kish, S.J. et al., N. Engl. J. Med. 318:876-880, 1988.

In PD and Parkinsonism, the cells that produce dopamine in the SNc are lost, leading to a deficit in dopaminergic signaling to the striatum. Because DA usually activates inhibitory striatal output to the SNr via D1 receptors in a healthy patient (as shown in FIGURE 1), this pathway is attenuated in PD. Conversely, because DA inhibits inhibitory striatal output to the GPe via D2 receptors in a healthy patient (as shown in FIGURE 1), this pathway is enhanced in PD. Therefore, a deficit in dopaminergic signaling to the striatum in PD has the net effect of causing inhibition of the excitatory pathway network from the thalamus to the cortex.

Cyclic adenosine monophosphate (cAMP) is a second messenger that mediates the biological response of cells to a wide range of extracellular stimuli. When the appropriate agonist binds to a specific cell surface receptor, adenylyl cyclase is activated to convert adenosine triphosphate (ATP) to cAMP. It is theorized that the actions induced by cAMP agonists within the cell are predominantly mediated by the action of cAMP-dependent proteins. The intracellular actions of cAMP are terminated by transport of the cell's nucleotide production or by enzymatic cleavage by cyclic nucleotide phosphodiesterases (PDEs), which lysozymes the 3'-phosphodiester bond to form 5'-adenosine monophosphate (5'-AMP), an inactive metabolite. Therefore, the intracellular PDE enzyme family regulates cAMP levels in cells.

FIGURE 2A illustrates a proposed model of the dopamine receptor-activated pathway in a healthy patient. As shown in FIGURE 2A, in healthy patients, dopamine (DA) (depicted as three arrows), which is produced by dopaminergic neurons in the substantia nigra pars compacta (SNc), binds to and activates the dopamine D1 receptor, leading to the activation of adenylyl cyclase and increased cAMP levels. cAMP-activated protein kinase A ("PKA") modulates the phosphorylation of downstream elements in intracellular signaling pathways, leading to neuron activation. As shown in FIGURE 2A, it is theorized that the dopamine receptor-activated intracellular signaling pathway is downregulated or antagonized by PDE7, which hydrolyzes cAMP to 5'monophosphate (5'AMP).

FIGURE 2B illustrates a proposed model of the dopamine receptor-activated pathway in an untreated patient with Parkinson's disease (PD). As shown in FIGURE 2B, in the PD patient, a reduced amount of dopamine (DA) (depicted as one arrow compared to three arrows in the healthy patient) is available for binding to the dopamine (D1) receptor. For example, as described with reference to FIGURE 1, the dopamine-producing cells in the SNc are lost, leading to a deficit in dopaminergic signaling to the striatum. The reduced level of DA binds and activates the Dopamine D1 receptor to a lesser degree in the PD patient, leading to minimal adenylyl cyclase activation and a blunted increase in cAMP levels. As a result, the degree of protein kinase A ("PKA") activation is lower, which in turn leads to less phosphorylation of downstream elements in intracellular signaling pathways and a lower degree of neuronal activation. As shown in FIGURE 2B, it is theorized that the reduced amount of activated dopamine receptor intracellular signaling pathway is further downregulated or antagonized by PDE7, which hydrolyzes cAMP to this 5'monophosphate (5'AMP), leading to low levels of activated PKA and reduced neuronal activation as compared to a healthy patient.

FIGURE 2C illustrates a proposed model of the dopamine receptor-activated pathway in a patient with Parkinson's disease (PD) treated with a PDE7 inhibitor. As shown in FIGURE 2C, in the PD patient, a reduced amount of dopamine (DA) (depicted as one arrow compared to three arrows in the healthy patient) is available for binding to the dopamine (D1) receptor. For example, as described with reference to FIGURE 1, dopamine-producing cells in the SNc are lost, leading to a deficit in dopaminergic signaling to the striatum. The reduced level of DA binds to and activates the D1 dopamine receptor to a lesser degree in the PD patient, leading to minimal activation of adenylyl cyclase and an attenuated increase in cAMP levels. However, as further shown in FIGURE 2C, the presence of a PDE7 inhibitory agent that is effective in inhibiting PDE7 enzymatic activity by blocking cAMP hydrolysis, thereby increasing intracellular cAMP levels, allows for a more normal degree of protein kinase A ("PKA") activation, which modulates the phosphorylation of downstream elements in intracellular signaling pathways, leading to an increase in neuronal activation.

In support of the dopamine signaling model shown in FIGURES 2A-2C, the present inventors have discovered that administration of a PDE7 inhibitor that inhibits PDE7 enzymatic activity results in the improvement of a movement abnormality associated with the pathology of a movement disorder, such as Parkinson's disease. The data presented here demonstrate that PDE7 inhibitors are effective in restoring limb movement, as measured by paw forward length, in an MPTP-treated mouse and that synergistic effects are observed when PDE7 inhibitors are combined with L-dopa in the MPTP mouse model. Based on the surprising discovery made by the present inventors, it is believed that PDE7 plays a role in postsynaptic and dopamine signaling in the brain, specifically in areas known to be associated with locomotion.

In addition to Parkinson's disease, abnormal basal ganglia function has also been implicated in a variety of neurological disorders with movement abnormalities. Such neurological disorders include restless legs syndrome (Hening, W. et al., Sleep 22:970-999, 1999). Therefore, based on the studies described here, it is believed that a PDE7 inhibitor will have a therapeutic effect in such neurological movement disorders.

Therefore, while not wishing to be bound by theory, it is believed that PDE7 inhibitors may be useful in treating neurological disorders characterized by abnormal basal ganglia function, such as a deficiency in dopamine receptor signaling, e.g., Parkinson's disease, post-encephalitic parkinsonism, drug-induced parkinsonism, dopamine-responsive dystonia, Shy-Drager syndrome, periodic limb movement disorder (PLMD), periodic limb movements in sleep (PLMS), and restless legs syndrome (RLS) by inhibiting PDE7 activity and thereby preventing cAMP degradation in the basal ganglia. It is therefore believed that PDE7 inhibitors may be useful in treating these and other neurological movement disorders and neurological disorders characterized by movement abnormalities that are currently treated with L-dopa, other dopamine agonists or precursors, or other dopaminergic agents.

In some aspects of the invention, PDE7 inhibitors are used to treat a movement abnormality associated with the pathology of a neurological disorder, whether or not such disorder is associated with a dopamine signaling defect or deficiency, wherein inhibition of PDE7 enzymatic activity is the primary therapeutic mode of action of the PDE7 inhibitor in treating the movement abnormality.

In some embodiments, the invention provides methods of treating a movement abnormality associated with the pathology of a neurological movement disorder, comprising administering to a patient in need thereof an amount of a PDE7 inhibitor effective to inhibit PDE7 enzymatic activity, wherein such inhibition of PDE7 enzymatic activity is the primary therapeutic mode of action of the PDE7 inhibitor in treating the movement abnormality. In some embodiments, the invention provides methods of ameliorating the symptoms of a movement disorder, including but not limited to a disorder of the dopamine receptor intracellular signaling pathway, comprising administering a PDE7 inhibitor that inhibits PDE7 enzymatic activity. In some embodiments, the neurological movement disorder is treatable with a dopamine receptor agonist or precursor of a dopamine receptor agonist. Parkinson's Disease

Parkinsonism is a clinical syndrome consisting of four cardinal signs: (1) resting tremor; (2) rigidity; (3) slow movement; and (4) impaired postural reflexes.

Bradykinesia calculations account for most Parkinsonian symptoms and signs. Parkinsonism can be categorized into the following etiological groups: the primary disorder referred to as Parkinson's disease, secondary, acquired Parkinsonism (due to drug or toxin exposures, previous strokes, or encephalitis), and "Parkinsonism-plus" syndrome (which includes decreased eye movements, orthostatic hypotension, cerebellar ataxia, or dementia in a Parkinsonian patient). Lesions of the substantia nigra with resulting loss of dopamine in the striatum result in the bradykinetic syndrome of Parkinsonism. In Parkinson's disease, there is a loss of pigmented neurons in the substantia nigra and cerebrospinal fluid, with subsequent loss of their dopamine and norepinephrine neurotransmitters.

Animal models of PD rely heavily on the serendipitous discovery that systemically administered MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) causes specific neuronal cell death in the substantia nigra of humans, monkeys, and rodents (Jakowec, M.W. et al., Comp. Med. 54(5):497-513, 2004). The origin of the cell death is reminiscent of what is seen in PD patients at the time of autopsy. Commonly used animal models for Parkinson's disease include a monkey MPTP model, a rat 6-OHDA model, and a mouse MPTP model. As described in Examples 5-7 herein, the MPTP-lesioned mouse model of PD can be used to evaluate the efficacy of PDE7 inhibitory agents useful in the method of the invention to reduce or lessen MPTP-induced changes in its stride length, grid step length, and grid paw failures (Tillerson, J.L. et al., Exp. Neurol. 178(l):80-90, 2002).

As demonstrated in Examples 5-7, PDE7 inhibitors are effective in restoring limb movement in a mouse treated with MPTP. Although current methods for treating Parkinson's disease generally involve treatment with dopamine receptor agonists, the methods of the present invention are aimed at inhibiting PDE7 phosphodiesterase activity in a patient with decreased dopamine signaling in order to increase cAMP levels, thereby leading to increased PKA activity. It is theorized that PDE7 inhibitors may have advantages over current PD medications or reduce the required levels of such medications. For example, chronic use of L-dopa, the most common PD medication, causes various dyskinesias (Bezard, E. et al., Nat. Rev. Neurosci. 2(8):577-88, 2001). Any alternative PD medication to L-dopa may help with this serious side effect.

As further demonstrated in Examples 5 to 7, the combination of PDE7 inhibitors and L-dopa, a dopamine receptor agonist, provides a synergistic effect, leading to further improvement in periodic movement in an MPTP-treated mouse. A drug used in conjunction with L-dopa that allows for the threat of L-dopa dosing, such as a PDE7 inhibitor, may delay the onset of dyskinesia. Furthermore, because increased dopamine levels resulting from L-dopa therapy can increase oxidative damage to compact neurons in the substantia nigra, an agent such as a PDE7 inhibitor that allows for the threat of L-dopa dosing may delay disease progression. Accordingly, the PDE7 inhibitors of the present invention may be administered in conjunction with L-dopa, other dopamine receptor agonists, dopamine receptor agonist precursors, or other dopaminergic agents, given in a combination dosage form, given concurrently (i.e., at the same time), or given sequentially (e.g., in rotation). Restless Legs Syndrome (RLS)

Restless legs syndrome (RLS) is a common neurological condition that also involves the dopamine system. RLS is a sensory motor disorder for which the major mandatory criteria for diagnosis are: (1) an urge to move the legs, usually associated with an uncomfortable sensation in the limbs; (2) worsening of symptoms during periods of rest and inactivity; (3) improvement of symptoms with movement; and (4) onset or worsening of symptoms during the evening or night. Allen, R.P. et al., Sleep Med 4:101-119, 2003. Supporting criteria, which are common but not essential for the diagnosis of RLS, include the presence of periodic limb movements of sleep (PLMS), which are involuntary movements of the lower limbs during sleep, often occurring in sequences of at least 4, with an intermovement interval of 5 to 90 seconds. (Baier et al., J. Neurological Sciences 198:71-77, 2002). Another supporting criterion for the diagnosis of RLS is responsible for low doses of dopaminergic treatments. Allen, R.P. et al., supra. RLS and PLMS are highly represented in patients affected by Parkinson's disease and other forms of parkinsonism. Poewe, W. et al., Neurology 63:S12-S16, 2004. It has been determined that the pathogenetic mechanism of RLS is characterized by a neurological dysfunction of the dopaminergic system. The dopaminergic system has been implicated in RLS by functional imaging studies (Turjanski, N. et al., Neurology 52:932-37, 1999) and by the strong efficacy of dopamine agonist treatment for human RLS and PLMS (Montplaisier, J. et al., Neurology 52:938-43, 1999; Trenkwalder, C. et al., Neurology 62:1391-97, 2004; and Walters, A.S. et al., Mov. Disord. 19:1414-23, 2004). For example, clinical studies with the following medications used to treat Parkinson's disease also show efficacy by RLS agonists: (1) DA: Sinemet™ (L-dopa, carbidopa), Stalevo™ (L-dopa, carbidopa entacapone), Permax™ (pergolide), Parlodel™ (bromocriptine); (2) D2,D3,D4 agonists: Mirapex™ (pramipexole), Requip™ (ropinirole); (3) mACh antagonists: Cogentin™ (benztropine), Artane™ (trihexyphenidyl); (4) MAO inhibitors: Eldepryl™ (selegiline); and (5) COMT inhibitor Tasmar™ (tolcapone). See, for example, Hentz J.G. et al., Mov Disord. 15(2): 324-7 (2000); Walters A.S. et al., Ann Neurol 24(3):455-8 (1988); Trenkwalder C. et al., Neurology 62(8): 1391-7 (2004); Polo O. et al., Clin Neuropharmacol 31(1):61 (2007); Kohnen R. Sleep 22(8):1073-81 (1999); and Shapiro C. Mov Disord 17(2): 398-401 (2002).

The MPTP mouse model described here is widely known as a model of Parkinson's disease, but it can also represent disorders characterized by dopamine insufficiency or those responsive to dopamine receptor agonists, such as restless legs syndrome. Therefore, the response observed in MPTP-treated animals, as demonstrated in Examples 5 to 7 above, can reasonably be considered transferable to restless legs syndrome and other movement disorders characterized by dopamine insufficiency, such as dopamine-responsive dystonia, Shy-Drager syndrome, periodic limb movements of sleep (PLMS), and Tourette syndrome.

Periodic limb movement disorder (PLMD)/periodic limb movements of sleep (PLMS) Periodic limb movement disorder (PLMD) is a syndrome characterized by sleep disturbance secondary to periodic limb movements of sleep (PLMS). While commonly associated with RLS (Manconi M. et al., Sleep Med. 8(5):491-7 (2007); Haba-Rubio J. et al., Neurophysiol Clin. 33(4): 180-4 (2003)), PLMD may also be observed in the setting of spinal cord damage (De Mello M.T. et al., Spinal Cord. 42(4):218-21 (2004)), narcoplepsy (Homyak M. et al., Sleep Med Rev. 10(3): 169-77 (2006)), other sleep disorders (Horyak, 2006 supra; Saletu M. et al., Hum Psychopharmacol. 16(2): 177-187 (2001)), or uremia (Walker S.L. et al., Sleep 19(3):214-8 (1996)). PLMD can occur in the absence of an identifiable primary pathology (Vetrugno R. et al., Neurol Sci. 28 Suppl 1:S9-S14 (2007), Horyak, 2006 supra). In all these settings, an underlying dysfunction in dopamine signaling is indicated by the clinical improvement observed with L-dopa (Wolkove N. et al., CMAJ. 176(10):1449-54 (2007), De Mello M.T. et al. 2004, supra) or dopamine agonists (Manconi M. et al., Sleep Med. 8(5):491-7 (2007); Haba-Rubio J. et al., Neurophysiol Clin. 33(4):180-4 (2003), Saletu M. et al., Hum Psychopharmacol. 16(2):177-187 (2001)). Therefore, because PLMD and PLMS are characterized by a dysfunction in dopamine signaling and are treatable with L-dopa, it is believed that the use of PDE7 inhibitory agents may be useful for treating PLMD and/or PLMS when administered to a patient in need thereof alone, or in conjunction with L-dopa or another dopamine receptor agonist concurrently or sequentially. The rat animal model described by Baier P.C. et al., J Neurol Sci. 15; 198(1-2):71-7 (2002), can be used to evaluate the efficacy of PDE7 inhibitory agents for the treatment of PLMS.

Multiple system atrophy including Shy-Drager syndrome Multiple system atrophy is a group of progressive neurodegenerative disorders that includes Shy-Drager syndrome, olivopontocerebellar atrophy, and striatonigral degeneration. characteristic symptoms include Parkinson's-like motor abnormalities, orthostatic hypotension, bladder dysfunction, and cerebellar dysfunction (Vanacore N., J Neural Transm. 112(12):1605-12 (2005). A pathological similarity with Parkinson's disease is suggested by the discovery of alpha-synuclein deposits in autopsy specimens from both diseases (Yoshida M., Neuropathology 27(5):484-93 (2007); Wenning G.K. et al., Acta Neuropathol. 109(2):129-40 (2005); Moore D.J. et al., Annu Rev Neurosci. 28:57-87 (2005). L-dopa is commonly used in therapy to alleviate parkinsonian symptoms with an estimated response rate between 33% and 60% (Gilman S. et al., J Neural Transm. 112(12):1687-94 (2005); Colosimo C. et al., J Neural Transm. 112(12): 1695-704 (2005)). Therefore, because some multiple system atrophy disorders (including Shy-Drager syndrome) are treatable with L-dopa, it is believed that the use of PDE7 inhibitor agents may be useful to treat those types of multiple system atrophy disorders, such as Shy-Drager syndrome, that are therapeutically amenable to treatment with a dopaminergic agent, when administered to a patient in need of it alone, or in conjunction with L-dopa, a dopamine receptor agonist, or another dopaminergic agent current or sequentially. It is known that the MPTP model is a model that is predictive of multiple system atrophy, including Shy-Drager syndrome. Stefanova N. et al., Trends Neurosci. 28(9):501-6 (2005). The animal model of multiple system atrophy, as described by Stefanova N. et al., Trends Neurosci. 28(9):501-6 (2005), can also be used to evaluate the efficacy of PDE7 inhibitor agents for the treatment of multiple system atrophy disorders such as Shy-Drager syndrome.

Therefore, based on the studies described herein, it is believed that the use of PDE7 inhibitors may be useful in treating multiple system atrophy disorders that are therapeutically amenable to treatment with dopaminergic agents, including Shy-Drager syndrome, when administered to a patient in need thereof alone, or in conjunction with current or sequential dopamine receptor agonists. Tourette syndrome

Tourette syndrome is a neurodevelopmental disorder in which the prominent symptoms are stereotyped movements or vocalizations or "tics" (Muller N. Dialogues Clin Neurosci. 9(2): 161-71 (2007); Leckman JF et al J Child Neurol. 21(8):642-9 (2006)). There is anatomical and neuroimaging evidence for involvement of the dopaminergic system in the basal ganglia in this disease (Muller N. Dialogues Clin Neurosci. 9(2):161-71 (2007)). While antipsychotics, which block dopamine D2 receptors, are one class of medications used to treat incapacitating tics in Tourette syndrome, a double-blind crossover clinical trial with the dopamine receptor agonist pergolide demonstrated that this medication significantly improves tics (Gilbert DL et al Neurology. 28;54(6): 1310-5 (2000)).

Therefore, because Tourette syndrome is characterized by dysfunction in dopamine signaling and is treatable with the dopamine agonist pergolide, it is believed that the use of PDE7 inhibitors may be useful in treating Tourette syndrome when administered to a patient in need of it alone, or in conjunction with dopamine receptor agonists or other dopaminergic agents, either topically or sequentially. Huntington's disease

Huntington's disease is a progressive, genetically determined, and neurologically fatal disease characterized by convulsive movements (chorea) that do not increase in severity and, in combination with cognitive enhancement, eventually lead to complete immobility and loss of function in activities of daily living. Selective loss of medium spiny neurons in the striatum is a prominent feature and is believed to be a primary cause of choreic movements (Standaert DG and Young AB in Goodman and Gilman's Pharmacological Basis of Therapeutics, 10th ed. McGraw-Hill, New York, 2001; Chapter 22, pp. 562-564). There are no medications that are useful in slowing the rate of progression of Huntington's disease, and very few that are consistently useful in improving symptoms. A recent review cited antipsychotic agents such as haloperidol as "possibly useful" in the treatment of choreic movements. The same review established that L-dopa and the dopamine agonist pramipexole were "possibly useful" for the treatment of rigidity (Bonelli RM et al. Curr Pharm Des. 12(21):2701- 20.(2006)). Some reports suggest that L-dopa or pramipexole may be useful in a specific variant (Westphal variant) of Huntington's disease in which parkinsonian symptoms are prominent (Bonelli RM et al. Clin Neuropharmacol. 25(l):58-60 (2002); Reuter I, J Neurol Neurosurg Psychiatry. 68(2):238-41(2000)). However, controlled trials have not been performed. Therefore, it is possible that a PDE7 inhibitor compound might be useful in Huntington's disease patients who are responsive to L-dopa, other dopamine agonists or precursors, or other dopaminergic agents. Dopamine-responsive dystonia:

Dopamine-responsive dystonia (DRD) is an early-onset, progressive, and broadly genetically determined neurological disease characterized by diffuse rigidity and other Parkinson's-like symptoms. Segawa M et al., Adv Neurol. 14:215-33 (1976). Dopamine depletion in the striatum is observed when nerve terminals are intact. A major cause of DRD is an inherited deficiency in the enzyme GTP cyclohydrolase, the rate-limiting enzyme in the synthesis of tetrahydrobiopterin (Segawa disease), which is in turn an essential cofactor for tyrosine hydroxylase. Ichinose H et al., J Biol Chem. 380(12):1355-64 (1999). This deficiency leads to depletion of dopa and dopamine in nigrostriatal terminals. Treatments with L-dopa/carbidopa combinations (e.g., Sinemet) are highly successful and are the standard of care in this disease. Jeon B, J Korean Med Sci. 12(4):269-79 (1997). Because of this responsibility of this disease by L-dopa and the integrity of the dopamine signaling pathway in medium spiny neurons, it is believed that the PDE7 inhibitor compound of the present invention may also prove to be effective treatments for DRD.

III. PDE7 inhibitors

Cyclic nucleotide phosphodiesterase type 7 (PDE7) is identified as a single family based on this primary amino acid sequence and distinct enzymatic activity. The PDE genes identified as PDE7 (PDE7A and PDE7B) code for cAMP-specific PDEs. Pharmacological and biochemical characterization of PDE7 shows a high affinity for cAMP (Km = 0.2 μM) that is unaffected by cGMP and selective inhibitors of other PDEs. PDE7 selectively degrades cAMP and is characterized as an enzyme that is not inhibited by rolipram, a selective inhibitor of PDE4, which is a distinct family of cAMP-specific PDEs. Two sub-types have been identified within the PDE7 family, PDE7A (Michael, T. et al., J Biol. Chem. 268(17):12925-12932, 1993; Han, P. et al., JBiol. Chem. 272(26): 16152- 16157, 1997) and PDE7B (US Patent No. 6,146,876; Gardner, C. et al., Biochem Res. Commun. The two gene products exhibited 70% identity in their C-terminal catalytic domains (Hetman J.M. et al., PNAS 97(l):472-476 (2000).

PDE7A has three splice variants (PDE7A1, PDE7A2, and PDE7A3); these variants are generated by alternative splicing at either the N or C terminus (Bloom, T. J. and J. A. Beavo, Proc. Natl. Acad. Sci. USA. 93:14188–14192, 1996). The nucleotide sequence of PDE7A, transcript variant 1, is accessible in public databases under Accession number NM_002603. The human PDE7A1 protein (SEQ ID NO:2 encoded by SEQ ID NO:1) has 456 amino acids and migrates at an apparent molecular weight of 53 to 55 kDa on reduced SDS-PAGE.

The nucleotide sequence of PDE7A, transcript variant 2, is accessible in public databases under Accession Number NM_002604. The human PDE7A2 protein (SEQ ID NO:4 encoded by SEQ ID NO:3) has 424 amino acids.

The PDE7A protein has a region of approximately 270 amino acids at the carboxy-terminal end that shows significant similarity (~23% homology) to analogous regions of other PDEs that hydrolyze cAMP. This region serves as the catalytic domain. The amino-terminal region of this protein is divergent from that of other PDEs and presumably mediates the regulatory and distinctive properties unique to this enzyme family.

The nucleotide sequence of human PDE7B is accessible in public databases under Accession Number NM_018945, given as SEQ ID NO:6 encoded by SEQ ID NO:7. Three splice variants of PDE7B have been reported: PDE7B 1, PDE7B2, and PDE7B3. PDE7B is published in WO 01/62904, US Patent No. 6,146,876.

Both PDE7B2 and PDE7B3 have unique N-terminal sequences. The human PDE7B gene products have an apparent molecular weight of 53-55 kDa on reduced SDS-PAGE (Sasaki, T., Kotera, J., Omori, K., Biochemical J. 361:211-220, 2002). Like PDE7A, PDE7B has a significantly conserved region of about 270 amino acids common to all PDEs at the carboxy terminus, which serves as the catalytic domain. Similar to the PDE7A protein, the amino-terminal region of the PDE7B protein is divergent and presumably accounts for regulatory and distinctive properties unique to the individual PDE families. The PDE7B protein shows homology to other cAMP-dependent PDEs (23%) within the catalytic domain. The PDE7B polypeptide is 61% homologous to PDE7A, according to WO 2004/044196. PDE7 is also uniquely localized in mammalian proteins relative to other PDE families. PDE7A expression has been detected in most tissues analyzed, including brain, heart, kidney, skeletal muscle, spleen, and uterus (Bloom et al., PNAS 93:14188, 1996). Within the brain, PDE7A is widely distributed in both neuronal and non-neuronal cell populations (Miro et al., Synapse 40:201, 2001). The widespread PDE7A expression in the brain, including the basal ganglia and substantia nigra, provides a theoretical basis for a role for PDE7A in motor control as well as other brain functions.

Whereas PDE7A expression is widely distributed in brain tissue, PDE7B brain expression is more restricted and highly enriched in areas linked to motor control, such as the striatum (Reyes-Irisarri et al., Neuroscience 132:1173, 2005). However, despite the presence of PDE7 in brain tissue, prior to the data discussed in this application, there were no data linking PDE7 to any specific CNS disease, such as Parkinson's disease. Prior to the use of PDE7 inhibitors, the focus was on immunological applications based on work demonstrating that PDE7 inhibition with small interfering RNAs (siRNAs) can regulate T cell proliferation. See Rotella, D.P., Drug Discovery 2007, 22-23.

Consistent with the dopamine signaling model shown in FIGURES 2A–2C, the origin of PDE7A and PDE7B expression overlaps with the dopaminergic system, supporting the theory that PDE7 is involved in the regulation of motor function. Therefore, while not bound by theory, it is believed that PD treatment by inhibiting PDE7 functions to aid dopamine signaling, which may be an alternative mechanism for PD treatment compared to dopamine receptor agonists. It is also believed that a PDE7 inhibitor may be useful as a therapeutic agent for administration in conjunction (i.e., in combination, concurrently, or sequentially) with one or more dopamine receptor agonists or other dopaminergic agents.

In practicing the methods of the invention, representative PDE7 inhibitory agents that inhibit the phosphodiesterase activity of PDE7 include: molecules that bind to PDE7 and inhibit PDE7 enzyme activity (such as small molecule inhibitors or blocking peptides that bind to PDE7 and reduce enzyme activity) and molecules that decrease PDE7 expression at the transcriptional and/or translational level (such as PDE7 antisense nucleic acid molecules, PDE7-specific RNAi molecules, and PDE7 ribozymes), thereby preventing PDE7 from cAMP cleavage. The PDE7 inhibitory agent can be used alone as the primary therapy or in combination with other therapeutics (such as dopamine receptor agonists) as an adjunctive therapy to enhance therapeutic benefits, as discussed supra.

Inhibition of PDE7 is characterized by at least one of the following changes that occurs as a result of administration of a PDE7 inhibiting agent according to the methods of the invention: the inhibition of PDE7-dependent enzymatic cleavage of the 3'-phosphodiester bond in cAMP to form 5'-adenosine monophosphate (5'-AMP) (measured, for example, as described in Example 1), a reduction in the gene or protein expression level of PDE7, measured, for example, by gene expression analysis (e.g., RT-PCR analysis) or protein analysis (e.g., Western blot).

In some embodiments, a PDE7 inhibitory agent is a molecule or composition that inhibits the expression of PDE7A, PDE7B, or both PDE7A and PDE7B, such as a small inhibitory nucleotide or antisense (e.g., siRNA) that specifically hybridizes to cellular mRNA and/or genomic DNA corresponding to PDE7 target genes so as to inhibit their transcription and/or translation, or a ribozyme that specifically cleaves the mRNA of a PDE7 target. Potency of PDE7 Inhibitory Agents

In one embodiment, a PDE7 inhibiting agent useful in the methods of the invention is a compound that is sufficiently potent to inhibit the enzymatic activity of PDE7 (PDE7A, PDE7B, or PDE7A and PDE7B) at an IC50 of <1 μM, preferably less than or about 0.1 μM. In one embodiment, the PDE7 inhibiting agent is sufficiently potent to inhibit the enzymatic activity of PDE7 (PDE7A, PDE7B, or PDE7A and PDE7B) at an IC50 of about 0.1 to about 500 nM. In one embodiment, the PDE7 inhibiting agent is potent to inhibit the enzymatic activity of PDE7 (PDE7A, PDE7B, or PDE7A and PDE7B) at an IC50 of about 1 to about 100 nM.

Representative methods for determining the IC50 for a PDE7 (PDE7A or PDE7B) inhibitory agent are provided in Example 1 herein and are well known in the art, such as the scintillation proximity assay (SPA) disclosed in Bardelle et al., Anal Biochem 15:275(2):148-55 (1999). Selective PDE7A or PDE7B Inhibitory Agents

In one embodiment, the PDE7 inhibitor useful in the method of the invention is a PDE7A inhibitory agent. In one embodiment, the PDE7A inhibitory agent is potent to inhibit PDE7A enzymatic activity at an IC50 of about 0.1 to about 500 nM. In one embodiment, the PDE7A inhibitor has an IC50 of about 1 to about 100 nM. A suitable assay for determining the IC50 for the PDE7A inhibitor uses recombinant human PDE7A2 enzymes expressed in a baculoviral system. This assay method is a modification of the SP A assay reported by Bardelle et al. supra. An exemplary assay for measuring PDE7A inhibition is provided in Example 1.

In some embodiments, the PDE7 inhibiting agent exhibits isozyme-selective activity against PDE7A. The PDE7A-selective inhibiting agent reduces PDE7A activity at least two-fold more than PDE7B activity, more preferably at least 10-fold, at least 20-fold, at least 50-fold, or at least 100-fold. In some embodiments, the PDE7A-inhibiting agent is an inhibiting agent that is at least 10-fold (such as at least 20-fold, or at least 50-fold, or at least 100-fold) more selective for inhibiting PDE 7A activity than for the enzyme activity of any other PDE (PDE 1-6, 7B, and 8-11).

In another embodiment, the PDE7 inhibitor useful in the method of the invention is a PDE7B inhibitor. Due to the potential for reduced side effects due to restricted expression of high levels of PDE7B and expression in areas of the brain linked to motor control (e.g., the striatum), PDE7B inhibitors may be useful for the treatment of neurological movement disorders such as Parkinson's disease.

In one embodiment, the PDE7B inhibitor has an IC50 of about 0.1 to about 500 nM. In one embodiment, the PDE7B inhibitory agent is sufficiently potent to inhibit PDE7B enzymatic activity at an IC50 of about 0.1 to about 500 nM. In one embodiment, the PDE7B inhibitor has an IC50 of about 1 to about 100 nM. Methods for determining the IC50 of the PDE7B inhibitor are well known in the art, such as the assays disclosed in Bardelle et al., supra. An exemplary example for measuring PDE7AB inhibition is provided in Example 1.

In some embodiments, the PDE7 inhibitor exhibits isozyme-selective activity against PDE7B. The PDE7B-selective inhibitory agent reduces PDE7B activity at least two-fold more than PDE7A activity, more preferably at least 10-fold, at least 20-fold, at least 50-fold, or at least 100-fold. In some embodiments, the PDE7B-inhibiting agent is an inhibitory agent that is at least 10-fold (such as at least 20-fold, or at least 50-fold, or at least 100-fold) more selective for inhibiting PDE7B activity than for the enzyme activity of any other PDE (PDE1-6, 7A, and 8-11). PDE7 Selectivity Compared to Other PDEs

In some embodiments, the PDE7 inhibitory agent has an IC50 for inhibition of PDE1B activity that is greater than 5-fold (such as at least 10-fold, at least 20-fold, or at least 50-fold, or at least 100-fold) the lesser of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity. In some embodiments, the PDE7 inhibitor is more potent (by 5-fold, 10-fold, 20-fold, 50-fold, or 100-fold) in inhibiting PDE7A or PDE7B activity (whichever PDE7A or PDE7B isozyme the PDE7 inhibitor has more effect on) than it is in inhibiting PDE1B activity. For the purpose of the present specification, by way of example, this property may be further simply stated as the PDE7 inhibitor is more potent (by 5-fold, 10-fold, 20-fold, 50-fold, or 100-fold) in inhibiting PDE7 activity than it is in inhibiting PDE1B activity.

Dual inhibition of both PDE7 and PDE1B may confer additional benefit in the treatment of movement disorders based on the report that knockout of the gene for PDE1B in mice stimulated dopamine metabolism and sensitized the animals to the effects of dopamine agonists (Siuciak et al., Neuropharmacology 53(1): 113-23 (2007)).

In some embodiments, the PDE7 inhibitory agent has an IC50 for inhibition of PDE 10 activity greater than 5-fold (such as at least 10-fold, or at least 20-fold, or at least 50-fold, or at least 100-fold) the lesser of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity. Dual inhibition of both PDE7 and PDE 10 may confer additional benefit in the treatment of movement disorders based on the report that selective PDE 10 inhibitors cause an increase in cAMP levels in the striatum (Siuciak J.A. et al., Neuropharmacology 51(2):386-96 (2006)).

In some embodiments, the PDE7 inhibitory agent has an IC50 for inhibition of PDE3 activity greater than 10-fold (such as at least 20-fold, at least 50-fold, or at least 100-fold) the lesser of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity. This is because administration of selective PDE3 inhibitors to patients with heart damage has been shown to increase their mortality rate (Packer M. et al., N Engl J Med. 325(21): 1468-75 (1991)).

In some embodiments, the PDE7 inhibitory agent has an IC50 for inhibition of PDE4 activity greater than 10-fold (such as at least 20-fold, at least 50-fold, or at least 100-fold) the lesser of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity. This is because knockout of one of the PDE4 genes in mice has been shown to lead to cardiac myopathy (Lehnart S.E. et al., Cell 123(l):25-35 (2005)).

In some embodiments, the PDE7 inhibiting agent has an IC50 for inhibition of PDE3 activity and PDE4 activity greater than 10-fold (such as at least 20-fold, at least 50-fold, or at least 100-fold) the lesser of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity.

In some embodiments, the PDE7 inhibiting agent has an IC50 for inhibition of PDE8 activity greater than 10-fold (such as at least 20-fold, at least 50-fold, or at least 100-fold) the lesser of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity.

In some embodiments, the PDE7 inhibitory agent has an IC50 for inhibition of PDE4 activity and PDE8 activity greater than 10-fold (such as at least 20-fold, at least 50-fold, or at least 100-fold) the lesser of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity. According to this embodiment, it is known that PDE families that specifically/preferably hydrolyze cAMP include PDE4, PDE7, and PDE8.

In some embodiments, the PDE7 inhibitory agent has an IC50 for inhibition of PDE1, PDE2, PDE3, PDE4, PDE8, PDE10, and PDE11 activity greater than 10-fold the lower of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity. According to this embodiment, it is known that PDE families that specifically/preferentially hydrolyze cAMP include the PDE4, PDE7, and PDE8 families, and the PDE1, PDE2, PDE3, PDE10, and PDE11 families that show substantial activity against both cAMP and cGMP.

In some embodiments, the PDE inhibitory agent is a selective PDE7 inhibitor for which the lower of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity is less than one-tenth (such as one-twentieth, one-fiftieth, or one-hundredth) the IC50 that the agent has for inhibition of any other PDE enzyme from the PDE 1-6 and PDE8-11 enzyme families.

A selective PDE7 inhibitor can be identified, for example, by comparing the ability of an agent to inhibit PDE7 enzyme activity (PDE7A, PDE7B, or PDE7A and PDE7B) to its ability to inhibit PDE enzymes from other PDE families. For example, an agent can be assayed for its ability to inhibit PDE7 activity as well as PDE1, PDE2, PDE3, PDE4, PDE5, PDE6, PDE8, PDE9, PDE10, and PDE11. Exemplary methods for comparing the ability of an agent to inhibit PDE7 enzyme activity to its ability to inhibit PDE enzymes from other PDE families are provided in Example 2 herein. The ratio of the inhibition IC50 for each of the PDE isozymes (1-6 and 8-11) to an inhibition IC50 of PDE7 (i.e., the more sensitive of PDE7A or PDE7B) can be determined by a standard in vitro, in vivo, or ex vivo assay such as that described herein.

PDE7 selectivity as compared to other non-molecular PDE targets known to be involved in neurological movement disorders

In some embodiments, the PDE7 inhibitory agent is selected for PDE7 and substantially inactive against non-PDE molecular targets known or believed to be involved in the pathology of a neurological movement disorder.

In some embodiments, the PDE7 inhibitory agent is a PDE7 inhibitory agent for which the lower of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity is less than one-half (such as less than one-fifth, less than one-tenth, such as less than one-twentieth, less than one-fiftieth, or less than one-hundredth) of the IC50 that the agent has for inhibition of activity at other molecular targets (i) known to be involved with the pathology of a neurological movement disorder selected from the group consisting of Parkinson's disease, post-encephalitic parkinsonism, dopamine-responsive dystonia, Shy-Drager syndrome, periodic limb movement disorder (PLMD), periodic limb movements in sleep (PLMS), and restless legs syndrome (RLS), or (ii) in which other drugs that are therapeutically effective for treating the action of the disorder.

In other embodiments, the PDE7 inhibitory agent is selected for PDE7 and substantially inactive against non-PDE molecular targets known to be involved in Parkinson's disease pathology. In some embodiments, the PDE7 inhibitory agent is a PDE7 inhibitory agent for which the lower of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity is less than one-half (such as less than one-fifth, less than one-tenth, less than one-twentieth, less than one-fiftieth, or less than one-hundredth) of the IC50 that the agent has for inhibition of activity at other molecular targets (i) known to be involved with the pathology of Parkinson's disease, such as cachechol-O-methyltransferase (COMT), monamine oxidase B (MAO-B), dopamine transporters (DAT), tyrosine hydroxylase, dopamine receptors, adenosine A2A receptors, muscarinic acetylcholine receptors, N-methyl D-aspartate (NMDA) receptors, gamma amino butyric acid (GABA) receptors, and gabapentin receptors, or (ii) wherein other drugs that are therapeutically effective for treating Parkinson's disease act. Exemplary methods comparing the ability of an agent to inhibit PDE7 enzyme activity by this ability to inhibit other molecular targets known to be involved in Parkinson's disease pathology are provided in Example 4 herein.

In other embodiments, the PDE7 inhibitory agent is selected by PDE7 and substantially inactive against non-PDE molecular targets known to be associated with the dopamine signaling pathway. In some embodiments, the PDE7 inhibitory agent is a PDE7 inhibitory agent for which the lower of the IC50 for inhibition of PDE7A activity and the IC50 for inhibition of PDE7B activity is less than one-half (such as less than one-fifth, less than one-tenth, such as less than one-twentieth, less than one-fiftieth, or less than one-hundredth) of the IC50 that the agent has for inhibition of activity at other molecular targets known to be associated with the dopamine signaling pathway, such as cachechol-O-methyltransferase (COMT), monamine oxidase B (MAO-B), dopamine transporters (DAT), tyrosine hydroxylase, dopa decarboxylase, dopamine receptors, adenylyl cyclase, protein kinase A (PKA), dopamine, and cyclic AMP-regulated phosphoprotein of molecular weight 32,000. (DARPP32) and protein phosphatase-1. Exemplary methods comparing the ability of an agent to inhibit PDE7 enzyme activity by its ability to inhibit other molecular targets known to be associated with the dopamine signaling pathway are provided in Example 4 herein. Types of PDE7 Inhibiting Agents

The PDE7 inhibitory agent can be any type of agent including, but not limited to, a chemical compound, a protein or polypeptide, a peptidomimetic, a nucleic acid molecule, or a ribozyme. In some embodiments, the PDE7 inhibitory agents are small molecule inhibitors including synthetic and natural substances that have a low molecular weight (i.e., less than about 450 g/mol), such as, for example, peptides, peptidomimetics, and non-peptide inhibitors such as chemical compounds. Chemical compounds:

PDE7 inhibitors useful in the methods of the invention include agents that are administered by a conventional route (e.g., orally, intramuscularly, subcutaneously, transdermally, transbucally, intravenously, etc.) into the bloodstream and are ultimately transported through the vascular system, crossing the blood-brain barrier, to inhibit PDE7 in the brain. Consequently, for these methods of administration, PDE7 inhibitors have the ability to cross the blood-brain barrier. Those PDE inhibitors described below that have the ability to cross the blood-brain barrier (e.g., those having a molecular weight of less than about 450 g/mol and that are sufficiently lyophilic) are useful in the methods of the invention when the inhibitors are administered by a route that ultimately transports the inhibitors to the brain in the bloodstream. The following is a description of exemplary PDE7 inhibitors useful in the methods of the invention.

In one embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in EP 1 454 897, WO 2003/053975 and US 2005/0148604, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formulas:

The substituents for the above compounds are defined as follows: A represents N or CR4, B represents a hydrogen atom or a halogen atom, R1 represents optionally substituted C3.7 cycloalkyl or tert-butyl, R2 represents hydrogen, methyl or ethyl, R3 represents a hydrogen, nitro, cyano or halogen atom, NR5R6, C(=X)R7, SO2NR5R6, OR8, NR8CONR5R6, NRSSO2R9, NR8CO2R9, a heteroaryl group, optionally substituted C6 alkyl, optionally substituted C6 alkenyl or optionally substituted saturated or unsaturated heterocycloalkyl, R4 represents hydrogen or C6 alkoxy substituted, if desired, by one or more fluorine atoms, R5 and R6 are the same or different and represent a hydrogen atom, optionally substituted C6 alkyl, optionally substituted heterocycloalkyl or optionally substituted acyl or, together with the nitrogen atom to which these are attached, form azetidinyl, pyrrolidinyl, piperidinyl, morpholino, thiomorpholino, piperazinyl, or homopiperazinyl, each of these groups being optionally substituted by optionally substituted C⁻⁻ alkyl, OH, C⁻⁻ alkoxy, CO⁻ ...

With respect to the above compounds, “optionally substituted” refers to an optionally substituted linear, branched, or cyclic alkyl group such as methyl, ethyl, propyl, or cyclohexyl; a hydroxyl group; a cyano group; an alkoxy group such as methoxy or ethoxy; an optionally substituted amino group such as amino, methylamino, or dimethylamino; an optionally substituted acyl group such as acetyl or propionyl; a carboxyl group; an optionally substituted aryl group such as phenyl or naphthyl; an optionally substituted heteroaryl group such as pyridinyl, thiazolyl, imidazolyl, or pyrazyl; an optionally substituted saturated or unsaturated heterocycloalkyl group such as piperazinyl or morphonyl; an optionally substituted carbamoyl group; an optionally substituted amido group; a halogen atom such as chlorine, fluorine, or bromine; a nitro group; an optionally substituted sulfone group; an optionally substituted sulfonylamido group; an oxo group; a urea group; and an optionally substituted linear, branched, or cyclic alkenyl group such as ethenyl, propenyl, or cyclohexenyl.

Examples of the heteroaryl group as R3 include a 5- to 7-membered monocyclic heteroaryl group having 2 to 8 carbon atoms and containing 1 to 4 heteroatoms consisting of oxygen atoms, nitrogen atoms, or sulfur atoms, and a polycyclic heteroaryl group comprising two or more such identical or different monocyclic compounds fused together, examples of the monocyclic and polycyclic heteroaryl groups being pyrrole, furyl, thienyl, imidazolyl, thiazolyl, pyridyl, pyrazyl, indolyl, quinolyl, isoquinolyl, and tetrazolyl. In one embodiment, a PDE7 inhibitor useful in the invention has the formula:

The activity of Compound 1 in inhibiting select PDEs is described in Examples 1 and 2. The efficacy of Compound 1 in the MPTP Parkinson's model is described in Examples 5 and 6.

In other embodiments, PDE7 inhibitors useful in the methods of the invention have the formulas:

In another embodiment, a PDE7 inhibitor useful in the methods of the invention has the formula:

The activity of Compound 2 in inhibiting select PDEs is described in Examples 1 and 2. The efficacy of Compound 2 in the MPTP Parkinson's model is described in Example 7.

In other embodiments, PDE7 inhibitors useful in the methods of the invention have the formulas: The preparation of the above compounds is described in EP 1 454 897, WO 2003/053975 and US 20050148604.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in US 2002/0198198, WO 2002/076953, WO 2002/074754, WO 2006/092691, Bioorganic & Medicinal Chemistry Letters 14 (2004) 4623-4626 and Bioorganic & Medicinal Chemistry Letters 14 (2004) 4627-4631, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formulas: The substituents for the above compounds are defined as follows: (a) Xb X2, X3 and X4 are the same or different and are selected from: N, provided that no more than two of the groups Xb X2, X3 and X4 simultaneously represent a nitrogen atom or, C-Rb in which R1 is selected from: Q1 or lower alkyl, lower alkenyl or lower alkynyl, these groups being unsubstituted or substituted by one or more groups Q2; the group X5-R5 in which, X5 is selected from: a single bond, lower alkylene, lower alkenylene or lower alkynylene; optionally interrupted by 1 or 2 heteroatoms chosen from O, S, S(=O), SO2 or N, the carbon atoms of these groups being unsubstituted or substituted by one or several groups, identical or different, selected from SR<„ OR<„ NR6R7, =O, =S or =NRÓ where R6 and R7 are the same or different and are selected from hydrogen or lower alkyl, and Rs is selected from aryl, heteroaryl, cycloalkyl optionally interrupted by C(=O) or with 1, 2 or 3 heteroatoms chosen from O, S, S(=O), SO2 or N, cycloalkenyl optionally interrupted by C(=O) or with 1, 2 or 3 heteroatoms chosen from O, S, S(=O), SO2 or N or a bicyclic group, these groups being unsubstituted or substituted by one or several groups selected from Q3, heteroaryl or lower alkyl optionally substituted by Q3; wherein Qb, Q2, and Q3 are the same or different and are selected from: hydrogen, halogen, CN, NO2, SO3H, P(=O)(OH)2, OR2, OC(=O)R2, C(=O)OR2, SR2, S(=O)R2, NR3R4, Q-R2, Q-NR3R4, NR2-Q-NR3R4, or NR3-Q-R2 wherein Q is selected from C(=NR), C(=O), C(=S), or SO2, R is selected from hydrogen or lower alkyl, and R2, R3, and R4 are the same or different and are selected from: hydrogen, lower alkyl optionally interrupted by C(=O), (CH2)n-aryl, (CH2)n-heteroaryl, (CH2)n-cycloalkyl optionally interrupted by C(=O) or with 1 or 2 heteroatoms chosen from O, S, S(=O), SO2, or N, where n is an integer selected from 0, 1, 2, 3, or 4; these groups being unsubstituted or substituted by one or several groups selected from lower alkyl, halogen, CN, CH3, SO3H, SO2CH3, CF3, C(=O)NHSO2CH3, ORf„ COORO, C(=O)Ré, NR6R7, C(=O)NR6R7, OR2NR6R7, where R^ and R7 are the same or different and are selected from hydrogen or lower alkyl optionally substituted by one or two groups selected from OR, COOR, or NRRR8 where R and R8 are hydrogen or lower alkyl, and R8 and R7 and/or R3 and R4, together with the nitrogen atom to which they are attached, can form a 4- to 8-membered heterocyclic ring which may contain one or two heteroatoms selected from O, S, S(=ZO), SO2 or N and which may be substituted by, a 4- to 8-membered heterocyclic ring which may contain one or two heteroatoms selected from O, S or N and which may be substituted by a lower alkyl or, a lower alkyl optionally substituted by OR', NR'R”, C(=O)NR'R” or COOR' wherein R' and R” are the same or different and are selected from H, lower alkyl optionally substituted by OR or COOR wherein R is hydrogen or lower alkyl and R' and R” together with the nitrogen atom to which they are attached, may form a 4- to 8-membered heterocyclic ring which may contain one or two heteroatoms selected from O, S or N or, (b) X is O, S or NR9 wherein R9 is selected from hydrogen, CN, OH, NH2, lower alkyl, lower alkenyl or lower alkynyl, these groups being unsubstituted or substituted by cycloalkyl optionally interrupted by 1 or 2 heteroatoms chosen from O, S, S(=O), SO2, or N, cycloalkenyl optionally interrupted by 1 or 2 heteroatoms chosen from O, S, S(=O), SO2, or N, aryl, heteroaryl, ORio, or NRjoRn wherein R10 and Rn are the same or different and are selected from hydrogen or lower alkyl; (c) Y is selected from O, S, or N—R12 wherein R12 is selected from hydrogen, CN, OH, NH2, lower alkyl, lower alkenyl, or lower alkynyl, these groups being unsubstituted or substituted by cycloalkyl optionally interrupted by 1 or 2 heteroatoms chosen from O, S, S(=O), SO2, or N, cycloalkenyl optionally interrupted by 1 or 2 heteroatoms chosen from O, S, S(=O), SO2, or N, aryl, heteroaryl, ORio, or NRioRn wherein R10 and Rn are the same or different and are selected from hydrogen or lower alkyl; (d) Z is chosen from CH-NO2, O, S, or NR14RI3 wherein Rn is selected from hydrogen, CN, OH, NH2, aryl, heteroaryl, cycloalkyl optionally interrupted by one or more heteroatoms chosen from O, S, S(=O), SO2, or N, cycloalkenyl optionally interrupted by one or more heteroatoms chosen from O, S, S(=O), SO2, or N, C(=O)RI4, C(=O)NR14R15, OR14 OR lower alkyl, unsubstituted or substituted by one or more groups that are the same or different and that are selected from OR]4 or NR14RI5; Ru and Rn being independently selected from hydrogen or lower alkyl, or R14 and R15, together with the nitrogen atom to which they are attached, may form a heterocyclic ring of 4- to 8-membered which may contain one or two heteroatoms chosen from O, S, or N and which may be substituted by a lower alkyl; (e) Z1 is chosen from H, CH3, or NR^Rp wherein R16 and Rn are the same or different and are selected from hydrogen, CN, aryl, heteroaryl, cycloalkyl optionally interrupted by one or more heteroatoms chosen from O, S, S(=O), SO2, or N, cycloalkenyl optionally interrupted by one or more heteroatoms chosen from O, S, S(=O), SO2, or N, C(=O)R14, C(=O)NRI4RI5, ORU, or lower alkyl unsubstituted or substituted by one or more groups selected from OR]4 OR NR14Ri5, R14 and R15 being chosen from hydrogen or lower alkyl, and, R14 and R15 and/or R6 and Rn, together with the nitrogen atom to which they are attached, may form a 4- to 8-membered heterocyclic ring that may contain one or two heteroatoms chosen from O, S, or N and that may be substituted by a lower alkyl; (f) A is a cycle selected from: wherein Ab A2, A3, A4, A5 and A6 are the same or different and are selected from O, S, C, C(=O), SO, SO2 or NR18 wherein R18 is selected from hydrogen, aryl, heteroaryl, cycloalkyl optionally interrupted by one or more heteroatoms chosen from O, S, S(=O), SO2 or N, cycloalkenyl optionally interrupted by one or more heteroatoms chosen from O, S, S(=O), SO2 or N, lower alkyl unsubstituted or substituted by aryl, heteroaryl, cycloalkyl optionally interrupted by one or more heteroatoms chosen from O, S, S(=O), SO2 or N, cycloalkenyl optionally interrupted by one or more heteroatoms chosen from O, S, S(=O), SO2 or N, CN, NR19R20, C(=O)NRI9R2O, OR19, C(=O)R19 or C(-O)ORI9 where R19 and R20 are identical or different and are selected from hydrogen or lower alkyl; * represents the carbon atom that is split between cycle A and the main chain cycle containing X and/or Y; each carbon atom of cycle A is unsubstituted or substituted by 1 or 2 groups, identical or different, selected from lower alkyl optionally substituted by OR2I, NR21R22, COOR21 or CONR21R22, lower haloalkyl, CN, F, =O, S02NR]9R2o, ORI9, SRI9, C(=O)ORI9, C(=O)NRI9R20 OR NR19R2O wherein R19 and R2o are identical or different and are selected from hydrogen or lower alkyl optionally substituted by OR2I, NR21R22, COOR21 or CONR21R22, wherein R21 and R22 are identical or different and are selected from hydrogen or lower alkyl, and R19 and R2O and/or, R21 and R22, together with the nitrogen atom to which they are attached, can form a 4- to 8-membered heterocyclic ring; Two non-adjacent atoms of the A-cycle may be linked by a chain of 2, 3, or 4 carbon atoms, each interrupted by a heteroatom chosen from O, S, or N; provided that no more than two of the Ab groups A2, A3, A4, A5, and A6 simultaneously represent a heteroatom, and their tautomeric forms, racemic forms, isomers, and pharmaceutically acceptable derivatives. With respect to the above compounds, halogen includes fluorine, chlorine, bromine, and iodine. The preferred halogens are F and Cl. Lower alkyl includes straight and branched carbon chains having 1 to 6 carbon atoms. Examples of such alkyl groups include methyl, ethyl, isopropyl, and tert-butyl. Lower alkenyl includes straight or branched hydrocarbon radicals having 2 to 6 carbon atoms and at least one double bond. Examples of such alkenyl groups are ethenyl, 3-buten-1-yl, 2-ethenylbutyl, and 3-hexen-1-yl. Lower alkynyl includes straight or branched hydrocarbon radicals having 2 to 6 carbon atoms and at least one triple bond. Examples of such alkynyl groups are ethynyl, 3-butyn-1-yl, propynyl, 2-butyn-1-yl, and 3-pentyn-1-yl. Lower haloalkyl includes a lower alkyl as defined above substituted by one or more halogens. An example of a haloalkyl is trifluoromethyl. Aryl is understood to refer to an aromatic carbocycle containing between 6 and 10 carbon atoms. An example of an aryl group is phenyl. Heteroaryl includes aromatic rings having 5 to 10 ring atoms, 1 to 4 of which are independently selected from the group consisting of O, S, and N. Representative heteroaryl groups have 1, 2, 3, or 4 heteroatoms in a 5- or 6-membered aromatic ring. Examples of such groups are tetrazole, pyridyl, and thienyl. Representative cycloalkyls contain 3 to 8 carbon atoms. Examples of such groups are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. The term "interrupted" means that in a backbone chain, a carbon atom is replaced by a heteroatom or a group as defined herein. For example, in "cycloalkyl or cycloalkenyl optionally interrupted by C(=O) or with 1 heteroatom chosen from O, S, S(=O), SO2, or N", the term "interrupted" means that C(==O) or a heteroatom can replace a ring carbon atom. Examples of such groups are morpholine or piperazine. Cycloalkenyl includes 3- to 10-membered cycloalkyl containing at least one double bond. Heterocyclic rings include heteroaryl as defined above and cycloalkyl or cycloalkenyl, as defined above, interrupted by 1, 2, or 3 heteroatoms chosen from O, S, S(=O), SO2, or N. Bicyclic substituents refer to two cycles, which are the same or different and which are chosen from aryl, heterocyclic ring, cycloalkyl, or cycloalkenyl, fused together to form said bicyclic substituents. An example of a bicyclic substituent is indolyl.

In one embodiment, a PDE7 inhibitor useful in the methods of the invention has the formula:

The activity of Compound 3 in inhibiting select PDEs is described in Examples 1 and 2. The efficacy of Compound 3 in the MPTP Parkinson's model is described in Example 7.

In other embodiments, PDE7 inhibitors useful in the methods of the invention have the formulas:

The preparation of the above compounds is described in US 2002/0198198, WO 2002/076953, WO 2002/074754, WO 2006/092691, Bioorganic & Medicinal Chemistry Letters 14 (2004) 4623-4626 and Bioorganic & Medicinal Chemistry Letters 14 (2004) 4627-4631.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in EP 1 193 261, WO 2002/28847, US 20030045557, US Patent No. 7,122,565, Bioorganic & Medicinal Chemistry Letters 14 (2004) 4607-4613 and Bioorganic & Medicinal Chemistry Letters 14 (2004) 4615-4621, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula:

The substituents for the above compounds are defined as follows: Y is S or O; R i is C 1 -C 1O alkyl, C 2 -C 10 alkenyl, C 2 -C 10 alkynyl, cycloalkyl, cycloalkenyl, heterocycle, aryl, or a polycyclic group; each optionally substituted by one or more identical or different X 1 -R 4 groups, wherein X] is a single bond, lower alkylene, C 2 -C 10 alkenylene, cycloalkylene, arylene, or bivalent heterocycle and R 4 is: (1) H, =O, NO 2 , CN, halogen, lower haloalkyl, lower alkyl, carboxylic acid bioester; (2) COOR 5 , C(=O) R 5 , C(=S) R 5 , SO 2 R 5 , SOR 5 , SO 3 R 5 , SR 5 , OR 5 ; (3) C(=O)NR7R8, C(-S)NR7R8, C(=CH-NO2)NR7R8, C(=NCN)NR7R8, C(=N-SO2NH2)NR7R8, C(=NR7)NHR8, C(=NR7)R8, C(=NR9)NHR8, C(=NR9)R8, SO2NR7R8 OR NR7R8, wherein R7 and R8 are the same or different and are selected from OH, R5, R6, C(=O)NR5R6, C(=O)R5, SO2R5, C(=NR9)NHR1O, C(=NR9)R1O, C(=CH-NO2)NR9R10, C(=N-SO2NH2)NR9R10, C(=N-CN)NR9R1O OR C(=S)NR9RI0; R2 is lower alkyl, C2-C10 alkenyl, C2-C10 alkynyl, cycloalkyl, cycloalkenyl, heterocycle, aryl; each optionally substituted by one or more groups which are the same or different and which are selected from: (1) H, carboxylic acid bioester, halo-lower alkyl, halogen, (2) COOR5, OR5, SO2R5, (3) SO2NRiiRi2, C(=O)NRIIRI2, NRnRn, wherein Rn and Rj2 are the same or different and are selected from OH, R5, R<„ C(=O)NR5R^, C(=O)R5, SO2R5, C(=S)NR9RIO, C(-CH-NO2)NR9RIO, C(=N-CN)NR9RI0, C(=N-SO2NH2)NR9R10, C(=NR9)NHRIO, or C(=NR9)RI0; R3 is X2-R'3, wherein X2 is a single bond or a group selected from C1-C4 alkylene, alkenylene C2-C6, C2-C6 alkynylene each optionally substituted by one or more groups which are the same or different and which are selected from: (1) H, C1-C3 alkyl, C3-C4 cycloalkyl, aryl, heterocycle, =O, CN, (2) OR5, =NR5, or (3) NR13Ri4 wherein R5 and Rw are the same or different and are selected from R5, R6, C(=O)NR5R6, C(=O)R5, SO2R5, C(=S)NR9RIO, C(=CHNO2)NR9R10, C(=NR9)NHRIO, or C(=NR9)RI0; R'3 is cycloalkyl, cycloalkenyl, aryl, heterocycle, or a polycyclic group; each optionally substituted by one or more groups X3-R7 wherein X3 is a single bond, lower alkylene, C2-C6 alkenylene, C2-C6 alkynylene, cycloalkylene, arylene, bivalent heterocycle or a bivalent polycyclic group and R17 is: (1) H, =O, NO2, CN, halo-lower alkyl, halogen, carboxylic acid bioester, cycloalkyl, (2) COOR5, C(=O)R5, C(=S)R5, SO2R5, SOR5, SO3R5, SR5, OR5; (3) C(=O)NRI5R16, C(=S)NR15Ri6, C(=N-CN)NR15R16, C(=NSO2NH2)NR15R16, C(=CH-NO2)NR15RI6, SO2NR15R16, C(=NR15)NHR16, C(=NRI5)RI6, C(=NR9)NHRI6, C(=NR9)R16 OR NRI5RI6 where Ris and Ri6 are the same or different and are selected from OH, R5, R(„ C(=O)NR5R6, C(=O)R5, SO2R5, C(=S)NR9R1O, C(=CH-NO2)NR9R10, C(=N-CN)NR9RIO, C(=N-S02NH2)NR9RIO, C(=NR9)NHR1O, or C(=NR9)RW, (4) heterocycle optionally substituted by one or more R5 groups; wherein R5 and R<, are the same or different and are selected from H, lower alkyl, C2-C6 alkenyl, C2-C6 alkynyl, X4-cycloalkyl, X4-cycloalkenyl, X4-aryl, X4-heterocycle, or X4-polycyclic group, wherein X4 is a single bond, lower alkylene, or C2-C6 alkenylene; each optionally substituted by one or several groups which are the same or different and selected from halogen, =O, COOR20, CN, OR2O, O-lower alkyl optionally substituted by OR20, C(=O)-lower alkyl, lower haloalkyl, wherein X5 is a single bond or lower alkylene and R1, R19, and R2O are the same or different and are selected from H or lower alkyl; X6 is heterocycle, X6 is aryl, X6 is cycloalkyl, X6 is cycloalkenyl, or X6 is a polycyclic group, wherein X6 is a single bond or lower alkylene, these groups being optionally substituted by one or more identical or different groups selected from halogens, COOR2I, OR2I, or (CH2)nNR2iR22 wherein n is 0, 1, or 2 and R1 and R22 are the same or different and are selected from H or lower alkyl; R9 is selected from H, CN, OH, lower alkyl, O-lower alkyl, aryl, heterocycle, SO2NH2, or wherein X5 is a single bond or lower alkylene and R8 and R19 are the same or different and are selected from H or lower alkyl; R10 is selected from hydrogen, lower alkyl, cyclopropyl, or heterocycle, or pharmaceutically acceptable derivatives thereof. With respect to the above compounds, aryl refers to an unsaturated carbocycle comprising exclusively carbon atoms in the cyclic structure, the number of which is between 5 and 10, including phenyl, naphthyl, or tetrahydronaphthyl. Heterocycle refers to an unsaturated or saturated monocycle containing between 1 and 7 carbon atoms in the cyclic structure and at least one heteroatom in the cyclic structure, such as nitrogen, oxygen, or sulfur, preferably from 1 to 4 heteroatoms, identical or different, selected from nitrogen, sulfur, and oxygen atoms. Suitable heterocycles include morpholinyl, piperazinyl, pyrrolidinyl, piperidinyl, pyrimidinyl, 2- and 3-furanyl, 2- and 3-thienyl, 2-pyridyl, 2- and 3-pyranyl, hydroxypyridyl, pyrazolyl, isoxazolyl, tetrazole, imidazole, triazole, and the like. Polycyclic groups include at least two cycles, identical or different, selected from aryl, heterocycle, cycloalkyl, and cycloalkenyl groups fused together to form said polycyclic group such as 2- and 3-benzothienyl, 2- and 3-benzofuranyl, 2-indolyl, 2- and 3-quinolinyl, acridinyl, quinazolinyl, indolyl, benzo[1,3]dioxolyl, and 9-thioxantanyl. Bicyclic groups refer to two cycles, either the same or different, chosen from aryl, heterocycle, cycloalkyl, or cycloalkenyl, fused together to form the so-called bicyclic groups. Halogen refers to fluorine, chlorine, bromine, or iodine. Lower alkyl refers to an alkyl that is linear or branched and contains 1 to 6 carbon atoms. Examples of lower alkyl groups include methyl, ethyl, propyl, butyl, isopropyl, tert-butyl, isobutyl, n-butyl, pentyl, hexyl, and others. Alkenyl refers to a linear or branched unsaturated carbon chain comprising one or more double bonds, preferably one or two double bonds. Alkynyl refers to a linear or branched unsaturated carbon chain comprising one or more triple bonds, preferably one or two triple bonds. Lower haloalkyl refers to a lower alkyl substituted with one or more halogens; preferred lower haloalkyl groups include perhaloalkyl groups such as CF3. Cycloalkyl refers to a saturated nanocarbocycle containing 3 to 10 carbon atoms; including cyclopropyl, 5-cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. Cycloalkenyl refers to an unsaturated nanocarbocycle containing 3 to 10 carbon atoms. Examples of suitable cycloalkenyls are 3-cyclohexene and 3-cycloheptene. Carboxylic acid bioester has the classical meaning; common carboxylic acid bioesters are tetrazol-5-yl, C(=O)N(H)OH, isoxazol-3-yl, 10-hydroxythiadiazolyl, sulfonamido, sulfonylcarboxamido, phosphonic acid, phosphonamido, phosphinic acid, sulfonic acids, acyl sulfonamido, mercaptoazole, acyl cyanamides.

In one embodiment, a PDE7 inhibitor useful in the methods of the invention has the formula: The activity of Compound 4 in inhibiting various PDEs is described in Examples 1 and 2. The efficacy of Compound 4 in the MPTP Parkinson's model is described in Example 7. In other embodiments, PDE7 inhibitors useful in the methods of the invention have the formulas:

The preparation of the above compounds is described in EP 1 193 261, WO 02/28847, US 20030045557, US Patent No. 7,122,565, Bioorganic & Medicinal Chemistry Letters 14 (2004) 4607-4613 and Bioorganic & Medicinal Chemistry Letters 14 (2004) 4615-4621.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in WO 2004/111054, US 2006/0128728, and US 2007/0270419, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formulas: The substituents for the above compounds are defined as follows: R1 is a substituted or unsubstituted C3.8 cycloalkyl group or tert-butyl group; R2 is a hydrogen atom or Cμ3 alkyl group; R3 is a group: NR5R6, C(=O)R7, or S(O)o-2Rs; R4 is a hydrogen atom or Cμ3 alkoxy group that is unsubstituted or substituted by one or more fluorine atoms; R5 and R<5 are the same or different from each other, a hydrogen atom, substituted or unsubstituted Cμ6 alkyl group, substituted or unsubstituted acyl group, substituted or unsubstituted heterocycloalkyl group, and substituted or unsubstituted heterocycloalkyl ring formed with a nitrogen atom that is linking R5 and R^; R7 is a group: OR9 or NR5R6; R8 is a hydrogen atom, a halogen atom, a group: NR5R<„ substituted or unsubstituted C1-6 alkyl group or substituted or unsubstituted aryl group; R9 is a hydrogen atom or substituted or unsubstituted C1-6 alkyl group or pharmaceutically acceptable salts or solvates thereof. With respect to the above compounds, the term “C1-C3 alkyl group” includes a straight-chain or branched-chain alkyl group having 1 to 3 carbon atoms. The term “C3-C8 cycloalkyl group” includes a cycloalkyl group having 3 to 8 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl. The term “heterocycloalkyl group” is a 3- to 7-membered heterocyclic group containing the same or different 1 to 4 heteroatoms, such as oxygen, nitrogen, or sulfur atoms, and examples include pyrrolidinyl, piperidinyl, piperazinyl, homopiperazinyl, tetrahydrofuryl, tetrahydropyranyl, morpholinyl, and azetidinyl. The term "C1 -C3 alkoxy group" means an alkoxy group having 1 to 3 carbon atoms. The term "acyl group" means an acyl group having 1 to 8 carbon atoms. The term "aryl group" is a phenyl, naphthyl, or biphenyl group having 6 to 12 carbon atoms, and the term "heteroaryl group" is a 5- to 7-membered monocyclic or polycyclic group containing 2 to 8 carbon atoms and the same or different 1 to 4 heteroatoms, such as oxygen, nitrogen, or sulfur atoms. Examples include pyrrole, furyl, thienyl, imidazolyl, thiazolyl, pyrazinyl, indolyl, quinolinyl, isoquinolinyl, tetrazolyl, pyridinyl, pyrazolyl, pyridazinyl, and Examples of suitable substituents for “substituted or unsubstituted C1-C6 alkyl group” include hydroxyl group and halogen atom, and examples of suitable substituents for “substituted or unsubstituted acyl group” include halogen atom and nitro group. In addition, examples of suitable substituents for “substituted or unsubstituted aryl group” include C1-C3 alkyl, halogen atom, amino group, acyl group, amide group, hydroxyl group, acylamino group, carboxyl group, and sulfonyl group. Examples of suitable substituents for “substituted or unsubstituted C3-C8 cycloalkyl group” include C1-C3 alkyl, hydroxyl group, and oxo group, and examples of suitable substituents for “substituted or unsubstituted heterocycloalkyl group” may include carboxy group, acyl group, alkoxy group, amino group, alkylamino group, acylamino group, hydroxyl group, oxo group, ethylenedioxy group, methyl group, ethyl group, and group. hydroxyethyl.

In other embodiments, PDE7 inhibitors useful in the methods of the invention have the formulas: The preparation of the above compounds is described in WO 2004/111054, US 20060128728 and US 20070270419.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in U.S. Patent No. 6,903,109, U.S. 2004/0082578, WO 2003/088963, and U.S. 2006/0154949, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula:

The substituents for the above compounds are defined as follows: (a) R1 is selected from the group consisting of: (i) COR5, wherein R5 is selected from H, optionally substituted Cμ8 straight or branched alkyl, optionally substituted aryl, and optionally substituted arylalkyl; wherein the substituents on the alkyl, aryl, and arylalkyl group are selected from Cμ8 alkoxy, phenylacetyloxy, hydroxy, halogen, p-tosyloxy, mesyloxy, amino, cyano, carboalkoxy, or NR20R21 wherein R2Q and R2I are independently selected from the group consisting of hydrogen, Cμ8 straight or branched alkyl, C3.7 cycloalkyl, benzyl, or aryl; (ii) COOR^, wherein R() is selected from H, optionally substituted Cμ8 straight or branched alkyl, optionally substituted aryl, and optionally substituted arylalkyl; wherein the substituents on the alkyl, aryl, and arylalkyl group are selected from Cμ8 alkoxy, phenylacetyloxy, hydroxy, halogen, p-tosyloxy, mesyloxy, amino, cyano, carboalkoxy, or NR20R21 wherein R20 and R21 are independently selected from the group consisting of hydrogen, Cμ8 straight or branched alkyl, C3.7 cycloalkyl, benzyl, or aryl; (iii) cyano; (iv) a lactone or lactam formed with R4; (v) CONR7R8 wherein R7 and R8 are independently selected from H, Cμ8 straight or branched alkyl, C3.7 cycloalkyl, trifluoromethyl, hydroxy, alkoxy, acyl, alkylcarbonyl, carboxyl, arylalkyl, aryl, heteroaryl, and heterocyclyl; wherein the alkyl, cycloalkyl, alkoxy, acyl, alkylcarbonyl, carboxyl, arylalkyl, aryl, heteroaryl, and heterocyclyl groups may be substituted by carboxyl, alkyl, aryl, substituted aryl, heterocyclyl, substituted heterocyclyl, heteroaryl, substituted heteroaryl, hydroxamic acid, sulfonamide, sulfonyl, hydroxy, thiol, alkoxy, or arylalkyl; or R7 and R8 when together with the nitrogen to which they are attached form a heterocyclyl or heteroaryl group; (vi) a carboxylic acid carboxylic ester or bioester including optionally substituted heteroaryl groups; (b) R2 is selected from the group consisting of optionally substituted alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted C3-7 cycloalkyl, optionally substituted heterocyclyl, wherein the heterocyclyl is 1,3-dioxolane or furan, or R2 is (c) R3 is one to four groups independently selected from the group consisting of: (i) hydrogen, halo, C1-8 straight or branched alkyl, arylalkyl, C3-7 cycloalkyl, C1-8 alkoxy, cyano, C1-4 carboalkoxy, trifluoromethyl, C1-8 alkylsulfonyl, halogen, nitro, hydroxy, trifluoromethoxy, C1-8 carboxylate, aryl, heteroaryl, and heterocyclyl; (ii) NR10R11 wherein R10 and Rn are independently selected from H, C1-8 straight or branched alkyl, arylalkyl, C3-7 cycloalkyl, carboxyalkyl, aryl, heteroaryl, or heterocyclyl, or R10 and Rn when together with the nitrogen to which they are attached form a heterocyclyl or heteroaryl group; (iii) NR12CORi3 wherein R12 is selected from hydrogen or alkyl and R13 is selected from hydrogen, alkyl, substituted alkyl, C1-3 alkoxy, carboxyalkyl, R30R3IN(CH2)P, R30R3INCO(CH2)P, aryl, arylalkyl, heteroaryl or heterocyclyl or R[2 and R)3 when together with the carbonyl group form a carbonyl-containing heterocyclyl group, wherein R30 and R31 are independently selected from H, OH, alkyl and alkoxy and p is an integer from 1 to 6, wherein the alkyl group may be substituted by carboxyl, alkyl, aryl, substituted aryl, heterocyclyl, substituted heterocyclyl, heteroaryl, substituted heteroaryl, hydroxamic acid, sulfonamide, sulfonyl, hydroxy, thiol, alkoxy or arylalkyl; (d) R4 is selected from the group consisting of (i) hydrogen, (ii) C1-3 straight or branched alkyl, (iii) benzyl, and (iv) NR^Ru, wherein R13 and R4 are independently selected from hydrogen and C1-6 alkyl; wherein the C1-3 alkyl and benzyl groups are optionally substituted by one or more groups selected from C3-7 cycloalkyl, C1-8 alkoxy, cyano, C1-4 carboalkoxy, trifluoromethyl, C1-8 alkyl sulfonyl, halogen, nitro, hydroxy, trifluoromethoxy, C1-8 carboxylate, amino, NR13Ri4, aryl, and heteroaryl, and (e) X is selected from S and O; and pharmaceutically acceptable salt, ester, and prodrug forms thereof.

In an alternative embodiment, Rμ R3 and R4 are as above and R2 is NRI5RI6, where R15 and R16 are independently selected from hydrogen, Cμ8 straight or branched chain alkyl, arylalkyl, C3.7 cycloalkyl, aryl, heteroaryl and heterocyclyl or R15 and R16 when together with the nitrogen to which they are attached form a heterocyclyl or heteroaryl group.

With respect to the above compounds, “alkyl” refers to straight-chain, cyclic, and branched alkyl. The alkyl group may be optionally substituted by one or more groups, such as halogen, OH, CN, mercapto, nitro, amino, C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkylthio, C1-C8 alkylamino, di(C1-C8 alkyl)amino, (mono-, di-, tri-, and per-)haloalkyl, formyl, carboxy, alkoxycarbonyl, C1-C8 alkylCO-O-, C1-C8 alkylCONH-, carboxamide, hydroxamic acid, sulfonamide, sulfonyl, thiol, aryl, aryl(C1-C8)alkyl, heterocyclyl, and heteroaryl. The term “bioisostere” is defined as “groups or molecules that have chemical and physical properties that produce broadly similar biological properties.” (Burger’s Medicinal Chemistry and Drug Discovery, M. E. Wolff, ed. Fifth Edition, Vol. 1, 1995, Pg. 785). The term “acyl” as used herein, used alone or as part of a substituent group, means an organic radical having 2 to 6 carbon atoms (branched or straight chain) derived from an organic acid by removal of the hydroxyl group. “Aryl” or “Ar,” used alone or as part of a substituent group, is a carbocyclic aromatic radical including, but not limited to, phenyl, 1- or 2-naphthyl, and others. The carbocyclic aromatic radical may be substituted by the independent substitution of 1 to 5 of its hydrogen atoms with halogen, OH, CN, mercapto, nitro, amino, C1-C8 alkyl, C1-C8 alkoxy, C1-C8 alkylthio, C1-C8 alkylamino, di(C1-C8 alkyl)amino, (mono-, di-, tri- and per-)haloalkyl, formyl, carboxy, alkoxycarbonyl, C1-C8 alkyl CO-O-, C1-C8 alkyl CO-NH- or carboxamide. Illustrative aryl radicals include, for example, phenyl, naphthyl, biphenyl, fluorophenyl, difluorophenyl, benzyl, benzoyloxyphenyl, carboethoxyphenyl, acetylphenyl, ethoxyphenyl, phenoxyphenyl, hydroxyphenyl, carboxyphenyl, trifluoromethylphenyl, methoxyethylphenyl, acetamidophenyl, tolyl, xylyl, dimethylcarbamylphenyl, and others. The term "heteroaryl" refers to a fully unsaturated cyclic radical having five to ten ring atoms of which one ring atom is selected from S, O, and N; 0 to 2 additional ring atoms are heteroatoms independently selected from S, O, and N, and the remaining ring atoms are carbon. The radical can be attached to the remainder of the molecule through any of the ring atoms. The terms "heterocycle," "heterocyclic," and "heterocycle" refer to an optionally substituted, fully or partially saturated cyclic group that is, for example, a 4- to 7-membered monocyclic, 7- to 11-membered bicyclic, or 10- to 15-membered tricyclic ring system, having at least one heteroatom on at least one carbon atom containing the ring. Each ring of the heterocyclic group may have 1, 2, or 3 heteroatoms selected from nitrogen atoms, oxygen atoms, and sulfur atoms, where the nitrogen and sulfur heteroatoms may also be optionally oxidized. The nitrogen atoms may be optionally quaternized.

The heterocyclic group may be attached to any heteroatom or carbon atom. In other embodiments, PDE7 inhibitors useful in the methods of the invention have the formulas:

The preparation of the above compounds is described in US Patent No. 6,903,109, US 20040082578, WO 2003/088963 and US 20060154949.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in U.S. Patent No. 6,958,328, WO 2002/085894 and U.S. 2003/0212089, each expressly incorporated herein by reference in their entirety. These PDE7 inhibitors have the same formula as that described above (e.g., U.S. Patent No. 6,903,109), except that R1 is not a carboxylic ester or carboxylic acid bioester. The preparation of these compounds is described in U.S. Patent No. 6,958,328, U.S. 2003/0212089 and WO 2002/085894.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in WO 2006/004040 and EP 1 775 298, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula:

The substituents for the above compounds are defined as follows: R1 is a substituted or unsubstituted C3.8 alkyl group, substituted or unsubstituted cycloalkyl group, or substituted or unsubstituted heterocycloalkyl group (e.g., cyclohexyl, cycloheptyl, or tetrahydropyranyl); R2 is a hydrogen atom or substituted or unsubstituted C1-3 alkyl group (e.g., methyl); R3 is a hydrogen atom, substituted or unsubstituted C1.3 alkyl group, or a halogen atom; and R4 is a substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, or a CONR5R6 or CO2R7 group, wherein R5 and R6 are the same or different from each other, a hydrogen atom; substituted or unsubstituted C1-6 alkyl group which may be substituted by a halogen atom, substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, substituted or unsubstituted heterocycloalkyl group, substituted or unsubstituted cycloalkyl group, a NR7COR8, COR8, NR9R10 group; substituted or unsubstituted cycloalkyl group; substituted or unsubstituted heterocycloalkyl group; substituted or unsubstituted aryl group; substituted or unsubstituted heteroaryl group or substituted or unsubstituted heterocyclyl group in which the ring is formed together with the nitrogen atom linking R5 and R<>; in which R7 is a hydrogen atom or a substituted or unsubstituted C1-3 alkyl group; in which R8 is a substituted or unsubstituted heterocycloalkyl group or an OH, OR7 or NR9R10 group; in which R9 and R10 are the same or different from each other, a hydrogen atom; substituted or unsubstituted C1-3 alkyl group, substituted or unsubstituted heterocycloalkyl group; substituted or unsubstituted acyl; a SO7R7 group or substituted or unsubstituted heterocycloalkyl group in which the ring is formed together with the nitrogen atom linking R5 and RÔ; or their pharmaceutically acceptable salts or solvates.

With respect to the above compounds, the term "cycloalkyl group" means a cycloalkyl group having 3 to 8 carbon atoms. The term "heterocycloalkyl group" can be a 3- to 7-membered monocyclic or polycyclic heterocyclic group containing the same or different 1 to 4 heteroatoms, such as oxygen, nitrogen, or sulfur atoms. The term "aryl group" can be an aromatic hydrocarbon group consisting of a mono-benzene ring or a fused benzene ring, such as phenyl, naphthyl, biphenyl, and others; or a dicyclic or tricyclic group consisting of a fused benzene ring with a cycloalkyl or heterocyclic ring, such as 1,2,3,4-tetrahydronaphthalene, 2,3-dihydroindene, indoline, coumarone, and others. The term "heteroaryl group" may mean a 5- to 7-membered monocyclic heteroaryl group or a polycyclic heteroaryl group having 2 to 8 carbon atoms with 1 to 4 heteroatoms, such as oxygen, nitrogen, or sulfur atoms, wherein the polycyclic heteroaryl group has a ring system condensed by the same or different monocyclic heteroaryl or benzene ring to each other; or a polycyclic group consisting of a heteroaryl group condensed with a cycloalkyl or heterocycloalkyl ring. Examples of suitable substituents of the present invention may include a straight-chain, branched, cyclic C1-C6 alkyl group, which may be substituted by one or more of methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, cyclohexyl, cycloheptyl, methoxymethyl, hydroxymethyl, trifluoromethyl, C1-C3 alkoxy group, halogen atom, and hydroxyl group; hydroxyl group; cyano group; substituted or unsubstituted alkoxy group such as methoxy, ethoxy group; amino group which may be substituted by CJ-C0 alkyl group or acyl group such as amino, methylamino, ethylamino, dimethylamino, acylamino and others; carboxylic group; substituted or unsubstituted ester group; phosphate group; sulfonic group; substituted or unsubstituted aryl group; substituted or unsubstituted heteroaryl group; saturated or unsaturated heterocycloalkyl group which may be substituted; substituted or unsubstituted carbamoyl group; substituted or unsubstituted amide group; substituted or unsubstituted thioamide group; halogen atom; nitro group; substituted or unsubstituted sulfone group; substituted or unsubstituted sulfonylamide group; oxo group; substituted or unsubstituted urea group; straight or branched chain cyclic alkenyl group such as ethenyl, propenyl, cyclohexenyl and others.

In other embodiments, PDE7 inhibitors useful in the methods of the invention have the formulas: The preparation of the above compounds is described in EP 1 775 298 and WO 2006/004040.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in WO 2004/111053 and US 2006/0128707, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formulas: The substituents for the above compounds are defined as follows: A is N or CR4; B is N or CH; R1 is a substituted or unsubstituted C3-8 cycloalkyl group or tert-butylum group; R2 is a hydrogen atom or C6 alkyl group; R3 is a hydrogen atom; nitro group; cyano group; a halogen atom; heteroaryl group; substituted or unsubstituted C6 alkyl group; substituted or unsubstituted C2-6 alkenyl group; saturated or unsaturated heterocycloalkyl group that is substituted or unsubstituted; a group: NR5R6, C(O)R7, SO2R7, OR8, NR8COR7, NR8SO2R7; R4 is a hydrogen atom or C1.3 alkoxy group that is unsubstituted or substituted by one or more fluorine atoms; R5 and R< are the same or different from each other; a hydrogen atom; substituted or unsubstituted C6 alkyl group; substituted or unsubstituted acyl group; or substituted or unsubstituted heterocycloalkyl group; R7 is a hydrogen atom; substituted or unsubstituted Cμ6 alkyl group; substituted or unsubstituted heterocycloalkyl group; OH; OR8 or NR5R6; R8 is a hydrogen atom, substituted or unsubstituted C1-6 alkyl group; or substituted or unsubstituted heterocycloalkyl group; or their pharmaceutically acceptable salts or solvates.

With respect to the above compounds, the term "C1-C6 alkyl group" refers to a straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms, and the term "C2-C6 alkenyl group" refers to a straight-chain or branched-chain alkenyl group having 2 to 6 carbon atoms. The term "cycloalkyl group" refers to a cycloalkyl group having 3 to 8 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. The term "heterocycloalkyl group" refers to a 3- to 7-membered heterocyclic group containing the same or different 1 to 4 heteroatoms, such as oxygen, nitrogen, or sulfur atoms. Examples include piperidinyl, pyrrolidinyl, piperazinyl, tetrahydrofuryl, tetrahydropyranyl, morpholinyl, azetidinyl, and homopiperazinyl. The term "heteroaryl group" refers to a 5- to 7-membered monocyclic or polycyclic group containing 2 to 8 carbon atoms and the same or different 1 to 4 heteroatoms, such as oxygen, nitrogen, or sulfur atoms. Examples include pyrrole, furyl, thienyl, imidazolyl, thiazolyl, pyrazinyl, indolyl, quinolinyl, isoquinolinyl, tetrazolyl, pyridinyl, pyrazolyl, pyridazinyl, and pyrimidinyl. The "halogen atom" includes fluorine, chlorine, bromine, and iodine. Examples of suitable substituent of “substituted or unsubstituted C1-C6 alkyl group”, “substituted or unsubstituted C3-C8 cycloalkyl group”, “substituted or unsubstituted alkenyl group”, “substituted or unsubstituted heterocycloalkyl group” and “substituted or unsubstituted acyl group” include a substituted or unsubstituted straight-chain or branched alkyl group such as methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl; a substituted or unsubstituted cycloalkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl; a hydroxyl group; a cyano group; an alkoxy group such as methoxy and ethoxy; a substituted or unsubstituted amino group such as amino, methylamino, ethylamino and dimethylamino; a substituted or unsubstituted acyl group such as acetyl and propionyl; a substituted or unsubstituted aryl group; a substituted or unsubstituted heteroaryl group; saturated or unsaturated heterocycloalkyl group that is substituted or unsubstituted; substituted or unsubstituted carbamoyl group; substituted or unsubstituted amide group; halogen atom; nitro group; substituted or unsubstituted sulfone group; oxo group; urea group; a straight-chain, branched-chain, or cyclic alkyl group that is substituted or unsubstituted such as ethenyl, propenyl, and cyclohexenyl. In other embodiments, PDE7 inhibitors useful in the methods of the invention have the formulas: The preparation of the above compounds is described in US 20060128707 and WO 2004/111053.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in U.S. Patent No. 6,617,357, U.S. 20020156064, and Molecular Pharmacology, 66:1679-1689, 2004, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula:

The substituents for the above compounds are defined as follows: R1 is NRaRb where Ra and Rb are independently H or C1-6 alkyl or represent a 5- to 7-membered ring comprised of carbon or carbon and one or more additional heteroatoms selected from O, N, or S; R2 is H, C1-8 alkyl, C1-3 alkyl-Ar, C1-3 alkyl, C3-6 cycloalkyl, C2-8 alkenyl, C2-4 alkenyl-Ar, or C2-4 alkenyl-C3-8 cycloalkyl, wherein Ar is substituted or unsubstituted phenyl; R3 is NO2, halo, CN, C(O)OR7, COR) or NRaRb where Ra and Rb are independently H or C1-6 alkyl; R4 is H, C₁₋₄alkyl, halo, C(O)NR;1Rb, C(O)OR7, C₁₋₄alkyl, OCHF2, CH2OR8, C₁₋₄alkyl-Ar, or CH2NHC(O)CH3; R5 is H, halo, or alkyl; Rh is C₁₋₄alkyl, C₁₋₄alkyl, or halo; R7 is hydrogen or an ester or amide-forming group; R8 is hydrogen or C₁₋₄alkyl; or a pharmaceutically acceptable salt or solvate thereof. In one embodiment, a PDE7 inhibitor useful in the methods of the invention has the formula:

The preparation of the above compounds is described in U.S. Patent No. 6,617,357, U.S. 20020156064 and Molecular Pharmacology, 66:1679-1689,

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in U.S. Patent No. 6,852,720, EP 1,348,433, and WO 2003/082277, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula:

The substituents for the above compounds are defined as follows: Ri is a group selected from cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, those groups being optionally substituted by one or more groups, identical or different, selected independently of one another from halogen, trifluoromethyl, nitro, cyano, oxo, NR4R5, CO2R4, CONR4R5, OR4, S(O)nR4, S(O)nNR4R5, tetrazolyl, and (C1-C6) alkyl that is optionally substituted by 1 to 3 groups, identical or different, selected independently of one another from OR4, NR4R5, and CO2R4; where n is an integer from 0 to 2 inclusive, R4 and R5 are identical or different and, independently of one another, are a hydrogen atom or a group of the formula XrRa, where Xi is a single bond or an alkylene group (C1-C6) and Ra is a group selected from alkyl (C1-C6), cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, R2 is a group selected from alkyl (C1-C6), alkenyl (C2-C6), alkynyl (C2-C6), aryl, and cycloalkyl, R3 is a group selected from cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, these groups being optionally substituted by one or more groups, identical or different, selected independently of one another from halogen, nitro, cyano, trifluoromethyl, oxo, alkyl (C1-C6), OR<„ NR6R7, CORO, CO2R6, CONHOH, CONR6R7, S(O)rnR6, S(O)mNR6R7, NR6COR7, NR6SO2R7, N(SO2R7)2, NRÓCONR7R8, C(=NCN)NR^R7, NR8C(=NCN)NR6R7 and tetrazolyl optionally substituted by a (C1-C4) alkyl, where m is an integer from 0 to 2 inclusive, R^ and R7 are identical or different and independently of one another are a hydrogen atom or a group of the formula X2Rb, where X2 is a single bond or an alkylene (C1-C6) group, Rb is a group selected from alkyl (C1-C6), cycloalkyl, heterocycloalkyl, aryl and heteroaryl, these groups being optionally substituted by 1 to 3 groups, identical or different, selected independently of one another from hydroxy, alkoxy (C1-C6), alkyl (C1-C6) alkylamino, monoalkyl (C1-C6)amino, dialkyl (C1-C6)amino (each alkylamino being identical or different independently of the other), carboxy, (C1-C6)alkoxycarbonyl and benzyl and R8 represents a hydrogen atom or a (C1-C6) alkyl group; a racemic form thereof, an isomer thereof, an N-oxide thereof or a pharmaceutically acceptable acid or base salt thereof. The preparation of the above compounds is described in US Patent No. 6,852,720, EP 1 348 433 and WO 2003/082277.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in U.S. Patent No. 6,753,340, U.S. 2003/0191167, EP 1,348,701, and WO 2003/082839, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula:

The substituents for the above compounds are defined as follows: Ria is a group selected from hydrogen, alkyl (C1-C6), and arylalkyl (C1-C6), Rib is a group selected from cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, those groups being optionally substituted by one or more groups, identical or different, selected independently of one another from halogen, trifluoromethyl, nitro, cyano, oxo, NR4R5, CO2R4, CONR4R5, OR4, S(O)nR4, S(O)nNR4R5, tetrazolyl, and alkyl (C1-C6) that is optionally substituted by 1 to 3 groups, identical or different, selected independently of one another from OR4, NR4R5, and CO2R4, wherein n is an integer from 0 to 2 inclusive, R4 and R5 are identical or different, and independently of one another are a hydrogen atom or a group of the formula XrRa, wherein Xi is a single bond or a C1-C6 alkylene group and Ra is a group selected from C1-C6 alkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, R2 is a group selected from C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, aryl, and cycloalkyl, R3 is a group selected from cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, these groups being optionally substituted by one or more groups, identical or different, selected independently of one another from halogen, nitro, cyano, trifluoromethyl, oxo, C1-C6 alkyl, OR^, NR6R7, COR^, CO2Rb, CONHOH, CONR6R7, S(O)mR6, S(O)mNR6R7, NR6COR7, NR6SO2R-, N(SO2R7)2J NRÓCONR7R8, C(=NCN)NR6R7, NR8C(=N-CN)NR6R7 and tetrazolyl optionally substituted by a (C1-C4) alkyl, where m is an integer from 0 to 2 inclusive, R^ and R7 are identical or different and independently of one another are a hydrogen atom or a group of the formula X2-Rb, where X2 is a single bond or an alkylene (CJ-CÓ) group, Rb is a group selected from (C1-C6) alkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl, these groups being optionally substituted by 1 to 3 groups, identical or different, selected independently of one another from hydroxy, (C1-C6) alkoxy, (C1-C6) alkyl, amino, monoalkylamino (C1-C6), dialkyl (C1-C6) amino (each alkylamino being identical or different independently of one another). on the other), carboxy, (C1-C6) alkoxycarbonyl and benzyl and R8 is a hydrogen atom or a (C1-C6) alkyl group or a racemic form thereof, an isomer thereof, an N-oxide thereof or a pharmaceutically acceptable acid or base salt thereof. The preparation of these compounds is described in US Patent No. 6,753,340, US 20030191167, EP 1 348 701 and WO 2003/082839.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in U.S. Patent No. 6,849,638, U.S. 2003/0119829, and WO 2002/088138, each of which is expressly incorporated herein by reference in its entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula:

The substituents for the above compounds are defined as follows: R1 and R2 are independently selected from the group consisting of hydrogen, alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, alkynyl of 2 to 8 carbon atoms, cycloalkyl of 3 to 7 carbon atoms, fully saturated heterocycle of 2 to 6 carbon atoms and 1 to 2 heteroatoms selected from NH, S, and O, aryl of 6 to 12 carbon atoms, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms, and various halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1, 2 heteroatoms selected from N, S and O, heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S, and O and R4-R5 or R1 and R2 combine to form, together with the nitrogen atom to which they are attached, a 5- to 7-membered saturated ring which may contain 1 to 2 additional heteroatoms selected from the group consisting of NH, NR8, S, and O, or combine to form, together with the nitrogen atom to which they are attached, a 5- to 7-membered unsaturated ring which may contain 1 to 2 additional heteroatoms selected from the group consisting of N, S, and O, wherein said saturated or unsaturated ring may be substituted by 1 to 2 substituents selected from the group consisting of OH, alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, cycloalkyl of 3 to 7 carbon atoms, fully saturated heterocycle of 2 to 6 carbon atoms, and 1 to 2 heteroatoms selected from NH, S and O, halogen, haloalkyl of 1 to 2 carbon atoms and various halogen atoms up to the perhalo level, alkoxy of 1 to 6 carbon atoms, haloalkoxy of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level and R9-R10 or R1 and R2 combine to form, together with the nitrogen atom to which they are attached, an 8- to 10-membered bicyclic saturated ring; R3 is selected from the group consisting of NH, S, S(=O)2 and O; R4 is selected from alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, alkynyl of 2 to 8 carbon atoms, C(=C), S(=O)2 and C(=O)O; R5 is selected from hydrogen, OH, alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, alkynyl of 2 to 8 carbon atoms, alkoxy of 1 to 8 carbon atoms, aryl of 6 to 12 carbon atoms, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, haloalkyl of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms and heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms and heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, cycloalkyl of 3 to 7 carbon atoms, fully saturated heterocycle of 2 to 6 carbon atoms and 1 to 2 heteroatoms selected from NH, S, and O and NRJR7, RÓ, and R7 are independently selected from hydrogen, alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, and alkynyl of 2 to 8 carbon atoms or R^ and Ry combine together with the nitrogen atom to which they are attached to form a 5- to 7-membered unsaturated ring which may contain 1 to 2 additional heteroatoms selected from N, S, and O or to form a 5- to 7-membered saturated ring which may contain 1 to 2 additional heteroatoms selected from NH, S, and O; R8 is selected from alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, alkynyl of 2 to 8 carbon atoms, R11-R12, cycloalkyl of 3 to 7 carbon atoms, fully saturated heterocycle of 2 to 6 carbon atoms and 1 to 2 heteroatoms selected from NH, S and O, aryl of 6 to 12 carbon atoms, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O; R9 is selected from alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, and alkynyl of 2 to 8 carbon atoms. R10 is selected from OH, aryl of 6 to 12 carbon atoms, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S, and O, and heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O; Rn is selected from alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, and alkynyl of 2 to 8 carbon atoms, and R12 is selected from cycloalkyl of 3 to 7 carbon atoms, fully saturated heterocycle of 2 to 6 carbon atoms and 1 to 2 heteroatoms selected from NH, S, and O, aryl of 6 to 12 carbon atoms, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O and heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O; and their pharmaceutically acceptable salts. The preparation of these compounds is described in US Patent No. 6,849,638, US 20030119829 and WO 2002/088138.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in US 2005/222138 and WO 2003/064389, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula:

The substituents for the above compounds are defined as follows: R 1 and R 2 are each independently (1) hydrogen atom or (2) C 1-8 alkyl, or R 3 and R 2 can, when together with the carbon atom to which they are attached, form Cycl, where R 1 and R 2 do not represent hydrogen atoms in the same period; Z is (1) CR 3 R 4 , (2) O, (3) S, or (4) a bond; R 3 and R 4 are each independently (1) hydrogen atom, (2) C 1-8 alkyl, (3) C 1-8 alkoxy, or (4) hydroxy, or R 3 and R 4 can, when together with the carbon atoms to which they are attached, form Cycl or C(O); R5 and R⁴ are each independently (1) hydrogen atom or (2) C1-8 alkyl, or R5 and R⁴ can, when together with the carbon atom to which they are attached to form Cycl; Cycl, which is represented by R⁴ and R⁴, R⁴ and R⁴, R5 and R⁴ is each independently (1) C3-10 cycloalkyl or (2) a 3- to 10-membered monocyclic heteroring comprising 1 to 2 heteroatoms selected from oxygen, nitrogen, and sulfur, and Cycl may be substituted for R⁴; R⁴ is (1) C⁴ alkyl, (2) C⁴ alkoxy, (3) hydroxy, (4) COOR⁴, (5) oxo, (6) SO⁴ R⁴ or (7) COR⁴; R⁴ is hydrogen atom or C⁴ alkyl; R⁴ and R⁴ are (1) C⁴ alkyl or (2) phenyl that may be substituted by Cμ8 alkyl; R7 and R8 are each independently (1) hydrogen atom, (2) Cμ8 alkyl, (3) Cμ8 alkoxy, (4) hydroxy, (5) cyano, (6) halogen atom, (7) COOR14, (8) CONR15R16, (9) CiC2, (10) C28 alkenyl, (11) C28 alkynyl, (12) NR5iR52, (13) nitro, (14) formyl, (15) C28 acyl, (16) Cμ8 alkyl substituted by hydroxy, Cμ8 alkoxy, CiC2, NR5IR52 or NR53-CiC2, (17) NR54COR55, (18) NR56SO2R57, (19) SO2NR58R59, (20) C2.8 alkenyl substituted by COORu, (21) CH=N-OH, (22) Cμ8 alkylene-NR60-(Cμ8 alkylene)-R6i, (23) Cμ8 alkylthio, (24) Cμ8 alkyl substituted by 1 to 3 halogen atoms, (25) Cμ8 alkoxy substituted by 1 to 3 halogen atoms, (26) Cμ8 alkoxy substituted by CiC2, (27) O-CiC2, (28) OSO2R^5 or (29) CH=N-OR137I R14 is hydrogen atom or Cμ8 alkyl; R51 and R52, R58 and R59 are each independently hydrogen atom or Cμ8 alkyl; hydrogen or Cμ8 alkyl; R53, R54, R56, and R^o are each independently hydrogen or Cμ8 alkyl; R55 is hydrogen, Cμ8 alkyl, or Cμ8 alkoxy; R57 is Cμ8 alkyl; Rei is NR62RÓ3 or hydroxy; R(S2) and R63 are each independently hydrogen or Cμ8 alkyl; Res is C18 alkyl; R137 is Cμ8 alkyl; (hereinafter this is abbreviated as ring) is CiC2 where the carbonyl-bonding group is carbon; R7, R8, and CiC2 represented by ring are each, independently, (1) a C345 mono-, bi-, or tricyclic (fused or spiro)carbon ring or (2) a 3- to 15-membered mono-, bi-, or tricyclic (fused or spiro)heteroring comprising 1 to 4 heteroatoms selected from oxygen, nitrogen, and sulfur; CiC2 may be substituted by 1 to 5 of Rj7 or Rn; Rn is: (14) phenyl, phenoxy or phenylthio, which can be substituted by 1 to 5 of R20, (15) Cμ8 alkyl, C2.8 alkenyl, Cμ8 alkoxy or Cμ8 alkylthio, which can be substituted by 1 to 5 of R21 (16) OCOR22, (17) CONR23R24, (18) SO2NR25R26 (19) COOR27, (20) COCOOR28, (21) COR29, (22) COCOR30, (23) NR3ICOR32, (24) SO2R33, (25) NR34SO2R35 OR (26) SOR^4; R1s and R1z, R31 and R34 are each independently hydrogen atom or Cμ8 alkyl; R20 and R21 are C11-8 alkyl, Cμ8 alkoxy, hydroxy, halogen atom, nitro or COOR36; R22 and RΔ4 are each independently Cμ8 alkyl; R23, R24, R25, and R26 are each independently hydrogen atom, Cμ8 alkyl, or phenyl; R27, R28, R29, R3O, R32, R33, and R35 are (1) C18 alkyl, (2) C28 alkenyl, (3) C18 alkyl substituted by 1 to 5 of R37, (4) diphenylmethyl, (5) triphenylmethyl, (6) CiC3, (7) C18 alkyl or C28 alkenyl substituted by CiC3, (8) C18 alkyl substituted by O-C1C3, S-C1C3, or SO2-C1C3; R3is hydrogen or C18 alkyl; R37 is C18 alkoxy, C18 alkylthio, benzyloxy, halogen, nitro, or COOR38; R38 is hydrogen, C18 alkyl, or C28 alkenyl; Cic3 is (1) a C3-15 mono-, bi- or tri-cyclic (fused or spiro)carbon ring or (2) a 3- to 15-membered mono-, bi- or tri-cyclic (fused or spiro)heteroring comprising 1 to 4 heteroatoms selected from oxygen, nitrogen and sulfur; CiC3 may be substituted by 1 to 5 of R39; R39 is (1) Cμ8 alkyl, (2) C2.8 alkenyl, (3) C2.8 alkynyl, (4) Cμ8 alkoxy, (5) Cμ8 alkylthio, (6) hydroxy, (7) halogen atom, (8) nitro, (9) 0x0, (10) cyano, (11) benzyl, (12) benzyloxy, (13) alkyl Cμ8, Cμ8 alkoxy or Cμ8 alkylthio substituted by 1 to 5 of R40, (14) phenyl, phenoxy, phenylthio, phenylsulfonyl or benzoyl which can be substituted by 1 to 5 of R», (15) OCOR42, (16) SO2R43, (17) NRuCORtf, (18) SChNR^Rp, (19) COORJS or (20)NR49R50; RIO is a halogen atom; Rn is Cμ8 alkyl, Cμ8 alkoxy, halogen atom or nitro; RI2, RB and R45 are Cμ8 alkyl; R44 and R48 are hydrogen atom or Cμ8 alkyl; R46 and R47, R49 and R50 are each independently hydrogen atom or Cμ8 alkyl; R17' is (1) SH, (2) NR^CHO, (3) Cic5, (4) Cp8 alkyl, C2-8 alkenyl or C2.8 alkynyl substituted by Cic5, (5) CO-(NH-amino acid residue-CO)n-OH, (6) NR67CONR68Ré9, (7) CONR70NR7IR72, (8) CONR73OR74, (9) CONR75COR76, (10) C(S)NR77R78, (11) CONR79C(S)COOR80, (12) NR8ICOCOOR82, (13) NR83COOR84, (14) CONR85C(S)R86, (15) OCOR87, (16) SOR88, (17) CONR89R90, (18) SO2NR9IR92, (19) COOR93, (20) COCOOR94, (21) COR95, (22) COCOR96, (23) NR97COR98, (24) SO2R99, (25) NR100SO2R101 or (26) NR102RI03; n is an integer from 1 or 2; R<>6, R73? R75, R77, R795 R«1, RS3? RS5, R97, R100 and R102 are hydrogen atom or Cμ8 alkyl; R67 and R68, R70 and R71 are each independently hydrogen atom or Cμ8 alkyl; R89 and R91 are (1) hydrogen atom, (2) C1-8 alkyl, (3) phenyl, or (4) C1-8 alkyl substituted by cyano or Cμ8 alkoxy; Rios is CiC6; RΓ9, R72, R74, R76, R78, R80, Rδ2, R84, R86, R87, R88, R90, and R92 are (1) hydrogen atom, (2) Cμ8 alkyl, (3) C28 alkenyl, (4) C28 alkynyl, (5) Cμ8 alkyl substituted by 1 to 5 of R104, (6) diphenylmethyl, (7) triphenylmethyl, (8) C1c6, (9) Cμ8 alkyl or C28 alkenyl substituted by C1C6, or (10) Cμ8 alkyl substituted by O-C1C6, S-C1c6, or SO2-C1c6; R104 is (1) C18 alkoxy, (2) C18 alkylthio, (3) benzyloxy, (4) halogen atom, (5) nitro, (6) COOR105, (7) cyano, (8) NR1O6Rio7, (9) N108COR109, (10) hydroxy, (11) SH, (12) SO3H, (13) S(O)OH, (14) OSO3H, (15) C28 alkenyloxy, (16) C28 alkynyloxy, (17) CORno, (18) SO2Rm, or (19) C18 alkoxy or C18 alkylthio substituted by hydroxy; R105 is hydrogen, C18 alkyl, or C28 alkenyl; R106 and R107 are each independently hydrogen atom or Cμ8 alkyl; R108 is hydrogen atom or Cμ8 alkyl; R109 and Rm are Cμ8 alkyl; Ruo is Cμ8 alkyl or halogen atom; R93, R94, R95, R96, R98, R99, and R101 are (1) C28 alkynyl, (2) Cμ8 alkyl substituted by R128 which may be substituted by 1 to 4 of R29, (3) CiC8, (4) Cμ8 alkyl or C28 alkenyl substituted by CiC8, or (5) Cμ8 alkyl substituted by O-C1C8, S-C1C8, or SO2-C1C8; Ri28 is (1) cyano, (2) NRIO6RIO7, (3) NRI08COR109, (4) hydroxy, (5) SH, (6) SO3H, (7) S(O)OH, (8) OSO3H, (9) C2.8 alkenyloxy, (10) C2.8 alkynyloxy, (11) CORno, (12) SO2Rm or (13) Cμ8 alkoxy or Cμ8 alkylthio substituted by hydroxy; Ri29has the same meaning as RW4; Cic5 and Cic6 can be replaced by 1 to 5 of RH2; RH2 is (1) Cμ8 alkyl, (2) C28 alkenyl, (3) C28 alkynyl, (4) Cμ8 alkoxy, (5) Cμ8 alkylthio, (6) hydroxy, (7) halogen atom, (8) nitro, (9) OxO, (10) cyano, (11) benzyl, (12) benzyloxy, (13) Cμ8 alkyl, Cμ8 alkoxy, or Cμ8 alkylthio substituted by 1 to 5 of (14) phenyl, phenoxy, phenylthio, or benzoyl which may be substituted by 1 to 5 of (15) CORH5, (16) SO2Rn6, (17) NR117COR118, (18) SO2NR119R120, (19) COOR^1, (20) NR122R123, (21) CORI24, (22) CONRI25RI26, (23) SH, (24) Cμ8 alkyl substituted by hydroxy or NRi27-benzoyl or (25) Cμ7; R13 is halogen; R114 is Cμ8 alkyl, Cμ8 alkoxy, halogen or nitro; Rus, RII6 and Rii8are Cμ8 alkyl; RII7J R121, R124 θ Rj27 are hydrogen atom or Cμ8 alkyl; R119 and R120, R122 and R123, R125 and R126 are each independently hydrogen atom or Cμ8 alkyl; Cic7 may be substituted by 1 to 5 groups selected from (1) Cμ8 alkyl, (2) Cμ8 alkoxy, (3) halogen atom or (4) nitro; Cic8 may be substituted by RI30 and this may further be substituted by 1 to 4 of R131; R130 is (1) COR124, (2) CONR125Ri26, (3) SH, (4) Cμ8 alkyl substituted by hydroxy or NRi27-benzoyl or (5) Cic7; R131 has the same meaning as RH2; English:Cyc5, CiC6, CiC7, and CiC8 are (1) C3-, bi-, or tri-cyclic (fused or spiro)carbon ring or (2) 3- to 15-membered mono-, bi-, or tri-cyclic (fused or spiro)heteroring comprising 1 to 4 of heteroatoms selected from 1 to 4 of oxygen, nitrogen, or sulfur; wherein when R17' is Cyc5, Cyc5 is not phenyl that may be substituted by 1 to 5 selected from Cμ8 alkyl, Cμ8 alkoxy, hydroxy, halogen atom, nitro, COOH, or COO(Cμ8 alkyl); wherein Cyc7 is not phenyl; Cyc4 is (1) C5-, monocyclic carboring or (2) 5- to 7-membered monocyclic heteroring comprising 1 to 2 of heteroatoms selected from oxygen, nitrogen, and sulfur; (abbreviated as dashed line hereinafter;) and (abbreviated as dashed line ba hereinafter;) are (1) a bond or (2) a double bond; R9 is (1) absent or (2) hydrogen atom; wherein when dashed line A is a bond, dashed line B is a double bond and R9 is absent, when dashed line A is a double bond, dashed line B is a bond and R9 is hydrogen atom and R6 is absent, and 2-(3,3-dimethyl-3,4-dihydro-(2H)-isoquinolin-1-ylidene)-1-phenylethan-1-one is excluded or a pharmaceutically acceptable salt thereof. The preparation of these compounds is described in US 2005222138 and WO 2003/064389.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in WO 2003/057149, expressly incorporated herein by reference in its entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: (1) X is selected from halogen and NRIR2, (2) Y is selected from NR3, S, and O, with the proviso that Y is not S when X is Cl, (3) R1 and R2 are independently selected from hydrogen, alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, alkynyl of 2 to 8 carbon atoms, cycloalkyl of 3 to 7 carbon atoms, polycycloalkyl of 5 to 9 carbon atoms, heterocycloalkyl of 2 to 6 carbon atoms and 1 to 2 heteroatoms selected from NH, S, and O, aryl of 6 to 12 carbon atoms, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and several halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and several halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and several halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and assorted halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms, or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S, and O and R4R5 or R1 and R2 combine to form, together with the nitrogen atom to which they are attached, a 5- to 7-membered monocyclic saturated ring which optionally contains 1 to 2 additional heteroatoms selected from the group consisting of NH, NR5, S, and O, or combine to form, together with the nitrogen atom to which they are attached, a 6- to 10-membered fused polycyclic saturated ring which optionally contains 1 to 2 additional heteroatoms selected from the group consisting of NH, NR6, S, and O, or combine to form, together with the nitrogen atom to which they are attached, a 5- to 7-membered saturated ring which optionally contains 1 to 2 additional heteroatoms selected from the group consisting of N, S, and O, wherein said monocyclic saturated ring, polycyclic saturated ring, or unsaturated ring may be substituted by 1 to 2 substituents selected from the group consisting of OH, alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, cycloalkyl of 3 to 7 carbon atoms, heterocycloalkyl of 2 to 6 carbon atoms, and 1 to 2 heteroatoms selected from NH, S, and O, halogen, haloalkyl of 1 to 2 carbon atoms, and various halogen atoms up to the perhalo level, alkoxy of 1 to 6 carbon atoms, haloalkoxy of 1 to 6 carbon atoms, and various halogen atoms up to the perhalo level, and R≡Rs, (4) R≡ is selected from hydrogen, alkyl from 1 to 8 carbon atoms, alkenyl from 2 to 8 carbon atoms, alkynyl from 2 to 8 carbon atoms, cycloalkyl from 3 to 7 carbon atoms and heteroaryl from 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, which may be substituted by alkyl from 1 to 6 carbon atoms, alkenyl from 2 to 6 carbon atoms, alkynyl from 2 to 6 carbon atoms, alkoxy from 1 to 6 carbon atoms, halogen, haloalkyl from 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, haloalkoxy from 1 to 6 carbon atoms and various halogen atoms up to the perhalo level, aryl from 6 to 12 carbon atoms or heteroaryl from 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, (5) R4 is selected from alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, alkynyl of 2 to 8 carbon atoms, C(=O), S(=O)2 and C(=O)O, (6) R5 is selected from hydrogen, OH, alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms carbon, alkynyl of 2 to 8 carbon atoms, alkoxy of 1 to 8 carbon atoms, thioxy of 1 to 8 carbon atoms, aryl of 6 to 12 carbon atoms, which can be replaced by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms carbon, halogen, haloalkyl from 1 to 6 carbon atoms and several halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and several halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and several halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and several halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S, and O, cycloalkyl of 3 to 7 carbon atoms, heterocycloalkyl of 2 to 6 carbon atoms and 1 to 2 heteroatoms selected from NH, S, and O, and NR9R10, (7) and R7 are independently selected from alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, and alkynyl of 2 to 8 carbon atoms, (8) R8 is selected from OH, aryl of 6 to 12 carbon atoms, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and several halogen atoms up to the perhalo level, haloalkoxy of 1 to 6 carbon atoms and several halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O and heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S and O, which may be substituted by alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkynyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halogen, haloalkyl of 1 to 6 carbon atoms and several halogen atoms up to the perhalo level, aryl of 6 to 12 carbon atoms or heteroaryl of 4 to 11 carbon atoms and 1 to 2 heteroatoms selected from N, S, and O; (9) R9 and R10 are independently selected from hydrogen, alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, and alkynyl of 2 to 8 carbon atoms, or R9 and R10 combine together with the nitrogen atom to which they are attached to form a 5- to 7-membered unsaturated ring which may contain 1 to 2 additional heteroatoms selected from N, S, and O, or to form a 5- to 7-membered saturated ring which may contain 1 to 2 additional heteroatoms selected from NH, NRn, S, and O; (10) R1 is selected from alkyl of 1 to 8 carbon atoms, alkenyl of 2 to 8 carbon atoms, and alkynyl of 2 to 8 carbon atoms, and their pharmaceutically acceptable salts. The preparation of these compounds is described in WO 2003/057149.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in US 20030092721, US Patent No. 7,022,849, WO 2002/102315 and US 2006116516, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: R1 is H or alkyl; R2 is (a) heteroaryl or heterocycle, each of which may be optionally substituted by one to three T1, T2, T3 groups, or (b) aryl fused to a heteroaryl or heterocycle ring in which the combined ring system may be optionally substituted by one to three T1, T2, T3 groups; L is (a) OR4, C(O)R4, C(O)OR4, SR4, NR3R4, C(O)NR3R4, NR3SO2R4b, halogen, nitro, or haloalkyl; or (b) alkyl, aryl, heteroaryl, heterocycle, or cycloalkyl, any of which may be optionally substituted by one to three T1a, T2a, and/or T3a groups; Yb Y2 and Y3 are independently (a) hydrogen, halo, or -OR^a or (b) alkyl, alkenyl, or alkynyl, any of which may be optionally substituted by one to three Tlb, T2b, and/or T3b groups; R3 and R4 are independently H, alkyl, alkenyl, aryl, (aryl)alkyl, heteroaryl, (heteroaryl)alkyl, cycloalkyl, (cycloalkyl)alkyl, heterocycle, or (heterocycle)alkyl, any of which may be optionally substituted by one to three Tia, T2a, and/or T3a groups; or R3 and R4 together with the nitrogen atom to which they are attached can combine to form a 4- to 8-membered heterocycle ring optionally substituted by one to three Tia, T2a, and/or T3a groups; R4a is hydrogen, alkyl, alkenyl, aryl, heteroaryl, (aryl)alkyl, (heteroaryl)alkyl, heterocycle, (heterocycle)alkyl, cycloalkyl, or (cycloalkyl)alkyl, any of which may be optionally substituted with one to three Tlb, T2b, and/or T3b groups; RIB is alkyl, alkenyl, aryl, (aryl)alkyl, heteroaryl, (heteroaryl)alkyl, cycloalkyl, (cycloalkyl)alkyl, heterocycle, or (heterocycle)alkyl, any of which may be optionally substituted with one to three Tia, T2a, and/or T3a groups; Z is N or CH; Tl-lb, T2-2b, and T3-3b are each independently; (1) hydrogen or T6, where T6 is (i) alkyl, (hydroxy)alkyl, (alkoxy)alkyl, alkenyl, alkynyl, cycloalkyl, (cycloalkyl)alkyl, cycloalkenyl, (cycloalkenyl)alkyl, aryl, (aryl)alkyl, heterocycle, (heterocycle)alkyl, heteroaryl, or (heteroaryl)alkyl; (ii) a group (i) that is itself substituted by one or more of the same or different groups (i); or (iii) a group (i) or (ii) that is independently substituted by one or more of the following groups (2) to (13) from the definition of T1-1b, T2-2b, and T3-3b; (2) -OH or -OT6; (3) -SH or -ST6; (4) -C(O)tH, -C(O)tT6, or -OC(O)T6, where t is 1 or 2; (5) -SO3H, -S(O)tT6 or S(O)tN(T9)T6; (6) halo; (7) cyano; (8) nitro; (9) -T4-NT7T8; (10) -T4-N(T9)-T5-NT7T8; (11) -T4-N(T10)-T5-T6; (12) -T4-N(T10)-T5-H and (13) oxo; T4 and T5 are each independently a single bond, TI 1S(O)tT12-, T11C(O)T12-, T11C(S)T12, T11OT12, T11ST12, T11OC(O)T12, T11C(O)OT12, T11C(=NT9a)T12 or TI 1C(O)C(O)T12; T7, T8, T9, T9a, and T10 are: (1) each independently hydrogen or a group given in the definition of T6, or (2) T7 and T8 may, together, alkylene or alkenylene, complete a 3- to 8-membered saturated or unsaturated ring together with the atoms to which they are attached, which ring is unsubstituted or substituted by one or more groups listed in the description of T1-1b, T2-2b, and T3-3b, or (3) T7 or T8, together with T9, may be alkylene or alkenylene complete a 3- to 8-membered saturated or unsaturated ring together with the nitrogen atoms to which they are attached, which ring is unsubstituted or substituted by one or more groups listed in the description of T1-1b, T2-2b, and T3-3b, or (4) T7 and T8 or T9 and T10 together with the nitrogen atom to which they are attached may combine to form a group N=CT13T14 where TI3 and TI4 are each independently H or a group given in the definition of T6; and TH and TI2 are each independently a single bond, alkylene, alkenylene, or alkynylene.

The preparation of these compounds is described in US 20030092721, US Patent No. 7,022,849, WO 2002/102315 and US 2006116516.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in U.S. Patent No. 6,838,559, U.S. 2003/0100571, and WO 2002/102314, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formulas: The substituents for the above compounds are defined as follows: R1 is H or alkyl; R2 is (a) heteroaryl or heterocycle each of which may be optionally substituted by one to three T1, T2, T3 groups; (b) aryl substituted by one to three T1, T2, T3 groups provided that at least one of T1, T2, T3 is other than H; or (c) aryl fused to a heteroaryl or heterocycle ring in which the combined ring system may be optionally substituted by one to three T1, T2, T3 groups; Y is alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocycle, heteroaryl, (aryl)alkyl, or (heteroaryl)alkyl any of which may be optionally substituted by one to three Tia, T2a, T3a groups; J is (a) hydrogen, halo, or OR4 or (b) alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocycle, or cycloalkyl any of which may be optionally substituted by one to three Tlb, T2b, T3b groups; Z is (a) OR4, SR4, NR3R4, NR3SO2R4a halogen, nitro, haloalkyl; or (b) alkyl, aryl, heteroaryl, heterocycle, or cycloalkyl any of which may be optionally substituted by one to three Tlc, T2c, T3c groups; R3 is H, alkyl, alkenyl, aryl, (aryl)alkyl, heteroaryl, (heteroaryl)alkyl, cycloalkyl, (cycloalkyl)alkyl, heterocycle, or (heterocycle)alkyl any of which may be optionally independently substituted where valency allows one to three Tlc, T2c, T3c groups; R4 is alkyl, alkenyl, aryl, (aryl)alkyl, heteroaryl, (heteroaryl)alkyl, cycloalkyl, (cycloalkyl)alkyl, heterocycle, or (heterocycle)alkyl, any of which may be optionally independently substituted where valence permits by one to three Ti d, T2d, or T3d groups, or R3 and R4 together with the nitrogen atom to which they are attached may combine to form a 4- to 8-membered ring heterocycle optionally substituted by one to three Tlc, T2c, or T3c groups; R4a is hydrogen, alkyl, alkenyl, aryl, heteroaryl, (aryl)alkyl, (heteroaryl)alkyl, heterocycle, (heterocycle)alkyl, cycloalkyl, or (cycloalkyl)alkyl, any of which may be optionally substituted by one to three Ti d, T2d, or T3d groups; Tl, Tia, Tlb, Tlc, Tld, T2, T2a, T2b, T2c, T2d, T3, T3a, T3b, T3c and T3d (hereinafter abbreviated as Tl-ld, T2-2d and T3-3d) are independently (1) hydrogen or T6, where T6 is (a) alkyl, (hydroxy) alkyl, (alkoxy) alkyl, alkenyl, alkynyl, cycloalkyl, (cycloalkyl) alkyl, cycloalkenyl, (cycloalkenyl) alkyl, aryl, (aryl) alkyl, heterocycle, (heterocycle) alkyl, heteroaryl or (heteroaryl) alkyl; (b) a group (a) which is itself substituted by one or more of the same or different groups (a) or (c) a group (a) or (b) which is independently substituted by one or more (preferably 1 to 3) of the following groups (2) to (13) from the definition of Tl-ld, T2-2d and T3-3d, (2) OH or OT6, (3) SH or ST6, (4) C(O)t H, C(O)t T6 or OC(O)T6, where t is 1 or 2; (5) SO3 H, S(O)t T6 or S(O)t N(T9)T6, (6) halo, (7) cyano, (8) nitro, (9) T4NT7 T8, (10) T4N(T9)-T5NT7 T8, (11) T4N(T10)-T5-T6, (12) T4N(T10)-T5H, (13) oxo, T4 and T5 are each independently a single bond, Tl lS(0)t-T12, T11-C(O)-T12, T11-C(S)-T12, Tl l-O-T12, -Tl lS-T12, -Tl lOC(O)-T12, - Tl l-(O)O-T12, -Tl lC(=NT9a)-T12 or Ti iC(O)-C(O)-T12; T7, T8, T9, T9a and T10 are (1) each independently hydrogen or a group given in the definition of T6, or (2) T7 and T8 may be, together, alkylene or alkenylene, complete a 3- to 8-membered saturated or unsaturated ring together with the atoms to which they are attached, which ring is unsubstituted or substituted by one or more groups listed in the description of T1-ld, T2-2d, and T3-3d, or (3) T7 or T8, together with T9, may be alkylene or alkenylene, complete a 3- to 8-membered saturated or unsaturated ring together with the nitrogen atom to which they are attached, which ring is unsubstituted or substituted by one or more groups listed in the description of T1-ld, T2-2d, and T3-3d, or (4) T7 and T8 or T9 and T10 together with the nitrogen atom to which they are attached may combine to form a group N=CT13 T14 where T13 and T14 are each independently H or a group given in the definition of T6 and T11 and T12 are each independently a single bond, alkylene, alkenylene, or alkynylene. The preparation of these compounds is described in U.S. Patent No. 6,838,559, US 20030100571, and WO 2002/102314.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in U.S. Patent No. 7,087,614, U.S. 2003/0162802, and WO 2002/192313, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: Ria is hydrogen or alkyl; R2a is W is S; Xi is alkoxy and X2 is alkyl; Z is halogen, haloalkyl, oxazolyl, NR3aR4a, C(O)-N(H)-alkylene-COOH, or phenyl that is unsubstituted or substituted by heteroaryl, COtH, or COtT6; R3a is hydrogen or alkyl; R4a is alkyl, alkoxy, unsubstituted or substituted (heteroaryl)alkyl, unsubstituted or substituted heterocycle, unsubstituted or substituted (heterocycle)alkyl, or (aryl)alkyl in which the aryl group is replaced by one or two groups Ti and/or T2 and/or further substituted by a T3 group, or R3a and R4a together with the nitrogen atom to which they are attached combine to form an unsubstituted or substituted heterocycle ring; Rsa is an unsubstituted or substituted (heteroaryl)alkyl or (aryl)alkyl in which the aryl group is replaced by one or two Ti and/or T2 groups and/or further substituted by a T3 group; or R5a and R^ together with the nitrogen atom to which they are attached combine to form an unsubstituted or substituted heterocycle ring; R^ is hydrogen or alkyl; J is hydrogen or alkyl; Ti and T2 are independently alkoxy, alkoxycarbonyl, heteroaryl, SO3H, or SO2Rga where R8a is alkyl, amino, alkylamino, or dialkylamino, or Ti and T2 together with the aryl ring to which they are attached combine to form a bicyclic ring; T3 is H, alkyl, halo, haloalkyl, or cyano; t is 1 or 2, and T6 is alkyl, haloalkyl, cycloalkyl, alkoxy, or heteroaryl. The preparation of these compounds is described in US Patent No. 7,087,614, US 20030162802 and WO 2002/192313.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in US 2003/0104974, WO 2002/088080 and WO 2002/088079, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formulas: The substituents for the above compounds are defined as follows: R1 is H or alkyl; R2 is optionally substituted heteroaryl or 4-substituted aryl; R3 is hydrogen or alkyl; R4 is alkyl, optionally substituted (aryl)alkyl, optionally substituted (heteroaryl)alkyl, optionally substituted heterocycle, or optionally substituted (heterocycle)alkyl, or R3 and R4 together with the nitrogen atom to which they are attached can combine to form an optionally substituted heterocycle ring; R5 is alkyl, optionally substituted (aryl)alkyl, or optionally substituted (heteroaryl)alkyl, and Rg is hydrogen or alkyl.

In a related embodiment, PDE7 inhibitors useful in the methods of the invention have the formula: wherein R1a is H or alkyl; R2a is optionally substituted heteroaryl; Z is halogen, alkyl, substituted alkyl, haloalkyl, or NR3aR4a; R3a is hydrogen or alkyl; R1a is alkyl, optionally substituted (heteroaryl)alkyl, optionally substituted heterocycle, optionally substituted (heterocycle)alkyl, or (aryl)alkyl in which the aryl group is substituted by one or two groups Ti and T2 and optionally further substituted by a T3 group; or R3a and R3a together with the nitrogen atom to which they are attached can combine to form an optionally substituted heterocycle ring; R5a is (aryl)alkyl in which the aryl group is substituted by one or two groups Ti and T2 and optionally further substituted by a T3 group; Rgais hydrogen or alkyl; R7ais hydrogen or alkyl; TI and T2 are independently alkoxy, alkoxycarbonyl, heteroaryl, or SO2R8a where RXA is alkyl, amino, alkylamino, or dialkylamino or TI and T2 together with the atoms to which they are attached can combine to form a ring (e.g., benzodioxole); T3 is H, alkyl, halo, haloalkyl, or cyano.

In another related embodiment, PDE7 inhibitors useful in the methods of the invention have the formula: wherein Rjb is H or alkyl; R2b is optionally substituted heteroaryl; R3b is H or alkyl; R', is optionally substituted (aryl)alkyl; Rsb is H, alkyl, or C(O)(CH2)vOYR6b , where Y is a bond or C(O), Rbb is hydrogen or alkyl, and v is an integer from 0 to 2; Ji and J2 are independently optionally substituted C1-13 alkylene, as long as Ji and J2 are not both greater than C2 alkylene; X4 and X5 are optional substituents attached to any available carbon atoms on one or both of Ji and J2, independently selected from hydrogen, OR7 , NR8R9 , alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, aryl, substituted aryl, heterocycloalkyl, or heteroaryl; R7 is hydrogen, alkyl, substituted alkyl, alkenyl, alkynyl, cycloalkyl, substituted cycloalkyl, C(O)alkyl, substituted C(O)alkyl, C(O)cycloalkyl, substituted C(O)cycloalkyl, C(O)aryl, substituted C(O)aryl, C(O)O-alkyl, C(O)O-substituted alkyl, C(O)heterocycloalkyl, C(O)heteroaryl, aryl, substituted aryl, heterocycloalkyl, and heteroaryl and R8 and R9 are independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, alkynyl, C(O)alkyl, C(O)substituted alkyl, C(O)cycloalkyl, substituted C(O)cycloalkyl, C(O)aryl, substituted C(O)aryl, C(O)O-alkyl, C(O)O-alkyl substituted, C(O) heterocycloalkyl, C(O) heteroaryl, S(O)2alkyl, S(O)2 substituted alkyl, S(O)2 cycloalkyl, S(O)2 substituted cycloalkyl, S(O)2 aryl, S(O)2 substituted aryl, S(O)2 heterocycloalkyl, S(O)2 heteroaryl, aryl, substituted aryl, heterocycloalkyl and heteroaryl or R8 and R9 when together with the nitrogen atom to which they are attached complete an optionally substituted heterocycloalkyl or heteroaryl ring.

In another related embodiment, PDE7 inhibitors useful in the methods of the invention have the formula: wherein Ric is H or alkyl; R2c is optionally substituted heteroaryl; Ric is H or alkyl; R2c is optionally substituted (aryl)alkyl, and X4 and X5 are optional substituents attached to any available carbon atoms in one or both of J1 and J2, independently selected from hydrogen, OR7, NR8R9, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, aryl, substituted aryl, heterocycloalkyl, or heteroaryl. The preparation of these compounds is described in US 20030104974, WO 2002/088080, and WO 2002/088079.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in US 2003/0092908 and WO 2002/087513, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: Rt is hydrogen or alkyl; R2 is (a) heteroaryl or heterocycle, each of which may be optionally substituted by one to three Tl, T2, T3 groups; (b) aryl substituted by one to three Tl, T2, T3 groups provided that at least one of Tl, T2, T3 is other than H; or (c) aryl fused to a heteroaryl or heterocycle ring in which the combined ring system may be optionally substituted by one to three Tl, T2, T3 groups; Z is NR3R4, NR3SO2R4a, OR4, SR4, haloalkyl, or halogen; R3 and R4 are independently H, alkyl, alkenyl, aryl, (aryl)alkyl, heteroaryl, (heteroaryl)alkyl, cycloalkyl, (cycloalkyl)alkyl, heterocycle, or (heterocycle)alkyl, any of which may be optionally, independently substituted where the valency permits one to three Tia, T2a, or T3a groups, or R3 and R4 may, when together with the nitrogen atom to which they are attached, form an optionally independently substituted heterocycle or heteroaryl ring where the valency permits one to three Tia, T2a, or T3a groups; R1a is alkyl, alkenyl, aryl, (aryl)alkyl, heteroaryl, (heteroaryl)alkyl, cycloalkyl, (cycloalkyl)alkyl, heterocycle, or (heterocycle)alkyl, any of which may be optionally, independently substituted where the valency permits one to three Tia, T2a, or T3a groups; R3b and Rtb are independently H, alkyl, alkenyl, aryl, (aryl)alkyl, heteroaryl, (heteroaryl)alkyl, cycloalkyl, (cycloalkyl)alkyl, heterocycle, or (heterocycle)alkyl; R5 is (1) hydrogen or cyano; (2) alkyl, alkenyl, alkynyl, cycloalkyl, (cycloalkyl)alkyl, aryl, (aryl)alkyl, heterocycle, (heterocycle)alkyl, heteroaryl, or (heteroaryl)alkyl, any of which may be optionally independently substituted where valency permits by one to three Tlb, T2b, or T3b groups, or (3) C(O)R$, C(O)OR6, C(O)-C(O)OR, or SO2R6U; Rs is H, alkyl, alkenyl, NR3bR4b, heterocycle, (heterocycle)alkyl, (hydroxy)alkyl, (alkoxy)alkyl, (aryloxy)alkyl, (NR3bR4b)alkyl, heteroaryl, aryl, or (aryl)alkyl, any of which may be optionally, independently substituted where the valence permits one to three Tlb, T2b, or T3b groups; Rba is alkyl, alkenyl, NR3bR4b, heterocycle, (heterocycle)alkyl, (hydroxy)alkyl, (alkoxy)alkyl, (aryloxy)alkyl, (NR3bR4b)alkyl, heteroaryl, aryl, or (aryl)alkyl, any of which may be optionally, independently substituted where the valence permits one to three Tlb, T2b, or T3b groups; J i and J 2 are independently optionally substituted C μ 3 alkylene, provided that J i and J 2 are not both greater than C 2 alkylene, and T 1-1b, T 2-2b and T 3-3b are each independently (1) hydrogen or T 6 , where T 6 is (i) alkyl, (hydroxy)alkyl, (alkoxy)alkyl, alkenyl, alkynyl, cycloalkyl, (cycloalkyl)alkyl, cycloalkenyl, (cycloalkenyl)alkyl, aryl, (aryl)alkyl, heterocycle, (heterocycle)alkyl, heteroaryl, or (heteroaryl)alkyl; (ii) a group (i) that is itself substituted by one or more of the same or different groups (i); or (iii) a group (i) or (ii) which is independently substituted by one or more (preferably 1 to 3) of the following groups (2) to (13) from the definition of T1-1b, T2-2b and T3-3b, (2) OH or OT6, (3) SH or ST6, (4) C(O)tH, C(O)tT6 or OC(O)T6, where t is 1 or 2, (5) SO3H, S(O)tT6 or S(O)tN(T9)T6, (6) halo, (7) cyano, (8) nitro, (9) T4-NT7T8, (10) T4-N(T9)-T5-NT7T8, (11) T4-N(T10)-T5-T6, (12) T4-N(T10)-T5H, (13) oxo, T4 and T5 are each independently (1) a single bond, (2) TI 1S(O)t-T12, (3) TI 1-C(O)-T12, (4) TI 1-C(S)-T12, (5) -T11-O-T12, (6) T11-S-T12, (7) TI 1-OC(O)-T12, (8) TI 1-C(O)-O-T12, (9) T11-C(=NT9a)-T12 or (10) TI 1-C(O)-C(O)-T12, T7, T8, T9, T9a and T10, (1) are each independently hydrogen or a group given in the definition of T6 or (2) T7 and T8 may together be alkylene or alkenylene, complete a 3- to 8-membered saturated or unsaturated ring together with the atoms around to which they are linked, which ring is unsubstituted or substituted by one or more groups listed in the description of Tl-lb, T2-2b, and T3-3b, or (3) T7 or T8, together with T9, may be alkylene or alkenylene to complete a 3- to 8-membered saturated or unsaturated ring together with the nitrogen atoms to which they are linked, which ring is unsubstituted or substituted by one or more groups listed in the description of Tl-lb, T2-2b, and T3-3b, or (4) T7 and T8 or T9 and T10 together with the nitrogen atom to which they are linked may combine to form a group N=CT13T14 where T13 and T14 are each independently H or a group given in the definition of T6, and T11 and T12 are each independently a single bond, alkylene, alkenylene, or alkynylene. The preparation of these compounds is described in US 20030092908 and WO 2002/087513.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in US 2004/0127707 and WO 2002/085906, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: R] is 1-2C-alkoxy or 1-2C-alkoxy that is completely or predominantly substituted by fluorine, R2 is fluorine, bromine, or chlorine, R3 and R4 are both hydrogen or together form an additional bond, R5 is Rg, CmH2lp-R7, CrlH2„-C(O)R8, CH(R9)2, CpH2p-Y-aryl, R1!, or R26, where R is 1-8C-alkyl, 3-10C-cycloalkyl, 3-7C-cycloalkylmethyl, 3-7C-alkenyl, 3-7C-alkynyl, phenyl-3-4C-alkenyl, 7-10C-polycycloalkyl, naphthyl, pyridyl, pyrazinyl, pyridazinyl, pyrimidyl, quinazolinyl, quinoxalinyl, cinnolinyl, isoquinolinyl, quinolinyl, indanyl, indazolyl, benzoxazolyl, benzothiazolyl, oxazolyl, thiazolyl, N-methylpiperidyl, tetrahydropyranyl, 6-methyl-3-trifluoromethyl-pyridin-2-yl, 1,3,4-trimethyl-1H-pyrazolo[3,4-b]pyridin-6-yl, 3-thiophen-2-yl[1,2,4]-thiadiazol-5-yl, 1,1-dioxide-tetrahydrothiophen-3-yl, 1-oxo-1,3-dihydro-isobenzofuran-5-yl, 4-(4-yl-but-1-oxy)benzoic acid or a phenyl radical unsubstituted or substituted by R^ie/or^2, wherein Réi is hydroxyl, l-4C-alkyl, 1-4C-alkoxy, nitro, cyano, halogen, carboxyl, hydroxycarbonyl-1-4C-alkyl, l-4C-alkoxycarbonyl, hydroxy-1-4C-alkyl, amino, mono- or di-l-4C-alkylamino, 1-4C-alkylcarbonylamino, aminocarbonyl, mono- or di-l-4C-alkylaminocarbonyl, aminosulfonyl, mono- or di-l-4C-alkylaminosulfonyl, 4-methylphenylsulfonamido, imidazolyl; tetrazol-5-yl, 2-(l-4C-alkyl)tetrazol-5-yl or 2-benzyltetrazol-5-yl and R<52 is l-4C-alkyl, l-4C-alkoxy, nitro or halogen, R-7 is hydroxyl, halogen, cyano, nitro, nitroxy(O-NO2), carboxyl, carboxyphenyloxy, phenoxy, 1-4C-alkoxy, 3-7C-cycloalkoxy, 3-7C-cycloalkylmethoxy, 1-4C-alkylcarbonyl, 1-4C-alkylcarbonyloxy, 1-4C-alkylcarbonylamino, 1-4C-alkoxycarbonyl, aminocarbonyl, mono- or di-1-4C-alkylaminocarbonyl, amino, mono- or di-1-4C-alkylamino or a piperidyl unsubstituted or substituted by R7I and/or R72, piperazinyl, pyrrolidinyl or morpholinyl radical, wherein R71 is hydroxyl, 1-4C-alkyl, hydroxy-1-4C-alkyl or 1-4C-alkoxycarbonyl and R72 is 1-4C-alkyl, carboxyl, aminocarbonyl or 1-4C-alkoxycarbonyl, R8 is a phenyl unsubstituted or substituted by R8] and/or R82, naphthyl, phenanthrenyl, or anthracenyl radical, wherein R8I is hydroxyl, halogen, cyano, 1-4C-alkyl, 1-4C-alkoxy, carboxyl, aminocarbonyl, mono- or di-1-4C-alkylaminocarbonyl, 1-4C-alkylcarbonyloxy, 1-4C-alkoxycarbonyl, amino, mono- or di-1-4C-alkylamino, 1-4C-alkylcarbonylamino, or 1-4C-alkoxy that is completely or predominantly substituted by fluorine and R82 is hydroxyl, halogen, 1-4C-alkyl, 1-4C-alkoxy, or 1-4C-alkoxy that is completely or predominantly substituted by fluorine, R9 is CqH2q phenyl, Y is a bond or O (oxygen), Aryl! is an unsubstituted phenyl, naphthyl, pyridyl, pyrazinyl, pyridazinyl, pyrimidinyl, quinazolinyl, quinoxalinyl, cinnolinyl, isoquinolyl, quinolyl, coumarinyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, benzotriazolyl, N-benzosucciniinidyl, imidazolyl, pyrazolyl, oxazolyl, thiazolyl, furyl, thienyl, pyrrolyl, a 2-(1-4C-alkyl)-thiazol-4-yl radical or a phenyl radical substituted by R10 and/or RH, where R1 is hydroxyl, halogen, nitro, cyano, 1-4C-alkyl, trifluoromethyl, 1-4C-alkoxy, carboxyl, hydroxycarbonyl-1-4C-alkyl, 1-4C-alkylcarbonyloxy, l-4C-alkoxycarbonyl, amino, mono- or di-1-4C-alkylamino, 1-4C-alkylcarbonylamino, aminocarbonyl, mono- or di-1-4C-alkylamino-carbonyl, imidazolyl or tetrazolyl and Rn is hydroxyl, halogen, nitro, l-4C-alkyl or l-4C-alkoxy, m is an integer from 1 to 8, n is an integer from 1 to 4, p is an integer from 1 to 6, q is an integer from 0 to 2, R12 is a radical of formula (a) where R13 is S(O)2-R14, S(O)2-(CH2)r-R15, (CH2)sS(O)2R16, C(O)R17, C(O)-(CH2)rRi8, (CH2)r(O)-R19, Hetarill, Aryl2 or Aryl3-1-4C-alkyl, RM is 1-4C-alkyl, 5-dimethylaminonaphthalin-l-yl, N(R20)R2I, phenyl or phenyl substituted by R22 and/or R23, R15 is N(R20)R2i, Ri6 is N(R20)R2I, Rn is 1-4C-alkyl, hydroxycarbonyl-1-4C-alkyl, phenyl, pyridyl, 4-ethylpiperazin-2,3-dion-l-yl, 2-oxo-imidazolidin-1-yl or N(R20)R2I, R1s is N(R2Q)R2I, R19 is N(R20)R2I, phenyl, phenyl substituted by R22 and/or R23 and/or R24, R20 and R2) are, independently of one another, hydrogen, 1-7C-alkyl, 3-7C-cycloalkyl, 3-7C-cycloalkylmethyl or phenyl or R20 and R2I together and with the inclusion of the nitrogen atom to which these are attached, form a 4-morpholinyl ring, a 1-pyrrolidinyl ring, a 1-piperidinyl ring, a 1-hexahydroazepino ring or a 1-piperazinyl ring of formula (b) wherein R25 is pyrid-4-yl, pyrid4-ylmethyl, 1-4C-alkyl-dimethylamino, dimethylaminocarbonylmethyl, N-methyl-piperidin-4-yl, 4-morpholino-ethyl or tetrahydrofuran-2-ylmethyl-, R22 is halogen, nitro, cyano, carboxyl, 1-4C-alkyl, trifluoromethyl, 1-4C-alkoxy, 1-4C-alkoxycarbonyl, amino, mono- or di-1-4C-alkylamino, aminocarbonyl 1-4C-alkylcarbonylamino or mono- or di-1-4C-alkylaminocarbonyl, R23 is halogen, amino, nitro, 1-4C-alkyl or 1-4C-alkoxy, R24 is halogen, Hetarily is pyrimidin-2-yl, thieno-[2,3-d]pyrimidin-4-yl, 1-methyl- 1H-pyrazolo-[3,4-d]pyrimidin-4-yl, thiazolyl, imidazolyl, or furanyl, Aryl2 is pyridyl, phenyl, or phenyl substituted by R22 and/or R23, Aryl3 is pyridyl, phenyl, phenyl substituted by R22 and/or R23, 2-oxo-2H-chromen-7-yl, or 4-(1,2,3-thiadiazol-4-yl)phenyl, r is an integer from 1 to 4, s is an integer from 1 to 4, R26 is a radical of formula (c) where R27 is C(O)R28, (CH2)tC(O)R29, (CH2)UR3O, Aryl4, Hetaryl2, phenylprop-1-en-3-yl or 1-methylpiperidin-4-yl, R28 is hydrogen, 1-4C-alkyl, OR31, furanyl, indolyl, phenyl, pyridyl, phenyl substituted by R34 and/or R35, or pyridyl substituted by R36 and/or R37, R29 is N(R32)R33, R30 is N(R32)R33, tetrahydrofuranyl or pyridinyl, R31 is 1-4C-alkyl, R32 is hydrogen, 1-4C-alkyl, 3-7C-cycloalkyl or 3-7C-cycloalkylmethyl, R33 is hydrogen, 1-4C-alkyl, 3-7C-cycloalkyl or 3-7C-cycloalkylmethyl or R32 and R33 together and with the inclusion of the nitrogen atom to which these are attached, form a 4-morpholinyl-, 1-pyrrolidinyl-, 1-piperidinyl- or 1-hexahydroazepinyl- ring, Aryl4 is phenyl, pyridyl, pyrimidinyl, phenyl substituted by R34 and/or R35, pyridyl substituted by R36 and/or R37, R34 is halogen, nitro, 1-4C-alkyl, trifluoromethyl or 1-4C-alkoxy, R35 is halogen or 1-4C-alkyl, R36 is halogen, nitro, 1-4C-alkyl, trifluoromethyl or 1-4C-alkoxy, R37 is halogen or 1-4C-alkyl, Hetaryl2 is indole-4-yl, 2-methyl-quinolin-4-yl, 5-chloro-6-oxo-1-phenyl-1,6-dihydro-pyridazin-4-yl, 3-phenyl-1,2,4-thiadiazol-5-yl or 3-o-tolyl-1,2,4-thiadiazol-5-yl, t is an integer from 1 to 4, u is an integer from 1 to 4, v is an integer from 1 to 2, X is -C(O)- or -S(O)2- and the salts of these compounds. The preparation of these compounds is described in US 20040127707 and WO 2002/085906.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in U.S. Patent No. 6,818,651, U.S. 20040044212, and WO 2002/040450, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: Ri indicates hydrogen and R2 indicates fluorine, chlorine, bromine, cyano, trifluoromethyl, or phenoxy, or Ri indicates hydrogen, fluorine, chlorine, bromine, trifluoromethyl, or cyano and R2 indicates hydrogen, R' and R” both indicate hydrogen or together represent a bond, and Ar represents a phenyl radical of the formulas IIa, IIb, or IIc. wherein R3 indicates hydrogen, hydroxyl, nitro, amino, carboxyl, aminocarbonyl, 1-4C-alkoxy, trifluoromethoxy, 1-4C-alkoxycarbonyl or mono- or di-1-4C-alkylaminocarbonyl, R4 represents 1-4C-alkyl, naphthalenyl, 5-dimethylaminonaphthalen-1-yl, phenylethen-2-yl, 3,5-dimethylisoxazol-4-yl, 5-chloro-3-methylbenzo[b]thiophen-2-yl, 6-chloro-imidazo[2,1b]-thiazol-5-yl or represents a phenyl or thiophene radical which is unsubstituted or is substituted by one or more identical or different radicals selected from the group halogen, cyano, 1-4C-alkyl, trifluoromethyl, 1-4C-alkoxy which is substituted wholly or mainly by fluorine, 1-4C-alkoxy, 1-4C-alkylcarbonylamino, 1-4C-alkoxycarbonyl, phenylsulfonyl, or isoxazolyl, or a hydrate, solvate, salt, hydrate of a salt, or solvate of a salt thereof. The preparation of these compounds is described in U.S. Patent No. 6,818,651, U.S. 20040044212, and WO 2002/040450. In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in WO 2002/040449, expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: R1 indicates hydrogen and R2 indicates fluorine, chlorine, bromine, cyano, trifluoromethyl, or phenoxy, or R1 indicates hydrogen, fluorine, chlorine, bromine, trifluoromethyl, or cyano and R2 indicates hydrogen, R' and R” both indicate hydrogen or together represent a bond, R3 indicates hydrogen, hydroxyl, nitro, amino, carboxyl, aminocarbonyl, 1-4C-alkoxy, trifluoromethoxy, 1-4C-alkoxycarbonyl, or mono- or di-1-4C-alkylaminocarbonyl, and R4 indicates C(O)-X-R5, N(H)-C(O)-R6, or N(H)-C(O)-N(H)-R2, where X indicates O or N(H), R5 indicates hydrogen, 1-4C-alkyl, 3-7C-cycloalkylmethyl, 6,6-dimethylbicyclo[3,3,l]hept-2-yl, 3-7C-alkynyl, 1-4C-alkylcarbonyl-1-4C-alkyl, aminocarbonyl-1-4C-alkyl, furan-2-ylmethyl, 2-pyridin-2-yleth-1-yl, 2-pyridin-3-ylmethyl, - methoxycarbonylprop-1-yl, 1-methoxycarbonyl-3-methylsulfanyl-et-1 -yl, 1-methoxycarbonyl-2-thiazol-2-yl-eth-l-yl or 4-methylthiazol-5-yl-eth-2-yl or represents a benzyl-, phenyl-eth-1-yl or 1-methoxycarbonyl-2-phenyl-eth-2-yl radical that is unsubstituted or substituted by one or more radicals selected from the halogen, trifluoromethyl and phenyl group, Ró indicates or 2-benzothiazol-6-yl, Ar2 represents furan-2-yl, furan-3-yl, thiophen-2-yl, indole-3-yl, 3-trifluoromethylphenyl, 3-methoxyphenyl or pyridin-3-yl, R7 represents 1-4C-alkyl, 3-7C-alkenyl, 3-7C-cycloalkyl, 1-ethoxycarbonyl-2-phenyl-eth-1-yl, thiophen-2-yleth-1-yl or a phenyl radical which is unsubstituted or substituted by one or more radicals selected from the group halogen, cyano, 1-4C-alkyl, trifluoromethyl, 1-4C-alkylthio, 1-4C-alkoxy, 1-4C-alkoxy which is totally or predominantly substituted by fluorine, 1-4C-alkylcarbonyl and phenoxy, or a salt thereof. The preparation of these compounds is described in WO 2002/040449. In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in WO 2001/098274, expressly incorporated herein by reference in its entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: W, X, Y, and Z, which may be the same or different, each represent a nitrogen atom or a C(R5) group [where R5 is a hydrogen or halogen atom or an alkyl, haloalkyl, alkoxy, haloalkoxy, hydroxy, -NO2, or -CN group] provided that two or more of W, X, Y, and Z are C(R5) groups; R1, R2, and R3, which may be the same or different, each is an atom or group -LI(AlkJ)rL2(Ré)s where Li and L2, which may be the same or different, is each a covalent bond or a linking atom or group, r is zero or the integer 1, Alki is an aliphatic or heteroaliphatic chain, s is an integer from 1, 2, or 3, and R^ is a hydrogen or halogen atom or a group selected from alkyl, -OR7 [where R7 is a hydrogen atom or an optionally substituted alkyl group], -SR7, NR7R8 [where R8 is as already defined by R7 and may be the same or different], -NO2, CN, CO2R7, SO3H, S(O)R7, SO2R7, OCO2R7, CONR7R8, OCONR7R8, CSNR7R8, OCR7, OCOR7 group, N(R7)COR8, N(R7)CSR8, S(O)NR7R8, SO2NR7R8, N(R7)SO2R8, N(R7)CON(R8)(R9) [where R9 is a hydrogen atom or an optionally substituted alkyl group], N(R7)CSN(R8)(R9), N(R7)SO2N(R8)(R9), C(R7)=NO(R8), cycloaliphatic, heterocycloaliphatic, aryl or heteroaryl]; provided that one or more of Rb, R2 or R3 is a substituent other than a hydrogen atom; R4 represents an optionally substituted phenyl, 1- or 2-naphthyl, pyridyl, pyrimidinyl, pyridazinyl or pyrazinyl group and their salts, solvates, hydrates and N-oxides. The preparation of these compounds is described in WO 2001/098274. In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in WO 2001/074786, expressly incorporated herein by reference in its entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: R1 represents an aryl or heteroaryl group; A, B, P, and E, which may be the same or different, each represent a nitrogen atom or a C(R2) group [where R2 is a hydrogen or halogen atom or an alkyl, haloalkyl, alkoxy, haloalkoxy, hydroxy, -NO2, or -CN group] provided that two or more of A, B, D, and E are C(R2) groups; X represents an oxygen or sulfur atom or an N(R3) group where R3 is a hydrogen atom or an alkyl group; Q, R, S, and T, which may be the same or different, each represent a nitrogen atom or a C(R4) group [where R4 is an atom or group -Li(Alky)rL2(R5)s where Li and L2, which may be the same or different, is each a covalent bond or a linking atom or group, r is zero or the integer 1, alkyl is an aliphatic or heteroaliphatic chain, s is an integer from 1, 2, or 3, and R5 is a hydrogen or halogen atom or a group selected from alkyl, OR^ [where R^ is a hydrogen atom or an optionally substituted alkyl group], SR^, NR6R? [where R7 is as already defined by R<, and may be the same or different], NO2, CN, CO2R«, Sosa S(O)R6, SO2R6, OCO2Ré, CONR6R7, OCONR6R7, CSNR7R7, OCR6, OCORÔ, N(R€)COR7, N(R6)CSR7, S(O)NR6R7, SO2NR6R7, N(R6)SO2R7; N(Ré)CON(R7)(R8) [where R« is a hydrogen atom or an optionally substituted alkyl group], N(R6)CSN(R7)(R8), N(R6)SO2N(R7)(RS), C(R6)∑=NO(R7) cycloaliphatic, heterocycloaliphatic, aryl or heteroaryl group] provided that two or more of Q, R, S and T are C(R4) groups and their salts, solvates, hydrates and N-oxides. The preparation of these compounds is described in WO 2001/074786.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in WO 2000/068230, expressly incorporated herein by reference in its entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: XYZ represents NR4-C=N or N^C-NR4; R1 represents H, alkyl, cycloalkyl, cycloalkylalkyl, arylalkyl, heteroarylalkyl, or heterocycloalkyl; R2 represents OR8, NR8R9, SRI3, alkyl, or CF3; R3 represents halogen, alkyl, CF3, or OR8; R4, which may be attached to X or Z, is a residue selected from in the bond occurs through any position in the saturated ring, as long as the bond is not in a position adjacent to V and the saturated ring can be replaced in any position with one or more R^; A, B, D, and E are the same or different and each represents ClnRs, N, or NO; V represents O, S, NR7, or C(L1mRi4)(L2nRi4); Q and W are the same or different and each represents CLnR5 or N; T represents O, S, or NR7; L1 and L2 are the same or different and each represents C(R15)2; m and n are the same or different and each represents 0, 1, 2, 3, 4, or 5; the R5S are the same or different and each represents H, halogen, alkyl, cycloalkyl, OR8, NR8R9, C02Rio, CONRnRu, CONHOH, SO2NRHR12, SONHR12, CORB, SO2RI3, SORI3, SRJ3, CF3, NO2 or CN; RÓ represents H, alkyl, cycloalkyl, OR8, NR8R9, C02Rio, CONRnR12, SO2NRΠR12, SONHR12, COR13, SO2Ri3, SOR13, SR13, CF3, CN or =O; R7 represents H or alkyl; R8 represents H, alkyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, heterocycle or heterocycloalkyl; R9 represents R8 or alkylcarbonyl, alkoxycarbonyl, alkylsulfonyl, cycloalkylcarbonyl, cycloalkoxycarbonyl, cycloalkylsulfonyl, cycloalkylalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkylsulfonyl, arylcarbonyl, arylsulfonyl, heteroarylcarbonyl, heteroarylsulfonyl, heterocyclocarbonyl, heterocyclosulfonyl, arylalkylcarbonyl, arylalkoxycarbonyl, arylalkylsulfonyl, heteroarylalkylcarbonyl, heteroarylalkoxycarbonyl, heteroarylsulfonyl, heterocycloalkylcarbonyl, heterocycloalkoxycarbonyl or heterocycloalkylsulfonyl; or NR8R9 represents a heterocyclic ring, such as morpholine; R1 represents H, alkyl, cycloalkyl, cycloalkylalkyl, arylalkyl, heteroarylalkyl or heterocycloalkyl; Rn and R12 are the same or different and are each selected from H, alkyl, cycloalkyl, cycloalkylalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, heterocycle, or heterocycloalkyl; the R14S are the same or different and are each selected from H, alkyl, cycloalkyl, OR8, NR8R9, CO2R10, CONRnRn, CONHOH, SO2NRnR12, SONnR12, COR13, SO2RI3, SORI3, SRB, CF3, NO2, and CN, provided that when both m and n represent 0, if one R14 is OR8, NR8R9, or SRI3, the other is not OR8, NR8R9, or SRI3, and R15 represents H, alkyl, or F or a pharmaceutically acceptable salt thereof. The preparation of these compounds is described in WO 2000/068230, incorporated herein by reference in its entirety.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in US 2004/0106631, EP 1 400 244 and WO 2004/026818, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: m is 1, 2, or 3; R 1 is methyl, chloro, bromo, or fluoro; R 2 is -Q 1 -Q 2 -Q 3 -Q 4 or (C 1 -C 6 ) alkyl, said (C 1 -C 6 ) alkyl is substituted by one to three OR 4 , COOR 4 , NR 4 R 5 , NRC(=O) R 4 , C(=O) NR 4 R 5 , or SO 2 NR 4 R 5 ; R 1 is (C 1 -C 6 ) alkyl substituted by one to three F, CN, S(=O) Re, SO 3 H, SO 2 R 6 , SRS, C(=O)-NH-SO 2 -CH 3 , C(=O) R 7 , NR'C(=O)R 7 , NR'SO 2 R 6 , C(=O) NR 7 R 8 , OC(=O) NR 7 R 8 , or SO 2 NR 7 R 8 ; R5 is H or (C1-C6) alkyl optionally substituted by one to three F, CN, S(=O)R6, SO3H, SO2R<„ SRS, C(=O)-NH-SO2-CH3, C(=O)R7, NR'C(=O)R7, NR'SO2R7), C(=O)NR7R8, OC(=O)NR7R8 OR SO2NR7R8 OR said (C1-C6) alkyl is (1) substituted by one to three OC(=O)R4a, SR4a, S(=O)R3, C(=NR9)R4a, C(—NR9)-NR4aR5a, NR-C(=NR9)-NR4aR5a, NRCOOR4a, NR- C(O)NRlaRsa, NR-SO2-NR4aR5a, NR-C(=NR9)-R4a or NR-SO2-R3; and (2) optionally substituted by one or two OR4a, COOR4a, C(=O)-R4a, NR4aR5a, NRC(=O)R4a, C(=O)NR4R5a or SO2NR4aR5a; R9 is H, CN, OH, OCH3, SO2CH3, SO2NH2 OR alkyl (Cr-C6) and R3 is alkyl (C1-C6) optionally substituted by one to three F, CN, S(=O)R6, SO3H, SO2R6, C(=O)-NH-SO2-CH3, OR7, SRS, COOR7, C(=O)R7, O- C(=O)NR7R8, NR7R8, NR'C(=O)R7, NR'SO2RÓ, C(=O)NR7R8 or SO2NR7R8; R4a and R5a are the same or different and are H or (C1-C6) alkyl optionally substituted by one to three F, CN, S(=O)R6, SO3H, SO2R6, C(=O)-NH-SO2-CH3, OR7, SR-;, COOR7, C(=O)R7, OC(=O)NR7R8, NR7Rg, NR'C(=O)R7, NR'SO2R6, C(=O)NR7R8, or SO2NR7R8; Q is a single bond or (C1-C6) alkylene; Q is a saturated 4- to 6-membered heterocyclyl comprising one or two O or N; Q3 is (C1-C6) alkylene; Q4 is a 4- to 8-membered aromatic or nonaromatic heterocyclyl comprising one to 4 O, S, S(=O), SO2 or N, said heterocyclyl being optionally substituted by one to three OR, NRR', -CN or (C 1 -C 6 ) alkyl; R is H or (C 1 -C 6 ) alkyl; R is (C 1 -C 6 ) alkyl optionally substituted by one or two OR'; R7 and R8 are the same or different and are H or (C 1 -C 6 ) alkyl optionally substituted by one or two OR'; R9 is H, CN, OH, OCH3, SO2CH3, SO2NH2 or (C 1 -C 6 ) alkyl; R' is H or (C 1 -C 6 ) alkyl and R” is H or (C 1 -C 6 ) alkyl; provided that (1) the atom of Q bonded to Q is a carbon atom and (2) the atom of Q4 bonded to Q3 is a carbon atom; or a racemic form, isomer, pharmaceutically acceptable derivative thereof. The preparation of these compounds is described in US 20040106631, EP 1 400 244 and WO 2004/026818.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in U.S. Patent No. 6,936,609 and U.S. Patent No. 20040249148, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: R1 represents aryl (C6-C10) which is optionally substituted identically or differently by radicals selected from the group consisting of halogen, formyl, carbamoyl, cyano, hydroxyl, trifluoromethyl, trifluoromethoxy, nitro, C1-C6 alkyl or C1-C6 alkoxy and optionally by a radical of the formula SO2NRSR6 wherein R5 and R6 independently of one another denote hydrogen or C1-C6 alkyl or NR5R5 indicates 4- to 8-membered heterocyclyl bonded through a nitrogen atom optionally substituted identically or differently by radicals selected from the group consisting of oxo, halogen, C1-C6 alkyl and C1-C6 acyl, R2 represents a saturated or partially unsaturated hydrocarbon radical having from 1 to 10 carbon atoms, R3 represents methyl or ethyl, A represents O, S, or NR7, wherein R7 denotes hydrogen or C1-C6 alkyl optionally substituted by C1-C3 alkoxy, E represents a C1-C3 bond or C1-C3 alkanediyl, R4 represents C6-C10 aryl or 5- to 10-membered heteroaryl, wherein aryl and heteroaryl are optionally substituted identically or differently by radicals selected from the group consisting of halogen, formyl, carboxyl, carbamoyl, -SO3H, aminosulfonyl, cyano, hydroxyl, trifluoromethyl, trifluoromethoxy, nitro, C1-C6 alkyl, C1-C6 alkoxy, 1,3-dioxa-propane-1,3-diyl, C1-C6 alkylthio, C1-C6 alkylsulfinyl, and C1-C6 alkylsulfonyl, -NR8R9 and optionally, heteroaryl or phenyl, 5- to 6-membered substituted by methyl in which R8 and R9 independently of each other indicate hydrogen, alkyl (C1-C6) or acyl (C1-Cβ) or salt thereof. The preparation of these compounds is described in US Patent No. 6,936,609 and US 20040249148.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in WO 2006/092692, expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formulas: where n is an integer from 1 to 4 and when stereocenters exist, each center can be independently R or S. The preparation of these compounds is described in WO 2006/092692.

In another embodiment, the PDE7 inhibitors useful in the methods of the invention are selected from those compounds generally and specifically disclosed in US 2006/229306 and WO 2004/065391, each expressly incorporated herein by reference in their entirety. In one embodiment, the PDE7 inhibitors useful in the methods of the invention have the formula: The substituents for the above compounds are defined as follows: R1 and R2 each (1) independently represents: (a) a hydrogen atom; (b) a group selected from alkyl, alkenyl, and alkynyl groups, wherein each alkyl, alkenyl, and alkynyl group is independently optionally substituted by one or more substituents selected from halogen atoms, hydroxy, alkoxy, aryloxy, alkylthio, hydroxycarbonyl, alkoxycarbonyl, mono- and di-alkylaminoacyl, oxo, amino, and mono- and di-alkylamino groups; or (c) a group of the formula (CH2)nR6, wherein n is an integer from 0 to 4 and R^ represents a cycloalkyl or cycloalkenyl group; (2) R1 and R2 form, together with the nitrogen atom to which they are attached, a 3- to 8-membered ring comprising 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur, which ring is saturated or unsaturated and optionally substituted by one or more substituents selected from halogen atoms, alkyl, hydroxy, alkoxy, acyl, hydroxycarbonyl, alkoxycarbonyl, alkylenedioxy, amino, mono- and di-alkylamino, mono- and di-alkylaminoacyl, nitro, cyano and trifluoromethyl groups; R3 is a group of the formula (CH2)nG, where n is an integer from 0 to 4 and G represents a monocyclic or bicyclic aryl or heteroaryl group comprising zero to four heteroatoms which group is optionally substituted by one or more substituents selected from: (1) halogen atoms; (2) alkyl and alkylene groups, in which each alkyl and alkylene group is independently optionally substituted by one or more substituents selected from halogen atoms and (3) phenyl, hydroxy, hydroxyalkyl, alkoxy, alkylenedioxy, aryloxy, alkylthio, amino, mono- and di-alkylamino, acylamino, nitro, acyl, hydroxycarbonyl, alkoxycarbonyl, cyano, difluoromethoxy and trifluoromethoxy groups; R4 represents a hydrogen atom, an alkyl or aryl group. The preparation of these compounds is described in US 2006229306 and WO 2004/065391.

Other compounds useful in the methods of the invention include imidazopyridine derivatives (WO 2001/34601), dihydropurine derivatives (WO 2000/68203), pyrrole derivatives (WO 2001/32618), benzothiopyranoimidazolone derivatives (DE 19950647), heterocyclic compounds (WO 2002/87519), guanine derivatives (Bioorg. Med. Chem. Lett. 11:1081, 2001), and benzothienothiadiazine derivatives (Eur. J. Med. Chem. 36:333, 2001). The disclosure of each published patent application and journal article listed above is expressly incorporated herein by reference in its entirety. Polypeptide or Peptide Inhibitors

In some embodiments, the PDE7 inhibitory agent comprises isolated PDE7 polypeptide or peptide inhibitors, including isolated natural peptide inhibitors and synthetic peptide inhibitors that inhibit PDE7 activity. As used herein, the term "isolated PDE7 polypeptide or peptide inhibitors" refers to polypeptides or peptides that inhibit PDE7-dependent cleavage of cAMP by binding to PDE7, competing with PDE7 for binding to a substrate, and/or directly interacting with PDE7 to inhibit PDE7-dependent cleavage of cAMP, that are substantially pure and are essentially free of other substances with which they may be encountered in a natural state to the extent practical and suitable for their intended use.

Peptide inhibitors have been used successfully in vivo to interfere with protein-protein interactions and catalytic sites. For example, peptide inhibitors for adhesion molecules structurally related to LFA-1 were recently approved for clinical use in coagulopathies (Ohman, E.M., et al., European Heart J. 16:50-55, 1995). Short linear peptides (<30 amino acids) have been reported to prevent or interfere with integrin-dependent adhesion (Murayama, O., et al., J. Biochem. 120:445-51, 1996). Longer peptides ranging in length from 25 to 200 amino acid residues have also been used successfully to block integrin-dependent adhesion (Zhang, L., et al., J. Biol. Chem. 271(47):29953-57, 1996). In general, longer peptide inhibitors have higher affinities and/or lower off-rates than shorter peptides and may therefore be more potent inhibitors. Cyclic peptide inhibitors have also been shown to be effective inhibitors of integrins in vivo for the treatment of human inflammatory disease (Jackson, D.Y., et al., J. Med. Chem. 40:3359-68, 1997). One method of producing cyclic peptides involves the synthesis of peptides in which the terminal amino acids of the peptide are cysteines, thereby allowing the peptide to exist in a cyclic form by the disulfide bond between the terminal amino acids, which has been shown to improve affinity and in vivo half-life for the treatment of hematopoietic neoplasms (e.g., U.S. Patent No. 6,649,592 issued to Larson). Synthetic PDE7 Peptide Inhibitors

PDE7 inhibitor peptides useful in the methods of the invention are exemplified by amino acid sequences that mimic target regions important for PDE7 enzyme activity, such as the catalytic domain of PDE7. PDE7A and PDE7B have 70% identity in the catalytic domain. (Hetman, J.M., et al., PNAS 97(l):472-476, 2000.) The catalytic domain of PDE7A1 is from amino acid residues 185 to 456 of SEQ ID NO:2. The catalytic domain of PDE7A2 is from amino acid residue 211 to 424 of SEQ ID NO:4. The catalytic domain of PDEB is from amino acid residue 172 to 420 of SEQ ID NO:6. Inhibitory peptides useful in practicing the methods of the invention range in size from about 5 amino acids to about 250 amino acids. Molecular modeling and rational molecular design can also be used to generate and screen for peptides that mimic the molecular structure of the PDE7 catalytic regions and inhibit PDE7 enzyme activity. Molecular structures used for modeling include the CDR regions of anti-PDE7 monoclonal antibodies. Methods for identifying peptides that bind to a particular target are well known in the art. For example, molecular imprinting can be used to de novo construct macromolecular structures, such as peptides, that bind to a particular molecule. See, for example, Shea, K.J., “Molecular Imprinting of Synthetic Network Polymers: The De Novo Synthesis of Macromolecular Binding and Catalytic Sties,” TRIP 2(5):[no page numbers], 1994. As an illustrative example, a method for preparing peptide-binding PDE7 mimics is as follows. Functional monomers from a binding region of an anti-PDE7 antibody that exhibits PDE7 inhibition (the template) are polymerized. The template is then removed, followed by polymerization of a second class of monomers in the void left by the template, to provide a new molecule that exhibits one or more desired properties that are similar to the template. In addition to preparing peptides this way, other PDE7-binding molecules that are PDE7 inhibitors, such as polysaccharides, nucleosides, drugs, nucleoproteins, lipoproteins, carbohydrates, glycoproteins, steroids, lipids, and other biologically active materials, can also be prepared. This method is useful for designing a wide variety of biological mimics that are more stable than their natural counterparts because these are typically prepared by free radical polymerization of functional monomers, resulting in a compound with a non-biodegradable backbone.

PDE7 inhibitor peptides can be prepared using techniques well known in the art, such as the solid-phase synthetic technique initially described by Merrifield in J. Amer. Chem. Soc. 85:2149-2154, 1963. Automated synthesis can be achieved, for example, using the Applied Biosystems 431A peptide synthesizer (Foster City, Calif.) according to the manufacturer's instructions. Other techniques can be found, for example, in Bodanszky, M., et al., Peptide Synthesis, second edition, John Wiley & Sons, 1976, as well as in other reference works known to those skilled in the art. The peptides can also be prepared using standard genetic engineering techniques known to those skilled in the art. A candidate PDE7 inhibitory peptide can be tested for the ability to function as a PDE7 inhibitory agent in one of several assays, including, for example, a PDE7 phosphodiesterase assay as described in Example 1. PDE7 Expression Inhibitors

In some embodiments of the methods of the invention, the PDE7 inhibitory agent is a PDE7 expression inhibitor capable of inhibiting PDE7 (PDE7A, PDE7B, or both)-dependent cAMP cleavage. In the practice of this embodiment of the invention, representative PDE7 expression inhibitors include PDE7 antisense nucleic acid molecules (such as antisense mRNA, antisense DNA, or antisense oligonucleotides), PDE7 ribozymes, and PDE7 RNAi molecules.

Antisense RNA and DNA molecules act to directly block translation of PDE7 mRNA by hybridizing to PDE7 mRNA and preventing translation of PDE7 protein. An antisense nucleic acid molecule can be constructed in several different ways as long as it is capable of interfering with PDE7 expression. For example, an antisense nucleic acid molecule can be constructed by inverting the coding region (or a portion thereof) of PDE7A1 cDNA (SEQ ID NO: 1), PDE7A2 cDNA (SEQ ID NO: 3), or PDE7B cDNA (SEQ ID NO: 5) relative to its normal transcriptional orientation to allow transcription of its complement. Methods for designing and administering antisense oligonucleotides are well known in the art and are described, for example, in Mautino et al., Hum Gene Ther 13:1027-37, 2002 and Pachori et al., Hypertension 39:969-75, 2002, each of which is hereby incorporated by reference.

The antisense nucleic acid molecule is usually substantially identical to at least a portion of the target gene or genes. The nucleic acid, however, does not need to be perfectly identical to inhibit expression. In general, higher homology can be used to compensate for the use of a shorter antisense nucleic acid molecule. The minimum percent identity is typically greater than about 65%, but a higher percent identity may exert more effective repression of expression than the endogenous sequence. A substantially higher percent identity of more than about 80% is typically preferred, although about 95% for absolute identity is typically more preferred.

The antisense nucleic acid molecule does not need to have the same intron or exon pattern as the target gene, and non-coding segments of the target gene can be equally effective in achieving antisense suppression of target gene expression as coding segments. A DNA sequence of at least 8 or so nucleotides can be used as the antisense nucleic acid molecule, although a longer sequence is preferable. In the present invention, a representative example of a useful PDE7 inhibitory agent is an antisense PDE7 nucleic acid molecule that is at least ninety percent identical to the complement of a portion of the PDE7A1 cDNA consisting of the nucleic acid sequence set forth in SEQ ID NO:1. Another representative example of a useful PDE7 inhibitory agent is an antisense PDE7 nucleic acid molecule that is at least ninety percent identical to the complement of a portion of the PDE7A2 cDNA consisting of the nucleic acid sequence set forth in SEQ ID NO:3. Another representative example of a useful PDE7 inhibitory agent is an antisense PDE7 nucleic acid molecule that is at least ninety percent identical to the complement of a portion of the PDE7B cDNA consisting of the nucleic acid sequence set forth in SEQ ID NO:5.

Targeting antisense oligonucleotides to PDE7 mRNA is another mechanism that can be used to reduce the level of PDE7 protein synthesis. For example, the synthesis of polygalacturonase and the muscarine acetylcholine receptor type 2 is inhibited by antisense oligonucleotides targeting their respective mRNA sequences (U.S. Patent No. 5,739,119 issued to Cheng and U.S. Patent No. 5,759,829 issued to Shewmaker). Furthermore, examples of antisense inhibition have been demonstrated with the nuclear protein cyclin, the multidrug resistance gene (MDG1), ICAM-1, E-selectin, STK-1, striatal GABAA receptor, and human EGF (see, e.g., U.S. Patent No. 5,801,154 issued to Baracchini; U.S. Patent No. 5,789,573 issued to Baker; U.S. Patent No. 5,718,709 issued to Considine; and U.S. Patent No. 5,610,288 issued to Reubenstein).

A system has been described that allows one of ordinary skill to determine which oligonucleotides are useful in the invention, which involves testing for suitable sites on the target mRNA using Rnase H cleavage as an indicator for sequence accessibility to the transcripts. Scherr, M., et al., Nucleic Acids Res. 26:5079-5085, 1998; Lloyd, et al., Nucleic Acids Res. 29:3665-3673, 2001. A mixture of antisense oligonucleotides that are complementary to certain regions of the PDE7 transcript is added to cell extracts expressing PDE7 and hybridized to create an RNAse H vulnerable site. This method can be combined with computer-assisted sequence selection, which can predict the optimal sequence selection for antisense compositions based on their relative ability to form dimers, hairpins, or other secondary structures that should reduce or prohibit specific binding to the target mRNA in a host cell. This secondary structure analysis and target site selection considerations can be performed using the OLIGO primer analysis software (Rychlik, L., 1997) and the BLASTN 2.0.5 algorithm software (Altschul, S.F., et al., Nucl. Acids Res. 25:3389-3402, 1997). Antisense compounds directed toward the target sequence preferably comprise from about 8 to about 50 nucleotides in length. Antisense oligonucleotides comprising from about 9 to about 35 or more nucleotides are particularly preferred. The inventors envisage that all oligonucleotide compositions in the range of 9 to 35 nucleotides (i.e., those of 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35 or more bases in length) are highly preferred for practicing the antisense oligonucleotide-based methods of the invention. Highly preferred target regions of the PDE7 mRNA are those that are at or near the translation start codon AUG and those sequences that are substantially complementary to the 5' regions of the mRNA, e.g., between regions 0 and +10 of the PDE7 gene nucleotide sequence (SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5).

The term "oligonucleotide" as used herein refers to an oligomer or polymer of ribonucleic acid (RNA) or deoxyribonucleic acid (DNA), or mimetics thereof. This term also covers those oligonucleobases composed of naturally occurring nucleotides, sugars, and covalent internucleoside linkages (backbones), as well as oligonucleotides bearing non-naturally occurring modifications. These modifications allow for the introduction of certain desirable properties not offered by naturally occurring oligonucleotides, such as reduced toxic properties, increased stability against nuclease degradation, and enhanced cellular uptake. In illustrative embodiments, the antisense compounds of the invention differ from natural DNA by modifying the phosphodiester backbone to extend the life of the antisense oligonucleotide, in which the phosphate substituents are replaced by phosphorothioates. Also, one or both ends of the oligonucleotide may be replaced by one or more acridine derivatives that intercalate between adjacent base pairs within a nucleic acid strand.

Another alternative to antisense is the use of "RNA interference" (RNAi). Double-stranded RNAs (dsRNAs) can cause gene silencing in mammals in vivo. The natural function of RNAi and co-suppression appears to be to protect the genome against invasion by mobile genetic elements, such as retrotransposons and viruses, that produce aberrant RNA or dsRNA in the host cell when they become activated (see, for example, Jensen, J., et al., Nat. Genet. 21:209–12, 1999). A double-stranded RNA molecule can be prepared by synthesizing two RNA strands capable of forming a double-stranded RNA molecule, each having a length of about 19 to 25 (e.g., 19 to 23) nucleotides. For example, a dsRNA molecule useful in the methods of the invention may comprise RNA corresponding to a portion of at least one of SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5, and their complement. Preferably, at least one RNA strand has a 3' overhang of 1 to 5 nucleotides. The synthesized RNA strands are combined under conditions that form a double-stranded molecule. The RNA sequence may comprise at least an 8-nucleotide portion of SEQ ID NO: 1, SEQ ID NO: 3, or SEQ ID NO: 5 with a total length of 25 nucleotides or less. Designing siRNA sequences for a given target is within the ordinary skill of the art. Commercial services are available for designing siRNA sequences and guaranteeing at least 70% expression knockdown (Qiagen, Valencia, CA). Exemplary PDE7 shRNAs and siRNAs are commercially available from Sigma-Aldrich Company (product # SHDNA-NM 002603; SASIHsOlOO 183420 to SASI_Hs01_00010490).

dsRNA can be administered as a pharmaceutical composition and by known methods, in which a nucleic acid is introduced into a desired target cell. Commonly used gene transfer methods include calcium phosphate, DEAE-dextran, electroporation, microinjection, and viral methods. Such methods are explained in Ausubel et al., Current Protocols in Molecular Biology, John Wiley & Sons, Inc., 1993. Therapeutic nucleic acid molecules can be modified to cross the blood-brain barrier. For example, a phosphorothioate antisense oligonucleotide directed toward the mid-Abeta region of amyloid precursor protein (APP) given by i.c.v. administration has been shown to reverse learning and memory deficits in a mouse model of Alzheimer's disease. Banks W.A. et al., Journal of Pharm. and Exp. Therapeutics, 297(3): 1113-1121, 2001. Ribozymes:

In some embodiments, a PDE7γ inhibitory agent is a ribozyme that specifically cleaves the mRNA of a PDE7 target, such as PDE7A, PDE7B, or both. Ribozymes that target PDE7 can be used as PDE7 inhibitory agents to decrease the amount and/or biological activity of PDE7. Ribozymes are catalytic RNA molecules that can cleave nucleic acid molecules having a sequence that is completely or partially homologous to the ribozyme sequence. It is possible to engineer ribozyme transgenes that encode RNA ribozymes that specifically pair with a target RNA and cleave the phosphodiester backbone at a specific site, thereby functionally inactivating the α-RNA. In performing this cleavage, the ribozyme is not itself altered and is thus capable of recycling and cleaving other molecules. The inclusion of ribozyme sequences within antisense RNAs confers RNA cleavage activity on them, thereby increasing the activity of the antisense constructs.

Ribozymes useful in practicing the invention typically comprise a hybridization region of at least about nine nucleotides that is complementary in nucleotide sequence to at least part of the target PDE7 mRNA and a catalytic region that is adapted for cleavage of the target PDE7 mRNA (see, generally, European Patent No. 0 321 201; WO 88/04300; Haseloff, J., et al., Nature 334:585-591, 1988; Fedor, M.J., et al., Proc. Natl. Acad. Sci. USA 87:1668-1672, 1990; Cech, T.R., et al., Ann. Rev. Biochem. 55:599-629, 1986).

Ribozymes can be targeted directly to cells in the form of RNA oligonucleotides incorporating ribozyme sequences or introduced into the cell as an expression vector encoding the desired ribozyme RNA. Ribozymes can be used and applied in the same manner as antisense polynucleotides. Antisense RNA and DNA, ribozymes, and RNAi molecules useful in the methods of the invention can be prepared by any method known in the art for the synthesis of DNA and RNA molecules. These include techniques for chemically synthesizing oligodeoxyribonucleotides and oligoribonucleotides well known in the art, such as solid-phase phosphoramidite chemical synthesis. Alternatively, RNA molecules can be generated by in vitro and in vivo transcription of DNA sequences encoding the antisense RNA molecule. Such DNA sequences can be incorporated into a wide variety of vectors that incorporate appropriate RNA polymerase promoters, such as the T7 or SP6 polymerase promoters. Alternatively, antisense cDNA constructs that synthesize antisense RNA constitutively or inducibly, depending on the promoter used, can be stably introduced into cell lines.

Several well-known modifications to DNA molecules can be introduced to increase stability and half-life. Useful modifications include, but are not limited to, the addition of flanking ribonucleotide or deoxyribonucleotide sequences to the 5' and/or 3' ends of the molecule or the use of phosphorothioate or 2' O-methyl in place of the phosphodiesterase linkages within the oligodeoxyribonucleotide backbone.

IV. EVALUATION METHODS FOR PDE7 INHIBITORS USEFUL IN THE TREATMENT OF A MOVEMENT ABNORMALITY ASSOCIATED WITH THE PATHOLOGY OF A NEUROLOGICAL MOVEMENT DISORDER

In another aspect, methods are provided for identifying an agent that inhibits PDE7 activity useful for treating a movement abnormality associated with the pathology of a neurological movement disorder in a mammalian subject in need thereof. The methods of this aspect of the invention comprise: (a) determining the IC50 for PDE7 inhibition activity for a plurality of each of the plurality of agents; (b) selecting agents from the plurality of agents having an IC50 for inhibition of PDE7 activity of less than about 1 μM; (c) determining the IC50 for inhibition of PDE4 activity of the agents having an IC50 for inhibition of PDE7 activity of less than about 1 μM; (d) identifying agents useful for treating a movement disorder by screening compounds having an ICj0 for inhibition of PDE4 activity greater than 10 times the IC50 for inhibition of PDE7; and (e) evaluating the activity of identified compounds in a neurological movement disorder model assay, wherein an agent that has an IC50 for inhibition of PDE7 of less than about 1 μM and an IC50 for inhibition of PDE4 activity greater than 10 times the IC50 for inhibition of PDE7 and is determined to be effective for treating at least one movement abnormality in a model assay is indicative of a PDE7 inhibitory agent useful for treating a movement abnormality associated with the pathology of a neurological movement disorder in a mammalian patient.

Representative agents that can be used in practicing the methods of this aspect of the invention include molecules that bind to PDE7 and inhibit PDE7 enzyme activity (such as small molecule inhibitors or blocking peptides that bind to PDE7 and reduce enzyme activity) and molecules that decrease PDE7 expression at the transcriptional and/or translational level (such as PDE7 antisense nucleic acid molecules, PDE7-specific RNAi molecules, and PDE7 ribozymes), thereby preventing PDE7 from cleaving cAMP.

V. Description of General Composition Settings

In one aspect, the invention provides a method of treating the movement abnormality associated with the pathology of a neurological movement disorder comprising administering to a patient in need thereof an amount of a PDE7 inhibitor agent effective to inhibit PDE7 enzymatic activity, wherein such inhibition of PDE7 enzymatic activity is the primary therapeutic mode of action of the PDE7 inhibitor in treating the movement abnormality. In some embodiments of the method, the neurological movement disorder is treatable with a dopamine receptor agonist or a precursor of a dopamine receptor agonist. In some embodiments of the method, the neurological movement disorder is selected from the group consisting of Parkinson's disease, Post-Encephalitic Parkinsonism, Dopamine Responsive Dystonia, Shy-Drager Syndrome, Periodic Limb Movement Disorder (PLMD), Periodic Limb Movements in Sleep (PLMS), and Restless Legs Syndrome (RLS).

In other embodiments, the neurological movement disorder is selected from the group consisting of Tourrette syndrome, Huntington's disease (i.e., Huntington's chorea), and drug-induced Parkinsonism.

For each of the PDE7 inhibitor chemical compounds useful in the methods of the present invention, possible stereoisomers and geometric isomers are also included. The compounds include not only racemic compounds, but also the optically active isomers. When a PDE7 inhibitor agent is desired as a single enantiomer, it can be obtained by resolution of the final product or by stereospecific synthesis of isomerically pure starting material or use of a chiral auxiliary reagent, e.g., see Ma, Z., et al., Tetrahedron: Asymmetry 8(6):883-888, 1997. In resolution of the final product, an intermediate or a starting material can be achieved by any suitable method known in the art. Additionally, in situations where tautomers of the compounds are possible, the present invention is intended to include all tautomeric forms of the compounds.

PDE7 inhibitors containing acidic moieties can form pharmaceutically acceptable salts with suitable cations. Suitable pharmaceutically acceptable cations include alkali metal cations (e.g., sodium or potassium) and alkaline earth metal cations (e.g., calcium or magnesium). Pharmaceutically acceptable salts of PDE7 inhibitors containing a basic center are acid addition salts formed with pharmaceutically acceptable acids. Examples include the hydrochloride, hydrobromide, sulfate or bisulfate, phosphate or hydrogen phosphate, acetate, benzoate, succinate, fumarate, maleate, lactate, citrate, tartrate, gluconate, methanefulgonate, benzenesulfonate, and p-toluenesulfonate salts. In light of the foregoing, any reference to compounds useful in the methods of the invention appearing herein is intended to include PDE7 inhibiting agents as well as their pharmaceutically acceptable salts and solvates.

The compounds of the present invention may be therapeutically administered as the raw chemical, but it is preferable to administer the PDE7 inhibitory agents as a pharmaceutical composition or formulation. Accordingly, the present invention further provides pharmaceutical compositions or formulations comprising a PDE7 inhibitory agent or its pharmaceutically acceptable salts, along with one or more pharmaceutically acceptable carriers and, optionally, other therapeutic and/or prophylactic ingredients. Suitable carriers are compatible with other ingredients of the formulation and non-toxic to the recipient thereof. The compounds of the present invention may also be loaded into a delivery system to provide sustained release or enhanced entry or activity of the compound, such as a liposomal or hydrogel system for injection, a microparticle, nanoparticle, or micelle system for oral or parenteral delivery, or a staged capsule system for oral delivery.

In particular, a selective PDE7 inhibitor agent useful in the present method is useful alone or in combination with one or more additional therapeutic agents, for example: a dopamine receptor agonist, a dopamine receptor agonist precursor, another dopaminergic agent, or combinations of the foregoing. Examples of dopamine receptor agonists and precursors include, for example, levodopa (also referred to as "L-dopa"), carbidopa, bromocriptine, pergolide, pramipexole, ropinirole, cabergoline, apomorphine, and lisuride. Other agents useful in combination with a selective PDE7 inhibitor agent include anticholinergic medications, such as biperidenHCl, benztropine mesylate, procyclidine, and trihexyphenidyl; monoamine oxidase B inhibitors, such as Eldepril™, Atapril™ and Carbex™, and the NMDA agonist amantadine (Symmetrel™).

In one embodiment, a selective PDE7 inhibitor agent is useful in combination with one or more additional therapeutic agents or precursors of therapeutic agents that activate the D1 dopamine receptor and/or increase the concentration of dopamine in nigrostriatal nerve terminals and/or the nigrostriatal synaptic cleft. Such agents include L-dopa, non-selective dopamine receptor agonists such as apomorphine, bromocriptine, and pergolide, and D1 selective agents such as ABT-431, A86929, and SKF38393.

In one embodiment, the invention provides a method of treating a movement abnormality associated with the pathology of Parkinson's disease comprising administering to a patient in need thereof an amount of a PDE7 inhibitor agent effective to inhibit PDE7 enzymatic activity, wherein such inhibition of PDE7 is the primary therapeutic mode of action of the PDE7 inhibitor in treating the movement abnormality. As demonstrated in Examples 5-7 herein, selective PDE7 inhibitors are useful in treating a movement abnormality associated with the pathology of Parkinson's disease. In the context of Parkinson's disease, treatment includes symptomatic therapy to decrease, alleviate, mask, or prevent the symptoms of at least one movement abnormality selected from the group consisting of resting tremor, rigidity, bradykinesia, or impaired postural reflexes.

Compounds and pharmaceutical compositions suitable for use in the present invention include those in which the active ingredient is administered in an amount effective to achieve its intended purpose. More specifically, a "therapeutically active amount" means an amount effective to prevent the development of symptoms in or alleviate existing symptoms of the patient being treated. The determination of effective amounts is well within the ability of those skilled in the art, especially in light of the detailed disclosure provided herein. It is further estimated that the amount of a compound of the invention required for use in treatment varies with the nature of the condition being treated and the age and condition of the patient, and is ultimately determined by the attending physician. In general, however, doses used for human treatment are typically in the range of 0.001 mg/kg to approximately 100 mg/kg per day.

A “therapeutically effective dose” refers to the amount of the compound that results in the achievement of the desired effect to treat or ameliorate the movement abnormality associated with the pathology of a neurological movement disorder. The toxicity and therapeutic efficacy of such compounds can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, for example, by determining the LD50 (the lethal dose to 50% of the population) and the ED50 (the therapeutically effective dose in 50% of the population).

In one embodiment, a therapeutically effective dose is an amount of PDE7 inhibiting agent sufficient to inhibit PDE7 enzyme activity in a neuronal cell. In another embodiment of the methods of the invention, a therapeutically effective dose is an amount of PDE7 inhibiting agent sufficient to inhibit PDE7 enzyme activity in striatal neurons. Determination of an effective dose of a PDE7 inhibiting agent sufficient to cross a cell membrane and inhibit PDE7 enzyme activity within a cell can be determined using a cellular assay for PDE7 inhibition as described by Smith S.J. et al., Molecular Pharmacology 66(6): 1679-1689 (2004), hereby incorporated by reference. Determination of an effective dose of a PDE7 inhibitory agent sufficient to inhibit PDE7 enzyme activity in the striatum can be determined using an assay to measure the effect of a PDE inhibitory agent on cAMP levels in the striatum as described in Siuciak J. A. et al., Neuropharmacology 51: 386-396 (2006), hereby incorporated by reference.

The dose ratio between toxic and therapeutic effects is the therapeutic index, expressed as the ratio of LD50 to ED50. Compounds that can exhibit high therapeutic indices are preferred. Data obtained from such analysis can be used to formulate a dosage range for use in humans. The dosage of such compounds preferably falls within a range of circulating concentrations that includes the ED50 range, depending on the dosage form and route of administration.

The toxicity and therapeutic efficacy of PDE7 inhibitors can be determined by standard pharmaceutical procedures using experimental animal models, such as the murine MPTP model described in Examples 5 to 7. Using such animal models, the NOAEL (no observed adverse effect level) and the MED (minimum effective dose) can be determined using standard methods. The dose ratio between the NOAEL and MED effects is the therapeutic ratio, expressed as the NOAEL/MED ratio. PDE7 inhibitors with large therapeutic ratios or indices are most preferred. Data obtained from cell culture assays and minimal studies can be used to formulate a dosage range for use in humans. The dosage of the PDE7 inhibitor is preferably within circulating concentrations that include the MED with little or no toxicity. Dosage may vary within this range depending on the dosage form and route of administration.

For any compound formulation, the therapeutically effective dose can be estimated using animal models. For example, the dose can be formulated in an animal model to achieve a circulating plasma concentration or brain tissue range that includes the MED. Quantitative levels of the PDE7 inhibitor in plasma or brain can also be measured, for example, as described in Example 4 herein.

The exact formulation, route of administration, and dosage can be chosen by the individual physician based on the patient's condition. The dosage amount and interval can be individually adjusted to provide plasma levels of the active moiety sufficient to maintain therapeutic effects.

The desired dose may be conveniently administered in a single dose or as multiple doses administered at appropriate intervals, for example, as two, three, four, or more subdoses per day. In practice, the physician determines the actual dosage regimen that is most appropriate for an individual patient, and the dosage varies with the age, weight, and response of the particular patient. The dosages described above are exemplary of the average case, but these may be individual examples in which higher or lower dosages are valued, and such are within the scope of the present invention.

The formulations of the present invention may be administered in a standard manner for the treatment of the indicated diseases, such as oral, parenteral, transmucosal (e.g., sublingual or via buccal administration), topical, transdermal, rectal, or via inhalation (e.g., nasal or deep lung inhalation). Parenteral administration includes, but is not limited to, intravenous, intraarterial, intraperitoneal, subcutaneous, intramuscular, intrathecal, and intraarticular. Parenteral administration may also be accomplished using a high-pressure technique, such as a POWDERJECT™ system.

In another aspect, this invention provides pharmaceutical compositions comprising a PDE7 inhibitory agent for the treatment of neurological movement disorders, such as Parkinson's disease, Post-Encephalitic Parkinsonism, Dopamine Responsive Dystonia, Shy-Drager Syndrome, Periodic Limb Movement Disorder (PLMD), Periodic Limb Movements in Sleep (PLMS), Tourette's syndrome, or Restless Legs Syndrome (RLS).

For buccal or oral administration, the pharmaceutical composition may be in the form of conventionally formulated tablets or lozenges. For example, tablets and capsules for oral administration may contain conventional excipients, such as binding agents (e.g., syrup, acacia, gelatin, sorbitol, tragacanth, starch mucilage, or polyvinylpyrrolidone), fillers (e.g., lactose, sugar, microcrystalline cellulose, cornstarch, calcium phosphate, or sorbitol), lubricants (e.g., magnesium stearate, stearate, stearic acid, talc, polyethylene glycol, or silica), disintegrants (e.g., potato starch or sodium starch glycolate), or wetting agents (e.g., sodium lauryl sulfate). The tablets may be coated according to methods well known in the art.

Alternatively, the compounds of the present invention may be incorporated into liquid oral preparations, such as aqueous or oily suspensions, solutions, emulsions, syrups, or elixirs, for example. Furthermore, formulations containing these compounds may be presented as a dry product for constitution with water or other suitable vehicles. Such liquid preparations may contain conventional additives, such as suspending agents such as sorbitol syrup, methyl cellulose, glucose/sugar syrup, gelatin, hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethyl cellulose, aluminum stearate gel, and hydrogenated edible fats; emulsifying agents such as lecithin, sorbitan monooleate, or acacia; non-aqueous vehicles (which may include edible oils) such as almond oil, fractionated coconut oil, oily esters, propylene glycol and ethyl alcohol and preservatives such as methyl or propyl p-hydroxybenzoate and ascorbic acid.

Such preparations may also be formulated as suppositories, for example, containing conventional suppository bases such as cocoa butter or other glycerides. Inhalation compositions can typically be provided as a solution, suspension, or emulsion that can be administered as a dry powder or as an aerosol using a conventional propellant, such as dichlorodifluoromethane or trichlorofluoromethane. Topical and transdermal formulations typically comprise conventional aqueous or non-aqueous vehicles, such as eye drops, creams, ointments, lotions, pastes, or in the form of medicated patches, dressings, or membranes.

Additionally, the compositions of the present invention may be formulated for parenteral administration by continuous injection or infusion. Formulations for injection may be in the form of suspensions, solutions, or emulsions in oily or aqueous vehicles and may contain formulatory agents, such as suspending, stabilizing, and/or dispersing agents. Alternatively, the active ingredient may be in powder form for constitution with a suitable vehicle (e.g., sterile hydrogen-free water) prior to use.

A composition according to the present invention may also be formulated as a depot preparation. Such long-acting formulations may be administered by implantation (e.g., subcutaneously or intramuscularly) or by intramuscular injection. Accordingly, the compounds of the invention may be formulated with suitable polymeric or hydrophobic materials (e.g., an emulsion in an acceptable oil), ion-exchange resins, or as sparingly soluble derivatives (e.g., an economically soluble salt).

Thus, the invention provides, in another aspect, a pharmaceutical composition comprising a PDE7 inhibitor together with pharmaceutically acceptable diluents or carriers thereof. The present invention further provides a process for preparing a pharmaceutical composition comprising a PDE7 inhibitor, which process comprises mixing a PDE7 inhibitor together with a pharmaceutically acceptable diluent or carrier therefor. Blood-Brain Barrier:

In some embodiments, the PDE7 inhibitory agent is administered to pass through or bypass the blood-brain barrier. Preferably, the inhibitory agent, compound, or composition administered in the method of treatment can pass through the blood-brain barrier in sufficient quantities and at a sufficient rate to allow treatment of the movement disorder. Methods for allowing agents to pass through the blood-brain barrier are known in the art and include minimizing the size of the agent, providing hydrophobic factors that facilitate passage, and conjugation to a carrier molecule that has substantial permeability across the blood-brain barrier.

In some embodiments, an effective amount of a PDE7 inhibitory agent is an amount that achieves a concentration within brain tissue at or above the IC50 for the activity of a given PDE7 inhibitory agent. In some embodiments, the PDE7 inhibitory agent is administered in a manner and dosage that gives a peak concentration of about 1, 1.5, 2, 2.5, 5, 10, 20, or more times the IC50 concentration for inhibition of the greater of PDE7A or PDE7B.

In some examples, a PDE7 inhibitor or combination of agents is administered by a surgical procedure that implants a catheter connected to a pump device. The pump device may be implanted or positioned extracorporeally. Administration of a PDE7 inhibitor may be in intermittent pulses or as a continuous infusion. Devices for injection into distinct areas of the brain are known in the art. In certain embodiments, the PDE7 inhibitor or a composition comprising a PDE7 inhibitor is administered locally to the ventricle of the brain, substantia nigra, striatum, locus ceruleus, nucleus basalis Meinert, pedunculopontine nucleus, cerebral cortex, and/or spinal cord for injection.

EXAMPLES Example 1

This example describes an assay for measuring the potency of PDE7 inhibitors and demonstrates the PDE7 inhibition potency of several representative PDE7 inhibitory agents useful in the methods of the invention.

Methods:

The compounds listed in Table 1 were tested for inhibitory activity in a PDE7 phosphodiesterase assay performed using human recombinant PDE7A and 7B enzymes expressed in a baculoviral system. The human recombinant PDE7A enzyme was purchased from BPS Bioscience (Catalog #60070), Genbank Accession Number NM_002603 (121 amino acid end) with an N-terminal GST tag, MW^60 kDa expressed in a Baculovirus infected Sf9 cell expression system, with the specific activity of 302 pmol/min/μg. The recombinant human enzyme PDE7B was purchased from BPS Bioscience (Catalog #60071), Genbank Accession Number NM_018945 (107 amino acid end), with an N-terminal GST tag, MW=66 kDa expressed in a Baculovirus infected Sf9 cell expression system, with the specific activity of 53 pmol/min/μg. TABLE 1: PDE7 inhibitor compounds PDE7 activity assay:

The assay method used was a scintillation proximity assay (SPA) (obtained from GE Healthcare, Product Code TRKQ7100), β with [ H]-cGMP as the substrate (SPA manual, Amersham Biosciences). Purified human PDE7A and PDE7B (obtained from BPS Bioscience, San Diego, CA) were diluted and stored in a solution containing 25 mM Tris-Cl (pH 8.0), 100 mM NaCl, 0.05% Tween 20, 50% glycerol, and 3 mM DTT. PDE7 assays were performed in the following reaction mixture (final concentrations): 50 mM Tris-Cl (pH 8.0), 8.3 mM MgCi2, 1.7 mM EGTA, 0.5 mg/ml BSA, 5% DMSO (except for OM056 which was in 2.5% DMSO) and 2 ng of PDE7A or 0.2 ng of PDE7B recombinant protein in a final volume of 0.1 mL.

For the determination of IC50 values against PDE7A or PDE7B, assays were performed in duplicate on a single plate at other inhibitor concentrations, with a known PDE7 inhibitor (BRL50481) as a positive control. Inhibitor concentrations ranged from 0.61 nM to 10,000 nM except in the case of OM056, so that the range is from 0.24 nM to 4,000 nM. Reactions were initiated by the addition of the enzyme, incubated for 20 minutes at 30°C and then terminated by the addition of 50 μl of SPA beads containing Zn2+.

The mixture was stirred, allowed to settle for 3 hours, and then [3H]-5'AMP production from the substrate was quantified by scintillation counting in a Wallac® plate counter. The resulting cpm lattice values were fitted by four logistic parameter models using Excel Solver®. Results:

The results of the PDE7 phosphodiesterase enzyme inhibition assay are summarized below in TABLE 2 and shown in FIGURES 3A through 6B. TABLE 2: IC50 Values for Representative PDE7 Inhibitor Compounds with Respect to PDE7A and PDE7B Inhibition *OM69 was previously assayed by the inventors for inhibition of PDE7A and PDE7B activity. It is noted regarding the IC50 value for PDE7B inhibition with OM69 that in the initial assay, using a different assay methodology, the IC50 value was determined to be 96.9 nM. In that initial assay, the background signal (counts per minute) was high relative to the peak signal and the Hill coefficient was low, a finding that calls into question the reliability of the initial assay results.

The assay results shown above in TABLE 2, indicating an IC50 value for PDE7B inhibition with OM69 of 4.8 nM, is believed to be a more accurate value; for example, as shown in FIGURE 3B, the r value for the fit to the 4-parameter logistic dose-response models is 0.9988, as would be expected for a simple competitive inhibitor. The IC50 value for PDE7A inhibition with OM69 in the initial assay work was 3.5 nM, not consistent with the value for PDE7A inhibition of 1.30 nM presented in Table 2.

FIGURES 3A, 4A, 5A, and 6A are graphs illustrating a PDE7A inhibitory activity (IC50) expressed as counts per minute ("CPM") versus the concentration of the representative PDE7 inhibitory agents OM69, OM955, OM956, and OM056, respectively, over a concentration range of 0.61 nM to 10,000 nM (for OM69, OM955, and OM956), or a concentration range of 0.24 nM to 4,000 nM (for OM056).

FIGURES 3B, 4B, 5B, and 6B are graphs illustrating the PDE7B inhibitory activity (IC50) expressed as counts per minute ("CPM") versus the concentration of the representative PDE7 inhibitory agents OM69, OM955, OM956, and OM056, respectively, over a concentration range of 0.61 nM to 10,000 nM (for OM69, OM955, and OM956), or a concentration range of 0.24 nM to 4,000 nM (for OM056).

These results indicate that OM69 and OM056 inhibit both PDE7A and PDE7B with high potency, while OM955 and OM956 inhibit both enzymes with moderate potency. Compounds OM69, OM056, OM955, and OM956 exhibit little or no selectivity between PDE7A and PDE7B.

Example 2

This example describes a series of assays for measuring the selectivity of PDE7 inhibitors and demonstrates that OM69 (compound 1), OM056 (compound 2), OM955 (compound 3), and OM956 (compound 4) each selectively inhibit PDE7 compared to all other phosphodiesterase enzymes tested. These assays include a representative sample of each PDE family with the exception of PDE6. Methods:

Phosphodiesterase activity as measured by a scintillation proximity assay (SPA, GE Healthcare: Product Code TRKQ7100) with [3H]-cAMP as the substrate for PDEs 3A, 4A, 8A, or with [3H]-cGMP as the substrate for PDEs 1B, 2A, 5A, 9A, 10A, and 11A. Purified human PDE1B, PDE2A, PDE3A, PDE4A, PDE5A, PDE8A, PDE9A, and PDE11A4 were obtained from BPS Bioscience, San Diego, CA. Purified murine PDE10A was also obtained from BPS Biosciences. It is noted that murine PDE10A exhibits an inhibitory manner that is indistinguishable from human PDE 10. Therefore, the results obtained using murine PDE10A are believed to be representative of human PDE 10.

The purified PDE enzymes were each diluted and stored in a solution containing 25 mM Tris-Cl (pH 8.0), 100 mM NaCl, 0.05% Tween 20, 50% glycerol, and 3 mM DTT. PDE assays were performed in the following assay cocktail (final concentrations): 50 mM Tris-Cl (pH 8.0), 8.3 mM MgCi2, 1.7 mM EGTA, 0.5 mg/ml BSA, 2.5% DMSO, and between 0.2 ng and 6 ng of PDE protein (depending on enzyme activity) in a final volume of 0.1 mL.

Assays were performed in duplicates at four concentrations (10 μM, 1.25 μM, 0.156 μM, and 0.019 μM) of the PDE7 inhibitors OM69 (compound 1), OM056 (compound 2), OM955 (compound 3), and OM956 (compound 4). Reactions were initiated by the addition of the enzyme, incubated for 20 minutes at 30°C, and then terminated by the addition of 50 μL of SPA beads containing Zn2+.

The mixture was stirred and allowed to settle for 3 hours. Then, the production of [3H]-AMP or [3H]-GMP from the substrate was quantified by scintillation counting in a Wallac® plate counter. The resulting cpm lattice values were fitted by four-parameter logistic models using Excel Solver®. To calculate selectivity ratios, the IC50 values obtained with each enzyme were divided by the IC50 values obtained with PDE7A in Example 1. Results:

TABLE 3 shows the results of selectivity assays with the four PDE7 inhibitor compounds tested against the panel of PDEs tested. The values in TABLE 3 are shown in units of fold selectivity for PDE7A versus the other PDEs and were determined by dividing the IC50 value against the indicated PDE by the IC50 value against PDE7A in Example 1. Thus, for example, the value of 342-fold for OM955 with PDEIB means that OM955 is 342-fold less potent as a PDEIB inhibitor compared to PDE7A. The numbers shown in parentheses are IC50 values against PDE7A of various compounds from Example 1. The fold selectivity values provided in TABLE 3 as "greater than" reflect situations in which the highest concentration of the compound inhibited the target enzyme only slightly (i.e., less than 50%), and higher concentrations should be used because the compound becomes insoluble in the assay mixture. As a result, only the minimum selectivity estimates should be generated. TABLE 3: PDE7A selectivity of representative PDE7 inhibitor compounds. Discussion of Results:

As shown above in TABLE 3, the representative PDE7 inhibitor agents OM69, OM056, OM955, and OM956 are all selected by PDE7A and PDE7B compared to PDE1B, PDE2A, PDE3A, PDE4A, PDE5A, PDE8A, PDE9A, PDE10A, and PDE1 IA.

As shown in TABLE 3, OM69 (compound 1) is a potent inhibitor of both PDE7A (IC50 = 1.3 nM) and PDE7B (IC50 = 4.8 nM), exhibiting greater than 1000-fold selectivity for PDE7A enzyme inhibition compared to other PDEs and 250-fold selectivity for PDE7B enzyme inhibition compared to other PDEs.

As further shown in TABLE 3, OM056 (compound 2) is a potent inhibitor of both PDE7A (IC50 = 5.7 nM) and PDE7B (IC50 = 9.27), exhibiting more than 400-fold selectivity for inhibiting the PDE7A enzyme compared to other PDEs and greater than 200-fold selectivity for inhibiting the PDE7B enzyme compared to other PDEs.

As further shown in TABLE 3, OM955 (compound 3) is a moderately potent inhibitor of both PDE7A (IC50 = 51.8 nM) and PDE7B (IC50 = 106 nM) and exhibits greater than 100-fold selectivity for inhibition of the PDE7A enzyme compared to the other PDEs and greater than 50-fold selectivity for inhibition of the PDE7B enzyme compared to the other PDEs.

Also as shown in TABLE 3, OM956 (compound 4) is a moderately potent inhibitor of both PDE7A (IC50 = 140 nM) and PDE7B (IC50 = 144 nM) and exhibits more than 71-fold selectivity for inhibition of both PDE7A and PDE7B enzymes compared to the other PDEs.

These results, taken together with the results described in Examples 4 to 7, demonstrate that inhibition of PDE7 activity is necessary and sufficient for the improvement in movement abnormalities observed after administration of these compounds in the MPTP mouse model. Furthermore, the use of selective PDE7 inhibitors rather than non-selective PDE inhibitors provides the advantage of lower toxicity because the latter will not significantly inhibit PDEs known to cause undesirable effects, such as PDE3 and PDE4.

Example 3

This example describes a method for assessing the metabolic stability of PDE7 inhibitors and the ability of PDE7 inhibitors to partition in mouse brain in vivo. Animal test protocol Mouse strain: C57BL/6J adult male; removed breeders, age 7 to 9 months (Jackson Laboratory, Bar Harbor, ME, USA), individually housed.

Compound administration: Each PDE7 inhibitor (OM69 (compound 1), OM056 (compound 2), OM955 (compound 3), and OM956 (compound 4)) was dissolved in a vehicle consisting of DMSO, 0.03 M phosphoric acid, and Tween 80 (5:95:0.2) and injected intraperitoneally at a dosage of 10 mg/kg.

Collection of blood and brain samples. Just prior to tissue collection, mice were anesthetized with avertin. Whole brain or plasma samples were collected from three animals per time point at 15 minutes, 30 minutes, 60 minutes, 120 minutes, and 240 minutes after injection. Blood samples were collected by retro-orbital bleeding. Plasma was prepared, and red blood cells were removed by centrifugation. The mice were perfused with saline to remove contaminated blood. The brains were removed and quickly frozen in liquid nitrogen for subsequent analysis. Plasma and brain samples were stored at -80°C or on dry ice, and compound concentrations were determined by LC/MS/MS analysis as follows:

Whole brain tissue was homogenized using a Mini-Beaddeater-8™ (BioSpec Products, Bartlesville, OK). Plasma or homogenized brain samples were precipitated with acetonitrile and filtered into 96-well formats using Captiva® 0.20 micron filtration plates (Varian Corp, Lake Forest, CA). The filtrates were evaporated under nitrogen to dryness at 50°C and were then reconstituted for LC-MS analysis.

Quantitative measurements of the inhibitor compound in plasma and brain samples were obtained using a Thermo Ultra triple quadrupole mass spectrometer (Thermo Fisher Scientific, San Jose, CA) using electrospray ionization in multiple reaction monitoring mode of data acquisition. Sample extracts were injected onto a 2.1 x 30 mm packed Xterra C18-MS high-pressure liquid chromatography (HPLC) column (Waters Corp, Milford, MA). The mobile phase eluting from the HPLC column was applied using a Thermo Surveyor MS Plus HPLC quaternary pumping system (Thermo Fisher Scientific, San Jose, CA) and an HTC PAL autoinjector (LEAP Technologies, Chapel Hill, NC). Results:

Data on the tissue concentration of OM69 (compound 1), OM056 (compound 2), OM955 (compound 3), and OM956 (compound 4) were collected from 3 mice per time point and averaged. FIGURE 7 graphically illustrates the plasma concentration, brain concentration, and brain/plasma ratio of compound OM69 (compound 1) over a 240-minute time course. As shown in FIGURE 7, within the first 15 minutes of exposure, OM69 was detected in plasma (51 ng/g) and brain tissue (25 ng/g). Peak levels were seen at 30 minutes post-IP injection (plasma 59 ng/g and brain 44 ng/g), after which both plasma and brain levels rapidly declined. At all points in the period when both plasma and brain levels were greater than the lower limit of the amount in the LC/MS/MS assay (2 ng/g), the brain to plasma ratios were 45 to 75%.

Using the method described for compound OM69, a ratio of total brain exposure (area under the curve: AUC) divided by total plasma exposure for each compound tested was calculated. The results are shown below in TABLE 4. Ratio values greater than "1" indicate that the compound was concentrated in the brain. Values shown as ">1" indicate that compound levels were already high in the brain by the time the first measurement was taken. Therefore, a ratio of 1 represents a minimum estimate in these cases. TABLE 4: Brain-to-Plasma Ratio of PDE7 Inhibitor Compounds. Discussion of Results:

The data shown in FIGURE 7 suggest that OM69 (compound 1) reaches brain concentrations of 44 ng/g, which convert to 124 nM within 30 minutes after injection of a 1 mg/kg dosage. Assuming linearity of absorption and uniform brain distribution, dosages of 0.1 mg/kg per mouse should be expected to produce maximal concentrations of 12.4 nM, which is sufficient to achieve PDE7 inhibition in the brain based on the IC50 values of 1.3 nM and 4.8 nM reported in Example 1. Analogous calculations for the three other compounds tested in the MPTP model (as described in Examples 5 through 7) yielded the following results for maximal brain concentrations at dosages and time points at which efficacy was observed: OM955: 241 nM at 0.5 mg/kg; OM956: 328 nM at 0.5 mg/kg; and OM056: 71 nM at 0.5 mg/kg. In each case, it is noted that these levels are at least 2-fold in excess of the highest of the compounds' IC50 values for inhibiting PDE7A or PDE7B.

Example 4

This example demonstrates that the representative PDE7 inhibitor OM69 (compound 1) does not interact significantly with known Parkinson's disease targets. Methods:

A representative PDE7 inhibitor, OM69 (compound 1), was tested against a panel of known Parkinson's disease targets to determine if there is evidence of interaction with any of the tested targets. Assays: 1. Cachechol-O-Methyltransferase (COMT) enzyme assay Cachechol-O-Methyltransferase (COMT) was assayed as described in Zurcher, G. et al., J. Neurochem 38:191-195, 1982, with the following modifications. The source of COMT was isolated from pig liver. The substrate was 3 mM Cachechol + S-Adenosyl-L-3β,[methyl-H]methionine. The vehicle control was 1% DMSO. Compound OM69 was tested at 10 μM in the incubation buffer (100 mM potassium phosphate, 10 mM MgC]2, 3 mM DTT containing 12 U/ml ADA, pH 7.4). The reaction was preincubated for 15 min at 37°C, COMT enzyme was added, and the reaction was incubated for 60 min at 37°C. [3H]-Guaiacol was counted and quantified. The positive control reference compound 3,5-Dinitrocatechol was performed in this assay, with a historical IC50 value of 0.31 μM. 2. MAO-B Monoamine Oxidase Enzyme Assay MAO-B Monoamine Oxidase was assayed as described in Urban, P. et al., FEBS Lett 286(1-2): 142-146, 1991, with the following modifications. Human recombinant MAO-B was isolated from insect Hi5 cells. The substrate was 50 μM Kynuramine. The vehicle control was 1% DMSO. Compound OM69 was tested at 10 μM in the incubation buffer (100 mM potassium phosphate, pH 7.4) in experiment 1. In experiment 2, compound OM69 was tested at 10 μM and 1 μM. The reaction was preincubated for 15 minutes at 37°C, MAO-B enzyme was added, and the reaction was incubated for 60 minutes at 37°C. Spectrofluorimetric quantification of 4-hydroxyquinoline was performed. The positive control reference compound R(-)-Deprenyl was performed in this assay, with a historical IC50 value of 5.3 nM. 3. Tyrosine Hydroxylase Enzyme Assay Tyrosine hydroxylase was assayed as described in Roskoski, R., Jr. et al., J. Biochem 218:363-370 (1993) with the following modifications. Tyrosine hydroxylase was isolated from Wistar rat brain. The substrate was 100 μM L-[3,5-3H]Tyrosine 4- L-Tyrosine. The vehicle control was 1% DMSO. Compound OM69 was tested at 10 μM in the incubation buffer (125 mM MES, pH 6.0, 0.5 mg/ml Catalase, 12.5 mM DTT, 0.5 mM (6R)-5,6,7,8-Tetrahydrobiopterin). The reaction was preincubated for 15 minutes at 37°C. Tyrosine hydroxylase enzyme was added and the reaction was incubated for 20 minutes at 37°C. [3H]-H20 was quantified. The positive control reference compound a-Methyl-L-P-Tyrosine was performed in this assay, with a historical IC50 value of 20 μM. 4. Dopamine D radioligand binding assay} A Dopamine D radioligand binding assay was performed as described in Dearry, A. et al., Nature 347:72-76, 1990, with the following modifications. Recombinant human Dopamine D1 receptor was expressed in CHO cells. The ligand used in the assay was 1.4 nM [3H]SCH-23390. The nonspecific ligand was 10 μM (+)-butaclamol. The vehicle control was 1% DMSO. Compound OM69 was tested at 10 pM in the incubation buffer (50 mM Tris-HCL, pH 7.4, 1.4 mM ascorbic acid, 0.001% BSA, 150 mM NaCl). The reaction was incubated for 2 h at 37°C. Radioligand binding was quantified. The positive control reference compound R(+)-SCH-23390 was performed in this assay, with a historical IC50 value of 1.4 nM. 5. Dopamine D2L Radioligand Binding Assay A Dopamine D2L radioligand binding assay was performed as described in Grandy, D.K. et al., PNAS 86:9762-9766, 1989, with the following modifications. Human recombinant Dopamine D2L receptor was expressed in CHO cells. The ligand used in the assay was 0.16 nM [ H]-spiperone. The nonspecific ligand was 10 μM Haloperidol. The vehicle control was 1% DMSO. Compound OM69 was tested at 10 μM in the incubation buffer (50 mM Tris-HCL, pH 7.4, 1.4 mM ascorbic acid, 0.001% BSA, 150 mM NaCl). The reaction was incubated for 2 h at 25°C. Radioligand binding was quantified. The positive control reference compound spiperone was performed in this assay, with a historical IC50 value of 0.26 nM. 6. Dopamine D3 Radioligand Binding Assay A Dopamine D3 radioligand binding assay was performed as described in Sokoloff, P. et al., Nature 347:146-151, 1990, with the following modifications. Recombinant human Dopamine D3 receptor was expressed in CHO cells. The ligand used in the assay was 0.7 nM [H]-spiperone. The nonspecific ligand was 25 μM S(-)Sulpiride. The vehicle control was 1% DMSO. Compound OM69 was tested at 10 μM in the incubation buffer (50 mM Tris-HCL, pH 7.4, 1.4 mM ascorbic acid, 0.001% BSA, 150 mM NaCl). The reaction was incubated for 2 h at 37°C. Radioligand binding was quantified. The positive control reference compound spiperone was performed in this assay, with a historical IC50 value of 0.36 nM. 7. Dopamine D4 2 Radioligand Binding Assay A Dopamine D4 2 radioligand binding assay was performed as described in Vantol, H.H.M. et al., Nature 350:610-614, 1991, with the following modifications. Recombinant human dopamine D4 receptor 2 was expressed in CHO-K1 cells. The ligand used in the assay was 0.5 nM [ H]-spiperone. The nonspecific ligand was 10 μM Halperidol. The vehicle control was 1% DMSO. Compound OM69 was tested at 10 μM in the incubation buffer (50 mM Tris-HCL, pH 7.4, 1.4 mM ascorbic acid, 0.001% BSA, 150 mM NaCl). The reaction was incubated for 2 h at 25°C. Radioligand binding was quantified. The positive control reference compound spiperone was performed in this assay, with a historical IC50 value of 0.5 nM. 8. Dopamine D5 Radioligand Binding Assay A Dopamine D5 radioligand binding assay was performed as described in Sunahara, R.K. et al., Nature 350:614-619, 1991, with the following modifications. Human recombinant Dopamine D5 receptor was expressed in CHO cells. The ligand used in the assay was 2 nM [3H]-SCH-23390. The nonspecific ligand was 10 μM Flupentixol. The vehicle control was 1% DMSO. Compound OM69 was tested at 10 μM in the incubation buffer (50 mM Tris-HCL, pH 7.4, 1.4 mM ascorbic acid, 0.001% BSA, 150 mM NaCl). The reaction was incubated for 2 hours at 37°C. Radioligand binding was quantified. The positive control reference compound R(+)-SCH23390 was performed in this assay, with a historical IC50 value of 1.5 nM. 9. Gabapentin Radioligand Binding Assay A Gabapentin radioligand binding assay was performed as described in Gee, N.S. et al., J. Biol. Chem. 271(10):5768- 5776, 1996, with the following modifications. Gabapentin was obtained from Wistar rat cerebral cortex. The ligand used in the assay was 0.02 μM [3H]Gabapentin. The nonspecific ligand was 100 μM Gabapentin. The vehicle control was 1% DMSO. Compound OM69 was tested at 10 μM in the incubation buffer (10 mM HEPES, pH 7.4). The reaction was incubated for 30 minutes at 25°C. Radioligand binding was quantified. The positive control reference compound Gabapentin was performed in this assay, with a historical IC50 value of 0.04 μM. 10. Dopamine Transporter (DAT) Radioligand Binding Assay A Dopamine Transporter (DAT) radioligand binding assay was performed as described in Giros, B. et al., Trends Pharmacol Sci 14:43-49, 1993, with the following modifications. Human recombinant DAT was expressed in CHO-K1 cells. The ligand used in the assay was 0.15 nM [ I]-RTT-55. The nonspecific ligand was 10 μM Nomifensine. The vehicle control was 1% DMSO. Compound OM69 was tested at 10 μM in the incubation buffer (50 mM Tris-HCl, pH 7.4, 100 mM NaCl, 1 μM Leupeptin, 10 μM PMSF). The reaction was incubated for 3 hours at 4°C. Radioligand binding was quantified. The positive control reference compound GBR-12909 was performed in this assay, with a historical IC50 value of 1.7 nM. 11. Adenosine A2A Receptor Radioligand Binding Assay

An Adenosine A2A receptor radioligand binding assay was performed as described in Varani, K. et al., Br. J. Pharmacol. 117:1693-1701, 1996, with the following modifications. Recombinant human A2A receptor was expressed in HEK-293 cells. The ligand used in the assay was 0.05 μM [3H]CGS-21680. The nonspecific ligand was 50 μM NECA. The vehicle control was 1% DMSO. Compound OM69 was tested at 10 μM in the incubation buffer (50 mM Tris-HCL, pH 7.4, 10 mM MgCj2, 1 mM EDTA, 2 U/mL Adenosine Deaminase). The reaction was incubated for 90 minutes at 25°C. Radioligand binding was quantified. The positive control reference compound CGS-21680 was performed in this assay, with a historical IC50 value of 0.13 μM. Results:

The results of the tests described above are summarized below in TABLE 5.

The amount of OM69 used in the assay is indicated in parentheses in the column labeled "OM69." Results are presented as percent inhibition of ligand binding to, or enzymatic activity at, the target. Positive controls were included in each assay as indicated to monitor assay performance. TABLE 5: Level of Inhibition of Known Parkinson's Disease Targets Representative PDE7 Inhibitor Agent with OM69 (Compound 1) Discussion of results:

The results shown in TABLE 5 further demonstrate that at a concentration that is 2000-fold greater than this IC50 for PDE7B, the representative PDE7 inhibitor OM69 does not substantially inhibit COMT, tyrosine hydroxylase, the dopamine transporter, the gabapentin receptor, or any of the dopamine receptor subtypes.

Regarding the adenosine A2A receptor result, although the results in TABLE 5 show that OM69 inhibited binding to A2A receptors by 41% at a concentration of 10 μM, it is believed that A2A is not a target of OM69 for at least the following reasons. As shown in Example 3, OM69 reached mouse brain levels of 30 to 60 ng/g after a 1 mg/kg dosage. Linear pharmacokinetics then assume a dosage of 0.1 mg/kg, which is highly effective in the MPTP mouse model as demonstrated in Examples 5 and 6, would produce brain levels of 3 to 6 ng/g, which is equivalent to 3 to 6 ng/ml or 8.5 to 17 nM. At this concentration, using a conservative IC50 value for OM69 of 10 μM, the percent occupancy of A2A receptors would be only about 0.17%. Therefore, the conclusion is that A2A is not a target for OM69.

Regarding the MAO-B assay, a 27% percent inhibition at a concentration of 1 μM would indicate an IC50 value of approximately 2.7 μM. Therefore, if OM69 were present in the brain at a concentration of 17 nM (as discussed in the previous paragraph), it would inhibit MAO-B by less than 0.7%. Therefore, the conclusion is that MAO-B is not a target for OM69.

Example 5

Pharmacological evaluation of a representative PDE7 inhibitor compound in the MPTP model of Parkinson's disease.

In this example, the representative PDE7 inhibitor, OM69 (compound 1), was evaluated in an initial study in the MPTP mouse model of Parkinson's disease. Animal testing protocol: Mouse strain: C57BL/6J adult males; breeder excises, 7 to 9 months of age (Jackson Laboratory, Bar Harbor, ME, USA), individually housed. Handling: Animals were handled daily for 2 weeks prior to injection to hold them accountable for behavioral testing. All mice were maintained on a standard 12-hour dark/light cycle and given ad libitum access to laboratory chow and water.

MPTP Administration. Mice received two subcutaneous injections of methylphenyltetrahydropyridine ("MPTP") at a dosage of 15 mg/kg (free base) with a 10- to 12-hour interval between injections. Control mice (sham-injured groups) were administered saline instead of MPTP.

Administration of the PDE7 inhibitor compound. Seven days after MPTP or saline administration, OM69 was administered to mice. For each dosage, a 100x stock of OM69 was prepared in 100% DMSO and subsequently diluted 100x in phosphate-buffered saline (PBS). Then, 100 μL of this IX solution was administered via intraperitoneal (IP) injection.

It was previously determined from pharmacokinetic studies that OM69 is washed out by mice within 12 hours, so dosing of various compounds tested on conservative days was used to maximize the information that could be obtained from each group of injured animals.

'Step length', prior to injection with MPTP or saline, animals were pre-trained to walk across a clean sheet of paper in their home cage without interruption. To determine step length, animals had their forepaws placed in black ink and measured the length of their forepaw steps during normal walking (only in a straight line). Animals were immediately returned to their home cage upon completion of the task. Step length was determined by measuring the distance between each step on the same side of the body, measuring from the middle toe of the first step to the heel of the second step. An average of at least four clean steps was calculated. Experimental protocol

The withdrawn male breeder mice (12 to 15 per group, 48-60 animals total) were treated with saline or 2 x 15 mg/kg MPTP (12 saline; 36 MPTP) to induce a Parkinsonian state (neurochemical loss of dopamine with corresponding behavioral deficits). A flow map schematically illustrating the protocol is shown in FIGURE 8.

As shown in Figure 8, on day one, baseline stride length was measured, and then mice were treated with MPTP (n = 9) or saline as a control (n = 10). On day eight, stride length was measured again, and the control value for stride length was derived from the stride length of the saline-treated animals. Following this measurement, the first measurements with L-dopa (5 mg/kg) or OM69 (0.1 mg/kg) were administered on day eight, as shown in Figure 8. Stride length was then measured for each animal 20 minutes after dosing. Neither L-dopa (5 mg/kg) or OM69 (0.1 mg/kg) altered the stride length of the saline-treated mice. Dosing with the treatments shown in Figure 8 was performed on successive days, with stride length measured 20 minutes after each dosing. As mentioned above, it was previously determined from pharmacokinetic studies that OM69 is washed out of mice within 12 hours of dosing, so the stride length test performed 20 minutes after dosing was believed to measure the effect of only the compounds administered on the day of treatment.

As shown in FIGURE 8, on day eight, animals in Group 1 were treated with L-dopa (5 mg/kg) and animals in Group 2 were treated with OM69 (0.1 mg/kg). On day nine, animals in Group 1 were treated with L-dopa (1 mg/kg) and animals in Group 2 were treated with OM69 (0.01 mg/kg). On day ten, the treatment groups were crossed over, and animals in Group 1 were treated with OM69 (0.01 mg/kg) and animals in Group 2 were treated with L-dopa (1 mg/kg).

As further shown in FIGURE 8, for the combination studies, all mice in Group 1 and Group 2 were combined. On day 11 following MPTP administration, all animals in Group 1 and Group 2 (n=9) were treated with the combination of L-dopa (1 mg/kg) and OM69 (0.01 mg/kg), with the lunge length test performed 20 minutes after dosing. On day 12 following MPTP administration, all animals in Group 1 and Group 2 (n=9) were treated with the combination of L-dopa (1 mg/kg) and OM69 (0.03 mg/kg), with the lunge length test performed 20 minutes after dosing. In these combination studies performed on Day 1 and Day 12, the average lunge length data from two of nine animals was not countable because these two animals performed earlier than walking at a normal speed, or this maintains initiation and cessation earlier than walking continuously. Therefore, these two animals were excluded and only the remaining seven animals (n=7) were counted for the combination studies. Increased step length

The MPTP model used in this example is a generally accepted mouse model of PD that is expected by those skilled in the art to be predictive of PD in humans (Tillerson, J.L. et al., Exp. Neurol. 178(l):80-90, 2002; Tillerson, J.L. et al., J. Neurosci Methods 123(2):189-200, 2003).

To evaluate and compare the effects of OM69 and L-dopa at these dosages, data from mice at equivalent dosages were pooled. Thus, the mean lunge length for animals treated with L-dopa (1 mg/kg) was determined using measurements obtained from all nine animals. Similarly, the mean lunge length for animals treated with OM69 (0.01 mg/kg) was determined using measurements obtained from all nine animals. The results of the MPTP study described in this example are provided in FIGURES 9–11.

FIGURES 9 to 11 are bar graphs illustrating the results of the painted paw lunge length test. This demonstrates that the representative PDE7 inhibitor OM69 (compound 1) increases lunge length in MPTP-lesioned mice and does so at significantly lower doses compared to L-dopa.

As shown in FIGURES 9 and 11, treatment of mice with MPTP decreased their lunge length as measured from the tracks left by the mice's dyed paws, compared to saline controls. See FIGURE 9 (#1 versus #4) and FIGURE 11 (#1 versus #2).

As shown in FIGURES 9 and 10, treatment of MPTP-treated mice with L-dopa increases their stroke length in a dose-dependent manner. See FIGURE 9 (#4 versus #5 and #6) and FIGURE 10 (#1 versus #2 and #6).

It was unexpectedly determined that the representative PDE7 inhibitor OM69 (Compound 1), when administered IP at 0.1 mg/kg, has the same effect in increasing the length of the lunge in MPTP-treated mice as a 50-fold higher dosage of L-dopa (5 mg/kg). As shown in FIGURE 9, at the aforementioned concentrations, both L-dopa (#5) and OM69 (#7) fully restored the length of the lunge seen without MPTP (#1) treatment. These results demonstrate the surprising finding that OM69 (Compound 1), a representative PDE7 inhibitor useful in the method of the invention, is effective in increasing the length of the lunge in MPTP mice at a significantly lower dosage compared to L-dopa.

As shown in FIGURES 9 through 11, at lower dosages of L-dopa (1 mg/kg) (see FIGURE 9, #6; FIGURE 10, #2) or OM69 (0.01 mg/kg) (see FIGURE 9 #8; FIGURE 10, #3) there is only a small effect seen on the lunge length of MPTP-treated mice. However, when these lower dosages of OM69 and L-dopa were administered in combination, the increase in lunge length was found to have a greater effect than the sum of the increase seen from either drug alone. See FIGURE 9, #9 and FIGURE 10 #4. These results demonstrate that administration of the representative PDE7 inhibitor OM69 (compound 1) is effective in increasing the length of the lunge in MPTP-lesioned mice at a significantly lower dosage compared to L-dopa and is therefore useful in the methods of the invention directed at treating a movement abnormality associated with the pathology of a movement disorder such as Parkinson's disease.

Example 6 Pharmacological evaluation of a representative PDE7 inhibitor compound in the MPTP model of Parkinson's disease: a confirmatory study

In this example, a representative PDE7 inhibitor, OM69 (compound 1), was evaluated in the MPTP mouse model of Parkinson's disease. This study was designed to confirm the findings in Example 5 and to provide statistical proof of the effects of OM69. Animal testing protocol. Mouse strain: Adult male C57BL/6J; breeder excises, 7 to 9 months of age (Jackson Laboratory, Bar Harbor, ME, USA), individually housed. Handling: Animals were housed daily for 2 weeks prior to injection to ensure accountability for behavioral testing. All mice were maintained on a standard 12-hour dark/light cycle and given ad libitum access to laboratory chow and water. MPTP administration: MPTP mice received 2 subcutaneous injections of methylphenyltetrahydropyridine ("MPTP") at a dose of 15 mg/kg (free base) with a 10- to 12-hour interval between injections. Control mice (sham injury groups) were administered saline instead of MPTP.

OM69 (compound 1) administration\ Seven days after MPTP/saline administration, OM69 was administered to mice. For each dosing, a 100x stock of OM69 was prepared in 100% DMSO and subsequently diluted 100x in phosphate-buffered saline (PBS). Then, 100 μL of this solution IX was administered intraperitoneally (IP).

'Step length', prior to injection with MPTP or saline, animals were pre-trained to walk across a clean sheet of paper in their home cage without interruption. To determine step length, the animals had their forepaws placed in black ink and the length of the forepaw steps during normal walking (in a straight line only) was measured. The animals were immediately returned to their home cage upon completion of the task. Step length was determined by measuring the distance between each step on the same side of the body, measuring from the middle toe of the first step to the heel of the second step. An average of at least four clean steps was calculated. Statistical analysis

Data were analyzed using Prism 4.0 software. Groups were analyzed by one-way ANOVA and post hoc Student-Newman-Keuls test when appropriate. Significance was considered reached at p < 0.05. Treatment groups in the advancement length graph that are statistically different are indicated by letters in Table 6. Groups that are not statistically different on part of a letter; groups that are not significantly different on part of a letter. Experimental protocol:

Male breeding mice removed (28 animals total) were treated with 2 x 15 mg/kg MPTP (12 saline; 36 MPTP) to induce a Parkinsonian state (neurochemical loss of dopamine with corresponding deficits). A flow map schematically illustrating the protocol is shown in FIGURE 12. On day 1, baseline stride length was measured, and then all mice were treated with either MPTP or saline. On day 8, stride length was measured again, and then the MPTP-treated animals were randomly divided into two groups of fourteen. As described in Example 5, dosing with the successive treatments indicated in FIGURE 12 occurred on consecutive days, and in each case, stride length was measured 20 minutes after dosing. The "n" values within the boxes on the flow map indicate the number of animals for which useful data were obtained on which day (occasionally, a few animals failed to perform the walking task). On day 9, animals in Group 1 were treated with OM69 (0.01 mg/kg) and Group 2 were treated with L-dopa (1 mg/kg). On day 10, animals in Group 1 were treated with OM69 (0.03 mg/kg) and Group 2 were treated with L-dopa (5 mg/kg). On day 11, animals in Group 1 were treated with OM69 (0.05 mg/kg) and Group 2 were treated with OM69 (0.1 mg/kg). On day 12, Group 1 was treated with OM69 (0.07 mg/kg). Subsequently, for the combination studies, the two groups were combined. On day 14, all animals were treated with both L-dopa (1 mg/kg) and OM69 (0.01 mg/kg). On day 15, all animals were treated with L-dopa (1 mg/kg) in combination with a higher dosage of OM69 (0.03 mg/kg). Results:

The results of these studies are summarized below in TABLE 6, in which the stride length of MPTP-injured mice treated with L-dopa at two different dosages, OM69 (compound 1) at five different dosages, and the combination of L-dopa and OM69 are compared to untreated control mice and MPTP-injured mice receiving the drug. FIGURE 18 illustrates a subset of these data. TABLE 6: Stride Length in MPTP-injured Mice Discussion of Results: Comparison of OM69 to L-dopa:

Referring to TABLE 6, in this experiment, MPTP causes a significant decrease in lunge length (letter "B" versus "A"). Treatment with 1 mg/kg L-dopa does not result in a significant increase in lunge length, but treatment with 5 mg/kg L-dopa returns lunge length to control (uninjured) values ("A" versus "A"). Treatment with low doses of OM69 (0.01 mg/kg or 0.03 mg/kg) also does not increase lunge length, but treatment with intermediate doses results in a statistically significant (p<0.05) increase in lunge length ("C" versus "B"). Treatment with a higher dosage (0.1 mg/kg) of OM69 also resulted in a statistically significant (p<0.05) increase in lunge length and, furthermore, restoration of lunge length to control (uninjured) values ("A" versus "A"). These results demonstrate that the PDE7 inhibitor compound OM69 is as effective as L-dopa in restoring lunge length in MPTP-treated mice and, furthermore, is approximately 50-fold more potent than L-dopa. OM69 and L-dopa administered in combination:

Two combination dosages of OM69 with L-dopa were also tested in this experiment. The first combination (1 mg/kg L-dopa plus 0.03 mg/kg OM69) caused a statistically significant (p<0.05) increase in lunge length of 1.13 cm, which was greater than the sum of non-significant increases with those agents alone at those dosages (0.35 cm). The second combination (1 mg/kg L-dopa plus 0.05 mg/kg OM69) also resulted in a statistically significant (p<0.05) increase in lunge length, and in addition to resuming lunge length to control (uninjured) values ("A" versus "A"), the magnitude of this increase (1.58 cm) was statistically significantly greater (p<0.0001) than the sum of the increase with 0.05 mg/kg OM69 plus the nonsignificant increase with 1 mg/kg L-dopa (0.8 cm), as represented by the theoretical additive bar on the right forepaw side of the map in FIGURE 18. These results strongly suggest that the PDE7 inhibitor compound OM69 and L-dopa interact in a greater than additive manner to correct the lunge length of the MPTP-treated mice.

Example 7 Pharmacological evaluation of a panel of representative PDE7 inhibitor compounds in the MPTP model of Parkinson's disease

In this example, a panel of representative PDE7 inhibitors was evaluated in the MPTP mouse model of Parkinson's disease to test the hypothesis that PDE7 inhibition will improve Parkinsonian symptoms in this model, regardless of the particular chemical structure of the inhibitor used, and that therefore, PDE7 inhibition is sufficient for the observed improvement in stroke length. Animal testing protocol. Mouse strain: C57BL/6J adult males; breeder excises, 7 to 9 months of age (Charles River Laboratories, Wilmington, MA), individually housed. Three groups of 35 mice were serially tested one week apart. Handling: The animals were handled daily for 2 weeks prior to injection to hold them accountable for behavioral testing. All mice were maintained on a standard 12-hour dark/light cycle and given ad libitum access to laboratory chow and water.

MPTP Administration. Mice received two subcutaneous injections of methylphenyltetrahydropyridine ("MPTP") at a dose of 15 mg/kg (free base) with a 10- to 12-hour interval between injections. Control mice (sham-lesion groups) received saline instead of MPTP. Stride length: Prior to injection with MPTP or saline, animals were pre-trained to walk across a clean sheet of paper in their home cage without interruption. To assess stride length, animals had their forepaws placed in black ink, and the stride length of their forepaws during normal walking (in a straight line only) was measured. Animals were immediately returned to their home cage upon completion of the task. Stride length was determined by measuring the distance between each step on the same side of the body, measuring from the mid-toe of the first step to the heel of the second step. An average of at least four clean steps was calculated. The checklist for this experiment was as follows: Week 0 - training for walking therapy: (at least 4-5 sessions) Day 1 - collect baseline step Day 2a - collect 2nd baseline step Day 2b - MPTP injections Day 7 - collect and assess for step deficit Day 8a - collect 2nd deficit steps Day 8b - begin compound trials Day 9 advanced - different dosages of the compounds were administered on successive days.

Compound Administration' Because of the wide variation in aqueous solubility among these compounds, a number of different formulations were required. L-dopa was administered in 100 μL of phosphate-buffered saline. For L-dopa-treated animals, the dopa decarboxylase inhibitor benserazide (100 μL of a 12.5 mg/kg solution) was administered 15 minutes prior to L-dopa treatment in order to minimize the destruction of L-dopa in the peripheral blood. OM955 (compound 3) and OM056 (compound 2) were administered in 200 μL of dimethyl acetamide:polyethylene glycol 400:0.03 M methanesulfonic acid (DMA:PEG:MSA-10%:40%:50%). OM956 (compound 4) was administered in 200 μL of 0.03 M tartaric acid (TA). FIGURES 13A and 13B show that neither of these vehicles, when administered alone, alters the length of the stride in MPTP-treated mice. Therefore, the observed treatment effects are due solely to the PDE7 inhibitor compound itself. For each compound tested, preliminary experiments were performed to identify the most effective dosages in the MPTP model. In some cases, it was observed that dosages greater than the optimal dosages did not produce a significant increase in stride length. This "overshoot" phenomenon has also been observed with L-dopa in MPTP-treated mice where lower dosages improve hypoactivity while higher dosages induce dyskinesias or uncontrolled movements (Lundblad M. et al., Exp Neurol. 194(l):66-75 (2005); Pearce R.K. et al., Mov Disord. 10(6):731-40 (1995); Fredriksson, A. et al, Pharmacol-Toxicol. 67(4): 295-301 (1990)). Experimental protocol:

Male reproductive mice were treated with saline or 2 x 15 mg/kg MPTP to induce a Parkinsonian state (neurochemical loss of dopamine with corresponding behavioral deficits). On day one, baseline lunge length was measured, and then mice were treated with MPTP or saline as a control. On day eight, lunge length was measured again, and the control value for lunge length was derived from the lunge length of saline-treated animals. Animals were then randomly assigned to treatment groups. Compound OM955 (compound 3) was tested at 0.1 mg/kg, 0.5 mg/kg, and 0.1 mg/kg in combination with 1 mg/kg L-dopa. Compound OM956 (compound 4) was tested at 0.1 mg/kg and 0.5 mg/kg. Compound OM056 (compound 2) was tested at 0.05 mg/kg, 0.1 mg/kg, 0.5 mg/kg, and 1 mg/kg. Results:

The results of this study are shown in FIGURES 14 to 17. FIGURE 14 shows that OM955 at a dose of 0.5 mg/kg causes a statistically significant improvement in the lunge length of MPTP-treated mice (p<0.005 compared to the MPTP group). At both 20 minutes and one hour after injection, lunge length is fully restored to that of uninjured animals. FIGURES 15A to C demonstrate that the combination of OM955 and L-dopa exerts greater than additive effects in restoring lunge length. FIGURES 15A and 15B show, respectively, that low doses of L-dopa (1 mg/kg) or OM955 (0.1 mg/kg) do not increase lunge length when administered alone. However, FIGURE 15C shows that when these low dosages are given together, the lunge length is completely restored to that of uninjured animals (p<0.005 compared to the MPTP group).

FIGURE 16 shows that OM956, also at a dose of 0.5 mg/kg, causes a statistically significant increase (p<0.01 compared to the MPTP group) in the lunge length of MPTP-treated animals. FIGURE 17 shows that OM056 at the lower dose of 0.05 mg/kg also causes a statistically significant increase (p<0.05 compared to the MPTP group) in the lunge length of MPTP-treated animals.

The results in this example show that three different PDE7 inhibitor compounds, which are structurally unrelated to each other and structurally unrelated to OM69, all cause the same complete recovery of stroke length in MPTP-treated animals that was observed with OM69 (as described in Examples 5 and 6). Because the only known common property of these compounds is their ability to inhibit PDE7, and because one of these compounds (OM69) was tested for interaction with other known Parkinson's disease targets and not found to interact significantly with them, it is concluded that PDE7 inhibitory activity is both necessary and sufficient for the improvement in stroke length reported with these compounds.

While illustrative embodiments have been illustrated and described, it will be appreciated that various changes may be made therein without departing from the spirit and scope of the invention.

Claims (2)

1. Use of a PDE7 inhibitor compound, characterized by the fact that it is in the preparation of a drug for the treatment of Parkinson's disease, in which the PDE7 inhibitor agent is a chemical compound selected from a group consisting of: 2. Use of the compound according to claim 1, characterized in that it further comprises the use of the PDE7 inhibitor compound in conjunction with an agent selected from the group consisting of a dopaminergic agent, a precursor of a dopaminergic agent, a therapeutic agent that activates the dopamine D1 receptor, a precursor of a therapeutic agent that activates the dopamine D1 receptor, a therapeutic agent that increases the concentration of dopamine in the nigrostriatal nerve terminal, a precursor of a therapeutic agent that increases the concentration of dopamine in the nigrostriatal nerve terminal, a therapeutic agent that increases the concentration of dopamine in the nigrostriatal synaptic cleft, and a precursor of a therapeutic agent that increases the concentration of dopamine in the nigrostriatal synaptic cleft; optionally, for example, wherein the dopaminergic agent is levodopa (L-dopa).