PDE10 Inhibitor Administered to Patients with Huntington’s Disease

SEATTLE, WA, USA I February 19, 2014 I Omeros Corporation (OMER) today announced dosing of the first patient in a second Phase 2 clinical trial of OMS824, the company’s phosphodiesterase 10 (PDE10) inhibitor being developed for the treatment of schizophrenia, Huntington’s disease (HD) and other cognitive disorders. The Phase 2 trial will evaluate the tolerability, safety, pharmacokinetics and performance on a battery of tests in patients with symptomatic HD.

Omeros previously reported results from its successful Phase 2 trial of OMS824 in patients with schizophrenia. This second Phase 2 trial will enroll approximately 120 patients with Huntington’s disease who will be randomized to receive placebo or one of three doses of OMS824. The dose levels were selected based on tolerability and PDE10 target occupancy results in Phase 1 studies conducted in healthy subjects. The doses evaluated in this Phase 2 trial are expected to be well tolerated and cover a range of PDE10 target occupancy in the brain. Efficacy will be assessed across three functional domains that are affected by the disease: motor, cognitive, and behavior. Patients in the trial are allowed to continue their usual medications based on the results of the earlier Phase 2 trial in which schizophrenia patients who took similar classes of drugs had no untoward interactions with OMS824. Interim results are expected in the second half of this year with final data projected to be available in 2015.

Huntington’s disease is estimated to affect approximately 31,000 patients in the U.S. The only drug approved by the U.S. Food and Drug Administration (FDA) to treat the disease is tetrabenazine, which is indicated for Huntington’s-related movement disorders. OMS824 has the potential to improve the cognitive and psychiatric abnormalities as well as the movement disorders associated with the disease. Omeros has been awarded Orphan Drug designation by the FDA to evaluate OMS824 in HD and recently received Fast Track designation from the FDA for the development of OMS824 to treat cognitive impairment in HD.  

Omeros recently announced that approximately 70-percent engagement at PDE10 was achieved in the positron emission tomography (PET) trial following dosing with OMS824 without evidence of extrapyramidal symptoms (EPS). There is currently one other PDE10 inhibitor being evaluated in patients with HD. Based on available information, OMS824 achieves greater PDE10 target occupancy without EPS than does any other PDE10 inhibitor previously or currently in development. Since the maximally tolerated dose of OMS824 has not been reached, Omeros plans to evaluate a higher dose of OMS824 in the PET trial to determine whether an even higher level of PDE10 occupancy can be achieved.

“The Omeros team continues to advance our OMS824 program rapidly and successfully for both of our initial clinical indications – Huntington’s disease and schizophrenia,” stated Gregory A. Demopulos, M.D., chairman and chief executive officer of Omeros. “Each of these disorders represents a significant unmet therapeutic need. Like treatments for schizophrenia, the only commercially available drug for Huntington’s addresses narrowly limited symptoms of the disease and is associated with poorly tolerated side effects. OMS824 holds the promise to expand the therapeutic reach across the disabling aspects of each of these diseases with better tolerability, and we look forward to additional clinical data later this year.”

About Omeros’ PDE10 Program
PDE10 is an enzyme that is expressed in areas of the brain linked to diseases that affect cognition and psychomotor functions, including Huntington’s disease and schizophrenia. Huntington’s disease is a hereditary neurodegenerative disorder that leads to movement, cognition, and behavioral abnormalities and premature death. Schizophrenia is a group of severe brain disorders characterized by an abnormal interpretation of reality, which can manifest as delusions, hallucinations, and/or disordered thinking and behavior. Cognitive dysfunction is responsible for substantial disability in both of these diseases and is not meaningfully improved by current medications. Omeros’ proprietary compound OMS824, currently in Phase 2 clinical programs, inhibits PDE10 and is being developed for the treatment of cognitive disorders. In addition to potential benefits on cognition, OMS824 could also improve the motor and psychiatric abnormalities in Huntington’s disease as well as the positive (e.g., hallucinations) and negative (e.g., flat affect) symptoms of schizophrenia. Omeros has been awarded Orphan Drug designation by the US FDA to evaluate OMS824 in Huntington’s disease, and received Fast Track designation from the FDA for the development of OMS824 to treat cognitive impairment in Huntington’s disease. An application for Fast Track designation for the evaluation of OMS824 in schizophrenia is currently under FDA review.

About Omeros Corporation
Omeros is a clinical-stage biopharmaceutical company committed to discovering, developing and commercializing small-molecule and protein therapeutics targeting inflammation, coagulopathies and disorders of the central nervous system. Derived from its proprietary PharmacoSurgery® platform, the Company’s lead drug product, OMS302 for lens replacement surgery, is currently under review for marketing approval by both the US Food and Drug Administration and the European Medicines Agency with commercial launch planned for 2014. Omeros’ six other clinical programs are focused on schizophrenia, Huntington’s disease and cognitive impairment; addictive and compulsive disorders; complement-related diseases; and preventing problems associated with surgical procedures. Omeros also has a proprietary GPCR platform, which is making available an unprecedented number of new GPCR drug targets and corresponding compounds to the pharmaceutical industry for drug development.

SOURCE: Omeros