SEATTLE, Feb. 19, 2014 /PRNewswire/ -- Omeros Corporation (NASDAQ: 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.