Omeros Corporation (NASDAQ: OMER) announced that OMS824, its phosphodiesterase 10 (PDE10) inhibitor, has received orphan drug designation from the U.S. Food and Drug Administration for the treatment of Huntington's disease. OMS824 selectively inhibits PDE10, an enzyme expressed in areas of the brain linked to a wide range of diseases that affect cognition, including Huntington's disease and schizophrenia. As previously reported, Phase 1 clinical results in healthy subjects demonstrated that OMS824 is well tolerated and suggest that it has a better clinical therapeutic index or "safety factor" than other PDE10 inhibitors in development. Omeros plans to begin a Phase 2 clinical trial evaluating OMS824 in patients with Huntington's disease later this year. A Phase 2 clinical trial of the drug is already underway in patients with schizophrenia.
Orphan designation by the FDA is granted to promote the development of drugs that target conditions affecting 200,000 or fewer U.S. patients annually and that are expected to provide significant therapeutic advantage over existing treatments. It qualifies a company for benefits that apply across all stages of drug development, including accelerated approval process, seven years of market exclusivity following marketing approval, tax credits on U.S. clinical trials, eligibility for orphan drug grants, and waiver of certain administrative fees.
Huntington's disease is estimated to affect approximately 31,000 U.S. patients annually, and the only FDA‑approved treatment for 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.
"Orphan designation by the FDA will help to accelerate the development of OMS824 and recognizes the important work conducted at Omeros," stated Gregory A. Demopulos, M.D., chairman and chief executive officer of Omeros. "The manifestations of Huntington's are devastating to both Huntington's patients and their families, yet there is only one currently approved therapeutic and it is focused on a single symptom of the disease. OMS824 holds the promise of expanding treatment across the constellation of debilitating effects of Huntington's. We look forward to working with the FDA to advance the clinical evaluation of OMS824 in patients suffering from Huntington's disease and plan to initiate enrollment in a Phase 2 trial later this year."