Phosphodiesterase 10, or PDE10, is an enzyme that is expressed in areas of the brain strongly linked to diseases that affect cognition, including Huntington's disease and schizophrenia. Cognitive dysfunction occurs early in these diseases and is responsible for substantial disability. PDE10 inhibitors have been shown to be effective in multiple animal models of behavior and cognition, and there remain substantial unmet clinical needs with current treatments. Our proprietary compound OMS824, which inhibits PDE10, has received orphan drug designation for the treatment of Huntington's disease and fast track designation for the treatment of cognitive impairment in patients with Huntington's disease.
OMS824 is in a Phase 2 clinical program for the treatment of Huntington's disease and a Phase 2 clinical program evaluating OMS824 for the treatment of schizophrenia. We are also evaluating other neurological indications for OMS824. Plans for continuation of the OMS824 program will be based on internal ongoing work and on discussions with the FDA. Clinical trials in our Huntington's program may progress, but if so are currently subject to dosing limitations pending agreement with the FDA. Clinical trials evaluating OMS824 in schizophrenia remain suspended at the request of the FDA until we submit to the FDA a protocol for a schizophrenia trial and receive its clearance to proceed.
As of February 28, 2017, we owned eight issued patents and six pending patent application in the U.S., and 22 issued patents and 41 pending patent applications in foreign markets, that are directed to proprietary PDE10 inhibitors.