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 inhibits PDE10 and is being developed in clinical programs for the treatment of cognitive disorders, including Huntington’s disease and schizophrenia. In Huntington’s disease, OMS824 may improve motor and behavioral abnormalities as well as cognition. In schizophrenia, OMS824 may have, in addition to cognitive enhancement, beneficial effects on the positive (e.g., hallucinations) and negative (e.g., flat affect) symptoms of the disease. OMS824 may address other limitations of current treatments for both schizophrenia and Huntington’s disease, for example, by avoiding the weight gain, hyperlipidemia, and the risk of sudden cardiac death associated with current antipsychotic medications as well as the depression and suicidal ideation seen with tetrabenazine, the only FDA-approved treatment for Huntington’s disease.
The FDA has designated OMS824 as an orphan drug for Huntington's disease. OMS824 has also received Fast Track designation from the FDA 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. Clinical trials in our Huntington’s program are currently subject to dosing limitations. The dosing limitations may potentially be removed pending generation, submission and FDA review of additional information. We are conducting nonclinical studies to generate additional data for further discussion with the FDA regarding the dosing limitations and are currently preparing for a re-designed Phase 2 clinical trial in patients with Huntington’s disease.
In our schizophrenia program, we have completed a Phase 2a trial evaluating OMS824’s tolerability, safety, pharmacokinetics, potential interactions with concomitant antipsychotic medications, and potential effects on cognition using a battery of cognitive tests in patients with schizophrenia. The drug was well tolerated in this trial and demonstrated comparable systemic pharmacokinetics when administered alone and concomitantly with approved antipsychotic agents. As we announced in October 2014, clinical trials evaluating OMS824 in schizophrenia are suspended currently at the request of the FDA. Given that there was no active schizophrenia trial at the time of program suspension, the FDA will address the OMS824 schizophrenia program when we have a related trial protocol ready for initiation.
As of March 8, 2016, we owned six issued patents and six pending patent application in the U.S., and 12 issued patents and 25 pending patent applications in foreign markets, that are directed to proprietary PDE10 inhibitors.