Omeros' OMS824 for brain diseases shows positive Phase 2a results Omeros announced additional positive results from a Phase 2a clinical trial of OMS824, the company's phosphodiesterase 10 inhibitor. Patients with schizophrenia were administered a higher dose than had been evaluated in any OMS824 trial, which resulted in approximately 50% higher plasma concentrations than did the previously reported highest dose and had a similar side-effect profile to those of the lower doses. OMS824 selectively inhibits PDE10, an enzyme expressed in areas of the brain linked to a wide range of diseases that affect cognition, including schizophrenia and Huntington's disease. OMS824 was tolerated with mild or moderate adverse events that were consistent with those seen in previous cohorts, were self-limited and did not result in any discontinuation of the drug. An additional PET trial cohort is planned in the coming weeks.