Omeros PDE10 inhibitor (OMS-643762) trial

Omeros Phosphodiesterase 10 (PDE10) inhibitor trial in Huntington’s disease patients

Omeros Corporation is a biotechnology company based in Seattle, Washington that is focused on developing novel therapeutics for inflammation and neurological disorders. Recently, Omeros announced the initiation of a Phase 2 clinical trial in HD patients to test the safety and efficacy of their PDE10 inhibitor in HD patients.

PDE10 is an enzyme predominantly expressed in the striatum, a region of the brain predominantly affected by HD.  PDE10 levels in HD patients have been observed to decrease with disease progression.  Recent evidence in pre-clinical (animal) models of HD suggests that the inhibition of PDE10 may have a therapeutic benefit on HD by restoring the neuronal circuitry in the indirect pathway of the basal ganglia.  Restoration of this pathway with inhibitors, may positively benefit both the HD motor and cognitive symptoms.

The Omeros trial is entitled a “Phase 2 randomized, double-blind, placebo-controlled, sequential cohort study to evaluate safety and efficacy of OMS643762 in subjects with Huntington's disease.”  The primary outcome measure of this study is to assess the safety of OMS643762 in HD patients. The secondary outcome measures of efficacy include: 1) motor function as measured by the Unified Huntington’s Disease Rating Scale - Total Motor Score and the Speeded Tapping Test score; 2) cognitive function as measured by a battery of six tests; 3) behavioral function as measured by a semi-structured interview to assess mood and behavior. In addition drug pharmacokinetics (the effects of the body on the drug) will also be assessed during the course of this 28 day trial.

The Omeros trial is being conducted by 11 research sites across the United States and Canada.  In all, they plan to enroll about 120 people with HD.  The goal is to complete the study by March 2015.  For more information on the inclusion and exclusion criteria for this trial, as well as a continuously updated list of research sites conducting this trial, please go to:

If interested in participating in this trial you should contact Lisa Kelbon from Omeros at 206-676-5000 or