Omeros Corporation (NASDAQ: OMER) today announced that OMS721, the company's lead human monoclonal antibody targeting mannan-binding lectin-associated serine protease-2 (MASP-2), the key regulator of the lectin pathway of the immune system, has received orphan drug designation from the U.S. Food and Drug Administration (FDA) for prevention of complement-mediated thrombotic microangiopathies (TMAs).
TMAs, including atypical hemolytic uremic syndrome and thrombotic thrombocytopenic purpura, are a family of rare, debilitating and life-threatening disorders characterized by multiple thrombi (clots) in the microcirculation of the body's organs, most commonly the kidney and brain. The lectin pathway, one of the principal complement activation pathways in the immune system, is thought to play a central role in the development of TMAs. By targeting MASP-2, OMS721 specifically blocks the lectin pathway. Omeros controls the worldwide rights to MASP-2 and all therapeutics targeting MASP-2.
Omeros is completing a Phase 1 study to assess the safety and pharmacokinetics of OMS721. As previously announced, at the highest subcutaneous dose administered to date in this study, OMS721 achieved serum concentrations that resulted in a high degree of inhibition of lectin pathway activation. The serum concentrations seen in the Phase 1 subjects are similar to those associated with efficacy in animal models of diseases, including TMA, linked to the lectin pathway. Omeros expects to report additional Phase 1 clinical data in early 2014. The Phase 2 clinical program evaluating OMS721 for the prevention of complement-mediated TMAs is expected to begin in the first quarter of 2014.