SEATTLE, March 4, 2014 /PRNewswire/ -- Omeros Corporation (NASDAQ: OMER) today announced that it has submitted to the U.S. Food and Drug Administration (FDA) an investigational new drug (IND) application to initiate the Phase 2 clinical program for 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. In the Phase 2 clinical program, Omeros will evaluate OMS721 in the treatment of thrombotic microangiopathies (TMAs), a family of orphan disorders, including atypical hemolytic uremic syndrome (aHUS) and thrombotic thrombocytopenic purpura (TTP), that occur in the microcirculation of the body's organs, most commonly the kidney and brain. Last month Omeros announced positive data following completion of dosing in the Phase 1 clinical trial of OMS721, which was conducted in the Netherlands under a Clinical Trial Application. In that study OMS721, whether administered by subcutaneous injection or intravenous infusion, was well tolerated and achieved a high degree of sustained lectin pathway inhibition, consistent with the significant efficacy of OMS721 seen in animal models of TMA, age-related macular degeneration and other lectin pathway-related disorders. The lectin pathway is one of the principal complement activation pathways and plays a central role in the innate immune response. The initial Phase 2 clinical trial is an open-label, two-stage ascending-dose-escalation trial in adult subjects with TMA. The objectives of the trial are to evaluate efficacy, safety, tolerability, pharmacokinetics, pharmacodynamics and immunogenicity of OMS721 in patients with TMAs, including aHUS, TTP and transplant-related TMA. Design of the trial is based on the final data from the Phase 1 clinical trial of OMS721 and on discussions with the FDA's Division of Hematology Products at a pre-IND meeting held earlier this year. The pre-IND meeting also included representation from the FDA's Office of Orphan Products Development given that OMS721 has been granted Orphan Drug designation from the FDA for prevention of complement-mediated TMAs. Enrollment into the Phase 2 clinical trial is expected to begin following FDA's clearance of the IND.