Omeros corpn., announces agreement with the FDA on primary endpoint for narsoplimab BLA in stem cell transplant-associated thrombotic microangiopathy

Omeros Corporation announced agreement with the FDA on the response-based primary endpoint for its pivotal trial to support the biologics license application (BLA) for narsoplimab to treat hematopoietic stem cell transplant-associated thrombotic microangiopathy (HSCT-TMA). Narsoplimab, also known as “OMS721,” is Omeros’ lead human monoclonal antibody targeting mannan-binding lectin-associated serine protease-2 (MASP-2).

As previously reported, FDA had already agreed to the majority of the criteria proposed for the response-based primary endpoint, and this agreement with FDA has finalized the remaining components of the endpoint. The response-based primary endpoint for HSCT-TMA requires a showing of both a beneficial effect on the underlying HSCT-TMA disease process and a meaningful improvement in patients’ clinical status. The endpoint includes laboratory measures and markers of organ function as well as platelet and red blood cell transfusion burden. Based on a review of the available data from the open-label, single-arm, pivotal trial, Omeros is confident that the study will meet the primary endpoint.