October 16, 2025 — Leads & Copy — Omeros Corporation (Nasdaq: OMER) announced the publication of a peer-reviewed manuscript in Blood Advances, a journal of the American Society of Hematology, detailing survival outcomes in adult patients with life-threatening transplant-associated thrombotic microangiopathy (TA-TMA) treated with narsoplimab across both the pivotal clinical trial and the global expanded access program (EAP). Narsoplimab inhibits MASP-2, the effector enzyme of the lectin pathway of complement, and is currently under review for marketing approval by both the U.S. FDA and the European Medicines Agency.
The manuscript, titled “Survival in Adults with High Risk TA-TMA—A Comparative Analysis of Narsoplimab Versus Supportive Care,” reports significant reductions in mortality risk across pivotal trial and EAP patient cohorts, treated with narsoplimab compared to a well-matched external control group who did not receive narsoplimab. Consistent with previous narsoplimab clinical studies, no safety signals of concern were observed. The full manuscript is available online.
Narsoplimab (OMS721) is an investigational, fully human monoclonal antibody that inhibits mannan-binding lectin-associated serine protease-2 (MASP-2), the effector enzyme of the lectin pathway of complement. A biologics license application (BLA) for narsoplimab in the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA) is currently under review by the FDA, and a corresponding marketing authorisation application (MAA) is under review by the European Medicines Agency’s (EMA’s) Committee for Medicinal Products for Human Use.
TA-TMA is a severe and often fatal complication of hematopoietic stem cell transplantation in both adults and children and is driven by systemic endothelial injury from conditioning regimens, immunosuppressants, infection, graft-versus-host disease, and other transplant-related factors. Approximately 30,000 allogeneic transplants are performed annually in the U.S and Europe. Recent studies estimate a 40-percent incidence of TA-TMA in allogeneic transplants. Mortality in severe TA-TMA can exceed 90 percent.
Omeros is a clinical-stage biopharmaceutical company focused on discovering, developing, and commercializing therapeutics for complement-mediated diseases, cancers, and addictive or compulsive disorders. Omeros’ lead MASP-2 inhibitor narsoplimab targets the lectin pathway of complement and is under regulatory review for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy.
For more information visit www.omeros.com.
Source: Omeros Corporation
