Omeros Corporation announced that data on organ function improvement from Omeros’ pivotal trial of narsoplimab for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy (HSCT-TMA) will be shared as an oral presentation at the 2021 European Hematology Association (EHA) Virtual Congress. The presentation, entitled Narsoplimab (OMS721) Treatment Contributes to Improvements in Organ Function in Adult Patients with High-Risk Transplant-Associated Thrombotic Microangiopathy, will be delivered by Miguel-Angel Perales, M.D., Chief of Adult Bone Marrow Transplant Service at Memorial Sloan Kettering Cancer Center. Hematopoietic stem cell transplant-associated thrombotic microangiopathy (HSCT-TMA) is a significant and often lethal complication of stem cell transplantation. This condition is a systemic, multifactorial disorder caused by endothelial cell damage induced by conditioning regimens, immunosuppressant therapies, infection, graft-versus-host disease, and other factors associated with stem cell transplantation. Endothelial damage, which activates the lectin pathway of complement, plays a central role in the development of HSCT-TMA. The condition occurs in both autologous and allogeneic transplants but is more common in the allogeneic population. In the United States and Europe, approximately 25,000 to 30,000 allogeneic transplants are performed annually. Recent reports in both adult and pediatric allogeneic stem cell transplant populations have found an approximately 40% incidence of HSCT-TMA, and high-risk features may be present in up to 80% of these patients. In severe cases of HSCT-TMA, mortality can exceed 90% and, even in those who survive, long-term renal sequalae (e.g., dialysis) are common. There is no approved therapy or standard of care for HSCT-TMA.