The U.S. Food and Drug Administration approved Omeros Corporation’s Yartemlea (narsoplimab) for hematopoietic stem cell transplant‑associated thrombotic microangiopathy (TA‑TMA), marking the first approved therapy for this life‑threatening transplant complication. The approval follows a Biologics License Application (BLA) review and gives clinicians a targeted option where supportive care has been the only standard. TA‑TMA is a microvascular thrombotic disorder that can follow hematopoietic stem cell transplantation and carries high morbidity and mortality; the new label is expected to affect transplant center protocols and reimbursement discussions. Omeros’ approval may also sharpen commercial focus on complement and lectin‑pathway inhibitors as a class in transplant‑related complications.