The U.S. Food and Drug Administration approved Omeros Corporation’s Yartemlea (narsoplimab) as the first therapy for hematopoietic stem cell transplant‑associated thrombotic microangiopathy (TA‑TMA). The approval establishes a branded option for a life‑threatening vascular complication of hematopoietic stem cell transplantation and provides clinicians with a targeted complement inhibitor. Omeros will begin commercialization efforts focused on transplant centers and hematology/oncology specialists. Regulators and centers will monitor real‑world uptake given TA‑TMA’s rarity and the need for rapid diagnosis. The approval also creates a commercial benchmark for future programs in post‑transplant complications.