Seattle, Jan 28 — Omeros Corporation (NASDAQ: OMER) today announced that the first commercial shipments of YARTEMLEA® (narsoplimab-wuug) to its distributors were completed last week, with orders from transplant centers beginning that same day. Both adult and pediatric patients with stem cell transplant-associated thrombotic microangiopathy (TA-TMA) are now receiving YARTEMLEA, including patients who have recently failed prior off-label C5-inhibitor regimens, in both hospital and outpatient settings.
YARTEMLEA is the first and only approved therapy for TA-TMA, an often-fatal complication of stem cell transplantation driven by activation of the lectin pathway of complement. YARTEMLEA, which was approved by the U.S. FDA on December 23, 2025, selectively inhibits MASP-2, the effector enzyme of the lectin pathway, blocking the pathway’s activation while preserving classical and alternative complement functions important for host defense against infection. YARTEMLEA is approved for use in adults and in children ages two years and older.
TA-TMA can occur following both autologous and allogeneic hematopoietic stem cell transplantation, with substantially higher prevalence following allogeneic transplant. Approximately 30,000 allogeneic transplants are performed annually in the United States and Europe. Recent studies estimate that TA-TMA develops in up to 56 percent of allogeneic transplant recipients, though the condition is thought to be frequently under-recognized, and timely diagnosis can be a key factor in outcomes.
A marketing authorization application for YARTEMLEA for the treatment of TA-TMA is currently under review by the European Medicines Agency with a decision expected in mid-2026.