Omeros Corporation reported that the U.S. Food and Drug Administration (FDA) will require additional time to review the Biologics License Application (BLA) for narsoplimab for the treatment of hematopoietic stem cell transplant-associated thrombotic microangiopathy (HSCT-TMA). The new Prescription Drug User Fee Act (PDUFA) target action date is October 17, 2021. As part of the ongoing BLA Priority Review, Omeros recently submitted a response to an FDA information request. FDA has classified the response as a major amendment, which requires additional time to review. The first drug submitted to FDA for approval in HSCT-TMA, narsoplimab has Breakthrough Therapy and Orphan designations in both HSCT-TMA and IgA nephropathy. The BLA for narsoplimab in HSCT-TMA was accepted for filing in January 2021 under FDA’s Priority Review program.