Multinational phase 2 study of narsoplimab for HSCT-associated thrombotic microangiopathy

Hematopoietic stem-cell transplantation-associated thrombotic microangiopathy (HSCT-TMA) is a serious complication with significant mortality and no approved therapy. HSCT-TMA results from endothelial injury, which activates the lectin pathway of complement. Narsoplimab is an inhibitor of the MASP-2 enzyme, the effector enzyme of the lectin pathway and an activator of the coagulation cascade. A multinational phase 2 study evaluated narsoplimab for HSCT-TMA in adult patients. The study found that patients treated with at least one dose of narsoplimab had a response rate of 61%, as determined by improvement in both laboratory markers and clinical status. Sixty-eight percent of patients achieved 100-day survival after HSCT-TMA diagnosis.