Mesoblast collaborating with BMT CTN on trial of Ryoncil in acute GvHD

Mesoblast (MESO) announced that, given the high rate of non-responsiveness to therapies in adults with severe acute graft versus host disease, or aGvHD, who fail corticosteroids, and the high mortality in these patients, Mesoblast and the National Institutes of Health, or NIH,-funded Blood and Marrow Transplant Clinical Trials Network -or BMT CTN – will collaborate on a pivotal trial of Ryoncil as part of first-line regimen in adults with severe aGvHD refractory to corticosteroids, or SR-aGvHD. The BMT CTN is a body representing U.S. centers responsible for performing approximately 80% of all U.S. allogeneic BMTs. In Grade III/IV SR-aGvHD 44-58% of adults treated with ruxolitinib did not achieve response at Day 28 in two studies that supported FDA approval. In patients who fail ruxolitinib survival remains as low as 20-30% by 100 days.Notably, use of Ryoncil in Mesoblast’s Expanded Access program in patients aged 12 and older with SR-aGvHD who failed ruxolitinib or other second-line agents was associated with 76% survival at Day 100. The trial protocol will be provided to FDA in order to initiate enrollment in Q1 2026.