Mesoblast Receives FDA Approval for New Potency Assay to Release Commercial Ryoncil Product

NEW YORK, Sept. 24, 2026 (GLOBE NEWSWIRE) -- Mesoblast Limited (Nasdaq:MESO; ASX:MSB), global leader in allogeneic cellular medicines for inflammatory diseases, today announced that it has received approval from the United States Food and Drug Administration (FDA) to implement a new potency assay, T-cell Proliferation Inhibition BioAssay (TIBA), for release and stability monitoring of all new commercial product lots of its FDA-approved mesenchymal stromal cell (MSC) product Ryoncil(®) (remestemcel-L-rknd).

The TIBA assay will ensure sufficient sensitivity to detect any shifts in potency of the commercial product that could arise during changes in manufacturing processes or production in new facilities. This assay will be used as part of a matrix to release each commercial batch of RYONCIL in conjunction with the existing potency assays which determine IL-2Rα inhibition and CAP (Cell Adhesion and Proliferation), as per the product's Biologics License. Together these assays ensure that the RYONCIL product is consistent, potent, and clinically effective.