Mesoblast secures FDA approval for new Ryoncil potency assay

Mesoblast Limited has received approval from the U.S. Food and Drug Administration (FDA) to implement a new potency assay for its mesenchymal stromal cell (MSC) product, Ryoncil (remestemcel-L-rknd).

The new T-cell Proliferation Inhibition BioAssay (TIBA) will be used for the release and stability monitoring of all new commercial product lots. It is designed to provide high sensitivity to detect potential shifts in product potency that may occur during manufacturing process changes or when production moves to new facilities. The TIBA assay will be integrated into a broader testing matrix alongside existing assays that measure IL-2Ra inhibition and Cell Adhesion and Proliferation (CAP).

Ryoncil is currently the only FDA-approved MSC therapy for patients aged two months or older with steroid-refractory acute graft versus host disease (SR-aGvHD). This regulatory milestone is intended to ensure consistent quality, potency, and clinical effectiveness as the company manages commercial production and manufacturing scale-up.