Mesoblast Receives FDA IND Clearance for RYONCIL Registrational Trial in Duchenne Muscular Dystrophy

On April 8, 2026, Mesoblast Limited announced that the U.S. FDA has granted Investigational New Drug (IND) clearance to proceed directly into a registrational clinical trial for RYONCIL (remestemcel-L) in patients with Duchenne muscular dystrophy (DMD). RYONCIL is already the first FDA-approved mesenchymal stromal cell (MSC) product, indicated for pediatric steroid-refractory acute graft-versus-host disease (SR-aGvHD). The upcoming registrational trial will be a randomized, placebo-controlled study involving 76 patients aged 5 to 9 years. Participants will receive seven infusions of 2 x 10^6 cells/kg over a nine-month period. The primary endpoint for the trial is the "time-to-stand" at nine months, which is a validated FDA endpoint for approval. Mesoblast is partnering with Parent Project Muscular Dystrophy (PPMD) to support patient recruitment and community engagement. The company aims to leverage RYONCIL's anti-inflammatory mechanism to reduce muscle degeneration and slow disease progression in the approximately 15,000 children living with DMD in the United States.