Mesoblast (NASDAQ:MESO) announced on April 7, 2026, that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application to proceed directly to a registrational trial for Ryoncil® (remestemcel-L) in children with Duchenne muscular dystrophy (DMD).
The agency’s decision allows the Australian cellular medicine company to bypass early-stage clinical work, significantly accelerating the development timeline for the therapy in this rare and fatal muscle-wasting disease.
The upcoming randomized trial will enroll 76 patients between the ages of 5 and 9.
Participants will receive seven infusions of 2 x 10⁶ cells/kg over a nine-month period, with the "time-to-stand" at nine months serving as the primary efficacy endpoint.
The FDA’s clearance to move directly into a registrational phase is based on several key factors, most notably Ryoncil’s established safety profile.
The therapy is already approved in several jurisdictions for pediatric steroid-refractory acute graft-versus-host disease (aGvHD), providing regulators with a substantial database of safety in children.
Additionally, Mesoblast cited strong preclinical data demonstrating efficacy in DMD models and the existence of an FDA-approved manufacturing process already in place.
DMD is a genetic disorder characterized by progressive muscle degeneration and weakness, primarily affecting boys.
Chronic inflammation and a failure of muscle repair mechanisms drive the disease's progression.
Ryoncil, an allogeneic mesenchymal stem cell therapy, is designed to modulate the immune response and promote a pro-regenerative environment in damaged tissues.
To ensure rapid enrollment and patient-centric trial design, Mesoblast is collaborating with Parent Project Muscular Dystrophy (PPMD), the leading advocacy group for the DMD community.
This partnership is expected to facilitate recruitment across major pediatric neurology centers in the United States.