Mesoblast Partners With PPMD To Support Enrollment For FDA-Cleared Registrational DMD Trial

Mesoblast Limited, a global leader in allogeneic cellular medicines for inflammatory diseases, announced that the U.S. Food and Drug Administration (FDA) has granted Investigational New Drug (IND) clearance for the company to move directly into a registrational clinical trial of Ryoncil (remestemcel-L-rknd) for Duchenne muscular dystrophy (DMD). DMD is a severe genetic disorder affecting approximately 15,000 children in the United States.

Ryoncil is the first mesenchymal stromal cell (MSC) therapy ever approved by the FDA and the only treatment authorized for children under 12 years old with steroid-refractory acute graft-versus-host disease (SR-aGvHD). The newly authorized trial builds on Ryoncil’s established safety record in pediatric patients, encouraging results from preclinical studies in DMD, and Mesoblast’s FDA-approved manufacturing platform. Because Ryoncil has demonstrated an ability to reduce inflammation in SR-aGvHD, Mesoblast aims to apply this same mechanism to DMD, with the goal of decreasing the inflammatory damage that drives muscle deterioration and slowing disease progression.

The registrational study will enroll 76 children between the ages of 5 and 9. Participants will be randomized to receive either Ryoncil—administered as seven infusions at a dose of 2 x 10⁶ cells per kilogram over a nine-month period—or placebo, in addition to standard care. The trial’s primary endpoint will be time-to-stand at nine months, a functional measure recognized by the FDA as an acceptable basis for approval in DMD. To support enrollment and raise awareness, Mesoblast is partnering with Parent Project Muscular Dystrophy (PPMD), which will assist with community outreach and patient identification.

Aravindhan Veerapandiyan, MD, Director of the Comprehensive Neuromuscular Program at Arkansas Children’s Hospital and the study’s Principal Investigator, noted that the trial aims to address the inflammatory processes that significantly contribute to worsening muscle damage in DMD. He explained that by using Ryoncil’s anti-inflammatory effects at an early stage, the study hopes to preserve remaining muscle tissue and potentially alter the course of the disease.

Silviu Itescu, Chief Executive of Mesoblast, stated that the company is encouraged by the FDA’s decision to allow a direct transition to a registrational trial. He emphasized that Mesoblast’s extensive safety experience with Ryoncil in pediatric SR-aGvHD, along with strong preclinical findings in DMD models, supports the potential for a new therapeutic approach for children living with this devastating condition.