Mesoblast Limited (NASDAQ: MESO) received Investigational New Drug clearance from the U.S. Food and Drug Administration to proceed directly to a registrational clinical trial evaluating Ryoncil® for Duchenne muscular dystrophy, the company announced April 10.

The trial will randomize 76 patients aged 5 to 9 years to receive either Ryoncil® (7 infusions of 2 x 106 cells/kg over 9 months) or placebo, in addition to standard care. The primary endpoint will measure time-to-stand at nine months, which the FDA has validated as an endpoint for approval.

Duchenne muscular dystrophy affects approximately 15,000 children in the United States. The X-linked genetic disorder causes progressive muscle degeneration affecting skeletal, respiratory and cardiac muscles due to the absence of functional dystrophin protein.

Ryoncil® is currently the only FDA-approved mesenchymal stromal cell product and the only treatment approved for children under age 12 with steroid-refractory acute graft-versus-host disease. The company aims to leverage the treatment's anti-inflammatory mechanism to reduce inflammation characteristic of Duchenne muscular dystrophy and preserve muscle function.

Mesoblast has contracted with Parent Project Muscular Dystrophy and the Duchenne Registry to support patient identification and trial awareness for the study. Dr. Aravindhan Veerapandiyan, Director of the Comprehensive Neuromuscular Program at Arkansas Children's Hospital, will serve as principal investigator.

"We are very pleased to have received clearance to proceed directly to a registrational study for DMD based on our preclinical data in DMD animal models and our extensive safety data in children with SR-aGvHD," said Silviu Itescu, Chief Executive of Mesoblast.