Mesoblast Limited has achieved its target of treating at least 300 patients in the MSB-DR004 pivotal Phase 3 randomized controlled trial of rexlemestrocel-L for chronic low back pain (CLBP) associated with degenerative disc disease. The trial aims to confirm the durable pain reduction from a single intra-discal injection seen in the earlier MSB-DR003 trial. This milestone ensures the study is well powered for success, with commercial manufacturing proceeding in parallel to facilitate a potential Biologics License Application (BLA) filing.

Silviu Itescu, Chief Executive of Mesoblast, stated that completing the patient enrollment target allows the company to proceed toward a results readout and subsequent approval filing as soon as possible. The primary endpoint is powered to show a significant difference in pain reduction at 12 months between rexlemestrocel-L and sham controls. Secondary endpoints include improvements in function, quality of life, and cessation of pain medication, including opioids.

The indication represents a significant commercial opportunity, with a prevalence of over 7 million people in the U.S. alone. Mesoblast projects potential peak year revenue of >US$10 billion with single-digit market penetration. The therapy has received Regenerative Medicine Advanced Therapy (RMAT) designation from the United States Food and Drug Administration (FDA), providing eligibility for priority review upon BLA submission.

Trial Details and Design

The MSB-DR004 trial is a 300-patient randomized, placebo-controlled confirmatory Phase 3 study. It is actively enrolling patients with chronic low back pain due to inflammatory degenerative disc disease of less than five years duration at multiple sites across the U.S. The FDA has agreed to the trial design and the 12-month primary endpoint of pain reduction as an approvable indication.

A particular focus of the trial is on patients currently using opioids, as discogenic back pain accounts for approximately 50% of prescription opioid usage in the U.S. Significant pain reduction and opioid cessation were observed in Mesoblast’s first Phase 3 trial.

Key Milestones and Designations

Mesoblast Limited announced Ryoncil net revenue of US$36 million for the fourth quarter ended June 30, 2026, with full-year revenue reaching US$115 million. The company cited strong uptake across major U.S. pediatric centers as the primary driver for the results, which exceeded initial projections. Chief Executive Dr. Silviu Itescu highlighted the momentum, stating that operational activities are well funded through revenue growth and a new five-year facility has freed up capital for strategic initiatives involving label extension and blockbuster products.

Ryoncil is the first mesenchymal stromal cell (MSC) product approved by the U.S. Food and Drug Administration (FDA) for any indication. It remains the only FDA-approved treatment for children under age 12 with steroid-refractory acute graft-versus-host disease (SR-aGvHD). The product is also being developed for additional inflammatory diseases, including SR-aGvHD in adults and biologic-resistant inflammatory bowel disease.

Financial Performance

The revenue figures are based on management’s preliminary estimates and remain subject to completion of customary year-end closing and audit procedures. The company’s capital position is reported as strong, with operational activities funded by the revenue growth observed during the period.

Strategic Outlook

Mesoblast anticipates continued revenue growth in the coming fiscal year, aligning with current momentum in pediatric centers. The company is also advancing its rexlemestrocel-L platform for heart failure and chronic low back pain. Commercial partnerships have been established in Japan, Europe, and China to support global expansion.