Mesoblast Limited (ASX:MSB) announced on July 14, 2026, that it has achieved its target of treating at least 300 patients in the pivotal Phase 3 randomised controlled trial, MSB-DR004. Mesoblast is a global leader in developing allogeneic cellular medicines for inflammatory diseases, focusing on off-the-shelf treatments for severe and life-threatening inflammatory conditions. This milestone pertains to rexlemestrocel-L, the company’s product candidate for chronic low back pain (CLBP) associated with degenerative disc disease, with the trial aiming to confirm durable pain reduction seen in an earlier study.
Mesoblast Chief Executive Silviu Itescu highlighted that completing patient enrolment ensures the trial is well-powered for success. He added that commercial manufacturing is progressing in parallel, aiming for an approval filing as soon as possible after trial results are available. The primary endpoint for MSB-DR004 is a significant reduction in low back pain at 12 months, comparing rexlemestrocel-L against sham controls. Secondary endpoints include improvements in function, quality of life, and the cessation of pain medication, notably opioids.
Rexlemestrocel-L has received Regenerative Medicine Advanced Therapy (RMAT) designation from the United States Food and Drug Administration (FDA) for CLBP due to degenerative disc disease. This designation provides eligibility for priority review upon filing a Biologics License Application (BLA). Chronic low back pain stemming from inflammation and degenerative disc disease affects over seven million people in the U.S. alone, representing a substantial market opportunity. Top-line results from the trial are anticipated in mid-CY2027, following the last treated patient’s 12-month follow-up.
