MESO · Mesoblast Limited

This announcement represents a HIGH material clinical and regulatory milestone for Mesoblast: the completion of enrollment in its confirmatory Phase 3 trial for rexlemestrocel-L in chronic low back pain (CLBP), a condition with profound public health and commercial implications. The trial’s design — a 300-patient, randomized, sham-controlled study with a 12-month primary endpoint of pain reduction — was pre-agreed with the FDA and directly builds on statistically and clinically meaningful outcomes observed in the earlier MSB-DR003 trial, including durable pain relief and opioid cessation over three years. Achievement of full recruitment triggers the countdown to top-line data in mid-CY2027, which will serve as the foundational evidence for the planned Biologics License Application (BLA) filing in Q3 CY2027. Critically, the therapy’s RMAT designation ensures access to FDA’s expedited development and review pathways, including rolling review and priority review eligibility — substantially de-risking the regulatory timeline relative to standard biologics. The filing and potential approval would position Mesoblast to address a large, underserved U.S. population (>7 million patients) where CLBP drives substantial disability and contributes disproportionately to the opioid epidemic (~50% of prescription opioid use). While no financial or operational metrics are disclosed, the successful execution of this pivotal trial is a prerequisite for commercialization and represents the most advanced validation to date of Mesoblast’s proprietary stromal cell platform in a high-prevalence, non-oncology, non-hematologic indication — significantly advancing the company’s strategic goal of delivering a non-opioid, disease-modifying therapy.