Rexlemestrocel-L - (MSB-DR004)

Aug. 16, 2026: Mesoblast Limited (NASDAQ: MESO, ASX: MSB) said it completed patient treatment in the pivotal randomized controlled Phase 3 MSB-DR004 trial of rexlemestrocel-L for chronic low back pain associated with degenerative disc disease. A total of 350 patients were randomized and treated with either a single intra-discal injection of rexlemestrocel-L or sham injection, up from 300 due to added enrollment.

The primary endpoint is durable pain reduction at 12 months; secondary endpoints include function, quality of life, and reduction/cessation of pain medication including opioids. The company said the trial is designed with FDA-agreed randomized, placebo-controlled design and a 12-month pain-reduction primary endpoint, which it says was previously met in its first Phase 3 trial, MSB-DR003.

Rexlemestrocel-L has FDA RMAT designation for this indication, which the company said provides eligibility for priority review once a BLA is filed. Top-line results from MSB-DR004 are expected in mid-calendar 2027 after the last treated patient completes 12 months of follow-up.

The release also notes Mesoblast’s approved product Ryoncil (remestemcel-L-rknd) for pediatric steroid-refractory acute graft-versus-host disease and says it is being developed further in adults with SR-aGvHD and in biologic-resistant inflammatory bowel disease.