Mesoblast’s Phase 3 Stem Cell for Lower Back Pain Trial Achieves Patient Recruitment, Results Expected Mid-2027

Key Points

• Mesoblast has reached the patient recruitment target in its pivotal Phase 3 trial of rexlemestrocel-L for chronic low back pain linked to degenerative disc disease.
• The placebo-controlled study is enrolling at least 300 patients to compare a single intra-discal injection of the allogeneic (donor derived) stromal cell therapy against sham control over 12 months.
• Top-line data are expected in mid-2027, and positive results are intended to support a planned FDA filing in the third quarter of 2027.

Phase 3 enrollment milestone

Mesoblast has reached the patient recruitment target in its pivotal Phase 3 trial of rexlemestrocel-L for chronic low back pain associated with degenerative disc disease. The study, called MSB-DR004, is a placebo-controlled trial designed to evaluate whether a single intra-discal injection can reduce low back pain over 12 months compared with sham treatment.

The study will follow at least 300 randomized patients, and secondary endpoints include function, quality of life, and cessation of pain medication, including opioids.

What the study is testing

Rexlemestrocel-L is an allogeneic (donor-derived) bone marrow-derived mesenchymal stromal cell (MSC) therapy. In this trial, it is being given with hyaluronic acid as a delivery agent for injection into the lumbar disc. Mesoblast said the Phase 3 study is intended to confirm findings from the earlier MSB-DR003 trial, where a single intra-discal injection was associated with clinically meaningful reductions in pain and opioid use for up to three years.

Rexlemestrocel-L has RMAT designation from the FDA for chronic low back pain due to degenerative disc disease, which may allow priority review once a Biologics License Application is filed.

Silviu Itescu, Chief Executive of Mesoblast, said: “This is a major milestone toward delivering on our corporate goal of bringing to market a non-opioid, disease-modifying therapy for patients suffering from chronic low back pain, a condition with significant unmet medical need.”

Timeline

Top-line results are expected in mid-2027 after the last randomized patient completes follow-up. If the readout is positive, Mesoblast plans to use the data to support an FDA filing in the third quarter of 2027.

Chronic low back pain caused by inflammation and degenerative disc disease affects more than 7 million people in the U.S., according to the company. Mesoblast also noted that discogenic back pain accounts for about half of prescription opioid use in the U.S., making opioid reduction an important part of the program’s rationale.

Want to keep up on regenerative medicine? Get the weekly newsletter here.