Mesoblast (ASX: MSB | NASDAQ: MESO) Completes Patient Recruitment in Pivotal Phase 3 Back Pain Trial, Eyes Mid-2027 Results

Mesoblast (ASX: MSB) has reached a significant milestone in its regenerative medicine pipeline, completing treatment of more than 300 patients in its pivotal Phase 3 clinical trial evaluating rexlemestrocel-L for chronic low back pain caused by degenerative disc disease.

The update marks the completion of patient enrolment, one of the biggest operational hurdles in large late-stage clinical trials. With recruitment now complete, the focus shifts from enrolling participants to assessing whether the therapy can meet its primary efficacy goals. Mesoblast expects topline results in mid-2027.

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For biotechnology companies, reaching full enrolment is often more than a procedural milestone. It signals that the study is sufficiently powered to evaluate whether the treatment delivers meaningful clinical benefit, reducing one layer of uncertainty as the program moves toward its most important stage.

The company is also preparing beyond the clinic. Alongside the trial, Mesoblast confirmed commercial manufacturing is already progressing, allowing it to move quickly towards regulatory submission if the study produces positive results. That parallel approach is less common among biotechnology companies, many of which only begin scaling manufacturing after successful clinical data.

The opportunity extends well beyond the trial itself. Chronic low back pain linked to degenerative disc disease affects more than seven million people in the United States, according to company data, and remains one of the leading causes of long-term disability worldwide. Treatment options are often limited to pain management, physiotherapy, steroid injections or surgery, while prolonged opioid use continues to be a major public health concern.

If approved, rexlemestrocel-L could become the first regenerative cell therapy specifically approved for this form of chronic back pain. Mesoblast believes the product has the potential to generate more than US$10 billion in peak annual sales with only single-digit penetration of its target market.

The program is supported by encouraging earlier clinical evidence. A previous Phase 3 study demonstrated durable reductions in pain alongside lower opioid use among treated patients, findings that helped shape the design of the current confirmatory trial and contributed to discussions with the US Food and Drug Administration.

The therapy has also received Regenerative Medicine Advanced Therapy (RMAT) designation from the FDA. The designation provides access to closer engagement with regulators and may allow for rolling submissions and priority review if the clinical results support an approval application.

The latest milestone builds on a series of developments for Mesoblast during 2026. The company has advanced the regulatory review of Ryoncil, provided FY2026 revenue guidance of US$115 million for the therapy, secured US$50 million in non-dilutive financing and continued expanding its commercial capabilities.

Taken together, those developments suggest the company is steadily shifting from being viewed primarily as a clinical-stage biotechnology developer towards a business with both commercial products and an advanced late-stage pipeline.

Chief Executive Officer Dr Silviu Itescu said completing recruitment represented an important step for the company’s largest development program.

“Completing our target of treating at least 300 patients in the placebo-controlled pivotal back pain trial ensures the trial is well powered for success. Commercial manufacturing is proceeding in parallel so that we can file for approval as soon as possible after trial results readout.”

While the milestone reduces operational risk, the most significant uncertainty remains clinical. The therapy must still demonstrate statistically meaningful improvements at the 12-month endpoint before Mesoblast can seek regulatory approval. Commercial adoption would then depend on reimbursement decisions, manufacturing execution and acceptance by physicians.

For now, attention turns to the next major catalyst. With patient recruitment complete and manufacturing already underway, Mesoblast has entered the final stage before a pivotal data readout that could shape the future of one of its largest pipeline opportunities.