Mesoblast Limited (NASDAQ: MESO, ASX: MSB) has completed patient treatment in the MSB-DR004 pivotal randomized controlled Phase 3 trial of rexlemestrocel-L for chronic low back pain (CLBP) associated with degenerative disc disease. The milestone marks a critical step toward potential regulatory approval for the allogeneic cellular medicine, targeting a market with a potential peak year revenue of greater than US$10 billion.

The trial enrolled 350 patients, an increase from the initial target of 300. The expansion was driven by strong demand from trial investigators to enroll their patients in the program. Participants were randomized to receive either an intra-discal injection of rexlemestrocel-L or a sham injection.

Trial Design and Endpoints

The primary endpoint of the MSB-DR004 trial aims to confirm durable pain reduction at 12 months following a single injection. This builds on earlier data from the MSB-DR003 trial, which successfully met this endpoint. Secondary endpoints include improvements in function, quality of life, and cessation of pain medication, including opioids.

Rexlemestrocel-L holds Regenerative Medicine Advanced Therapy (RMAT) designation from the U.S. Food and Drug Administration (FDA) for CLBP due to degenerative disc disease. This designation provides eligibility for priority review once the Biologics License Application (BLA) is filed.

Market Potential

Chronic low back pain caused by inflammation and degenerative disc disease affects over 7 million people in the U.S. alone. Mesoblast estimates the indication has a potential peak year revenue of greater than US$10 billion, even with single-digit market penetration.

Silviu Itescu, Chief Executive of Mesoblast, stated that completing treatment of 350 patients is a momentous milestone as the company counts down to the 12-month read-out.

What the Numbers Show

The increase in enrolled patients from 300 to 350 enhances the statistical power of the trial. With a larger sample size, the study is better positioned to demonstrate a significant treatment benefit of rexlemestrocel-L compared to controls, addressing the high prevalence of the condition which accounts for approximately 50% of opioid prescriptions in the U.S.

Mesoblast Limited (NASDAQ: MESO, ASX: MSB) reported US$36 million in net revenue from its flagship cellular medicine Ryoncil for the fourth fiscal quarter ended June 30, 2026. This quarterly performance contributed to a first full-year post-FDA approval net revenue of US$115 million for the product, with US$66.5 million generated in the second half alone. The strong commercial uptake positions the therapy for expanded use in adult patients with steroid-refractory acute graft versus host disease (SR-aGvHD), a market segment three times larger than the current pediatric indication.

The filing, submitted as an Appendix 4C activity report, details the company’s financial and operational progress. Mesoblast’s net operating cash spend for the full year was US$43.8 million, including US$13.4 million in the second half. To strengthen its balance sheet, the company drew down US$50 million from an existing five-year facility to extinguish all maturing debt obligations, leaving it with US$103 million in cash as of June 30, 2026.

Financial Highlights

Operational Progress and Pipeline

Mesoblast is advancing its strategy to extend the FDA-approved label for Ryoncil beyond pediatric patients to adults with SR-aGvHD. The registration trial for this label extension has commenced, with up to 40 sites across the U.S. expected to activate this year. These sites represent approximately 60% of the ~8,500 annual U.S. allogeneic adult bone marrow transplant population.

Additionally, the U.S. Food and Drug Administration (FDA) granted Investigational New Drug (IND) clearance for a registrational trial evaluating Ryoncil in ambulatory children aged 5-9 years with Duchenne muscular dystrophy (DMD), affecting approximately 15,000 children in the U.S.

In its pipeline for rexlemestrocel-L, Mesoblast achieved its target of treating at least 300 patients in the MSB-DR004 pivotal Phase 3 trial for chronic low back pain associated with degenerative disc disease. Patients will be followed through the twelve-month primary endpoint to assess pain reduction. The company also received a Biologics License Application (BLA) filing number from the FDA for rexlemestrocel-L in preventing life-threatening gastrointestinal bleeding in end-stage heart failure patients with left ventricular assist devices.

Corporate Governance and Compensation

As required by ASX listing rule 4.7, Mesoblast disclosed director remuneration in Item 6 of its Appendix 4C cash flow report. Fees to Non-Executive Directors totaled US$185,862, while consulting payments to Non-Executive Directors were US$100,000. Salary payments to full-time Executive Directors amounted to US$400,206 for the quarter.

What the Numbers Show

The revenue trajectory indicates accelerating adoption of Ryoncil, with second-half revenues (US$66.5 million) significantly outpacing the first half. The decision to extinguish maturing debt using existing credit facilities rather than raising new equity preserves shareholder value and extends the company’s runway. With US$103 million in cash and a clear path to expanding Ryoncil into larger adult markets, Mesoblast is positioning itself for potential FDA approvals that could drive further commercial scale.