Mesoblast Limited (NASDAQ:MESO), a biotechnology company specializing in innovative cellular medicines, provided an update on the early clinical application of its FDA-approved product Ryoncil (remestemcel-L-rknd) in treating pediatric patients with steroid-refractory acute graft-versus-host disease (SR-aGvHD). This condition, a serious complication arising after allogeneic hematopoietic cell transplantation, is characterized by a lack of response or progression following standard high-dose systemic steroid therapy within seven days.
Ryoncil holds the distinction of being the first mesenchymal stromal cell (MSC) therapy approved by the U.S. Food & Drug Administration for any indication. Since its commercial availability beginning in March 2025, Mesoblast has been monitoring its use in the approved pediatric population of children aged two months and older.
Patient Outcomes and Treatment Course
Data were reported for the first 25 pediatric patients treated with Ryoncil in a real-world medical setting following the product’s market launch. Of these patients, 21 (84%) completed the initial 28-day treatment regimen as outlined in the FDA approval label and were alive at time of reporting. Meanwhile, four patients did not complete the full 28-day course; these individuals had previously been treated with and failed alternative therapies and succumbed to severe SR-aGvHD within 28 days.
These preliminary outcomes are consistent with earlier clinical trials conducted for Ryoncil, underscoring the therapy’s potential efficacy when administered promptly after steroid resistance is identified. Mesoblast highlights the critical role of initiating Ryoncil therapy as early as possible following the onset of steroid refractoriness to maximize chances of completing the prescribed treatment course and improving survival rates.
Expansion of Access and Coverage
Mesoblast reported onboarding 45 transplant centers into its Ryoncil treatment program, with a target of 64 centers planned to cover approximately 94% of all transplants performed in the United States. This extensive network aims to facilitate timely access to the therapy for eligible patients nationwide.
Regarding reimbursement, Ryoncil now benefits from coverage extending to over 260 million individuals under federal and commercial health plans. The U.S. Centers for Medicare & Medicaid Services (CMS) provides Federal Medicaid coverage, supplemented by mandatory fee-for-service Medicaid coverage across all states.
Effective October 1, 2025, the CMS issued a dedicated Healthcare Common Procedure Coding System (HCPCS) J-Code for Ryoncil, greatly enhancing the ease of billing and reimbursement. This development has led to increased utilization of Ryoncil under CMS coverage compared with commercial plans during the most recent quarter, an important factor in driving broader patient access.
Upcoming Clinical Trials and Market Prospects
Building on the momentum in the pediatric population, Mesoblast seeks to expand the FDA label for Ryoncil to include adults suffering from severe steroid-refractory aGvHD. This adult patient segment represents a market potentially three times larger than that of the pediatric group.
To support this label expansion, a pivotal clinical trial targeting adults with severe SR-aGvHD will be launched, conducted in collaboration with the National Institutes of Health (NIH)-funded Bone Marrow Transplant Clinical Trials Network. Site enrollment for this trial is expected to begin in the current quarter.
Financial Performance and Additional Regulatory Feedback
Mesoblast disclosed $35.1 million in gross revenue from Ryoncil sales for the quarter ended December 31, 2025, reflecting a strong 60% increase sequentially. This financial performance illustrates growing market acceptance and uptake of the therapy.
Separately, the company recently provided an update on regulatory interactions regarding another allogeneic cell therapy product, rexlemestrocel-L, targeting chronic discogenic low back pain (CLBP). Feedback from the FDA concerning a potential Biologics License Application indicated that data from the MSB-DR003 trial showed pain intensity improvements favoring the treatment compared to placebo, a positive signal for the candidate's future development.
Stock Performance
Following these announcements, Mesoblast’s shares were trading up 1.77% at $19.01 as of Tuesday, based on Benzinga Pro data.