Source: Mesoblast Limited

NEW YORK, Jan. 26, 2026 - Mesoblast Limited (Nasdaq:MESO; ASX:MSB), global leader in allogeneic cellular medicines for inflammatory diseases, today provided an update on use of Ryoncil (remestemcel-L-rknd) since commercially available in March 2025 for the approved label in children 2 months and older with steroid-refractory acute graft-versus-host disease (SR-aGvHD). Ryoncil is the first mesenchymal stromal cell (MSC) product approved by the U.S. Food & Drug Administration (FDA) for any indication.1

Of the first 25 patients treated with Ryoncil in a ‘real-world’ clinical setting post launch, 21 were alive (84%) and completed the initial 28-day treatment regimen as per the FDA approval label. The four patients who did not complete the 28-day treatment course had been offered and failed other therapies prior to use of Ryoncil and died of severe SR-aGvHD within 28 days. These early data are consistent with the prior clinical experience with Ryoncil. The outcomes highlight our focus on getting patients on Ryoncil therapy as early as possible following steroid resistance to enable completion of an initial 28-day treatment course and maximize survival.

To ensure that no patient is left behind in receiving this potentially life-saving therapy, Mesoblast has established a patient access hub termed MyMesoblast, where Ryoncil is available for ordering. Additional information is available on ryoncil.com, where valuable resources for healthcare providers, patients and caregivers can be found.

To date 45 transplant centers have been onboarded, with a target of 64 centers which account for 94% of transplants performed in the U.S. Ryoncil coverage by government and commercial payers already extends to over 260 million U.S. lives with Federal Medicaid coverage by U.S. Centers for Medicare & Medicaid Services (CMS) and mandatory fee-for-service Medicaid coverage in all U.S. states. Issuance on October 1, 2025, of a specific Healthcare Common Procedure Coding System (HCPCS) J-Code by CMS for billing and reimbursement resulted in greater usage of Ryoncil under CMS coverage versus commercial coverage in the last quarter.2

These commercial activities will continue to serve the company well as it seeks to expand the FDA label for Ryoncil to adults with severe SR-aGvHD, a market size approximately three times that of the pediatric SR-aGvHD population. A pivotal trial of Ryoncil in adults with severe SR-aGvHD will be conducted with the NIH-funded Bone Marrow Transplant Clinical Trials Network (BMT-CTN) and is expected to commence site enrollment this quarter.

“We are delighted to see the excellent early survival rates in the real-world experience with Ryoncil in children with this devastating disease,” said Mesoblast Chief Executive Dr. Silviu Itescu. “Our strong early results and the streamlined process that is in place to provide access to the product underscores the importance of early physician referral and treatment initiation in order to give Ryoncil the best chance to save as many precious lives as possible." **