Mesoblast has announced a major step toward expanding treatment options for adults with severe acute graft-versus-host disease (aGvHD) who no longer respond to corticosteroids.
The company will partner with the NIH-funded Blood and Marrow Transplant Clinical Trials Network (BMT CTN) on a pivotal trial evaluating Ryoncil (remestemcel-L-rknd) as part of first-line therapy for steroid-refractory aGvHD (SR-aGvHD).
This collaboration is significant. BMT CTN represents U.S. centers performing nearly 80% of all allogeneic bone marrow transplants—making it one of the most influential bodies in the field.
Why This Trial Matters?
Adults with severe SR-aGvHD face poor outcomes:
- 44–58% of patients treated with ruxolitinib do not respond by Day 28
- Those who fail ruxolitinib show only 20–30% survival by Day 100
- Mortality remains high despite available therapies
Early data from Mesoblast’s Expanded Access Program is more encouraging. In patients 12+ years old who failed ruxolitinib or other second-line agents, Ryoncil recorded 76% survival at Day 100.
This disparity underscores the urgent need for better first-line strategies in adults.
What the New Trial Will Explore?
Mesoblast and FDA recently aligned on the appropriate patient population and timing for Ryoncil’s pivotal trial.
The trial will:
- Randomize patients immediately after they develop steroid refractoriness
- Compare ruxolitinib alone versus ruxolitinib + Ryoncil
- Target adults with Grade III/IV SR-aGvHD
- Aim to start enrollment in Q1 2026
The goal is clear: deliver treatment earlier, when patients have the best chance of survival.
Leadership Insights
Dr. John Levine, Chair of the BMT CTN Steering Committee, said:
“We are delighted to be partnering with Mesoblast. We aim to extend the use of this potentially life-saving treatment, already FDA-approved in children, to adults with severe SR-aGvHD.”
Silviu Itescu, CEO of Mesoblast, added:
“This remains a major unmet need. The adult market is 3–4 times larger than the pediatric market, and our partnership with BMT CTN is critical for expanding access.”
About the Organizations
Mesoblast
A global leader in allogeneic, off-the-shelf cellular medicines for life-threatening inflammatory diseases. The company focuses on developing therapies that address major unmet needs in conditions like aGvHD.
BMT CTN
A premier NIH-funded network responsible for high-quality, multi-institutional clinical trials in cellular therapies and bone marrow transplantation.
To date, BMT CTN has:
- Completed 52 Phase II and III trials
- Enrolled 16,600+ patients
- Operated across 125+ transplant centers
Its collaborative structure includes the CIBMTR, NMDP, and Emmes Company LLC, ensuring scientific rigor and broad clinical reach.
