FDA Approval of Ryoncil: First MSC Therapy for Pediatric SR-aGVHD
On December 18, 2024, the Food and Drug Administration sanctioned remestemcel-L-rknd (Ryoncil, Mesoblast, Inc.), an allogeneic bone marrow-derived mesenchymal stromal cell (MSC) therapy, for steroid-refractory acute graft versus host disease (SR-aGVHD) in pediatric patients aged 2 months and older. Ryoncil is the inaugural MSC therapy approved by the FDA.
Efficacy and Safety
The efficacy was assessed in MSB-GVHD001 (NCT02336230), a multicenter, prospective, single-arm trial involving 54 pediatric patients with steroid-refractory acute graft-versus-host disease (SR-aGVHD) following allogeneic hematopoietic stem cell transplantation (HSCT). Patients exhibited Grade B to D SR-aGVHD, omitting Grade B skin-only cases, as per the International Blood and Marrow Transplantation Registry Severity Index Criteria.
SR-aGVHD was characterized as aGVHD that either advanced after 3 days or failed to improve within 7 consecutive days of methylprednisolone administration (2 mg/kg/day or its equivalent). Patients who underwent second-line aGVHD treatment before screening were excluded.
The primary efficacy outcome indicators were the overall response rate (ORR) at Day 28 and the duration of the overall response. The Overall Response Rate (ORR) encompassed complete response (CR) and partial response (PR) rates.
The overall response rate (ORR) at Day 28 was 70% (95% confidence interval: 56.4, 82.0), comprising a complete response (CR) rate of 30% (95% CI: 18.0, 43.6) and a partial response (PR) rate of 41% (95% CI: 27.6, 55.0). The median duration of response, measured from Day 28 to progression, initiation of new systemic medication for aGVHD, or any cause of death, was 54 days (range 7 to 159+).
The predominant nonlaboratory adverse effects (incidence ≥20%) included viral infections, bacterial infections, nonspecific infections, fever, bleeding, edema, stomach pain, and hypertension.
The advised dosage is 2 X 10^6 MSC/kg of body weight administered via intravenous infusion biweekly for 4 consecutive weeks, totaling 8 infusions. Infusions are given a minimum of three days apart. Treatment may persist contingent upon the response observed 28 days following the initial administration of remestemcel-L-rknd.
How CancerFax Helps
CancerFax is a specialist cancer access and patient-navigation platform. We help patients and families understand their options, organise medical records, coordinate hospital communication, and support cross-border treatment planning where appropriate.
We help collect and organise reports, scans, pathology, biomarker results, and treatment history for structured case review.
We communicate with hospitals or trial teams to assess whether a case may be suitable for further screening.
We support appointment coordination, document submission, translation, and direct communication with international departments.
For international patients, we help with practical coordination — travel planning, hospital admission guidance, and local support.
If this option is not suitable, we help explore other relevant treatments, clinical trials, or advanced care pathways.
From inquiry through to follow-up, our coordinators provide a single point of contact for the family.
CancerFax does not guarantee treatment access, eligibility, or clinical outcome. Our role is to help patients access accurate information, structured review, and appropriate specialist pathways.
About Dr. Nishant Mittal
Dr. Nishant Mittal is a highly accomplished researcher with over 13 years of experience in the fields of cardiovascular biology and cancer research. Significant contributions to stem cell biology, developmental biology, and innovative research techniques mark his career. Research Highlights Dr. Mittal's research has focused on several key areas: 1) Cardio…
✓ Reviewed for medical accuracy by the CancerFax review panel.
Medical Disclaimer
This article is for educational purposes only and should not replace medical advice, diagnosis, or treatment from a qualified oncology specialist. Every patient's case is different. Treatment decisions should always be made after a review of complete medical records by the treating medical team.
Treatment availability, eligibility, timelines, and access can change. Any clinical trial participation depends on detailed review and approval by the trial hospital or investigator.