On December 18, 2024, officials with the FDA approved remestemcel-L-rknd (Ryoncil, Mesoblast, Inc.), the first 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.1
Researchers evaluated efficacy in MSB-GVHD001 (NCT02336230), a multicenter, prospective, single-arm study in 54 pediatric patients with SR-aGVHD after allogeneic hematopoietic stem cell transplantation. Patients had grade B to D SR-aGVHD, excluding grade B skin alone (International Blood and Marrow Transplantation Registry Severity Index Criteria).
The main efficacy outcome measures were overall response rate (ORR) at day 28 and duration of overall response. ORR at day 28 was 70% (95% confidence interval [CI]: 56.4-82), including a complete response rate of 30% (95% CI: 18.0-43.6) and a partial response rate of 41% (95% CI: 27.6-55). The median duration of response calculated from response at day 28 to either progression, new systemic therapy for aGVHD, or any-cause death, was 54 days (range 7, 159+).
The most common nonlaboratory adverse reactions (incidence ≥20%) were viral infectious disorders, bacterial infectious disorders, infection–pathogen unspecified, pyrexia, hemorrhage, edema, abdominal pain and hypertension.
The recommended dose is 2 X 106 MSC/kg body weight per intravenous infusion given twice a week for 4 consecutive weeks for a total of 8 infusions. Infusions are administered at least 3 days apart. Treatment may be continued based on response at 28 days after initial remestemcel-L-rknd treatment.
Reference
- FDA. FDA approves remestemcel-L-rknd for steroid-refractory acute graft versus host disease in pediatric patients [press release]. Published December 18, 2024. Accessed January 31, 2025. www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-remestemcel-l-rknd-steroid-refractory-acute-graft-versus-host-disease-pediatric