FDA D.I.S.C.O. Burst Edition: FDA approval of Ryoncil (remestemcel-L-rknd) for steroid-refractory acute graft versus host disease in pediatric patients
Regulatory approval: On Dec 18, 2024, the FDA approved Ryoncil (remestemcel-L-rknd), an allogeneic bone marrow–derived mesenchymal stromal cell therapy, for steroid-refractory acute graft-versus-host disease (aGVHD) in pediatric patients aged ≥2 months. Efficacy was assessed in a single-arm study (MSB-GVHD001; n=54) with Grade B–D steroid-refractory aGVHD (excluding Grade B skin alone), reporting a Day 28 overall response rate of 70% and a median response duration of 54 days.
FDA approval (Dec 18, 2024): Ryoncil for pediatric steroid-refractory aGVHD
The FDA granted approval on December 18, 2024 to Ryoncil (remestemcel-L-rknd), an allogeneic bone marrow–derived mesenchymal stromal cell therapy, for steroid-refractory acute graft-versus-host disease (aGVHD) in pediatric patients 2 months of age and older. The agency noted this is the first FDA-approved mesenchymal stromal cell therapy.
Supporting evidence
Efficacy was evaluated in MSB-GVHD001, a multicenter, prospective, single-arm study enrolling 54 pediatric patients with steroid-refractory aGVHD after allogeneic hematopoietic stem cell transplantation. Eligible patients had Grade B to D steroid-refractory aGVHD, excluding Grade B skin alone (per International Blood and Marrow Transplantation Registry Severity Index Criteria).
Steroid-refractory aGVHD was defined as progression within 3 days or no improvement within 7 consecutive days of methylprednisolone. Patients who had received a second-line aGVHD therapy prior to screening were excluded.
Primary efficacy outcomes were overall response rate (ORR) at Day 28 and duration of overall response. Reported Day 28 ORR was 70%, comprising 30% complete responses and 41% partial responses. Median duration of response (from Day 28 response to progression, new systemic aGVHD therapy, or death) was 54 days.
Safety
Nonlaboratory adverse reactions reported in >20% of patients included viral infectious disorders, bacterial infectious disorders, infection (pathogen unspecified), pyrexia, hemorrhage, edema, abdominal pain, and hypertension.