FDA Approves First MSC Therapy to Treat GvHD

January 02, 2025

The U.S. Food and Drug Administration approved the first mesenchymal stromal cell (MSC) therapy, remestemcel-L-rknd, to treat steroid-refractory acute graft-versus-host disease (SR-aGVHD) in pediatric patients aged 2 months and older. Marketed as Ryoncil by Mesoblast, Inc., remestemcel received FDA’s fast track, orphan drug and priority review designations.

FDA based its approval on findings from a single-arm study of 54 pediatric patients with SR-aGVHD after allogeneic hematopoietic stem cell transplantation (HSCT). The study’s primary efficacy endpoints were the overall response rate (ORR) at day 28 and the duration of the response.

At day 28, the ORR was 70% (95% confidence interval [CI]: 56.4, 82.0), including a complete response (CR) rate of 30% (95% CI) and a partial response rate of 41% (95% CI). The median duration of response — measured from day 28 to progression, new systemic therapy or mortality — was 54 days.

The most frequently reported nonlaboratory adverse reactions included viral and bacterial infections, unspecified pathogen infections, fever, bleeding, swelling, abdominal pain and hypertension.