FDA Approves Mesoblast's Ryoncil, Pioneering First MSC Therapy for GVHD After Rejections

Mesoblast Limited has secured a landmark FDA approval for Ryoncil (remestemcel-L), making it the first mesenchymal stromal cell (MSC) therapy authorized in the United States for treating steroid-refractory acute graft-versus-host disease (GVHD) in patients as young as two months old[1][2]. GVHD is a severe complication following allogeneic stem cell transplantation, with donor cells attacking the host and causing serious symptoms like rash, diarrhea, and itching[2]. Ryoncil, made from MSCs derived from unrelated donors, shows immunomodulatory activity that helps mitigate inflammation and improve clinical outcomes in GVHD patients[1][2]. This approval follows considerable regulatory challenges, having faced rejections in 2020 and 2023, but was supported by a Phase III trial demonstrating significant efficacy in pediatric patients[2].