An Off-the-Shelf Cell Therapy to Calm Cytokine Storms

This episode of The BioReport explores Mesoblast's groundbreaking FDA-approved cell therapy, RyanCell, the first allogeneic mesenchymal stromal cell therapy approved in the U.S. for treating steroid-refractory acute graft-versus-host disease (GVHD) in pediatric patients. CEO Silvio Tescu discusses the science behind these immunomodulatory cells—derived from healthy donors, expanded at scale, and capable of calming cytokine storms without provoking immune rejection. The therapy has demonstrated remarkable efficacy, with 70% responder rates and 5-year survival in children, a dramatic improvement over historical mortality rates of 70-80%. Beyond GVHD, Mesoblast is expanding into larger indications like inflammatory heart disease and degenerative disc disease, where early data shows significant reductions in pain and cardiovascular events. The company has also developed a second-generation therapy, Rexlimextrocel, engineered for greater potency and targeted delivery. Despite an initial FDA advisory panel rejection, Mesoblast’s persistence and rigorous manufacturing validation led to approval, offering key lessons in regulatory resilience. The therapy is now commercially adopted with strong payer coverage and high gross margins, positioning it as a scalable, off-the-shelf solution for severe, treatment-resistant inflammatory conditions.