Mesoblast's Ryoncil Hits U.S. Market as First FDA-Approved MSC Therapy

Mesoblast (ASX:MSB), announced that its flagship therapy, Ryoncil® (remestemcel-L), is now available for purchase in the United States. The launch marks a milestone, as Ryoncil is the first mesenchymal stromal cell (MSC) therapy approved by the FDA for any indication.

Ryoncil is aimed at paediatric patients aged two months and older suffering from steroid-refractory acute graft-versus-host disease (SR-aGvHD), a severe condition in which traditional corticosteroids don't work as a treatment option. And it's associated with a very high mortality rate.

Ryoncil to be administered to GVHD paediatric patients who are unable to tolerate corticosteroids, known as steroid refractory.

The treatment plan involves intravenous infusions given twice a week over four weeks.

To help patients get access, Mesoblast has rolled out the MyMesoblast™ hub, offering support with insurance, financial assistance, and ordering.

The company has already secured favourable medical policies from nine commercial insurers, covering around 37 million people in the U.S. Mesoblast is also working on joining the National Drug Rebate Agreement with Medicaid.

Clinical Trials and FDA Approval Process

Ryoncil’s approval was based onclinical trials demonstrating its efficacy and safety in paediatric patients. In its pivotal Phase 3 trial, the therapy significantly improved survival rates compared to historical controls, with a notable proportion of patients achieving a complete response by day 28. The study included patients who had failed to respond to steroid treatment, highlighting the urgent need for effective therapies in this population. The FDA approval for the drug was received on December 18, 2024.

A Fast-Tracked Commercial Rollout

Getting Ryoncil approved and launched in under three months is a big win for Mesoblast, showing how quickly it can move in the fast-growing cell therapy space. “Making Ryoncil available so quickly is a big step in our mission to deliver cutting-edge cellular treatments to patients who need them most,” said Dr. Silviu Itescu, CEO of Mesoblast. “This reflects our team’s dedication and the urgency to help children and families facing this devastating disease.”

Mesoblast said its working with more insurers to expand coverage and expects additional approvals soon.

What’s Next for Mesoblast?

Ryoncil’s U.S. launch is its starting however it is pushing for broader regulatory approvals worldwide. Mesoblast has made commercial partnerships in Japan, Europe, and China.

Beyond SR-aGvHD, Ryoncil is being developed for adult indications and biologic-resistant inflammatory bowel disease. Meanwhile, its second key asset, rexlemestrocel-L, is being tested for heart failure and chronic low back pain.