Mesoblast inches closer to graft versus host disease approval

Sept. 21, 2023

Following a Type A meeting with the FDA, Mesoblast is inching closer to securing approval for its treatment of adult and pediatric steroid-refractory acute graft versus host disease (SR-aGVHD).

In a statement this week, Mesoblast shared the latest update on remestemcel-L, also known as Ryoncil, after years of regulatory delays. During the meeting, Mesoblast presented clinical data for its improved version of the drug manufactured after 2008 to support its efficacy in pediatric patients. Currently, no approved treatments exist for this condition in children under 12. 

The data showed higher survival rates for children treated with the new drug. Still, the agency emphasized that the primary outstanding requirement for pediatric approval revolves around providing additional proof that the potency assay can guarantee the continual effectiveness of the commercial product.

To address the adult indication, the FDA expressed willingness to consider Mesoblast's proposed trial design for adults, specifically a single-arm registration trial for adults and children over 12 with SR-aGVHD who have failed other treatments. 

Ryoncil’s regulatory hurdles began on October of 2020, when the FDA issued a CRL in response to the drug's BLA. At the time, the agency recommended that Mesoblast conduct at least one additional randomized, controlled study in adults and/or children to provide further evidence of effectiveness. Mesoblast resubmitted its BLA in January 2023, including long-term follow-up data showing 50% survival over more than four years for patients treated with the drug. But in August 2023, the FDA issued another CRL to Mesoblast's resubmission, requesting more data to support marketing approval.

Despite the hiccups, Mesoblast is going all in. Just a few weeks ago, the company revealed that its CEO, Silviu Itescu, and CMO, Eric Rose, are taking a 30% salary cut to support the program.