2 years after rejection, Mesoblast sees long-term cell therapy survival data key to FDA resubmission

 Mesoblast has established another pillar of the evidence it thinks will support a second run at the FDA for its cell therapy, touting long-term data from the study at the center of its rejected application as the key to its planned resubmission.

Two years ago, the FDA issued a complete response letter for Mesoblast’s request for approval of its allogeneic cell therapy remestemcel-L in children with steroid-resistant graft-versus-host disease (GVHD). The FDA knocked back the filing, despite its advisory committee voting that the data supported the efficacy, after identifying a need for “at least one” additional randomized clinical trial.

Mesoblast recently went back to the FDA clutching information on clinical and potency assay items that the agency flagged up in its 2020 rejection. Now, the Australian biotech has presented data it hopes will support “a successful regulatory outcome for remestemcel-L during the first half of the upcoming calendar year.”

The data come from the phase 3 trial that formed the basis of the original filing for approval. While the primary endpoint of the study looked at the response rate after 28 days, Mesoblast continued to track the participants and now has four years of follow-up. 

Overall survival was 63% at one year, 51% at two years and 49% at four years. Median survival clocked in a “two to three years,” according to Mesoblast. The company compared its survival data favorably to results for Incyte’s Jakafi, although differences between the studies raise questions about the validity of the comparison.

The validity of cross-trial comparisons was a topic of debate late time Mesoblast sought approval, with the FDA noting the “absence of appropriate concurrent or historical controls” at the time. FDA officials questioned whether “the one statistically-positive single-arm trial, in a landscape of the multiple negative clinical trials for the treatment of aGVHD, including randomized controlled trials, is adequate to allow one to conclude that remestemcel-L is effective.”

https://www.fiercebiotech.com/biotech/2-years-after-rejection-mesoblast-touts-long-term-cell-therapy-survival-data-key-fda