
An FDA advisory panel decision of 9-1 to recommend the clearance of Mesoblast Limited’s graft-versus-host-disease (GVHD) cell treatment was a harsh tease for the Australian firm.
After a period of more than four years and two instances of rejection by the FDA, Mesoblast has at long last received approval from the U.S. regulator for its first approved medication.
The FDA approved Ryoncil (remestemcel-L), a ready-to-use cell therapy for patients aged 2 months and older with acute GVHD who are unresponsive to steroid treatment.
Ryoncil is the first FDA-approved therapy using mesenchymal stromal cells (MSC) for any indication. MSCs are extracted from the bone marrow of donors who are not related; they possess the capability to develop into various cell types.
The stamp of approval came three weeks before the FDA’s projected deadline for a decision. “It gives everybody a lovely Christmas present—and a happy new year,” Mesoblast CEO Silviu Itescu, who created the firm 20 years ago, stated on a conference call.
The firm faced significant challenges after the second FDA rejection, prompting Mesoblast to implement expense reductions that included a 30% salary decrease for Itescu. However, after the approval, Mesoblast’s share price surged by 36% by Thursday morning.
The clearance mitigates the disappointment from FDA refusals in October 2020 and August 2023. In both instances, the regulator sought further effectiveness evidence. In the first comprehensive response letter, the FDA requested an additional study. Mesoblast ultimately persuaded the FDA by providing long-term statistics and further data regarding high-risk patients, in addition to consenting to perform a study for adults.
Mesoblast also revised its potency tests, which had been a persistent concern with the FDA, to demonstrate the uniformity of the identity, endurance, quality, purity, and dosing form of the medicine evaluated in the pediatric study.
In the phase 3 research, 89% of patients exhibited Grade C or Grade D seriousness of GVHD, with 70% achieving overall responses (OR) by the 28th day, including 30% who attained full responses. Mesoblast said that OR indicates survival rate in acute GVHD.
Annually, around 10,000 patients in the U.S. get an allogeneic bone marrow transplant, of whom 1,500 are children, and over 50% of these children suffer acute GVHD. Approximately half of that subgroup exhibit resistance to standard-of-care steroids.
In a statement, transplant expert Joanne Kurtzberg, M.D., described acute GVHD as a catastrophic illness with a significantly unfavorable prognosis.
Mesoblast will introduce Ryoncil in the next weeks. Itescu did not disclose its pricing but said it would be similar to other recently authorized cell and gene treatments.
Itescu said that the firm aims to broaden the authorization of Ryoncil for children and adults with inflammatory diseases. The company aspires to ultimately get approval for Revascor, a heart failure medication acquired from Angioblast 14 years earlier.