FDA Panel Votes Overwhelmingly In Support Of Mesoblast's Allogeneic Cell Therapy

(RTTNews) - Mesoblast Limited (MESO) gave investors a pleasant surprise today, securing the FDA panel's overwhelming recommendation for its lead asset Ryoncil, proposed for pediatric steroid-refractory acute graft versus host disease. Not many would have expected Ryoncil to garner the advisory committee's positive vote after the release of the FDA briefing documents on August 10 - so much so that the company's stock price lost nearly 35 percent of its value that day.

Ryoncil (remestemcel-L) contains culture-expanded mesenchymal stem cells derived from the bone marrow of an unrelated donor and is designed to be administered to patients in a series of intravenous infusions.

What is acute graft versus host disease?

Acute graft versus host disease is a potentially life-threatening complication of an allogeneic bone marrow transplant wherein the donor's immune cells (T cells) mistake the healthy cells of the recipient, i.e. patient, as foreign and start attacking them.

According to the Center for International Blood and Marrow Transplant Research, there are roughly 30,000 allogeneic bone marrow transplants globally per year for diseases including hematological cancers, with 25% of all cases in the pediatric population. Nearly 50% of allogeneic BMT patients develop aGVHD. Systemic high-dose steroids can control acute graft versus host disease in many patients. But in some patients, the acute GVHD is refractory to this mainstay of treatment and it is known as steroid-refractory aGVHD.

Currently, there are no products approved in the United States for the treatment of steroid-refractory aGVHD in children under 12, and off-label options have demonstrated mixed efficacy with high toxicity.

AdCom Vote

The FDA's Oncologic Drugs Advisory Committee, which reviewed Ryoncil today, voted 9 to 1 recommending its approval.

Final Decision

Ryoncil is under Priority Review by the FDA and a final decision is expected on September 30, 2020. The FDA usually follows the recommendations of its advisory panels, although it is not required to do so.

If approved, Mesoblast plans to launch Ryoncil in the United States this year.

Ryoncil in Japan

Ryoncil is already marketed in Japan for the treatment of children and adults with acute Graft Versus Host Disease, under the brand name Temcell, by Mesoblast's licensee JCR Pharmaceuticals Co., Ltd.

Mesoblast receives royalty revenues from the sales of Temcell in Japan. For the nine months ended March 31, 2020, Mesoblast's commercialization revenue from sales of Temcell was US$5.9 million compared to US$3.3 million in the year-ago period.

MESO closed Wednesday's trading at $11.81. Trading in MESO was halted on Thursday, pending the FDA panel review.