FDA approves Mallinckrodt's regenerative skin burn graft after 4-month delay

Following months of regulatory delays in the wake of the COVID-19 pandemic, the FDA has finally approved Mallinckrodt’s regenerative tissue graft for the treatment of deep partial-thickness burns, also referred to as second-degree burns.

StrataGraft is made from two kinds of human skin cells grown together to provide a layered scaffold that gives the patient’s own skin a place to grow as the body heals from the injury.

The goal of the treatment—which previously secured a priority review plus the agency’s orphan drug and regenerative medicine advanced therapy designations—is to help reduce the amount of the patient’s own healthy skin needed for a surgical graft. The self-donation technique creates a secondary wound as a result of the graft.

“Serious burns can be an incredibly difficult injury to treat and can adversely affect more than just the skin,” said Peter Marks, M.D., Ph.D., director of the FDA’s Center for Biologics Evaluation and Research, who called the StrataGraft a novel approach.

“The goal of burn management is to help the patient return to the highest level of functionality and independence possible, while improving the overall quality of life,” Marks added in an agency statement.

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This past February, Mallinckrodt said it would have to wait longer than planned for the FDA to complete its review of the StrataGraft manufacturing plant as agency inspectors worked through a backlog of manufacturing sites following COVID-19 lockdowns and travel restrictions.

At the time, the company said it was moving forward with studies of StrataGraft under an expanded access program. Meanwhile, a report by the Government Accountability Office noted that the FDA was unable to complete more than 1,000 inspections planned for 2020.

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Early on in StrataGraft’s development, the human keratinocytes—the most common cell of the skin’s epidermal layer—were grown in combination with mouse cells. However, mouse cells are no longer used in the manufacturing process, and clinical studies produced no reports of graft rejection.

Meanwhile, because the graft contains human donor cells, there is a risk of transmission of infectious diseases, the FDA said. No cases with StrataGraft have been reported.

Mallinckrodt’s Stratatech subsidiary is also studying the topical graft in the severe, full thickness injuries known as third-degree burns. And the product previously received financial support from the U.S. Biomedical Advanced Research and Development Authority, which cited its potential uses following a radiological or nuclear explosion.

The company is also in the early stages of developing and testing a genetically engineered human skin substitute, known as ExpressGraft, for chronic, non-healing wounds and diabetic foot ulcers.