Burn patients with the most severe wounds need an autograft: the removal of that person’s own healthy skin, which is then transplanted to the burn site. There is now a regenerative medicine alternative. The FDA has approved an engineered skin product that is applied to the wound and used as a scaffold for a patient’s skin cells to grow.
The government’s decision for the product, called StrataGraft, covers the treatment of adults whose burn injury still leaves some of the deep layers of the skin intact. StrataGraft was developed by Mallinckrodt Pharmaceuticals, based in Dublin, Ireland, and is designed to reduce the need for autografts, a procedure that can create additional complications and also leave a patient with a different wound healing process.
The FDA based its approval on the results of two clinical studies that included a total of 101 adults with deep burns, partial thickness, caused by a heat source such as fire, hot surfaces, or boiling water. In both studies, each patient served as a test subject and a control. Two burn wounds of comparable area and depth were identified in each patient. These wounds were randomly selected to receive treatment with StrataGraft or Autograft – each patient received both treatments.
The main objective of the study was to measure the percentage of StrataGraft treatment sites that achieved complete wound closure, thereby reducing the need for additional autograft treatment. According to one of the studies recently published in Burns magazine, treatment with StrataGraft eliminated the need for tissue harvesting for an autograft in all but three of 71 patients. After three months, 92% of the StrataGraft treated wounds were closed.
StrataGraft is made from two types of human skin cells, keratinocytes and dermal fibroblasts. These cells grow together to form a bilayered construct or scaffold. The 100 square centimeter product is for topical use only. The size of the StrataGraft applied should match the wound surface area as per the prescribing information. The constructs can be tailored to the wound size.
Because StrataGraft is made from cells from human donors as well as some animal materials, the FDA warns that the product carries some risk of transmitting infectious diseases or pathogens. No such problems were reported in clinical studies. The patients’ immune systems did not reject StrataGraft as foreign, and no infection was reported. The most common treatment-related adverse reaction was itching, which was reported in 11 patients. Other side effects included blisters, scarring, and slower healing at the treatment site.
StrataGraft was originally developed by Stratatech, a Madison, Wisconsin-based startup whose science stems from research at the University of Wisconsin. Mallinckrodt acquired Stratatech in 2017 for approximately $ 76 million upfront and an additional $ 121 million in connection with milestone payments.
StrataGraft was among the first products to receive FDA approval under the name Regenerative Medicine Advanced Therapy (RMAT), part of the 21st Century Cures Act, which aims to promote the development of novel therapies in regenerative medicine. Bristol Myers Squibb received its first RMAT approval in February for its Breyanzi cancer cell therapy.
Stratatech’s research was supported by the United States Department of Advanced Research and Development for Biomedicine, which is interested in the product as a tool for a mass accident event that requires the treatment of burns. Patients with conventional burns would also benefit, said Steven Romano, Mallinckrodt’s chief scientific officer, in a corporate video accompanying the announcement of the company’s regulatory decision.
“StrataGraft’s approval is an important milestone for burn medicine,” said Romano. “In the past two to three decades, there has been little progress in treating the type of burn for which StrataGraft is indicated. Burn surgeons now have a new treatment that will help reduce the need for an autotransplant. “
Photo by Mallinckrodt Pharmaceuticals