On May 19, 2023, the U.S. Food and Drug Administration (FDA) announced the approval of Vyjuvek™ for the treatment of wounds associated with dystrophic epidermolysis bullosa (DEB) in adult and pediatric patients 6 months and older. DEB is a rare genetic disorder that results from the mutation of a gene involved in the production of COL7A1, a protein essential in strengthening and stabilizing layers of the skin and nails. When inadequate amounts of COL7A1 are present, there may be separation between the layers of the skin, causing blisters and wounds. Symptoms often appear at birth and can affect individuals at various levels of severity. Patients with dominant DEB (DDEB) may experience mild blistering of the knees, elbows, hands and feet while those with recessive DEB (RDEB) may experience much more blistering. This blistering can become debilitating and extremely painful, leading to disfigurement, vision loss, other medical complications and potentially death.
Vyjuvek™ is a gene therapy that is applied to a patient’s wounds once weekly by a health care professional. It uses a genetically modified herpes-simplex virus (HSV) to bring working copies of COL7A1 genes to blisters and wounds. COL7A1 proteins are produced at the site, holding the layers of the skin together. Vyjuvek™ was studied in a randomized, double-blinded, placebo-controlled clinical trial of 31 individuals with DEB. Patient ages ranged from 1 to 44 years. All but one participant presented with the RDEB type. Efficacy was measured by comparing the proportion of complete wound closure between patients treated with Vyjuvek™ versus the placebo group. After 24 weeks, 65% of participants treated with Vyjuvek™ had complete wound closure, compared to only 26% of those participants receiving placebo. The most reported adverse reactions were redness, rash, itching, chills, cough and runny nose. Vyjuvek™ received Orphan Drug, Fast Track, Priority Review and Regenerative Medicine Advanced Therapy designations. It also received an FDA Rare Pediatric Disease Priority Review Voucher.