FDA approval for the first-ever redosable gene therapy, Vyjuvek, for the treatment of dystrophic epidermolysis bullosa.- Krystal Biotech

Vyjuvek is the first-ever redosable gene therapy and the first and only medicine approved by the FDA for the treatment of DEB, both recessive and dominant, that can be administered by a healthcare professional in either a healthcare professional setting or in the home.

DEB is a rare and serious disease that affects the skin and mucosal tissues caused by one or more mutations in the COL7A1 gene. The COL7A1 gene is responsible for the production of functional COL7 protein that forms anchoring fibrils necessary to bind the dermis (inner layer of the skin) to the epidermis (outer layer of the skin). The lack of functional anchoring fibrils in DEB patients leads to extremely fragile skin that blisters and tears with minor friction or trauma. DEB patients suffer from open wounds, which lead to recurrent skin infections and fibrosis that can cause fusion of fingers and toes, and ultimately increase the risk of developing an aggressive form of skin cancer.

The FDA approval of Vyjuvek is based on two clinical studies. The GEM-1/2 trial was an intra-patient, open label, single center, randomized, placebo-controlled study showing that repeat topical applications of Vyjuvek were associated with durable wound closure, full-length cutaneous COL7 expression, and anchoring fibril assembly with minimal reported adverse events. The GEM-3 trial was an intra-patient, double-blinded, multi-center, randomized, placebo-controlled study that met both its primary endpoint of complete wound healing at six months and its key secondary endpoint of complete wound healing at three months. Vyjuvek was well tolerated with no drug-related serious adverse events or discontinuations due to treatment-related events.

“Data from GEM-1/2 trial and our GEM-3 trial, published in Nature Medicine and the New England Journal of Medicine, respectively, demonstrated the strength of both studies showing that Vyjuvek safely and effectively improved wound healing,” said Suma Krishnan, President, Research & Development, Krystal Biotech, Inc. “For so many years, all we have been able to offer DEB patients was palliative care, but now, based on the strength of the Company’s clinical trial data, there is a safe and effective FDA approved treatment.”

See-"In vivo topical gene therapy for recessive dystrophic epidermolysis bullosa: a phase 1 and 2 trial"-Irina Gurevich, Pooja Agarwal, PeiPei Zhang,John A. Dolorito, et al. Articles https://doi.org/10.1038/s41591-022-01737-y.

See- "Trial of Beremagene Geperpavec (B-VEC) for Dystrophic Epidermolysis Bullosa". Shireen V. Guide, M.D., Mercedes E. Gonzalez, M.D., Brittani Agostini. et al. N Engl J Med 2022;387:2211-9. DOI: 10.1056/NEJMoa2206663.