Topical Gene Therapy for Dystrophic EB Shows Promise Topical Gene Therapy for Dystrophic EB Shows Promise

INDIANAPOLIS – An investigational topical treatment for dystrophic epidermolysis bullosa (DEB) known as beremagene geperpavec (B-VEC) showed durable and statistically significant improvement in complete wound healing at 3 and 6 months compared with placebo, according to results from a small phase 3 study.

DEB is a serious, ultra-rare genetic blistering disease caused by mutations in the COL7A1 gene, encoding for type VII collagen and leading to skin fragility and wounds. No approved therapies are currently available. In the study, treatment was generally well tolerated.

“B-VEC is the first treatment that has not only been shown to be effective, but the first to directly target the defect through topical application,” the study’s principal investigator, Shireen V. Guide, MD, said in an interview during a poster session at the annual meeting of the Society for Pediatric Dermatology. “It delivers type VII collagen gene therapy to these patients, which allows healing in areas that they may have had open since birth. It’s been life-changing for them.”

B-VEC is a herpes simplex virus (HSV-1)-based topical, redosable gene therapy being developed by Krystal Biotech that is designed to restore functional COL7 protein by delivering the COL7A1 gene. For the phase 3, multicenter, double-blind, placebo-controlled study known GEM-3, Guide, who practices dermatology in Rancho Santa Margarita, Calif., and her colleagues, including M. Peter Marinkovich, MD, from Stanford (Calif.) University, and Mercedes Gonzalez, MD, from the University of Miami, enrolled 31 patients aged 6 months and older with genetically confirmed DEB. Each patient had one wound treated randomized 1:1 to treatment with B-VEC once a week or placebo for 6 months. The mean age of the 31 study participants was 17 years, 65% were male, 65% were White, and 19% were Asian.

The primary endpoint was complete wound healing (defined as 100% wound closure from exact wound area at baseline, specified as skin re-epithelialization without drainage) at 6 months. Additional endpoints included complete wound healing at 3 months and change in pain associated with wound dressing changes.

At 3 months, 70% of wounds treated with B-VEC met the endpoint of complete wound healing, compared with 20% of wounds treated with placebo (P < .005). At 6 months, 67% of wounds treated with B-VEC met the endpoint of complete wound healing compared with 22% of those treated with placebo (P < .005).

Of the total wounds that closed at 3 months, 67% of wounds treated with B-VEC were also closed at 6 months, compared with 33% of those treated with placebo (P = .02). In other findings, a trend toward decreased pain was observed in wounds treated with B-VEC vs. those treated with placebo.

B-VEC was well tolerated with no treatment-related serious adverse events or discontinuations. Three patients experienced a total of five serious adverse events during the study: anemia (two events), and cellulitis, diarrhea, and positive blood culture (one event each). None were considered related to the study drug.

Guide, who is on staff at Children’s Health of Orange County, Orange, Calif., characterized B-VEC as “very novel because it’s very practical.”

To date, all treatments for DEB “have been extremely labor intensive, including skin grafting and hospitalizations. It’s a topical application that can be done in the office and potentially applied at home in the future. It’s also durable. Not only are the [treated] areas closing, but they are staying closed.”

Kalyani S. Marathe, MD, MPH, director of the dermatology division at Cincinnati Children’s Hospital, who was asked to comment on the study, said that topical application of B-VEC “allows the side effect profile to be very favorable. The results are remarkable in the amount of wound healing and reduction in pain.”

The tolerability of this medication “is crucial,” she added. “EB patients have a lot of pain from their wounds and so any treatment needs to be as painless as possible for it to be usable. I’m very excited about the next phase of studies for this medication and hopeful that it heralds new treatments for our EB patients.”

In June 2022, the manufacturer announced that it had submitted a biologics license application to the Food and Drug Administration for approval of B-VEC for the treatment of DEB, and that it anticipates submitting an application for marketing authorization with the European Medical Agency (EMA) in the second half of 2022.

Guide disclosed that she has served as an investigator for Krystal Biotech, Innovaderm Research, Arcutis, Premier Research, Paidion, and Castle Biosciences. Marathe disclosed that she has served as an adviser for Verrica, and that Cincinnati Children’s Hospital is a site for the next phase studies for B-VEC.

This article originally appeared on MDedge.com, part of the Medscape Professional Network. It was updated on 7/26/2022.