# Efficacy and Safety of the Topical Gene Therapy Beremagene Geperpavec‐svdt (B‐VEC) in an Open‐Label Study of Japanese Subjects With Dystrophic Epidermolysis Bullosa

## TL;DR

A gene therapy called B-VEC was tested in Japan for treating dystrophic epidermolysis bullosa, showing effective wound healing and good safety over a year.

## Contribution

This study confirms the efficacy and safety of B-VEC in Japanese patients with dystrophic epidermolysis bullosa.

## Key findings

- 100% of primary wounds showed complete closure at 6 months, and 75% remained closed at 9 and 12 months.
- Patient-reported outcomes showed reduced pain and improved quality of life.
- All adverse events were mild or moderate and unrelated to treatment.

## Abstract

Dystrophic epidermolysis bullosa (DEB) patients have pathogenic variants in COL7A1, leading to skin fragility, blistering, and scarring. Beremagene geperpavec‐svdt (B‐VEC) is a replication‐defective herpes simplex virus type 1 (HSV‐1)‐based gene therapy vector administered topically to deliver functional COL7A1 to DEB wounds. In a United States (US) Phase 3 study, B‐VEC significantly improved wound healing at 3 and 6 months compared to placebo, and in a US open‐label extension (OLE) study, weekly B‐VEC administration was well tolerated for up to 112 weeks. The present study was conducted to confirm the efficacy and safety of B‐VEC in a cohort of Japanese DEB patients receiving weekly B‐VEC treatment (4.0 × 109 plaque forming units (PFU)/mL) for 52 weeks. Wound healing assessments were conducted on a Primary Wound at visits corresponding to Month 3 (the secondary efficacy endpoint), Month 6 (the primary efficacy endpoint), and Months 9 and 12 (exploratory durability endpoints). Patient‐reported outcome (PRO) measures were employed as exploratory analyses of efficacy. Safety was assessed by adverse events (AEs) and clinical laboratory tests. Five subjects enrolled in the study; one discontinued due to challenges with following wound dressing disposal guidelines. The study met its primary and secondary efficacy endpoints with 100% of Primary Wounds demonstrating complete closure at Months 6 and 3, respectively; durable complete closure was observed in 3/4 (75%) of wounds at Months 9 and 12. PROs indicated decreased pain, improvement in skin‐specific quality of life, and moderate to high treatment satisfaction. Four subjects reported ten AEs; all were assessed as mild or moderate in severity and unrelated to treatment by Investigators. None were serious, severe, or led to treatment/study discontinuation. The results of the Japan OLE study are in agreement with the US Phase 3 and OLE studies, demonstrating the efficacy and safety of B‐VEC in Japanese patients with DEB.

Trial Registration: Japan Registry of Clinical Trials: jRCT2053230075