Topical gene therapy for DEB promising
A topical gene therapy has been shown to be effective for wound healing in patients with dystrophic epidermolysis bullosa (DEB). The study was published in the Dec. 15, 2022 edition of The New England Journal of Medicine.
Patients with DEB have genetic mutations in COL7A1, which encodes type VII collagen, preventing them from making the collagen VII protein. This leads to skin shear and blistering, ulcerative, and painful wounds.
The beremagene geperpavec (B-VEC) gel used in this study, developed by researchers at California’s Stanford Medicine, contains a modified herpes simplex virus that delivers a copy of the collagen VII gene to the skin. This creates the missing protein and stabilizes the structure of the skin.
This small Phase 3 double-blind, placebo-controlled clinical trial involved 31 patients 18 years or younger with genetically confirmed DEB. For each patient, a primary wound pair was selected, with the wounds matched according to size, region, and appearance. The wounds within each pair were randomly assigned in a 1:1 ratio to receive weekly application of B-VEC or placebo for 26 weeks during wound dressing changes. Secondary endpoints included assessment of complete wound healing at three months and the change from baseline to weeks 22, 24, and 26 in pain severity during bandage changes.
Results showed that 67% of the wounds were completely healed at six months, compared to 22% of those treated with placebo (difference, 46 percentage points; 95% confidence interval [CI], 24 to 68; p=0.002). Complete wound healing at three months occurred in 71% of the wounds treated with B-VEC compared to 20% of those with placebo (difference, 51 percentage points; 95% CI, 29 to 73; p<0.001). The mean change from baseline to week 22 in pain severity during wound-dressing changes was −0.88 with B-VEC and −0.71 with placebo (adjusted least-squares mean difference, −0.61; 95% CI, −1.10 to −0.13). The researchers note that similar mean changes were observed at weeks 24 and 26.
“We saw no inflammation, significant side effects or immune neutralization of the drug, even with repeated administration of the gel over the six months of the trial period,” senior author Dr. Peter Marinkovich said in a press release. He is the director of Stanford Medicine’s Blistering Disease Clinic.
Pruritus and mild systemic side effects such as chills were observed. The researchers say longer trials with more participants are warranted.