Managing dystrophic epidermolysis bullosa (DEB) can be difficult. DEB is a rare genetic condition which causes fragile, easily blistered skin. There are multiple DEB subtypes with their own inheritance patterns and symptom severity. Regardless of the subtype, doctors have struggled to find interventions for patients and their families to stop the blistering from happening. While bandaging helped protect against infection, finding an effective treatment option has been a focus of research over the last few years.
As shared in BioPharmaDive, that research was ultimately fruitful and culminated in the development and subsequent approval of Vyjuvek, a therapy developed by Krystal Biotech. This treatment is approved for affected individuals who are six months old or older. A topical therapy, Vyjuvek is described as:
a herpes-simplex virus type 1 (HSV-1) vector-based gene therapy indicated for the treatment of wounds in patients 6 months of age and older with dystrophic epidermolysis bullosa with mutation(s) in the collagen type VII alpha 1 chain (COL7A1) gene.
Applying Vyjuvek helps to promote wound healing. Its approval was supported by data from a Phase 3 clinical study. Study findings published in the New England Journal of Medicine show that after 3 months of treatment, 71% of wounds treated with Vyjuvek saw complete wound healing (compared to just 20% of those using the placebo). Vyjuvek also lessened pain.
The Basics of Dystrophic Epidermolysis Bullosa (DEB)
COL7A1 gene mutations cause dystrophic epidermolysis bullosa. Normally, this gene plays a role in type VII collagen subunits; these play a role in how strong and structured your connective tissue is. These mutations cause deficient or absent type VII collagen. As a result, the skin becomes incredibly fragile. Recessive dystrophic epidermolysis bullosa severe generalized (RDEB-sev gen) and RDEB generalized (RDEB-gen) are inherited in an autosomal recessive pattern. This means that people must inherit one defective gene from each parent. Dominant dystrophic epidermolysis bullosa (DDEB) is inherited in an autosomal dominant pattern, so you only need to inherit one mutated gene.
Symptoms vary based on specific DEB subtype. For example, RDEB-sev gen (the classic and most severe DEB subtype) is often characterized by widespread blistering and missing skin at birth. The blisters can even form in mucous membranes. In this subtype, the blisters often leave scarring; if in the digestive tract, that can make it difficult to eat. People with RDEB-sev gen also may experience malnutrition, fused skin between the fingers and toes, joint deformities, vision loss, lost fingernails and toenails. Other forms of RDEB often cause blistering on the knees, hands, elbows, and feet. This form is characterized by scarring in blistered areas, as well as nail malformations. Finally, in DDEB, symptoms and blistering are often milder. In some cases, abnormal nails are the only sign.
