UK approves topical gene therapy for 'butterfly children'

A novel topical gene therapy for the treatment of a rare genetic skin disorder has been approved by the Medicines and Healthcare products Regulatory Agency (MHRA).

Vyjuvek (beremagene geperpavec) is the first gene therapy approved in the UK for dystrophic epidermolysis bullosa (DEB), and the second approved drug treatment for epidermolysis bullosa overall, following the 2023 approval of the non-gene therapy topical gel Filsuvez for partial-thickness wounds. DEB is a severe genetic disease caused by mutations in the COL7A1 gene, which encodes type VII collagen. This protein is responsible for holding the layers of the skin together, meaning its absence leaves patients with extremely fragile skin that blisters and scars easily, even after minor friction or contact. Because of the condition's severity and delicacy, affected children are often referred to as 'butterfly children'.

'This approval provides a new treatment option for patients living with DEB,' said Julian Beach, MHRA executive director of healthcare quality and access. 'As with all medicines, we will continue to closely monitor the safety and effectiveness of [Vyjuvek] as it is used more widely.'

Developed by Krystal Biotech, Vyjuvek is a gel that is applied directly to wounds. The therapy works by delivering functional copies of the COL7A1 gene into skin cells to support wound healing, without altering the patient's DNA. In a clinical trial involving 31 patients aged one to 44 years, 67 percent of wounds treated with the therapy were completely healed after six months, compared with 22 percent in the placebo group.

Its method of delivery differs from most existing gene therapies, which are typically administered through invasive procedures such as injections or surgery and often require specialist clinical supervision. Vyjuvek is formulated as a topical gel applied directly to wounds, making it the first approved topical gene therapy for DEB in the UK. According to the MHRA, the treatment can be administered either at home or in a healthcare setting, potentially reducing the need for hospital-based procedures for patients and their families.

In 2022, researchers at Stanford Medicine, California, published early clinical trial findings demonstrating that the treatment – then known as B-VEC – promoted wound healing in patients with DEB (see BioNews 1139). The therapy, developed in collaboration with Krystal Biotech, was later approved by the US Food and Drug Administration (FDA) in 2023, becoming the first topical gene therapy authorised for the treatment of DEB in the USA (see BioNews 1191). The European Medicines Agency subsequently reviewed and approved the treatment for use in the European Union (see BioNews 1280).

Krystal Biotech has now received UK marketing authorisation for Vyjuvek, while the National Institute for Health and Care Excellence (NICE) is currently assessing its clinical and cost effectiveness for NHS use. A decision is expected in July. Published estimates suggest the treatment could cost approximately $300,000 per patient per year, although pricing arrangements may vary. Because Vyjuvek is applied repeatedly to wounds over time, patients may require ongoing treatment depending on the severity and persistence of symptoms.