Gel for the treatment of butterfly people has passed the final stage of testing
Researchers have reported the successful completion of a gene therapy trial to treat butterfly syndrome.Results from the final phase of the clinical trial showed that the gel, which contains DNA, helps heal the wounds of patients with bullous epidermolysis (butterfly syndrome) and prevent further skin damage. The new therapy is under review by the U.S. Food and Drug Administration (FDA) and could be approved as early as next year.
The B-VEC therapy gel is designed to treat a subtype of butterfly syndrome known as dystrophic bullous epidermolysis. It is caused by mutations in the COL7A1 gene. It encodes a type of collagen, specifically a rope-like protein that helps attach the outer layer of skin to the lower layer. People with dystrophic bullous epidermolysis lack this stabilization, so their skin layers rub against each other and form blisters.
The gel delivers working copies of the COL7A1 gene directly to patients' damaged skin. It contains herpes virus modified so that it cannot multiply in human cells and carries two copies of COL7A1. The researchers note that herpes is well suited to this therapy: it can evade immunity and carry large fragments of DNA.
In the trial, 28 patients were applied the gel to one of their wounds once a week for about six months, while the other wound of similar size was treated with a placebo gel. After three months, 71% of the wounds treated with B-VEC had completely healed, compared to 20% of the wounds treated with placebo. In addition, the effect persisted for up to six months, preventing the formation of new wounds.
Bullous epidermolysis or butterfly syndrome is a rare genetic disorder in which the human skin is extremely sensitive to external influences. Blisters and erosions form on it at the slightest injury or minor trauma. Currently, there are no approved treatments. Doctors only treat the symptoms as the blisters appear on the skin. This includes cleaning the skin wounds, covering them with ointments and dressings, and replacing these dressings daily.
Patients' wounds often reopen during healing and may remain open for months or even years. Chronic wounds and accumulation of scar tissue put patients at risk for life-threatening infections, limb deformities and squamous cell skin cancer.
Researchers note that the gel was applied in clinical settings during trials, but when it is approved by the FDA, it can be used on its own at home when the dressing is changed.