Biotech companies are getting creative with how they deliver DNA fixes into people’s bodies. Last Friday, the US Food and Drug Administration (“FDA”) approved sales of the first gene therapy that is an ointment directly applied to the body – as well as the first intended to be used on the same person repeatedly.
The gene therapy treatment, called Vyjuvek, was developed by the Pittsburgh startup Krystal Biotech and is approved for treating anyone older than six months of age with this specific form of epidermolysis bullosa. It introduces a missing gene to skin cells so they can make collagen. It’s already helping people with dystrophic epidermolysis bullosa, a rare inherited disease that makes skin incredibly fragile. The topical ointment helps to heal the disease’s chronic, blistering wounds, while an eyedrop version can prevent scar tissue from building up in their eyeballs and improve their vision.
The gene treatment is unusual as it doesn’t involve injection or altering immune cells outside the body. Gene delivery usually involves placing a DNA strand inside a virus naturally equipped to enter a human cell and drop off the gene. In Krystal’s case, the company is using herpes simplex virus, the same one that causes cold sores. HSV-1, as the virus is known, is very common which means it is fairly safe, but it also has the advantage that it naturally evades the immune system.
Since 2017, the FDA has approved five gene therapies for rare inherited diseases – Krystal’s will make it six – and several others for treating blood cancer. But those earlier treatments are all delivered by injection or by altering immune cells outside the body. By formulating gene therapy into an ointment that’s rubbed on, Krystal has achieved what its CEO, Krish Krishnan, has called “a simple, convenient, patient-friendly way to provide the missing gene to these patients.”
The novel delivery strategy is already being studied to treat other rare skin conditions. An inhaled gene therapy to treat cystic fibrosis is also being explored. Krystal has already demonstrated the versatility of its approach by developing an eye-drop version of Vyjuvek at the request of an ophthalmologist.
Gene replacement for skin may also have lucrative future uses in cosmetics. A subsidiary established by Krystal has begun testing a version of Vyjuvek on volunteers to try to reverse crow’s feet and other wrinkles caused when people’s bodies make less collagen as they age.
Krystal Biotech is among dozens of companies seeking innovative ways to deliver replacement genes to more locations in the human body, including hard-to-reach organs like the brain.