Topical Gene Therapy Effective in Treating Debilitating Eye Condition
- Bascom Palmer Eye Institute researchers have shown that the gene therapy B-VEC effectively treats dystrophic epidermolysis bullosa.
- This is the first time topical gene therapy has been used in the eye.
- A pediatric patient who had lost most of his vision responded well to the B-VEC treatment and now has normal vision.
Researchers at the University of Miami Miller School of Medicine’s Bascom Palmer Eye Institute have shown that a new gene therapy, B-VEC (VYJUVEK™), is effectively treating severe eye issues in a pediatric patient with a rare disease, dystrophic epidermolysis bullosa (DEB), that also affects skin and other organs.
This is the first time topical gene therapy has been used in the eye. The case study was published on February 7 in the New England Journal of Medicine.
“I had been treating this patient for several years, and there was little we could do for him,” said Alfonso L. Sabater, M.D., Ph.D., associate professor of clinical ophthalmology at the Miller School and director of Bascom Palmer’s Corneal Innovation Lab. “We tried surgery, platelet-rich plasma and other approaches, but nothing worked, until now.”
“He Couldn’t See Much at All”
Caused by a mutation in the COL7A1 gene, DEB impairs type VII collagen production and can lead to severe blistering and scar formation on skin, inside the mouth and stomach and on the eyes.
The patient, now 14, had been coming to Bascom Palmer for DEB treatment since he was 4. With blisters on his skin and eyes, and other issues, he had lost significant vision and had an associated condition, symblepharon, in which the eyelid and eye stuck together.
“He couldn’t see much at all,” said Dr. Sabater, who has been treating the patient since he was 8. “Every time we conducted surgery, the scar tissue would come back, and it was just getting worse. I told him, ‘Let’s wait until we can find something that can fix the underlying genetic problem.’”
Treatment Contains Functional COL7A1 Genes
B-VEC was designed to do just that. The topical gel contains re-engineered herpes viruses armed with functional COL7A1 genes. When B-VEC is applied, the viruses deliver their genetic payload, generating more normal type VII collagen production.
As soon as he learned about B-VEC, Dr. Sabater recognized its potential to help his patient and possibly others. However, before that could happen, they would have to conduct preclinical research to prove the therapy would be effective in eyes.
The team worked closely with B-VEC developer Krystal Biotech to reformulate the therapy as an eyedrop and conduct the studies. Because the therapy was already in clinical trials for skin blistering, it was relatively easy to gain expanded access to treat DEB patients with eye issues.
Once they received the go-ahead from the Food & Drug Administration, the team began administering B-VEC to the patient, with excellent results.
“The difference this time was that, when we started applying the gene therapy, the scar tissue was not coming back after surgery,” said Dr. Sabater. “It’s been a year and a half, and it hasn’t grown back. In the past, it would have come back in three months. Now that he can see, he no longer needs his mom to help him with his homework and he can watch TV and play video games. He has normal vision.”