Opal Sandy, who was born completely deaf because of a rare genetic condition and can now hear ... [+]
A toddler has been able to hear for the first time after being treated with a pioneering gene therapy for deafness.
The girl, Opal Sandy from the U.K., according to the BBC, has a hereditary mutation in a gene called otoferlin, an important part of allowing people to sense sound in the cells of the ear. Deafness caused by otoferlin mutations is very rare, accounting for less than 1% of all people who are deaf. Only 30 to 50 people a year in the United States are diagnosed with otoferlin-related deafness.
"This is a relatively rare form of deafness," said Dr. Lawrence Lustig, M.D., chair of Columbia University’s Department of Otolaryngology, an investigator on the clinical trial who was presenting the work at the American Society for Gene and Cell Therapy annual meeting in Baltimore. "But because we have good cellular preservation in the cochlea, it gives us a wonderful opportunity to intervene in early childhood to try to rescue hearing loss before degeneration occurs.”
The CHORD study is run by biotechnology company Regeneron in collaboration with physicians at academic hospitals in the U.K., Spain and the U.S. The experimental therapy, DB-OTO, received Orphan Drug, Rare Pediatric Disease and Fast Track Designations from the U.S. Food and Drug Administration.
The therapy uses a genetically modified virus injected into a small area of the ear to fix the faulty gene.
Sandy was given the therapy when she was 10 months old and monitored for side-effects. She experienced only mild ones, many of which were considered to be unrelated to the injected therapy. She was also given various hearing tests, and she showed signs of improvement just four weeks after the therapy. After three months, the child showed remarkable improvement. Her hearing in the treated ear was considered to be normal for all typical conversation tone sound frequencies six months after the therapy.
"At 24 weeks, she has essentially normal hearing," said Lustig, noting that at higher frequencies of sound the child is still considered to have some mild loss of hearing ability.
Dr. Lustig also talked about a second patient, a 4-year-old male who received the therapy more recently and is showing similar, early signs of improvement in his hearing six weeks after the treatment.
A new gene therapy has restored hearing in a young girl with hereditary deafness. Stock photo.
"We feel this is going to be a viable treatment for genetic deafness, for patients with otoferin-related hearing loss," said Lustig in the presentation. "With the DB-OTO CHORD trial now enrolling participants in sites across the U.S. and Europe, we’re part of the beginning of a new era of gene therapy research that looks to create treatment options that address the root cause of profound genetic deafness.”
