FDA Approves First Gene Therapy for Genetic Deafness. Regeneron Is Giving It Away Free.

The Food and Drug Administration approved on Wednesday the first gene therapy for genetic deafness — a single injection that restored meaningful hearing in 80% of treated patients in clinical trials — and the company that developed it says the drug won’t cost eligible patients in the United States anything.

Regeneron’s Otarmeni targets a rare inherited form of hearing loss caused by mutations in the OTOF gene. That gene provides the blueprint for a protein called otoferlin, which the inner ear requires to transmit sound signals to the brain. Children born with two defective copies hear nothing from birth.

Results from the CHORD clinical trial showed 16 of 20 treated participants — infants and children from 10 months to 16 years old — achieved hearing thresholds that typically eliminate the need for cochlear implants by week 24. About 42 percent reached hearing levels considered fully normal, including the ability to hear whispers. Among the initial cohort published in the New England Journal of Medicine, nine of 12 children stopped using cochlear implants after treatment.

“This unprecedented breakthrough in gene therapy has already proven to be life-changing for many of the children in our clinical trial and their families,” said George Yancopoulos, Regeneron’s co-chair and chief scientific officer.

One injection, one chance

Otarmeni is delivered as a single dose per ear. A trained surgeon infuses it directly into the cochlea under general anesthesia, using the same basic approach as cochlear implantation. Unlike a cochlear implant, which uses an external device to bypass damaged inner hair cells, Otarmeni delivers a functioning copy of the OTOF gene to those cells so they can begin producing otoferlin on their own.

The therapy required an unusual engineering solution. The OTOF gene is too large to fit in a single standard viral delivery vehicle, so Regeneron built a dual-vector system that splits the gene across two carriers and reassembles it inside the target cells. Otarmeni is the first dual-AAV gene therapy the FDA has ever approved.

The approval is accelerated rather than full. Continued authorization depends on results from the ongoing confirmatory portion of the CHORD trial. Otarmeni is the second therapy this spring to clear the FDA’s National Priority Voucher pilot program; the agency is also using the program to accelerate access to the experimental pancreatic-cancer drug daraxonrasib, authorizing an expanded-access protocol within 48 hours of the manufacturer’s request.

“The FDA approval of Otarmeni signals a new era in the treatment of genetic forms of hearing loss, where reinstating 24/7 natural hearing is now possible,” said Dr. A. Eliot Shearer, a pediatric otolaryngologist at Boston Children’s Hospital who served as a CHORD trial investigator.

A drug priced at zero

Regeneron announced it will provide Otarmeni at no charge for the drug itself to clinically eligible patients in the United States. That pledge does not extend to the surgical administration procedure, which requires an operating room, general anesthesia, and post-procedure follow-up care whose costs vary by institution and payer.

About 50 newborns in the United States are diagnosed with OTOF-related hearing loss each year. At that scale, the patient population is too small to support premium rare-disease pricing — and Regeneron has no near-term competition in the indication.

One mother whose son was enrolled in the CHORD trial described the first time he heard her voice after treatment: “That was like the most surreal moment a mother can feel.”

The fastest approval of its kind

The FDA cleared Otarmeni 61 days after Regeneron filed its biologics license application, tied for the fastest such approval in modern FDA history. The review proceeded under the Commissioner’s National Priority Voucher program, a pilot initiative designed to accelerate consideration of treatments for rare diseases with unmet medical need. Otarmeni is the sixth drug approved under the program and the first gene therapy.

FDA Commissioner Marty Makary said the timeline was a proof of concept as much as an approval. “Today’s approval is a significant milestone in the treatment of genetic hearing loss,” he said. “Through the national priority voucher pilot program, the agency is accelerating therapies for rare diseases with unmet medical needs while proving we can successfully review even the most complex submissions — such as novel dual vector gene therapies and combination products requiring coordination across multiple offices and centers — in significantly shortened timeframes.”

Otarmeni is also Regeneron’s first approved genetic medicine, and the first gene therapy the FDA has cleared that restores a neurosensory function to normal levels.

Who it can help — and who it can’t

OTOF mutations account for roughly 2 to 8 percent of congenital sensorineural hearing loss, meaning the vast majority of people with hearing impairment are outside Otarmeni’s current scope. The therapy is not available to patients who already have a cochlear implant in the ear being treated, or to those whose imaging rules out safe cochlear access.

Surgeons must complete Regeneron-specific training before administering the therapy, and the number of certified centers will be limited in the early going.

Broader gene therapy research for other deafness-causing mutations is ongoing at multiple institutions, but no other candidate is close to regulatory review.

“What is more exciting than seeing a child hear their mother’s voice for the first time?” said Jonathon Whitton, who leads Regeneron’s auditory program.