FDA approves Otarmeni, first U.S.-cleared gene therapy for genetic hearing loss

The U.S. Food and Drug Administration on Thursday approved Otarmeni, a Regeneron Pharmaceuticals gene therapy for a rare inherited form of deafness, marking the first U.S.-cleared gene therapy for genetic hearing loss and the first approved therapy that uses two adeno-associated virus, or AAV, vectors.

The agency said the treatment, formally known as lunsotogene parvec-cwha, was approved April 23 under accelerated approval and reviewed through FDA Commissioner Marty Makary’s National Priority Voucher pilot program. FDA said the decision came 61 days after Regeneron filed its biologics license application, making it the sixth approval under the program, the first gene therapy approved through it and “tied for the fastest BLA approval in modern FDA history.”

“Today’s approval is a significant milestone in the treatment of genetic hearing loss,” Makary said in the FDA announcement.

Otarmeni is not a treatment for hearing loss broadly. It is cleared for pediatric and adult patients with severe-to-profound or profound sensorineural hearing loss caused by molecularly confirmed biallelic pathogenic variants in the OTOF gene, provided they still have preserved outer-hair-cell function and have not previously received a cochlear implant in the same ear.

The therapy is designed for an ultra-rare condition. FDA said OTOF variants account for an estimated 2% to 8% of inherited non-syndromic congenital hearing-loss cases. Regeneron said the disorder affects roughly 50 newborns a year in the United States.

Otarmeni is a one-time biologic-device combination product given as a single dose per ear. It is surgically delivered into the cochlea, the inner-ear structure involved in hearing, using an administration kit and infusion pump supplied with the product. FDA and Regeneron said it must be administered by surgeons experienced in intracochlear surgery and trained on the procedure.

The approval was based on early results from CHORD, an ongoing multi-center, single-arm clinical trial. FDA said 24 pediatric patients ages 10 months to 16 years were enrolled. Of those, 20 were evaluable for efficacy, and 16 of 20, or 80%, showed improved hearing on pure-tone audiometry at the primary time point.

FDA and Regeneron also said some participants followed for longer periods later achieved normal hearing, including the ability to detect whispers. In Regeneron’s announcement, A. Eliot Shearer, a physician-scientist quoted by the company, said, “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.”

Even so, the approval is tightly defined and not yet full validation of long-term benefit. Because Otarmeni was granted accelerated approval, continued FDA clearance may depend on confirmatory evidence showing durability and meaningful clinical benefit. The agency said that includes outcomes such as speech development and quality of life.

Safety remains an important part of that follow-up. Common adverse events reported in the trial included middle ear infection, also called otitis media, nausea and vomiting, dizziness, procedural pain, gait disturbance and nystagmus, which causes involuntary eye movements. FDA also said clinicians should monitor for surgical complications and transient vestibular effects, including balance problems. The therapy is contraindicated when anatomical access to the inner ear is not feasible.

Regeneron said it will provide Otarmeni at no cost to clinically eligible patients in the U.S. Still, the company said patients may face out-of-pocket costs tied to surgery, facility care or provider services.

The approval is notable not just because it offers a treatment option for a very small group of patients, but because it clears a technical hurdle that has limited gene therapy development for some disorders. The OTOF gene is too large to fit into a standard single AAV vector, so Otarmeni uses a dual-AAV approach to deliver the genetic material.

That makes Thursday’s decision both a clinical breakthrough for a narrow group of patients with OTOF-related deafness and a regulatory milestone for gene therapy more broadly. But for now, the drug’s promise rests on early trial data in a small pediatric study population, with longer-term confirmation of hearing durability and day-to-day benefits still required.