Otarmeni is the first FDA-approved gene therapy for OTOF-related hearing loss, showing rapid hearing gains in the CHORD trial.
The US Food and Drug Administration (FDA) has granted accelerated approval for lunsotogene parvec-cwha (Otarmeni), making it the first and only gene therapy indicated for genetic hearing loss caused by biallelic variants in the OTOF gene.
The approval, announced by Regeneron Pharmaceuticals on April 23, 2026, marks a milestone in genetic medicine as the first FDA-approved gene therapy to restore a neurosensory function to normal levels, according to the company. Regeneron also announced it will provide the gene therapy at no cost to clinically eligible individuals in the United States, although the company noted administration-related out-of-pocket expenses may still apply.¹
"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 A. Eliot Shearer, MD, PhD, an otolaryngologist at Boston Children's Hospital, an associate professor at Harvard Medical School, and a CHORD trial investigator. "In the pivotal trial, the one-time gene therapy demonstrated rapid, meaningful and consistent hearing responses, with most children achieving remarkable hearing improvements."¹
Lunsotogene Parvec is an adeno-associated virus (AAV) vector-based gene therapy that delivers a functional copy of the OTOF gene directly into the cochlea via intracochlear infusion under general anesthesia.¹ Expression is driven by a proprietary cell-specific Myo15 promoter designed to restrict otoferlin production to hair cells that normally express the protein.
The approval is based on results from the CHORD trial, an ongoing phase 1/2, multicenter, open-label study evaluating the safety, tolerability, and efficacy of Otarmeni administered via intracochlear infusion in patients aged 10 months to 16 years with OTOF-related hearing loss.¹ In total, 20 participants received a single dose—10 unilaterally and 10 bilaterally.
The primary endpoint was improvement in hearing sensitivity by average pure tone audiometry (PTA) at week 24. Eighty percent of participants (16 of 20) achieved a PTA threshold of 70 dB hearing level (HL) or better, a level that typically enables natural hearing without cochlear implantation. An additional participant reached this threshold by week 48.
A key secondary endpoint , auditory brainstem response (ABR) at 90 dB or better, was met by 70% of participants (14 of 20) at 24 weeks. Among participants followed to 48 weeks, all prior responders maintained their treatment response, and 42% (5 of 12) achieved normal hearing including perception of whispers (≤25 dB HL).¹
Several limitations warrant consideration. The CHORD trial enrolled only 20 participants, typical of ultra-rare disease studies but limiting generalizability. Follow-up data beyond 48 weeks remain limited, and long-term durability of hearing restoration is not yet established. The accelerated approval pathway requires confirmatory evidence of clinical benefit. Patients with prior cochlear implantation in the treated ear, abnormal mastoid pneumatization, or clinically significant middle or inner ear anatomic variations were excluded. Regulatory submissions in additional markets are planned.¹
Lunsotogene parvec-cwha received Orphan Drug, Rare Pediatric Disease, Fast Track, and Regenerative Medicine Advanced Therapy designations from the FDA.¹ The European Medicines Agency has also granted Orphan Drug Designation.
“Today’s approval is a significant milestone in the treatment of genetic hearing loss,” said FDA Commissioner Marty Makary, MD, MPH, in a press release from the FDA.2 “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.”
