The FDA has granted accelerated approval to Otarmeni (lunsotogene parvec-cwha), an adeno-associated virus (AAV) vector–based gene therapy for pediatric and adult patients with severe-to-profound or profound sensorineural hearing loss associated with biallelic OTOF variants, according to Regeneron.1
FDA Grants Accelerated Approval to Otarmeni Gene Therapy for OTOF-Related Hearing Loss
The decision, granted under the FDA Commissioner’s National Priority Voucher program, introduces the first FDA-approved gene therapy for this form of genetic hearing loss.1
Clinically, the approval matters because OTOF-related hearing loss has historically been managed with hearing devices or cochlear implantation rather than disease-targeted treatment.
Clinical Significance and Treatment Landscape Shift
“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, a CHORD trial investigator at Boston Children’s Hospital and Harvard Medical School, in the company’s announcement.1
Key Facts
- Drug: lunsotogene parvec-cwha
- Class: AAV vector gene therapy
- Indication: OTOF-related SNHL
- Population: Pediatric and adult patients
- Primary end point: PTA ≤70 dB HL at 24 wk
- Primary result: 16/20 met end point
- Key secondary: ABR ≤90 dB at 24 wk
- Secondary result: 14/20 responded
- Common AEs: otitis, dizziness, nystagmus
- US status: FDA accelerated approval
The indication is limited. Per the press release, Otarmeni is approved for patients with molecularly confirmed biallelic OTOF variants, preserved outer hair cell function, and no prior cochlear implant in the same ear.1
The therapy is delivered through intracochlear infusion under general anesthesia and is not recommended when preoperative imaging suggests inner-ear access is not feasible because of anatomic constraints.
CHORD Trial Design and Patient Population
The approval was based on the ongoing Phase 1/2 CHORD trial, a multicenter, open-label registrational study enrolling infants, children, and adolescents with OTOF-related hearing loss.
In the pivotal dataset cited by the company, 20 participants aged 10 months to 16 years received a single dose either unilaterally (n = 10) or bilaterally (n = 10). All participants reportedly had profound hearing loss by behavioral pure tone audiometry (PTA) at baseline and no auditory brainstem response (ABR) at maximal sound levels.
Efficacy Outcomes at 24 and 48 Weeks
At 24 weeks, 16 of 20 participants (80%) reached the primary endpoint of hearing improvement to a PTA threshold of 70 dB hearing level or less; 1 additional participant reached that threshold by week 48. A key secondary endpoint was met by 14 of 20 participants (70%), who demonstrated an ABR response at 90 dB or less by week 24.
Among 12 participants followed through 48 weeks, all prior responders reportedly maintained response, and 5 patients (42% of those followed) achieved hearing thresholds of 25 dB or less, which the company described as normal hearing including whispers.
Regulatory Pathway and Safety Profile
The FDA granted accelerated approval on the basis of week-24 PTA improvement, with continued approval contingent on verification of clinical benefit in the confirmatory portion of CHORD. In terms of safety, caution is suggested as the dataset is small and treatment requires surgery.
In the CHORD safety population (n = 24), the most common adverse reactions, each occurring in at least 5%, were otitis media, vomiting, nausea, dizziness, procedural pain, gait disturbance, and nystagmus. The prescribing information summarized in the release also notes procedure-related risks associated with inner-ear surgery, including vertigo, tinnitus, cerebrospinal fluid leak, partial facial weakness, meningitis, mastoiditis, wound infection, and inner-ear inflammation.
Mechanism of Disease and Rationale for Gene Therapy
The disease target is biologically distinct. OTOF encodes otoferlin, a protein needed for synaptic transmission between inner hair cells and the auditory nerve; pathogenic biallelic variants are a known cause of autosomal recessive nonsyndromic deafness, often classified as DFNB9.2,3
Because cochlear hair cell structures may remain anatomically present, OTOF-related hearing loss has been considered a plausible candidate for gene replacement strategies.2 Preclinical work has supported AAV-mediated otoferlin delivery, although clinical evidence remains early.3
For patients with confirmed OTOF-related disease, a gene therapy could alter the timing and sequencing of these interventions, unresolved questions include durability beyond the first year, outcomes in adults, comparative effectiveness vs cochlear implantation, and reproducibility across broader surgical settings.
Regeneron said it will provide the product free of charge in the US to clinically eligible patients, while noting that out-of-pocket costs may still fall outside the company’s control.1
References
- Regeneron Pharmaceuticals, Inc. Otarmeni (lunsotogene parvec-cwha) approved by FDA as first and only gene therapy for genetic hearing loss; Regeneron to provide Otarmeni for free in the U.S. News release. April 23, 2026. Accessed April 23, 2026. https://investor.regeneron.com/news-releases/news-release-details/otarmenitm-lunsotogene-parvec-cwha-approved-fda-first-and-only
- Roux I, Safieddine S, Nouvian R, et al. Otoferlin, defective in a human deafness form, is essential for exocytosis at the auditory ribbon synapse. Cell. 2006;127(2):277-289.
- Al-Moyed H, Cepeda AP, Jung S, et al. A dual-AAV approach restores fast exocytosis and partially rescues auditory function in deaf otoferlin knock-out mice. EMBO Mol Med. 2019;11(12):e9396.