FDA Approves Regeneron's Otarmeni — World's First Gene Therapy for Genetic Hearing Loss, Offered Free in the US

The FDA approves Otarmeni (lunsotogene parvec-cwha), Regeneron's dual AAV (adeno-associated virus) vector-based gene therapy for severe-to-profound sensorineural hearing loss caused by biallelic OTOF (otoferlin) gene mutations. In the pivotal CHORD trial, 80% of participants met the primary hearing endpoint after a single treatment. With longer follow-up, 42% of treated patients achieved hearing ability in the normal range — including whisper-level sound detection. The approval came just 61 days after Regeneron submitted the biologics license application (BLA), making it one of the fastest major BLA approvals in modern FDA history. The therapy was approved under the FDA's Commissioner's National Priority Voucher (CNPV) program, a new pathway created to incentivize therapies for conditions of major public health significance. In a landmark move, Regeneron announced it would provide Otarmeni at no cost in the United States — in stark contrast to the $2.2 million price tag of Casgevy. OTOF-related hearing loss affects an estimated 1–3% of all congenitally deaf children globally (up to 20,000 in the US). The therapy delivers a functional copy of the OTOF gene via a split-intein dual-AAV approach (required because OTOF's coding sequence at 5.9 kb exceeds the single-AAV cargo limit), directly to cochlear inner hair cells. The approval expands gene therapy into the neurosensory domain and sets a significant precedent for access pricing.