Regeneron’s Otarmeni™ (lunsotogene parvec) has been accepted by the EMA under Accelerated Assessment for OTOF‑related hearing loss, following FDA accelerated approval in April 2026. Backed by pivotal CHORD trial data, the gene therapy could become the first EU‑approved treatment for congenital otoferlin deficiency.
Written By: Mahathi Palivela, PharmD
Reviewed By: Pharmacally Editorial Team
Regeneron Pharmaceuticals has achieved a significant European regulatory milestone with the European Medicines Agency (EMA) accepting the Marketing Authorization Application (MAA) for Otarmeni™ (lunsotogene parvec) under Accelerated Assessment.
The filing positions Otarmeni to become the first approved gene therapy in the European Union for biallelic OTOF variant‑associated hearing loss, an ultra‑rare inherited condition affecting an estimated 46 newborns annually across the region.
The therapy previously received EMA Orphan Designation. Otarmeni™ was recently granted accelerated approval by the U.S. Food and Drug Administration in April 2026.
Disease Context
OTOF‑related hearing loss results from mutations in the OTOF gene, which disrupt production of otoferlin, a protein essential for synaptic transmission between cochlear hair cells and the auditory nerve. Although inner ear structures remain anatomically intact, patients experience profound congenital sensorineural hearing loss from birth. Conventional hearing devices, including cochlear implants, can amplify sound but cannot fully restore natural auditory signaling, underscoring the need for gene therapy approaches.
Gene Therapy Platform
Otarmeni employs a dual adeno‑associated virus serotype 1 (AAV1) vector system to deliver a functional copy of the OTOF gene directly into cochlear hair cells. Expression is restricted to target sensory cells via a proprietary Myo15 promoter, designed to restore physiological auditory signaling.
CHORD Trial Data
The pivotal Phase 1/2 CHORD study (NCT05788536) enrolled 24 infants, children, and adolescents aged 10 months to 16 years, who received a single intracochlear infusion of Otarmeni either unilaterally or bilaterally. Interim data from 20 patients supported the therapy’s accelerated approval in the United States in April 2026.
- Endpoints: Hearing recovery was assessed using pure tone audiometry (PTA) and auditory brainstem response (ABR), both standard measures of auditory function.
- Baseline: All participants entered with profound hearing loss and absent ABR responses at maximum sound levels.
- Efficacy: Interim results demonstrated restoration of ABR responses in a majority of treated patients, alongside clinically meaningful improvements in PTA thresholds.
- Safety: No unexpected adverse events were reported, with intracochlear administration generally well tolerated.
The ongoing multicenter trial continues to enroll pediatric and adult patients across sites in the United States, United Kingdom, Spain, Germany, and Japan. Part A evaluated unilateral dosing through dose escalation, while Part B expanded treatment to bilateral administration at the selected dose.
Strategic Significance
If approved, Otarmeni would represent the first gene therapy in Europe for congenital hearing loss, establishing a precedent for inner ear genetic medicine. Regeneron plans additional regulatory submissions in Japan and other global markets, as commercialization efforts expand beyond the United States. The company is expected to align launch strategies with newborn screening programs and audiology networks, aiming to integrate genetic testing into early diagnosis and intervention pathways.
Path to Approval and Market Impact
The EMA’s accelerated review underscores the therapy’s potential to address a high unmet medical need. A Committee for Medicinal Products for Human Use (CHMP) opinion could be issued within the next 12 months, paving the way for a landmark approval in the EU. For Regeneron, Otarmeni represents both a scientific breakthrough in auditory gene therapy and a strategic expansion into rare disease markets.
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About the Writer
Mahathi Palivela (LinkedIn) is pursuing PharmD and has a strong interest in Clinical Pharmacy and Patient safety. She is passionate about handling and analyzing patient data, and translating clinical insights into clear, meaningful summaries. She aims to apply this interest in Medical Writing and Pharmacovigilance, focusing on improving patient outcomes through careful data interpretation and communication.