Gene Therapy Trial for Otoferlin Gene-mediated Hearing Loss

Criteria for Inclusion: 1. Participants may be of any age, based on Cohort Criteria 2. At least two mutations in the otoferlin gene 3. Clinical presentation of Profound (Part A) or Severe to Profound (Parts B, C, and D) bilateral sensorineural hearing loss as assessed by ABR 4. Preserved distortion product otoacoustic emissions (DPOAEs) 5. Able and willing to comply with all study requirements, including willingness to participate in a separate long term follow-up study after completion of this trial Criteria for Exclusion: 1. Persistent ear infections, anatomic or other abnormalities of the ear, and/or medical conditions that would contraindicate undergoing surgery, anesthesia, and/or administration of investigational gene therapy 2. Cochlear Implant(s) in the ear(s) to receive AAVAnc80-hOTOF 3. Prior participation in a clinical trial with an investigational drug, within six months prior to administration, or any prior participation in a gene therapy clinical trial (with the exception of AK-OTOF-101 for Part D participants)