FX-322 in Sensorineural Hearing Loss

Inclusion Criteria: 1. Adult aged 18-65 years. 2. Established diagnosis of stable sensorineural hearing loss (no changes of 10 dB or more at any frequency) by standard audiometric measures for \>6 months. 3. Documented medical history consistent with hearing loss being caused by noise exposure or sudden sensorineural hearing loss (documented audiogram at least 6 months prior to screening required). 4. Female subjects must be of non-childbearing potential or will need to utilize two methods of highly effective contraception during the study participation (e.g. hormonal contraception or an intrauterine device and condoms) or remain abstinent. Male subjects should use condoms with spermicide during the course of the study or remain abstinent. Subjects should not donate sperm or ova during the study period. Exclusion Criteria: 1. Perforation of tympanic membrane or other tympanic membrane disorders that would interfere with the delivery and safety assessment of an intratympanic medication or reasonably be suspected to affect tympanic membrane healing after injection in either ear. This includes a current tympanostomy tubes. 2. Any conductive hearing loss of 10 dB or more at two or more frequencies in either ear. 3. A pure tone average of 70 dB or greater at 500Hz, 1000Hz, 2000Hz, and 4000Hz in the ear to be injected. 4. Active chronic middle ear disease or a history of major middle ear surgery, as an adult, in the ear to be injected. 5. Subject has had an intratympanic injection in either ear within 6 months of the screening visit. 6. History of clinically significant vestibular symptoms at the discretion of the investigator. 7. History of clinically significant systemic autoimmune disease (e.g. rheumatoid arthritis, Sjogren's syndrome, multiple sclerosis, psoriasis). 8. History of head or neck radiation treatment or exposure. 9. History of substance abuse within 2 years of the Screening Visit. 10. Positive urine pregnancy test or breast-feeding. 11. Any known factor, condition or disease that, in the view of the investigator, might interfere with treatment compliance, study conduct or interpretation of the results such as psychiatric disease or suicidal tendencies.