The purpose of the study is to determine whether AM-111 is effective in the treatment of acute inner ear hearing loss (acute sensorineural hearing loss, ASNHL).

Inclusion Criteria:

• Patients with unilateral acute sensorineural hearing loss (ASNHL) with onset 48 hours or less ago
• Mean earing loss compared with the unaffected contralateral ear of at least 30 dB in the 3 most affected contiguous frequencies
• Age ≥ 18 years and ≤ 60 years
• Negative pregnancy test for women of childbearing potential
• Able to attend the on-study visits
• Written informed consent before participation in the study

Exclusion Criteria:

• Bilateral ASNHL, if not resulting from acoustic trauma
• Suspected perilymph fistula or membrane rupture
• Barotrauma
• Average air bone gap higher than 20 dB in 3 contiguous frequencies
• History of Meniere disease, autoimmune hearing loss, radiation-induced hearing loss, endolymphatic hydrops, suspected retro-cochlear lesion or fluctuating hearing loss
• Previous ASNHL incident within the past 6 weeks
• Evidence of acute or chronic otitis media or otitis externa on examination
• Any drug-based therapy for inner ear hearing loss that is ongoing or was performed in the past 2 weeks
• Any ongoing or planned concomitant medication for the treatment of tinnitus until 30 days after administration
• Any therapy known as ototoxic (e.g. aminoglycosides, cisplatin, loop diuretics, quinine etc.) in the past 6 months prior to study inclusion
• History of drug abuse or alcoholism
• Any clinically relevant respiratory, cardiovascular, neurological (except vertigo or tinnitus), or psychiatric disorders
• Known hypersensitivity, allergy or intolerance to the study medication or any history of severe abnormal drug reaction
• Women who are breast-feeding, pregnant or who plan a pregnancy during the trial
• Women of childbearing potential who declare being unwilling or unable to practice contraception such as combined oral contraceptives, injectables, hormonal intra-uterine devices, vasectomised partner or sexual abstinence
• Concurrent participation in another clinical trial or participation in another clinical trial within 30 days prior to study entry
• Any current anticoagulant therapy (e.g. Aspirin, Marcumar, etc)