TÜBINGEN, GERMANY — Acousia Therapeutics GmbH, a clinical-stage biotechnology company developing treatments for acute and chronic inner ear hearing loss, today announced positive top-line efficacy results from its completed Phase 2a PROHEAR study. ACOU085 (INN: Bimokalner) is a proprietary small-molecule therapy that has demonstrated efficacy across multiple preclinical models of hearing loss, including drug-induced ototoxicity.
The exploratory, placebo-controlled, split-body Phase 2a PROHEAR study evaluated the otoprotective efficacy of a single 6 mg transtympanic dose of ACOU085 compared with placebo in patients with testicular cancer receiving cisplatin chemotherapy and at risk for cisplatin-induced sensorineural hearing loss.
Among the young participants with normal baseline hearing, more than 90% developed ototoxicity in at least one ear, as defined by ASHA criteria, after three cycles of cisplatin (300 mg/m²). The hearing loss primarily affected the extended high-frequency range (10–16 kHz) and was generally mild to moderate in severity.
Preliminary Top-Line Efficacy Results
According to the company, patients who developed ototoxicity and received ACOU085 demonstrated a clinically meaningful reduction in pure-tone audiometry (PTA) threshold increases at affected frequencies compared with placebo following the final cisplatin cycle. Additional analyses of the PROHEAR study, including post-hoc evaluations, are ongoing and are expected to be submitted for publication in a peer-reviewed journal.
“This is an important and encouraging milestone toward establishing Kv7.4 activation as a novel therapeutic approach for multiple forms of hearing loss. This broad therapeutic potential addresses a significant unmet medical need, which current device-based solutions only partially meet. The clinical results for ACOU085 create a compelling opportunity to advance Kv7.4 modulation into broader patient populations,” said Professor Hubert Löwenheim, Chair of Otorhinolaryngology – Head & Neck Surgery at Tübingen University Medical Center and Scientific Supervisor of the PROHEAR Study.
Management Commentary
“Today represents an exciting advancement for cancer patients at risk of cisplatin-induced hearing loss,” said Tim Boelke, M.D., CEO & CMO of Acousia Therapeutics GmbH. “Our novel drug candidate has the potential to prevent permanent inner ear damage commonly seen after cisplatin-based chemotherapy.”
The Acousia team will attend the BIO International Convention in San Diego from June 22–25, 2026, where the company plans to discuss collaboration opportunities with potential strategic partners for the next phase of clinical development.
ACOU085 (Bimokalner)
ACOU085 is a first-in-class, etiology-agnostic otoprotective agent administered through a standard transtympanic injection using a proprietary slow-release gel formulation. Cisplatin-induced hearing loss is a permanent side effect of chemotherapy that results from irreversible damage to the cochlea’s outer hair cells (OHCs). By modulating the Kv7.4 potassium channel target encoded by KCNQ4 in OHCs, ACOU085 has demonstrated the potential in preclinical studies to reduce cisplatin-induced hearing loss and preserve outer hair cell integrity.
About Acousia Therapeutics GmbH
Acousia Therapeutics GmbH is a privately held, clinical-stage biotech company based in Tübingen, Germany. The company is dedicated to the identification of small molecules for the effective prevention and treatment of different hearing loss etiologies. Acousia is focused on the development of proprietary drug candidates, which are designed to affect the sensory outer hair cells (OHC) in the cochlea of the inner ear. The unique dual mode of action of its small-molecule Kv7.4 activators combines acute functional OHC enhancement and sustained OHC protection and aims to both enhance and preserve a patient’s natural hearing. Acousia Therapeutics develops drugs for both local and systemic administration.
Source: Acousia Therapueutics
