Acousia Therapeutics GmbH has announced reaching the halfway mark in patient enrollment for its Phase 2 PROHEAR clinical trial, evaluating ACOU085 (bimokalner) for the prevention of cisplatin-induced hearing loss in testicular cancer patients undergoing chemotherapy.
The milestone represents significant progress in addressing one of chemotherapy's most common and debilitating side effects. Cisplatin, a cornerstone treatment in modern oncology used in over 500,000 cancer patients annually worldwide, has dramatically improved survival rates but often at the cost of permanent hearing damage.
"This marks a significant milestone on Acousia's journey to offer a treatment for the prevention of permanent hearing loss caused by cisplatin," said Professor Hubert Löwenheim, Chair of the Department of Otolaryngology – Head & Neck Surgery at Tuebingen University and Scientific Supervisor of the study.
The Critical Need for Ototoxicity Prevention
Cisplatin revolutionized testicular cancer treatment after its introduction in the late 1970s, improving the 5-year survival rate from approximately 5% to an impressive 98%. However, this life-saving efficacy comes with significant trade-offs, as up to 80% of patients treated with cisplatin experience clinically relevant hearing loss.
Professor Löwenheim emphasized the severity of the problem observed in the current trial: "Preventing this often overlooked side effect is critical for cancer patients. Notably, all PROHEAR participants who have received ≥300 mg/m² of cisplatin to date have developed ototoxicity. This is higher than reported in most, if not all, previous studies."
This high incidence of hearing damage underscores the urgent need for preventive treatments, as hearing loss can significantly impact quality of life, communication abilities, and social functioning in cancer survivors.
Innovative Trial Design and Mechanism
The PROHEAR Study employs a unique placebo-controlled, randomized, double-blind, split-body design. Each participant receives ACOU085 in one ear and a placebo in the contralateral ear, allowing for direct comparison of treatment efficacy within the same patient while controlling for individual variations in cisplatin metabolism and sensitivity.
ACOU085 (bimokalner) represents a first-in-class approach to hearing protection. The small-molecule drug targets the KCNQ4-encoded Kv7.4 potassium channel in the outer hair cells of the inner ear. It is administered through a standard transtympanic procedure using a proprietary slow-release gel formulation designed to maximize local efficacy.
Preclinical models have demonstrated that ACOU085 effectively reduces cisplatin-induced hearing loss through this targeted mechanism, offering hope for a preventive strategy that doesn't interfere with cisplatin's anti-cancer efficacy.
Trial Progress and Future Outlook
The PROHEAR Study is currently being conducted at 13 leading German ENT university clinics and continues to actively recruit participants. According to Acousia Therapeutics, enrollment is on track to complete by the end of the second half of 2025.
The trial represents a significant advancement in addressing a major unmet need in oncology supportive care. If successful, ACOU085 could become the first approved treatment specifically designed to prevent cisplatin-induced hearing loss, potentially changing the standard of care for hundreds of thousands of cancer patients annually.
For testicular cancer patients in particular, who often receive high cumulative doses of cisplatin and have decades of life ahead after treatment, a solution to prevent permanent hearing damage would represent a substantial improvement in survivorship care.
Interested individuals can find more information about the PROHEAR Study on clinicaltrials.gov or by contacting Acousia Therapeutics directly.
