Tübingen (OTE) – Acousia Therapeutics GmbH, a clinical-stage
biotechnology company
pioneering treatments for acute and chronic inner ear hearing loss,
today announced positive top-line efficacy results from its completed
Phase 2a PROHEAR Study. ACOU085 is a proprietary, first-in-class
small molecule that has demonstrated robust and reproducible efficacy
across multiple preclinical hearing loss models, including drug-
induced ototoxicity.
The exploratory, placebo-controlled, split-body Phase 2a PROHEAR
Study assessed the otoprotective efficacy of a 6 mg transtympanic
dose of ACOU085 compared to placebo in testicular cancer patients at
risk of cisplatin-induced sensorineural hearing loss.
Among the young, hearing-healthy participants, more than 90%
developed ototoxicity in at least one ear, as defined by ASHA
criteria, after three cisplatin cycles (300 mg/m²). The hearing loss
primarily affected the extended high-frequency range (10–16 kHz),
with mild to moderate severity.
Preliminary Top-Line Efficacy Results
In patients who developed ototoxicity, treatment with ACOU085
resulted in a clinically meaningful prevention of pure-tone
audiometry (PTA) threshold increases at affected frequencies,
compared to placebo, following the final cisplatin cycle. Further
analysis of the PROHEAR Study results, including post-hoc
evaluations, is ongoing and will 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 (June 22–25, 2026) to discuss collaboration opportunities
with strategic partners for the next phase of clinical development.
ACOU085 (Bimokalner)
ACOU085 is a first-in-class, etiology-agnostic otoprotective
agent, administered via a standard transtympanic injection using a
proprietary slow-release gel formulation. Cisplatin-induced hearing
loss is a severe, permanent side effect caused by irreversible damage
to the cochlea’s outer hair cells (OHCs). By modulating the
biologically validated Kv7.4 potassium channel target (encoded by
KCNQ4) in OHCs, ACOU085 has demonstrated significant potential to
reduce cisplatin-induced hearing loss and preserve OHC integrity in
preclinical studies.
