March 23, 2026 —
Six-month follow-up results from Cohort 2 of the Audiogene Phase 1/2 clinical trial suggest that Sensorion’s investigational AAV gene therapy SENS-501 continues to show encouraging early signs of efficacy in children with genetic congenital deafness caused by mutations in the OTOF gene. The updated data indicate sustained improvements in hearing responses and support a potential dose-response relationship, reinforcing confidence in the therapy’s development.
Congenital hearing loss caused by otoferlin deficiency (DFNB9) results from mutations in the OTOF gene, which plays a critical role in transmitting sound signals from inner ear hair cells to the auditory nerve. Without functional otoferlin, this signaling process fails, leading to severe to profound deafness at birth. Sensorion’s SENS-501 (OTOF-GT) is designed to restore hearing by delivering a functional copy of the OTOF gene directly into cochlear hair cells using an adeno-associated virus (AAV) vector. By restoring the molecular machinery responsible for sound transmission, the therapy aims to recover auditory function in affected patients.
The Audiogene trial evaluates the safety, tolerability, and early efficacy of intra-cochlear administration of SENS-501 in infants and toddlers aged 6 to 31 months. Targeting treatment at an early stage of development is particularly important, as brain plasticity during early childhood increases the likelihood that treated patients can develop normal speech and language abilities.
In the trial’s second cohort, three patients received a higher dose of SENS-501. Two of these patients showed directional improvements in pure-tone audiometry at three months, and these improvements were maintained at the six-month follow-up. When combined with earlier observations from the lower-dose Cohort 1—where initial signs of auditory pathway activation were detected—the results suggest a dose-dependent biological effect. Across all six patients treated in the dose-escalation phase, the surgical procedure and gene therapy administration were well tolerated, with no serious adverse events reported.
Based on the emerging dose-response trend, Sensorion is evaluating the possibility of introducing a third dose level in the ongoing study. The company plans to consult with regulatory authorities while continuing to monitor the evolving regulatory landscape for hearing-loss gene therapies.
The clinical insights gained through Audiogene are also strengthening Sensorion’s broader AAV gene therapy platform as the company prepares to advance its next program, GJB2-GT (SENS-601). This candidate targets mutations in the GJB2 gene, the most common genetic cause of congenital deafness and responsible for approximately 50% of autosomal recessive non-syndromic hearing loss worldwide.
Like SENS-501, the SENS-601 program is built on AAV-mediated gene delivery, designed to introduce a functional GJB2 gene to restore the ionic balance required for proper sound transduction in the inner ear. The therapy is being developed in collaboration with the Institut Pasteur, and CTA-enabling studies are progressing toward regulatory submissions. Sensorion plans to submit a Clinical Trial Application (CTA) in the first half of 2026, followed by a U.S. IND submission by the end of 2026.
Together, the ongoing Audiogene trial and the advancement of SENS-601 highlight the growing potential of AAV gene therapy for treating genetic hearing loss, a field that currently lacks approved disease-modifying treatments. If successful, these programs could open the door to new therapies capable of restoring hearing in patients with previously untreatable inherited forms of deafness.
