Sensorion (Euronext Growth Paris:ALSEN), a clinical-stage biotechnology company that specialises in hearing loss therapies, on Tuesday announced preliminary positive safety and efficacy data from the first cohort of its Phase 1/2 Audiogene clinical trial evaluating SENS-501, a gene therapy candidate targeting congenital deafness linked to mutations in the OTOF gene.

All five patients treated to date, aged 6 to 31 months and without cochlear implants, tolerated the therapy and surgical procedure well, with no serious adverse events reported.

Cohort 1 included three patients who received a low dose of SENS-501. Early signs of hearing improvement were observed in one patient, an 11-month-old, with measurable gains across multiple standard auditory assessments. The patient showed positive auditory brainstem response at two frequencies and a 16-point increase in IT-MAIS scores, representing a 145% improvement from baseline.

Recruitment for the second cohort, testing a higher dose of SENS-501, is nearly complete.

Audiogene is designed as a dose-escalation study followed by a dose-expansion phase, with safety as the primary endpoint and auditory brainstem response assessed at 12 months.

SENS-501 uses adeno-associated viral vectors to deliver a functional copy of the OTOF gene, aiming to restore auditory signal transmission in young children during a critical window for language development.