Sensorion Reports Early Data from the SENS-501 Audiogene Trial

Editor’s note — September 24, 2026

This is an early company report on an experimental gene therapy, not evidence of an approved or established treatment. The low-dose cohort contained only three children, and the detailed hearing result below concerns one child at three months. Safety and efficacy require continued trial follow-up and independent review.

Sensorion announced preliminary results from the low-dose group of Audiogene, its Phase 1/2 trial of SENS-501 for congenital hearing loss associated with OTOF gene variants. It said the higher-dose group was under way and recruitment was nearly complete. The company identified itself as a clinical-stage biotechnology developer; its ticker was listed as FR0012596468–ALSEN.

Early safety observations

Sensorion said five children had received treatment at the time of the report and that SENS-501 administration and the intracochlear procedure had been well tolerated. Participants were 6–31 months old under the trial protocol and had not received cochlear implants at injection. The company reported no serious adverse events or serious side effects among those treated so far. Small early cohorts cannot rule out later or less common harms.

Low-dose cohort and one child's response

The first group included three children receiving 1.5E11 vector genomes per ear, the company's stated minimum effective dose in preclinical work. The main initial goal was to examine safety and feasibility of intracochlear delivery. Sensorion reported early hearing-response signs in participant 3, who was 11 months old at injection. Assessments included auditory brainstem response (ABR), pure-tone audiometry (PTA) and parent-reported outcomes.

At three months, Sensorion reported positive ABR responses at two frequencies, with a best threshold of 70 dB. Pure-tone testing showed improvement at two speech frequencies, with a best threshold of 90 dB. Parents reported changes in response to sound and speech: the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) score rose by 16 points, described as a 145% relative improvement from baseline, and the child reached expected age-related milestones on the LittlEARS parent questionnaire.

These measures describe one participant in an early trial; they do not show restored normal hearing or establish an average treatment effect. The company said it would update the program when higher-dose data matured.

Clinician comment and trial design

Professor Catherine Birman of the Children's Hospital at Westmead in Australia called the early response encouraging while emphasizing that the first dose was low and primarily intended to assess safety of treatment and surgery. She said further follow-up and evaluation of the higher dose were needed. She also expressed hope that earlier hearing access might help language development; this was a rationale for treating children under three, not an outcome demonstrated by the preliminary data.

Audiogene is registered as NCT06370351 and was developed within a strategic collaboration with the Institut Pasteur. Professor Natalie Loundon, a pediatric ENT surgeon and investigator at Necker–Enfants Malades Hospital within AP-HP in Paris, leads the clinical research described in the article. The trial tests intracochlear SENS-501 in children 6–31 months old with OTOF-related hearing loss who have had no cochlear implant in either ear.

The dose-escalation phase has two groups of three children each: 1.5E11 vector genomes per ear in group one and 4.5E11 per ear in group two. After escalation, an expansion group is planned at a selected dose. Safety is the main endpoint during escalation; in expansion, the primary endpoint is ABR at 12 months after injection. The no-implant criterion helps researchers observe the therapy's auditory effects without concurrent or prior cochlear implantation.

Original report: The Hearing Review.