US agency approved gene therapy for deafness
The US FDA moved quickly when the research confirmed earlier international research
The US Food and Drug Administration announced approval of a gene therapy for treating a rare form of hearing loss on 23 April 2026. Although there have been earlier preliminary reports of the therapy’s benefits, the FDA approval came after publication of studies in scientific journals: a study reported by Jiang et al. (2026) in Nature and by the CHORD Study Group (2026) in the New England Journal of Medicine.
Whereas earlier studies (e.g., Chung et al., 2025) had shown that the therapy successfully induced functional OTOF gene expression in mice, the reports by Jiang et al. (2026) and the CHORD Study Group (2026) reported positive outcomes after a one-time infusion (usually into just one ear) of an otherwise inert virus carrying genetic material that encodes a protein that allows inner ear hair cells to transmit sound vibrations to the brain. For individuals (many of them children) who were congenitally deaf, the therapy worked. The studies reported that 75% to 90% of participants had greatly improved hearing as a result of the treatment. There were few and only minor adverse effects.
It is important to note that this therapy is only appropriate for one specific form of deafness, autosomal recessive deafness. Also, special educators should realize that some advocates in the Deaf community may disagree with providing such therapies, because they disagree with efforts that distance or remove individuals from the Deaf community.
In a press release on it’s investment Web site, Regeneron Pharmaceuticals, the business that has helped develop and will market Otarmeni™—the therapy—announced that the treatment “will be made availably by Regeneron for free in the U.S,” Of course, companies need to make $$…but does anyone else wonder why this product should be free in only one country?
Abstacts
Abstract for the Jiang et al. study:1
Autosomal recessive deafness, caused by OTOF gene mutations, is characterized by severe-to-complete congenital deafness. Although gene therapy has shown benefits in a small number of patients, its safety and efficacy across broader age ranges and longer follow-up periods, as well as predictors of treatment outcomes, remain unclear. In this single-arm, multicentre trial conducted at eight centres, 42 participants (aged 0.8–32.3 years) received adeno-associated virus (AAV) serotype 1 carrying a human OTOF coding transgene (AAV1-hOTOF) at three vector dose groups, with up to 2.5-year follow-up. The primary end point was dose-limiting toxicity within 6 weeks. The secondary end point assessed efficacy and adverse events. No dose-limiting toxicities were observed. Grade 3 adverse events included decreased neutrophil count. Hearing was recovered in 90% of participants treated with AAV1-hOTOF, with gradual and stable improvement in auditory brainstem response threshold from greater than 97 ± 1 dB normalized hearing level at baseline to 54 ± 3, 51 ± 3, 50 ± 3 and 42 ± 5 dB normalized hearing level at 1, 1.5, 2 and 2.5 years, respectively, and behavioural audiometry improving from greater than 96 ± 3 dB hearing level at baseline to 37 ± 5 dB hearing level at 2.5 years. Participants aged 0.5–18 years showed greater hearing improvement than adults. A higher number of present distortion product otoacoustic emissions at baseline or biallelic non-truncated OTOF variants was associated with better hearing recovery. Participants with hearing recovery demonstrated gradual improvement in speech perception. AAV1-hOTOF is well-tolerated and efficacious across a broader patient population, with sustained therapeutic benefits for up to 2.5 years.
Abstract from the CHORD Study Group:
BACKGROUND
Genetic deficiency of otoferlin, a protein critical to synaptic transmission by the sensory hair cells of the ear, causes congenital deafness. Medicines to treat the condition are lacking; children typically receive cochlear implants. DB-OTO is a dual adeno-associated virus 1 gene therapy that delivers human OTOF complementary DNA (encoding otoferlin) regulated by a hair cell–specific promoter.
METHODS
We conducted an open-label, single-group, first-in-human registrational study to evaluate DB-OTO. Children with OTOF variants and profound deafness (defined by an average audiometric threshold of >90 decibel hearing level [dB HL], indicating an inability to hear a gas-powered lawn mower) received an intracochlear infusion of DB-OTO (7.2×1012 vector genomes per ear) in one or both ears. The primary efficacy end point was an average threshold on behavioral pure-tone audiometry (PTA) at week 24 of 70 dB HL or less, a clinical standard that generally avoids cochlear implantation and enables natural acoustic hearing. A key secondary end point was the presence of an auditory brain-stem response to a click stimulus at a threshold at or below 90 dB normalized hearing level (db nHL) at week 24. Safety assessments included adverse events, laboratory results, and vestibular testing.
RESULTS
A total of 12 children have been enrolled in the study. After a single infusion of DB-OTO, a PTA average threshold of 70 dB HL or less at week 24 (primary end point) and an auditory brain-stem response at or below 90 dB nHL (key secondary end point) were found in 9 of the 12 participants (75%; 95% confidence interval, 43 to 95; P=1.1×10−13 for both end points). Six participants could hear soft speech without assistive devices, and 3 had average normal hearing sensitivity. A total of 67 adverse events occurred or worsened during or after treatment, none of which led to discontinued participation in the study.
CONCLUSIONS
DB-OTO gene therapy improved hearing in patients with OTOF-related deafness, enabling natural acoustic hearing and normalizing hearing sensitivity in 3 of 12 treated patients. (Funded by Regeneron Pharmaceuticals; ClinicalTrials.gov number, NCT05788536.)
I am not sure whether the CHORD Study Group report is open access. If Dear Readers can find their way to the report, however, one can find videos of the actual surgical procedure adding the altered material to an ear. There are also videos of children, some of which have appeared in public media in 2025 and 2026. Here is an example of a report from the BBC via YouTube:
Press coverage
The 23 April 2026 FDA press release about the approval is available; it is a press release, so it’s pretty puffed up about the FDA. Many news organizations reported about the FDA approval of the therapy. Here is an incomplete list:
Sriparna Roy for Reuters 23 April 2026: Regeneron wins FDA approval for first gene therapy for genetic hearing loss.
Rob Stein for US NPR on 22 April 2026, Gene therapy for a rare type of deafness shows lasting results, and on 23 April 2026, The FDA gives the green light to the first gene therapy for deafness.
Gina Kolata of the New York Times on 23 April 2026, New Gene Therapy Enables Children With a Rare Form of Deafness to Hear: The treatment, the first of its kind, was approved by the Food and Drug Administration on Thursday. “Our baby was born deaf, and now he can hear,” said one parent.
Jocelyn Kaiser of Science on 23 April 2026, First treatment for an inherited hearing disorder will be free in the United States.
There are other reports, too, so “do your own research!”
References
CHORD Study Group. (2026). DB-OTO Gene therapy for inherited deafness. The New England journal of medicine, 394(11), 1074-1083. https://www.nejm.org/doi/full/10.1056/NEJMoa2400521
Chung, Y., Koehler, S. D., Cancelarich, S., Gibson, T. M., Pregernig, G., Becker, L., , Artinian Q.-A., Goodliffe, J. W., Pan, N., Qiuocley, T. M., Senpati, A., Slade, P. G., Smith, L. M., So, K. S., Zhang, X., Corrales, C. E., Weber, P., Macdonald, L. E. , Zambrowicz, B., Economides, A. N., Kyratsous, C. A., Burns, J. C., Palermo, A. T., Savin, L. R., Lee, J., Valayannopoulos, C., Witton, J. P., & Drummond, M. C. (2025). Functional, sustained recovery of hearing in Otoferlin-deficient mice using DB-OTO, a hair-cell-specific AAV-based gene therapy. Molecular Therapy Methods & Clinical Development, 33(4). https://doi.org/10.1016/j.omtm.2025.101577
Jiang, L., Cheng, X., Lv, J. Chen, Y., Chen, X., Zhai, R., Zhang, L., Han, L., Zhang, Y., Zhang, JK., Deng, D., Huang, Z., Can, Q., Zhang, X., Wang, D., Wang, Y., Chen, L., Yu, S., Guo, L. Zhang, B., Wang, H., Zhou, Y., Dai, L., Wang,. W., Zhag, L., Yin, Y., Ggencg, G., Zhou, Z., Want, W., Chen, B., Lu, W., Jiang, H., Gao, Z., Shi, D., Xiong, Y., Zhao, Y., Yuan, W., Wang, Q., Geng, G., Li, H., Chen, Z.-Y. & Shu, Y. Multicentre gene therapy for OTOF-related deafness followed up to 2.5 years. Nature (2026). https://doi.org/10.1038/s41586-026-10393-y
Footnotes
I removed the footnote numbers from this abstract.