Gene therapy has shown promising results in restoring hearing to children with a specific type of genetic deafness. A new study published in The Lancet details how six children with DFNB9, a form of hereditary deafness caused by mutations in the OTOF gene, experienced restored hearing after receiving gene therapy.
The clinical trial, conducted at the Eye & ENT Hospital of Fudan University in Shanghai and co-led by investigators from Mass Eye and Ear, involved introducing a functional version of the OTOF gene into the inner ear of the children using an inactive virus. The OTOF gene is crucial for producing otoferlin, a protein essential for transmitting sound signals from the ear to the brain. The children, aged one through seven, were observed for 26 weeks following the treatment.
Remarkable Hearing Recovery
The results revealed that five of the six children, initially classified as having total deafness, regained their hearing. According to the study, these children recovered "the restored ability to conduct normal conversation." This marks a significant advancement, as Dr. Zheng-Yi Chen from Mass Eye and Ear and Harvard Medical School noted, "This is the first time where a brand-new type of gene therapy approach can actually be used to treat the children who are completely deaf and regain the function of hearing."
Addressing a Critical Need
Hearing loss affects a significant portion of the population, and currently, there are no FDA-approved drugs to treat generic hearing loss. Untreated hearing loss in children can severely impact their development, particularly in the first three years of life when brain development is most sensitive to communication and auditory input.
Trial Details and Future Directions
The gene therapy was administered via a surgical procedure where it was placed into the inner ear using a device that partially lifts the eardrum. In one case at the Children’s Hospital of Philadelphia, an 11-year-old boy with otoferlin gene-mediated hearing loss received a single, small dose containing copies of the normal gene. Post-surgery, his hearing improved from profound deafness to mild-to-moderate hearing loss in the treated ear.
Researchers plan to expand the study to include more patients and extend the follow-up period to ensure the treatment's long-term efficacy and safety. The ultimate goal is to broaden the application of this gene therapy to treat other types of genetic deafness. The findings from this trial were presented at the Association for Research in Otolaryngology Annual Meeting.
