FDA Approves First Gene Therapy for Deafness

Why this is here: Researchers successfully split the otoferlin gene into two parts, which recombined inside the cell roughly 90% of the time, creating a functional copy.

The Food and Drug Administration approved the first gene therapy in the world to treat a form of deafness, in the United States. Researchers at Harvard Medical School, led by Dr.

Jeffrey Holt and Dr. Zheng-Yi Chen, spent 25 years developing the treatment. It targets a mutated gene called otoferlin, preventing signals from reaching the brain.

A single injection delivers a working copy of the gene using two viral vectors directly into the inner ear. In a trial of 20 infants, children, and teens, roughly 42% achieved normal hearing after treatment. The therapy proved safe, with only minor, temporary side effects like ear infections.

However, the therapy’s effectiveness depends on early intervention. Dr.

Daniel Choo of the University of Cincinnati College of Medicine notes the best outcomes occur when treatment begins before age three, when the brain is most receptive to language development. While the therapy offers a new option, cochlear implants remain standard care for many, and using both approaches may not be possible. Researchers are now focusing on applying this method to other genetic causes of hearing loss.