(Yicai) April 24 -- Chinese researchers have demonstrated that a gene therapy for a specific form of congenital hearing loss remains both safe and effective over a follow-up period of two and a half years, paving the way for potential large-scale clinical use.

A research team from Fudan University’s Eye and ENT Hospital, in collaboration with seven other hospitals, conducted a clinical trial for gene therapy targeting congenital deafness caused by mutations in the OTOF gene, according to a study published in Nature on April 22.

A total of 42 patients, aged between nine months and 32 years, received the gene therapy. The study found that 90 percent of patients regained hearing after treatment, with improvements continuing steadily over time. Over the next 30 months, those patients who responded to the treatment were continuously monitored for changes in hearing, speech development and overall safety.

Among the responders, all of them were able to hear normal conversation levels, the study showed. Of these, 57 percent could detect very soft sounds similar to library-level noise while 43 percent were able to hear whispers.

There are approximately 26 million people worldwide living with congenital deafness, with cases caused by OTOF gene mutations considered one of the more severe types. However, there are no approved treatments currently available.

To address this, the team led by Shu Yilai and Li Huawei from the Eye and ENT Hospital developed a gene therapy that delivers a functional copy of the ‌OTOF gene directly into the inner ear via injection, enabling patients to regain hearing.

The study not only confirms the long-term effectiveness and safety of gene therapy but also expands its potential use from children to infants and adults, offering hope to more families affected by congenital deafness, Shu, who is also deputy director of the hospital, told the media.

Editor: Kim Taylor