Gene therapy restores hearing in five of six deaf children in trial

- An experimental gene therapy being developed by a Chinese company restored hearing in children with congenital deafness, researchers working on a clinical trial reported yesterday, adding to growing evidence of the efficacy of such treatments.

Five of six young children with profound deafness experienced hearing recovery and improvements in speech recognition six months after treatment with the therapy from Refreshgene Therapeutics, according to the report published in The Lancet.

“The results from this study are truly remarkable. We saw the hearing ability of children improve dramatically week by week, as well as the regaining of their speech,” Zheng-Yi Chen of Mass Eye and Ear and Harvard Medical School, who worked on the trial, said in a statement.

All of the children had profound deafness caused by mutations of the OTOF (otoferlin) gene. A functioning otoferlin protein is necessary for the transmission of the sound signals from the ear to the brain.

OTOF mutations account for 2% to 8% of cases of congenital deafness, earlier research suggests. One out of every 1,000 children born in the U.S. has moderate to profound hearing loss.

In surgical procedures performed at the Eye & ENT Hospital of Fudan University, researchers used a harmless virus to carry a version of the human OTOF gene into patients’ inner ears.

After 26 weeks, five of the six children demonstrated hearing recovery, with dramatic improvements in speech perception and the ability to conduct conversation, the researchers reported.