Echoes of Hope: Bilateral Gene Therapy Unlocks a World of Sound for Children Born Deaf

Stereo Sound of Success: Gene Therapy Orchestrates Hearing Recovery in Deaf Children

In a groundbreaking clinical trial, researchers have successfully administered gene therapy to both ears of children born with inherited deafness, offering hope for millions of people worldwide. The trial, conducted at the Eye & ENT Hospital of Fudan University in Shanghai, China, in collaboration with the Mass Eye and Ear Hospital in Boston, Massachusetts, has shown promising results in recovering hearing in both ears affected by OTOF gene mutations that cause autosomal deafness.

Congenital deafness affects more than 26 million people globally, and until now, no pharmaceutical drugs or treatments have been available to cure genetic deafness. However, the emergence of gene therapy has opened up new possibilities for restoring hearing ability and improving the quality of life for those affected.

The trial builds upon a previous phase in which the treatment was only provided to one of the children's ears. The main goal of this second trial was to restore hearing abilities in both ears, allowing patients to perceive sounds in three dimensions, which is crucial for effective communication and everyday tasks like driving.

Five children participated in this first-of-a-kind bilateral trial, with the first child receiving gene therapy in both ears in July 2023. The therapy involves delivering functional copies of the human OTOF gene via adeno-associated virus (AAV) into the inner ear through a specialized, minimally invasive surgery.

During the follow-up period of either 13 or 26 weeks, all five children experienced hearing recovery in both ears, with notable improvements in understanding speech and identifying the location of sounds. Remarkably, two children even developed the ability to appreciate music, indicating that the therapy can restore more complex auditory functions.

Zheng-Yi Chen, study co-senior author and an associate scientist in the Eaton-Peabody Laboratories at Mass Eye and Ear, expressed his enthusiasm for the results, stating, "The results from these studies are astounding. We continue to see the hearing ability of treated children dramatically progress, and the new study shows added benefits of the gene therapy when administrated to both ears, including the ability for sound source localization and improvements in speech recognition in noisy environments."

The trial is still ongoing, with follow-up monitoring and check-ups of the five children. If approved, this gene treatment has the potential to restore hearing to millions of children worldwide who suffer from DFNB9, a specific kind of hereditary deafness caused by mutations in the OTOF gene.

Chen and his team are hopeful that this approach can be expanded to treat deafness caused by other genes or non-genetic causes. "Our ultimate goal is to help people regain hearing no matter how their hearing loss was caused," Chen added.

The results of this groundbreaking study were published in the prestigious journal Nature Medicine, highlighting the significance of this breakthrough in the field of gene therapy and its potential to revolutionize the treatment of inherited deafness.