10 May 2024

Girl hears for first time after pioneering gene therapy

by Hannah Williams

A gene therapy treatment has restored hearing to a toddler born with profound bilateral hearing loss, Cambridge University Hospitals NHS Foundation Trust reports.

The parents of Opal Sandy, from Oxfordshire, described their amazement when she turned to their clapping just four weeks after the infusion to her right ear at Addenbrooke's Hospital in Cambridge.

Opal is the first British participant and the youngest to receive the therapy as part of the CHORD trial's investigation into whether gene therapy can provide hearing for children born with a hearing loss caused by auditory neuropathy spectrum disorder (ANSD).

About 10% of children born with a permanent hearing loss in the UK have this type of deafness. Some have a mutation in the OTOF gene that codes for a protein called otoferline, which sends nerve signals from the inner ear to the brain.

Children with ANSD often pass the newborn hearing screening because the hair cells work, unlike for many other permanent childhood hearing impairments. Opal's hearing loss was picked up early through genetic testing because her sister has the condition.

Professor Manohar Bance, an otologist and the chief investigator at the Cambridge site, said the therapy marked a new era in deafness treatments. "It also supports the development of other gene therapies that may prove to make a difference in other genetic-related hearing conditions, many of which are more common than auditory neuropathy."

Opal has a cochlear implant in her other ear. Now 18 months old, she can respond to quiet speech even when not wearing her implant.

Patients in the study's first phase receive a low dose to one ear, delivered via the harmless AAV1 virus. If all goes well, those in the second phase will receive a higher dose. In the third phase, the plan is to introduce the gene therapy to both ears.

The CHORD trial is sponsored by Regeneron biotechnology company. Children are being enrolled in the UK, the US and Spain.