Published: 09 May 2024
A girl born deaf can now hear unaided after participating in a world-first trial.
The CHORD study is for children born with hearing loss due to a genetic condition called auditory neuropathy. Auditory neuropathy is a condition where the ear can detect sound normally, but has a problem sending signals to the brain.
This can be caused by a fault in the OTOF gene. The gene makes a protein called otoferlin that allows cells in the ear to communicate with the hearing nerve. Changes in this gene can reduce sound transmission from the inner hair cells to the hearing nerves.
Gene therapy aims to deliver a working copy of the faulty OTOF gene. The treatment is given using a neutralised virus, injected into the inner ear under general anaesthetic.
The study started in 2023 using a treatment made by Regeneron and is supported by NIHR Cambridge Clinical Research Facility and NIHR Cambridge Biomedical Research Centre.
First patient treated in the global gene therapy trial
Opal Sandy is the first patient treated in the global gene therapy trial. Opal was born completely deaf because of neuropathy. She was treated shortly before her first birthday.
During surgery, while Opal was given the gene therapy in right ear, a cochlear implant was fitted in her left ear.
- Within four weeks Opal responded to sound using her right ear
- After 24 weeks Opal had close to normal hearing levels for sounds such as whispering
- Six months after the treatment Opal can respond to her parents’ voices and can communicate words such as “Dada” and “bye-bye”
Opal’s mother, Jo Sandy, said: “When Opal could first hear us clapping unaided it was mind-blowing - we were so happy when the clinical team confirmed at 24 weeks that her hearing was also picking up softer sounds and speech. The phrase ‘near normal’ hearing was used, and everyone was so excited that such amazing results had been achieved.”
Professor Manohar Bance is the chief investigator for the trial. He is also an ear surgeon at Cambridge University Hospitals NHS Foundation Trust. He said: “These results are spectacular and better than I expected. Gene therapy has been the future of otology and audiology for many years and I’m so excited that it is now finally here. This is hopefully the start of a new era for gene therapies for the inner ear and many types of hearing loss.”
Dr Richard Brown, Consultant Paediatrician at CUH, who is an investigator on the CHORD trial, said: “The development of genomic medicine and alternative treatments is vital for patients worldwide, and increasingly offers hope to children with previously incurable disorders. It is likely that in the long run such treatments require less follow up so may prove to be an attractive option, including within the developing world. Follow up appointments have shown effective results so far with no adverse reactions and it is exciting to see the results to date.”
International research
Doctors in other countries, including China, are exploring very similar treatments for the OTOF gene mutation. Around 20,000 people across the US, UK, Germany, France, Spain and Italy are thought to have auditory neuropathy due to OTOF mutations, which shows the potential significance of a successful treatment. Patients are being enrolled in the study in the US, UK and Spain.
Addenbrooke’s Hospital in Cambridge is participating in the trial. Read more on the Cambridge University Hospitals website.
Photo of Opal Sandy taken by Cambridge University Hospitals