A British toddler’s hearing has been restored after she became the first person in the world to take part in a pioneering gene therapy trial, in a development which doctors say heralds a new era in the treatment of deafness.
Opal Sandy was born hearing nothing due to auditory neuropathy, a condition that disrupts nerve impulses traveling from the inner ear to the brain and can be caused by a faulty gene.
But after receiving an infusion with a working copy of the gene during ground-breaking surgery that took just 16 minutes, the 18-month-old can hear almost perfectly and enjoys playing with toy drums.
Her parents were left “scratched” when they realized she could hear about the treatment for the first time. “I couldn’t really believe it,” said Opal’s mother, Jo Sandy. “It was… bonkers.”
The girl, from Oxfordshire, was treated at Addenbrooke’s Hospital, part of the Cambridge University Hospitals NHS Foundation Trust, which Test of agreement. More deaf children from the UK, Spain and the US are being recruited for the trial and will all be followed up for five years.
Prof Manohar Bance, an ear surgeon at the trust and lead investigator for the trial, said the initial results were “better than I hoped or expected” and could cure patients with this type of deafness.
“We have results from [Opal] which is very spectacular – so close to normal hearing recovery. So we hope that this can be a potential cure.”
He added: “There was so much work, decades of work… to finally see something that actually worked in people…. It was quite spectacular and really a bit awe-inspiring. It felt very special.”
Auditory neuropathy can be caused by an error in the OTOF gene, which makes a protein called otoferlin. This enables cells in the ear to communicate with the auditory nerve. To overcome the error, the new therapy from biotech firm Regeneron sends a working copy of the gene to the ear.
A second child also recently received the gene therapy treatment at University Hospitals in Cambridge, with positive results.
The overall Chord trial consists of three parts, with three deaf children including Opal receiving a low dose of gene therapy in one ear only.
Another set of three children will receive a high dose on one side. Then, if it is proven safe, more children will receive a dose in both ears at the same time. In total, 18 children worldwide will be recruited for the trial.
Opal is the first patient worldwide to receive the therapy and is “the youngest worldwide to be done so far as far as we know”, said Bance.
The gene therapy – DB-OTO – is specific for children with OTOF mutations. A harmless virus is used to carry the working gene into the patient.
The trial is “just the beginning of gene therapies,” Bance said. “This heralds a new era in the treatment of deafness.”
Martin McLean, a senior policy adviser at the National Deaf Children’s Society, said deafness should never be a barrier to happiness or fulfillment. “Many families will welcome these developments, and we look forward to learning about the long-term outcomes for the children who are treated.”
With Opal’s hearing restored, her parents now have a new problem to contend with: their daughter’s new favorite hobby is banging cutlery on the table to make as much noise as possible.