
Gene therapy may help treat congenital deafness
According to the results of a study by the Chinese company Refreshgene Therapeutics, as part of a clinical trial of AAV1-hOTOF gene therapy, hearing was restored to 5 out of 6 children with congenital deafness.
The clinical trial, conducted at the Massachusetts Medical Center for Vision and Hearing (MEE) in Boston, enrolled six children aged one to 18 years with autosomal recessive nonsyndromic deafness type 9 (DFNB9), caused by a mutation in the OTOF gene. According to the researchers, a defect in this gene leads to dysfunction of the otoferlin protein, whose main function is to transmit sound signals from the ear to the brain.
Refreshgene Therapeutics has developed a drug that is an OTOF transgene on adeno-associated virus serotype 1 (AAV1), intended for one-time injection into patients' inner ear at different dosages. After drug administration, patients were examined for 26 weeks.
6 months after therapy, 5 out of 6 patients had restored hearing and improved speech understanding.
No patients experienced any serious adverse events during the study, but 46 adverse events did occur, including a decrease in neutrophil counts in one study participant.
However, according to the results of the study, the drug was found to be effective and safe for the treatment of children with congenital deafness.
According to the researchers, this is the first clinical trial to study the effectiveness of gene therapy to treat DFNB9. In the future, it is planned to organize larger studies involving a larger number of patients in order to verify the effectiveness of this treatment method.
According to WHO: “More than 5% of the world's population, or 430 million people, require rehabilitation to address disabling hearing loss (432 million adults and 34 million children). It is estimated that by 2050, more than 700 million people, or one in ten, will have disabling hearing loss.
“Disabling” hearing loss in the better-hearing ear is greater than 35 decibels (dB). Almost 80% of these people live in low- and middle-income countries. Hearing loss is more widespread among older people, with the problem affecting more than 25% of people over the age of 60.”