US-China Collaboration Successfully Restores Hearing in Children Through Gene Therapy

Groundbreaking gene therapy trials conducted jointly by the US and China have achieved a historic milestone by restoring hearing in five children, a significant breakthrough.

LONDON, ENGLAND - AUGUST 27: A child covers his ears from the loud music as he sits in a bus shelter on the final day of the Notting Hill Carnival on August 27, 2018 in London, England.

Hearing Restoration for Children

Conducted at the Eye & ENT Hospital of Fudan University in Shanghai, and co-led by the Massachusetts Mass Eye and Ear Hospital in Boston, the study showcased the potential of a novel gene treatment in addressing hereditary deafness in children.

Interesting Engineering reported that the outcomes revealed that five out of the six children who underwent the gene therapy experienced restored hearing and exhibited enhanced speech recognition.

The significance of this achievement is emphasized by Zheng-Yi Chen, DPhil, an associate scientist in the Eaton-Peabody Laboratories at Mass Eye and Ear, who noted that the results from the study are truly remarkable.

Chen highlighted the critical role of intervention, stating that if children are unable to hear, their brain development can be adversely affected. The observed improvement in the hearing ability of the children, coupled with the gradual recovery of their speech, underscores the promising impact of gene therapy.

The research focused on children diagnosed with DFNB9, a form of autosomal recessive deafness resulting from a genetic mutation inherited from both parents.

This genetic condition stems from mutations in the OTOF (otoferlin) gene, hindering the production of a functional otoferlin protein crucial for transmitting sound signals from the ear to the brain.

To develop a novel gene therapy, researchers utilized an adeno-associated virus (AAV) carrying a modified version of the human OTOF gene. Through a precise surgical procedure, this gene was introduced into the inner ears of the patients.

This approach aimed to correct the genetic issue by providing patients with a functional OTOF gene, addressing the root cause of hereditary deafness.

Seeing Promising Results

After 26 weeks, an improvement in hearing was observed in five of the children, as indicated by ABR testing showing a decrease of 40-57 dB. This was accompanied by significant enhancements in speech perception, allowing the children to actively engage in normal conversations.

Importantly, EurekAlert reported that the absence of "dose-limiting toxicity" emphasized that the gene therapy did not elicit severe side effects that would constrain its dosage.

The team at the Eye & ENT Hospital of Fudan University, led by Yilai Shu, the lead study author, expressed excitement about being trailblazers in initiating the clinical trial of OTOF gene therapy.

They successfully translated findings from basic research in the animal model of DFNB9 to achieve hearing restoration in children with DFNB9, as conveyed in a press release.

In another significant occurrence, an 11-year-old boy has become the first recipient of gene therapy in the United States to address congenital deafness.

According to the New York Times, he received treatment at the Children's Hospital of Philadelphia and had been grappling with Otoferlin deafness since birth. Following the treatment, the boy gained the ability to hear for the first time.