Clinical trial results show that two new gene therapies have helped several children with a rare inherited form deafness to hear.
Both therapies target the gene. otoferlinA protein in the inner-ear that allows nerve cells to translate sound vibrations into electrical signals that the brain can interpret. Mutations of the otoferlin genes cause About 1% – 8% of casesCongenital deafness is when a child is born without hearing. Even so, mutations of the gene are rare and affect only a small percentage of people. An estimated 200,000 people worldwide.
The new gene therapies deliver otoferlin-producing genes directly to the inner ear using harmless modified viruses. Early data suggest that the treatments work for most patients — although much more research is needed to get the therapies fully approved.
The results of this study are truly amazing. Zheng-Yi ChenIn a press release,, an associate researcher at the Eaton-Peabody Laboratories at Mass Eye and Ear and a professor at Harvard Medical School said. “We observed the hearing ability of the children improving dramatically week by week,” said Chen who is involved in an of the trials.
The results of Chen’s and colleagues’ trials were published on Wednesday, January 24th in the journal The Lancet. They will be presented at the annual meeting on February 3, 2019. Association for Research in Otolaryngology.
Six children were included in the trial. They were treated at an affiliated hospital with Fudan University, Shanghai. All six children had two mutant copies otoferlin genes and had a complete hearing loss before treatment. They ranged in age between 1 and 6 years.
The gene therapy they received contained adeno-associated viruses — a type of virus Gene therapy is often used to treat diseases — whose genes had been scooped out and replaced with the otoferlin gene. Scientists split the otoferlin genes in half and placed each half in a viral vessel. Researchers had tested the safety and efficacy of this treatment on animals, including nonhuman primates and mice.
During the trial each child received the gene therapy through a membrane separating the middle ear and the inner ear. Within 26 weeks, all children but one showed “robust” hearing recovery. The hearing improvements started to appear four to six weeks after treatment, along with improvements to the kids’ speech perception.
Three of these children had a cochlear implantIn their untreated ear. These implants improve hearing by bypassing the inner ear. This allows sound to reach the cerebral cortex in a more direct way. They allow children with otoferlin deafness, to hear some sounds, but they are not as rich and full.
After treatment, all three children were able verbally to communicate with their implants turned off. The two remaining children, who did not have implants, were able to hear and perceive speech for the first.
Researchers reported that the treatment did not cause any serious side-effects, but there were some milder and temporary effects such as fever or transient changes in the white blood cell count. The researchers said that further studies on larger groups of children will be needed to determine the best dose and safety of this one-time treatment.
The six children who were part of the Fudan University study were treated between October 20,22 and June 20,23. In the U.S. a trial of very similar gene therapy was started recently.
Aissam Dam, an 11-year old boy, became the first patient in the U.S. trial on Oct. 4, 2023. The New York Times reported. He was treated by the Children’s Hospital of Philadelphia. This is one of the many sites that are testing the new Akouos gene therapy, made by Eli Lilly.
During Aissam’s surgery, doctors partially lifted his eardrum and inserted an implant into the membrane separating the middle ear and inner ear. CHOP representatives have been announcedTuesday, 23 January. This device delivered gene therapy to inner ear cells. Aissam is now only mildly to moderately deaf on the treated ear, four months after treatment.
Aissam told The New York Times, via interpreter: “There is no sound that I dislike.” “They’re all great.”
Again, Aissam is only the first child treated with the therapy in the U.S. His initial results — which will also be presented at the upcoming ARO meeting — now clear the way for the trial leaders to test the treatment in younger kids, who may have a better chance of acquiring spoken language afterward.
Trials of similar gene therapy are currently underway or about to start in ChinaThe Times reported that Europe is a growing market.
This article is only intended to provide information and not medical advice.
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