The FDA Approves the First-Ever Gene Therapy for Deafness, Which Aims to Restore Hearing in Kids With a Rare Inherited Condition
The agency’s decision is based on results from a clinical trial in which the treatment improved hearing in 80 percent of the pediatric participants. However, Deaf community advocates worry about the push to cure hearing loss
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On April 23, the Food and Drug Administration approved the first-ever gene therapy for a rare, congenital form of deafness. The treatment’s maker, biotechnology company Regeneron, says it plans to provide the therapy for free to patients in the United States.
“This really is life-changing for families with children with hearing loss,” says Eliot Shearer, a pediatric otolaryngologist at Boston Children’s Hospital, who helped lead a clinical trial investigating the treatment, to Berkeley Lovelace Jr. at NBC News.
The therapy, called Otarmeni, is approved for the treatment of otoferlin deafness, a type of genetic hearing loss that affects an estimated 50 babies born each year in the United States. It accounts for about 2 percent to 8 percent of people with inherited deafness.
This form of deafness is caused by a mutated gene that encodes a faulty protein called otoferlin. Normally, this protein helps special cells deep in the ear transmit sound signals to the brain. With defective otoferlin, sound waves are detected by the ears, but the signals aren’t sent for neural processing.
In gene therapy, clinicians can replace a problematic gene with a working version. To deliver Otarmeni, doctors make a small incision and deliver the new gene into the cochlea, a snail-shaped organ in the inner ear. That’s where those sound-transmitting cells are located.
Need to know: How do our ears detect sounds?
When sound hits your eardrum, it causes three tiny bones in the middle ear to move, and one of them taps on a window on the cochlea. This organ is lined with special cells called hair cells and is filled with fluid. The bone tapping causes the cochlear fluid to move, which makes certain hair cells bend. In response, they send electrical messages to the brain, which it processes as sound.
The new treatment relies on the same surgery used to insert an electronic cochlear implant, which was previously the only treatment for otoferlin deafness. However, noises processed with the device often sound robotic or tinny, and high pitches generally don’t come through well.
The FDA based its approval on results of a clinical trial in which 20 children, ages 10 months to 16 years, received the gene therapy. The treatment improved hearing in 80 percent of the participants within a year of their surgery, and 42 percent of them could hear so well they could detect whispers.
“We have now entered the era of biological treatment for inner ear hearing loss,” says Daniel Lee, director of pediatric otology and neurotology at Massachusetts Eye and Ear, to the New York Times’ Gina Kolata. He was not involved with Regeneron’s trial.
John Germiller, a pediatric otology surgeon at the Children’s Hospital of Philadelphia who was also not involved in Regeneron’s study, thinks the next step for the field is to investigate treatments targeting genes that cause progressive hearing loss, not necessarily in babies. Hearing loss and damage to sound-transmitting cells in the cochlea tend to happen at the same time, he tells the Times, so the goal would be to use gene therapy to save the remaining cells.
Researchers in other countries are also developing gene therapies for otoferlin deafness. Findings from a clinical trial in China, published April 22 in the journal Nature, add to the growing consensus that the approach works. This experimental treatment recovered hearing in 90 percent of the 42 participants, some of whom were adults.
While advancements are being made in this field, the efforts have been criticized by members of the Deaf community who say gene therapy will make deaf people an “endangered species.”
“For the signing and Deaf community to continue to exist, we need to have a critical mass of people,” said Teresa Blankmeyer Burke, a bioethicist at Gallaudet University, a college for deaf and hard-of-hearing people, through a sign language interpreter, to STAT’s O. Rose Broderick in 2024. “What happens if the number of deaf people dwindles to a low enough point? What is the impact of that technology, then?”
Jaipreet Virdi, a historian of medicine, technology and disability at the University of Victoria in Canada, tells NPR’s Rob Stein that the gene therapies seem to reinforce the idea that deafness should be eradicated. “We’re saying: ‘Oh, deafness is a problem, and we must fix that.’”
Still, for some people, such treatments have brought life-changing joy. Sierra Smith’s young son, Travis, participated in Regeneron’s trial, she tells NPR. About three months after he received the therapy, she was driving while Travis slept in the backseat.
Suddenly, she laughed loudly and woke him up—the first time that had ever happened.
“That was like the most surreal moment a mother can feel when your son first hears your voice,” Smith says.
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