New gene therapy enables children with a rare form of deafness to hear
The Food and Drug Administration on Thursday approved a gene therapy that can cure a rare, inherited form of deafness. The treatment is the first to restore normal hearing to children born deaf.
The therapy’s maker, Regeneron, plans to make it free to any child who needs it. “We wanted to make a statement,” said Dr. George Yancopoulos, Regeneron’s chief scientific officer, on Thursday morning.
He explained that the company wants to ensure that its treatment “reaches its full potential and helps as many people as possible.” President Trump is expected to discuss the new treatment in a briefing on Thursday afternoon.
Gene therapies for other diseases that cost millions of dollars have had dismal sales.
The therapy, called Otarmeni, is intended for children with otoferlin deafness, a rare form of hearing loss caused by a mutation in a single gene. The mutation destroys a protein in the inner ear that is required for sound transmission to the brain.
Although otoferlin deafness accounts for only 2 to 8 percent of congenital hearing loss, the new treatment is “game-changing,” Dr. Dylan Chan, a pediatric otolaryngologist at the University of California, San Francisco.
He added: “This is the first time in history that there is a medical therapy that enables deaf children to hear.”
Dr. Chan was a paid consultant to Regeneron and Eli Lilly, which is also developing a gene therapy for otoferlin deafness. He is also principal investigator for Lilly’s clinical trial of the treatment.
Dr. Daniel Lee, the director of pediatric otology and neurotology at the Massachusetts Eye and Ear Infirmary, said he also considers the therapy groundbreaking. “We have now entered the era of biological treatment for sensorineural hearing loss,” he said.
Dr. Lee is on the advisory board of a small biotech company, Skylark Bio, which is developing a gene therapy for another form of inherited deafness.
Previously, the only treatment for otoferlin deafness was a cochlear implant, an electronic device inserted into the inner ear. The implants can restore sound, but not normal hearing. And the sounds seem robotic or tinny.
People with cochlear implants have difficulty coping in noisy environments. You don’t hear high frequencies. And at night they have to recharge their batteries so that they stay deaf until morning.
In addition to Regeneron and Lilly, two other companies in China and France are also developing gene therapies for otoferlin deafness.
Dr. Eliot Shearer, a pediatric surgeon specializing in hearing loss at Boston Children’s Hospital, said otoferlin gene therapy is just the beginning of a treatment for deafness. “There are over 150 known genetic causes of hearing loss and thousands of mutations in these genes,” said Dr. Shearer. “Now that it is known that it is possible to correct genetic hearing loss, new possibilities are opening up.”
Dr. Shearer is principal investigator of the Regeneron and Lilly Otoferlin clinical trials.
To treat deafness with gene therapy, researchers had to solve one problem: getting the genes into the cochlea, a spiral-shaped cavity almost in the middle of the skull. The cochlea is filled with fluid and lined with 3,500 inner hair cells, each tuned to a specific pitch.
Sound vibrations spread through the liquid and bend the microscopic hairs. When a hair cell bends, it is triggered. An electrical signal travels to the brain via the auditory nerve and the person hears the sound.
Researchers focused on otoferlin deafness because the cause was clear. The otoferlin gene is only expressed in the hair cells of the inner ear. The inner ear structures, including the hair cells, are intact. To enable patients to hear, doctors simply had to provide a working copy of the otoferlin gene.
Otolaryngologists had long assumed that injecting a drug into the inner ear would inevitably damage the delicate cells and membranes of the cochlea.
But children with Otoferlin deafness already cannot hear. Even if a gene therapy attempt damaged their inner ears, they could still receive cochlear implants.
“It was the perfect destination,” said Dr. Chan.
Kerri M., whose baby Miles suffered from Otoferlin deafness, said gene therapy “completely changed our lives.” She spoke on condition of anonymity because she wanted to prevent her son’s diagnosis from appearing on the Internet.
Dr. Shearer said Miles’ hearing loss was so severe that he could not hear a jet engine if it was near him.
Miles received Regeneron therapy on May 19, 2025, when he was 13 months old. At his last visit, his hearing was normal.
“We are so lucky,” his mother said. “Our baby was born deaf and now he can hear.”
Most children who received the gene therapy had their hearing restored, but not all were as lucky as Miles. So far, said Dr. Chan, about 80 percent of patients who were successfully treated in clinical trials were able to hear well without the need for cochlear implants.
Most still needed a hearing aid, but about 30 percent of those who could hear after treatment were like Miles – their hearing was within normal limits.
The next target for scientists working on gene therapies to correct deafness is mutations in the GJB2 gene. It is the most common form of congenital hearing loss in children, accounting for about 20 percent of cases.
Dr. Lee explained that the biology of GJB2 deafness is more complex than that of otoferlin because cells in the cochlea are damaged. In contrast, Otoferlin’s gene therapy is like repairing a broken wire – the cells are normal, they just can’t transmit a signal.
Dr. Lee said Skylark Bio hopes to start a clinical trial of gene therapy for GJB2-related deafness in children ages 9 months to 7 years in the United States this year.
Dr. John Germiller, a pediatric otologist at Children’s Hospital of Philadelphia and the University of Pennsylvania, predicted that the next frontier will be people with genes that cause progressive hearing loss, and not necessarily babies.
Hearing loss and the loss of hair cells in the cochlea tend to occur together, he said. The aim is to save the remaining hair cells using gene therapy.
Dr. Germiller is principal investigator of the Lilly Otoferlin trial and treated the first patient in the United States two years ago.
Dr. Chan expressed an even more ambitious hope for the future – the end of most forms of deafness.
“Many people are working to reprogram cells in the inner ear to rebuild themselves,” said Dr. Chan. The hope is to restore the cochlea.
“That,” added Dr. Chan added, “is the ultimate holy grail.”
