In a laboratory room, a small boy, deaf from birth, sits as a tone rings. There is no reaction. His face doesn’t change.
Six weeks later, after a single injection of an experimental gene therapy, the same toddler returns to the same room. The tone plays. The child’s head turns towards the sound. And somewhere off screen, the boy’s grandfather says his name. The boy turns around and looks. He can hear.
“When the parents realized that their child responded to the sound, they cried,” says Dr. Yilai Shu of Fudan University Eye and Ear, Nose and Throat Hospital, who co-led the trial, in a video showing the results. “The whole family cried.” The video shows another child, thirteen weeks after treatment, dancing to music.
Here’s what gene therapy can do in 2026. The clip comes from the international clinical trial of an OTOF gene therapy conducted by Mass Eye and Ear and China’s Fudan University that provided the underlying science behind a drug that the Food and Drug Administration (FDA) approved last week.
On April 23, the FDA granted accelerated approval to Otarmeni, a gene therapy from pharmaceutical company Regeneron for severe to profound hearing loss caused by mutations in a gene called OTOF. In a pivotal trial, 80 percent of treated patients achieved measurable hearing and 42 percent achieved the level needed to pick up whispers. Two and a half years after treatment, 90 percent of patients in the underlying multicenter trial could still hear.
It is a drug that certainly seems like a miracle to those participating in the trials, as it takes patients from silence to sound. But what may seem almost as miraculous is how far the broader field of gene therapies like Otarmeni, which delivers a functional copy of a broken gene directly into a patient’s cells, has come.
In 1999, the nascent field of gene therapy virtually collapsed when a teenager named Jesse Gelsinger died four days after being injected with an experimental gene therapy at the University of Pennsylvania, the first publicly identified death in a gene therapy clinical trial. In the years that followed, funding evaporated, careers ended, and “gene therapy” became a cautionary tale.
It took years and major changes in the way gene therapies are administered for this field to recover. And now, 27 years after Gelsinger’s tragic death, we have a gene therapy that can effectively reverse some types of congenital hearing loss. The next decade is no longer about whether gene therapy can deliver clinical results. It’s about whether you can deliver results to enough patients, at prices people can actually afford, for diseases that affect more than a few hundred children a year.
Get those answers right and what some consider a miracle in 2026 could become common medicine.
After Gelsinger’s death, the FDA halted gene therapy trials in the United States, the National Institutes of Health tightened oversight, and the Penn study’s principal investigator, James Wilson, was banned from clinical trials for five years and stripped of his administrative titles. In the lean years that followed, two things happened.
The first was a change in delivery. Gene therapies use engineered viruses to deliver restorative genes to a patient’s cells. The therapy used in Gelsinger was carried out by an adenovirus, which is highly immunogenic, meaning that the human immune system recognizes them and reacts violently. It was that immune reaction that killed Gelsinger.
The field subsequently turned increasingly to adeno-associated viruses (AAVs), which are smaller, more tolerable, and capable of slipping a payload into the right cells without triggering a five-alarm immune reaction. AAV vectors are now the workhorse of in vivo gene therapy, including at Otarmeni.
The second thing that happened was CRISPR. Adapted in 2012 by Jennifer Doudna and Emmanuelle Charpentier as a precision gene-editing tool, CRISPR could do something AAV couldn’t: find a specific spot in the patient’s own DNA and rewrite the letters there, fixing the broken gene in its place. CRISPR also gave gene therapy a cultural moment it hadn’t had since before Gelsinger. Money and talent returned to the field, including the AAV shows that produced Otarmeni.
The clearest sign that something has changed in the field is the growing list of therapy approvals. In December 2017, the FDA cleared Luxturna for hereditary blindness due to RPE65 mutations, the first gene therapy in the US for an inherited disease. Two years later, Zolgensma was approved for spinal muscular atrophy, a debilitating disease that, in its severe form, kills children before the age of two. In 2022, Hemgenix made hemophilia B the first bleeding disorder with a unique solution. In 2023, Casgevy and Lyfgenia did the same for sickle cells, and Casegevy became the first CRISPR therapy approved by the FDA.
The sickle cell approvals are the most important because they are the first for a large patient population; 100,000 Americans suffer from it, mostly black and historically underserved. Gene therapies are also proof of concept that the underlying CRISPR mechanism can be redirected to multiple different targets. Verve Therapeutics is using base editing to permanently disable PCSK9, a gene that controls the amount of LDL cholesterol that remains in the bloodstream, with the promise of a one-time treatment instead of daily statins for patients at high cardiovascular risk. Early data from the trials showed an average 53 percent drop in LDL cholesterol. Trials are open for additional hereditary blindness genes, Pompe disease, and a long list of single-gene diseases.
The science is working, but paying for it is another matter.
Here are the list prices for the recent approvals: Luxturna at $850,000 per patient, Zolgensma at $2.13 million, Casgevy at $2.2 million, Lyfgenia at $3.1 million, and Hemgenix at $3.5 million. Two-thirds of U.S. sickle cell patients receive Medicaid and only 16,000 are eligible for Casgevy under the current label. Regeneron has committed to providing Otarmeni for free in the US, but that only works because OTOF’s patient pool is small: an estimated 50 babies a year. That math won’t work for more common disorders.
While cost may not be an issue for families who might qualify for Otarmeni, it is not the only concern. Cochlear implants, the standard treatment for OTOF patients for decades, have been contested within deaf culture since the 1980s, with many arguing that deafness should be seen as an identity and not a deficit. Gene therapy applied to babies makes that issue even more complicated, since children treated with gene therapy cannot consent to the change. And not everyone would make that decision.
Beyond economic and cultural issues, we lack gene therapy for Alzheimer’s, schizophrenia, or any of the polygenic (i.e. caused by multiple genes) diseases that cause enormous amounts of suffering. The cochlea is a good gene therapy target because it is small and accessible, and OTOF is a single-gene disorder. The brain and Alzheimer’s are neither of those things. The platform that will work in a child’s inner ear in 2026 will not offer universal cures by 2030, or much beyond.
However, what gene therapies will do is continue to complete the list. The next time a parent is diagnosed with a rare disease for their child, the question increasingly will not be whether anyone is working on a gene therapy, but how soon it will be ready.
A version of this story originally appeared in the Good News newsletter. Register here!