Test time has arrived: the first person has been treated a highly anticipated gene therapy trial which aims to encourage older cells to adopt a younger identity.
The clinical trial will test a new approach that involves activating three genes that appear to “partially reprogram” old cells, allowing them to behave as if they were young again. Some scientists say partial reprogramming could rejuvenate old organs. But this trial will test activating all three genes as an approach to treating the disease – in this case, a form of glaucoma, a disease that can cause blindness.
The hope is that the proteins encoded by these genes will allow the regeneration of neurons in the optic nerve, which connects the eye to the brain and which can be damaged in people with glaucoma. These neurons do not normally regenerate in adults. The trial’s sponsor company, Life Biosciences in Boston, Massachusetts, announced June 9 that it had treated its first participant.
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The stakes are high. The trial will test the safety of the reprogramming approach, which is an ongoing concern in the field. Animal studies in several laboratories have suggested that partial reprogramming can be done safely, but there are concerns that it could tip some cells into a cancerous state.
“Reprogramming has a big advantage if it can be used safely in humans,” says Matt Kaeberlein, co-founder of Optispan, a preventive medicine company focused on longevity in Seattle, Washington. “The technology is still in its early stages and the potential for catastrophic side effects is high.”
As a result, the eye is probably a good first place to try the technique, Kaeberlein says, because the risks of life-threatening side effects are lower with changes to the eye than to some other organs.
Go back in time
The goal of partial reprogramming is to push older adult cells back in time, restoring the characteristics of young cells without pushing old cells so far back that they completely lose their specialized identity – and function. To do this, Life Biosciences exploits three of the four genes that, in the laboratory, can be manipulated to reprogram adult cells into a stem cell-like state.
In 2020, researchers in David Sinclair’s lab at Harvard Medical School in Boston, Massachusetts, and their colleagues found that activation of these three genes in mice with damaged optic nerves promoted neuron regeneration and reverse vision loss in aged mice and mice with glaucoma. Since then, Life Biosciences has studied this approach in rodents and monkeys and found no serious side effects from the treatment, said Sharon Rosenzweig-Lipson, the company’s chief scientific officer.
In the clinical trial, Life Biosciences aims to treat up to 12 people with glaucoma and ultimately include some participants with an acute, severe disease called NAION, which also causes eye nerve damage.
The company relies on a virus commonly used in gene therapy to carry the three reprogramming genes into retinal ganglion cells, whose long arms make up the optic nerve. As an added safety feature, the system is designed so that the genes are activated when the participant takes an antibiotic called doxycycline. If the antibiotic is withdrawn, the genes turn off. “It gives us a lot of control,” says Rosenzweig-Lipson. “And the ability to not only turn it on, but turn it off and not leave the expression any longer than necessary to rejuvenate the cells.”
Real youth
The success of the trial would be a boon for people with glaucoma and NAION, but whether it means the modified cells are truly “younger” and can be reprogrammed to improve longevity is a broader question, says Pete Williams, a translational neurobiologist at the Center for Eye Research Australia in Melbourne.
Rosenzweig-Lipson says the company is tackling “one age-related disease at a time.” “We are not considering full-body rejuvenation at this time,” she says. “We hope to get there one day, but we’re not there yet.” Life Biosciences has also studied its approach in animal models of liver disease.
For eye conditions, Williams welcomes a new strategy for treating retinal nerve damage, an area he says doesn’t get enough funding or attention. But the public attention focused on Life’s treatment also worries him. “There was a lot of hype about it,” he says. “If this goes catastrophically wrong, it could ruin us all in the future.” »
This article is reproduced with permission and has been published for the first time June 9, 2026.
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