In one step Toward broader use of gene editing, a treatment that uses Crispr has successfully reduced high cholesterol levels in a small number of people.
In a trial led by Swiss biotechnology company Crispr Therapeutics, 15 participants received a single infusion designed to turn off a liver gene called ANGPTL3. Although rare, some people are born with a mutation in this gene that protects against heart disease, with no apparent ill effects.
The highest dose tested in the trial reduced both “bad” LDL cholesterol and triglycerides by an average of 50% within two weeks of treatment. The effects lasted at least 60 days, the duration of the trial. The findings were presented today at the American Heart Association annual meeting and published in the New England Journal of Medicine.
Nobel Prize-winning Crispr technology has primarily been used to treat rare diseases, but these latest findings, although early, add to the evidence that the DNA editing tool could also be used to treat common illnesses.
“This will likely be one of the most important moments in the development arc of Crispr in medicine,” Samarth Kulkarni, CEO of Crispr Therapeutics, told WIRED. The company is behind the only approved gene editing treatment on the market, Casgevy, which treats sickle cell disease and beta thalassemia.
The American Heart Association estimates that about a quarter of adults in the United States have high LDL levels. A similar number have high triglycerides. LDL cholesterol is the waxy substance found in the blood that can clog and harden arteries over time. Triglycerides, on the other hand, are the most common type of fat in the body. High levels of both substances increase the risk of heart attack and stroke.
The phase I trial was conducted in the UK, Australia and New Zealand between June 2024 and August 2025. Participants were aged 31 to 68 and had uncontrolled levels of LDL cholesterol and triglycerides. The trial tested five different doses of the Crispr infusion, which took about two and a half hours on average to administer.
“These are very sick people,” says Steven Nissen, lead author and academic director of the Heart, Vascular and Thoracic Institute at the Cleveland Clinic, who independently confirmed the trial results. “The tragedy of this disease is not only that people die young, but that some of them will have a heart attack and their lives will never be the same. They don’t return to work, they develop heart failure.”
One trial participant, a 51-year-old man, died six months after receiving the lowest dose of the treatment, which was not associated with lower cholesterol and triglycerides. The death was related to his existing heart condition, not the experimental treatment Crispr. The man suffered from a rare, hereditary genetic form of high cholesterol and had previously undergone several procedures to improve blood flow to his heart.
