Gene editing therapy reduced cholesterol levels by half

In one step towards wider use of gene editing, a treatment that brings benefits Crispy was able to successfully reduce high cholesterol levels in a small number of people.

In a study by the Swiss biotech company Crispr Therapeutics, 15 participants received a one-time infusion designed to turn off a gene in the liver ANGPTL3. Although rare, some people are born with a mutation in this gene that protects against heart disease without any obvious negative consequences.

The highest dose tested in the study reduced both LDL “bad” cholesterol and triglycerides by an average of 50 percent within two weeks of treatment. The effect lasted for at least 60 days, the duration of the experiment. The results were presented today at the annual meeting of the American Heart Association and published in The New England Journal of Medicine.

The Nobel Prize-winning Crispr technology was largely used Treatment of rare diseasesBut these latest findings, while still early, bolster evidence that the DNA-editing tool could also be used to treat common medical conditions.

“This will likely be one of the biggest moments in the development of Crispr in medicine,” Samarth Kulkarni, CEO of Crispr Therapeutics, tells WIRED. The company is behind the only approved gene editing treatment on the market. Casgevythat treats sickle cell anemia and beta thalassemia.

The American Heart Association Estimates that about a quarter of adults in the US have elevated LDL levels. A similar number have high triglycerides. LDL cholesterol is the waxy substance in the blood that can clog and harden arteries over time. Triglycerides are now the most common type of fat in the body. High levels of both increase the risk of heart attack and stroke.

The Phase I study was conducted between June 2024 and August 2025 in the United Kingdom, Australia and New Zealand. The participants were between 31 and 68 years old and had uncontrolled levels of LDL cholesterol and triglycerides. The study tested five different doses of Crispr infusion, which took an average of about two and a half hours to administer.

“These are very sick people,” said Steven Nissen, senior author and scientific director of the Heart, Vascular and Thoracic Institute at the Cleveland Clinic, who independently confirmed the study’s results. “The tragedy of this disease is not only that people die young, but that some of them also suffer a heart attack and their lives will never be the same again. If they can’t go back to work, they develop heart failure.”

One study participant, a 51-year-old man, died six months after receiving the lowest dose of treatment that was not associated with reductions in cholesterol and triglyceride levels. The death was related to his existing heart disease, not the experimental Crispr treatment. The man had a rare, inherited genetic form of high cholesterol and had previously undergone several procedures to improve blood flow to his heart.