In a significant advancement for gene editing, a new treatment utilizing CRISPR has effectively lowered high cholesterol levels in a small group of individuals. A trial led by the Swiss biotech firm Crispr Therapeutics involved 15 participants who received a one-time infusion designed to deactivate a liver gene known as ANGPTL3. Some individuals are born with a mutation in this gene that offers protection against heart disease without any negative side effects, although such occurrences are uncommon.
The highest dose tested in this trial resulted in a remarkable average reduction of 50 percent in both “bad” LDL cholesterol and triglycerides within two weeks of treatment. These effects persisted for at least 60 days, which was the duration of the trial. The findings were shared at the American Heart Association’s annual meeting and published in The New England Journal of Medicine.
While the Nobel Prize-winning CRISPR technology has primarily focused on rare diseases, these new results suggest that this DNA-editing tool could also be effective for more common health issues. “This will probably be one of the biggest moments in the arc of CRISPR’s development in medicine,” says Samarth Kulkarni, CEO of Crispr Therapeutics. The company is known for having the only approved gene-editing treatment available, Casgevy, which targets sickle cell disease and beta thalassemia.
The American Heart Association estimates that around 25% of adults in the U.S. have elevated LDL levels, and a similar number have high triglycerides. LDL cholesterol is a waxy substance in the blood that can lead to clogged and hardened arteries over time, while triglycerides are the most common type of fat in the body. Elevated levels of both can increase the risk of heart attacks and strokes.
Conducted in the UK, Australia, and New Zealand from June 2024 to August 2025, the Phase I trial included participants aged 31 to 68 with uncontrolled LDL cholesterol and triglyceride levels. The trial assessed five different doses of the CRISPR infusion, which typically took about two and a half hours to administer.
“These are very sick people,” states Steven Nissen, senior author and chief academic officer of the Heart, Vascular and Thoracic Institute at Cleveland Clinic, which independently verified the trial’s results. “The tragedy of this disease is not just that people die young, but some of them will have a heart attack, and their lives are never the same again. They don’t get back to work, they develop heart failure.”
One participant, a 51-year-old man, passed away six months after receiving the lowest dose of the treatment, which did not result in reduced cholesterol or triglycerides. His death was linked to his pre-existing heart disease and not the experimental CRISPR treatment. The man had a rare inherited genetic condition causing high cholesterol and had undergone multiple procedures to enhance blood flow to his heart.
