These results came from the first human clinical trial of a treatment based on CRISPR-Cas9 gene-editing technology, a revolutionary tool used to precisely modify DNA within human cells.
The new experimental treatment, called CTX310, is administered via a single intravenous injection. It uses tiny fat-based molecules to deliver CRISPR technology to the liver, where it disables a specific gene known as ANGPTL3, which is responsible for producing a protein that affects blood lipid levels.
When this gene is disabled, levels of bad cholesterol (LDL) and triglycerides, which are associated with an increased risk of heart disease and stroke, decrease.
Interestingly, some people are born with natural mutations that disable this gene, allowing them to live with low levels of fat without any health problems. This has led researchers to seek to mimic this effect therapeutically using CRISPR technology.
The trial included 15 adult patients from Australia, New Zealand and the United Kingdom, aged between 18 and 75, who suffered from chronically high levels of lipids despite receiving the most effective treatments possible.
The trial was conducted in 6 medical centers between June 2024 and August 2025, under the supervision of researchers from the Victoria Heart Institute at Monash University in Australia.
Participants received a single dose of intravenous CTX310 ranging from 0.1 to 0.8 mg per kilogram of body weight, after being pre-treated with anti-allergy and anti-inflammatory drugs to avoid any immune reactions.
The results showed that levels of bad cholesterol and triglycerides decreased significantly within just two weeks of the injections, and this decrease lasted for at least 60 days.
At the highest dose, the reduction rate reached approximately 60% on average, a result that exceeded initial expectations, which ranged between 30% and 40%.
"This is an unprecedented achievement — a one-time treatment that simultaneously achieves a double reduction in cholesterol and triglycerides," said Dr. Luke J. Lavin, MD, a preventive cardiologist at the Cleveland Clinic and the study's lead researcher. "If its effectiveness is confirmed in larger studies, it could change the future of lifelong lipid disorders treatment."
The researchers reported that the treatment was relatively safe, with no serious complications. Three participants experienced mild, temporary symptoms such as back pain and nausea during the injection procedure, but these symptoms quickly resolved with supportive care. Doctors also observed a temporary elevation in liver enzymes in one patient, but these returned to normal within days without any further intervention.
So far, no long-term side effects have been observed, but the researchers explained that follow-up will continue for 15 years, in line with the instructions of the US Food and Drug Administration (FDA) to ensure the safety of permanent gene therapies.
This treatment is the first gene intervention to achieve a substantial and simultaneous reduction in two types of fats associated with heart disease, giving hope to patients who do not respond well to conventional drugs such as statins.
Dr. Steven E. Nissen, of the Cleveland Clinic Heart Institute and a participant in the study, pointed out that the biggest challenge in treating cholesterol is the poor adherence of patients to long-term medications, adding: "The possibility of using a one-time treatment that lasts for years represents a major leap forward in the prevention of heart disease."
The researchers plan to launch the second phase of clinical trials in late 2025 or early 2026, involving larger numbers of patients and diverse age and gender groups, with the aim of confirming the long-term effectiveness and safety of the treatment.
The study results were announced during the American Heart Association's 2025 Scientific Sessions, held in New Orleans, USA, between November 7 and 10, and the research paper was simultaneously published in the New England Journal of Medicine.