First-in-human CRISPR cuts bad cholesterol 52.5% at 12 months

One infusion was followed by a year of monitoring. At Cleveland Clinic, 15 patients with medication-resistant lipid disorders received CTX310, an experimental CRISPR-Cas9 gene-editing therapy, and the highest dose cut LDL (“bad”) cholesterol by 52.5% and triglycerides by 47.8% from baseline. The first-in-human Phase I trial found no serious adverse events related to the therapy during that year.

CTX310 carries the CRISPR-Cas9 editing mechanism into the liver, where it switches off ANGPTL3. Turning off that gene can lower LDL cholesterol and triglycerides, both linked to heart disease. Participants received a single infusion at doses ranging from 0.1 to 0.8 mg/kg after pretreatment with corticosteroids and antihistamines.

The result extends data first presented in November 2025: reductions reported after two months persisted at 12 months across the tested doses. At the highest dose, LDL cholesterol and triglycerides fell by approximately 50% on average after one year. Cleveland Clinic cardiologist Luke Laffin, the study’s first author, said the team was encouraged by the durability and the absence of serious safety events, while continuing to seek larger studies.

So what changes for patients? For people whose lipid disorders resist medication, a one-time infusion could, if larger trials confirm the result, offer a way to lower both measures through a year. The current study measured lipid levels and treatment-related safety; it does not yet establish how CTX310 affects heart disease itself.

Long-term certainty will take time. Additional safety follow-up is planned for the next 15 years, as recommended by the FDA for gene-editing therapies. The findings were presented at the 2026 European Society of Cardiology annual meeting and published in the New England Journal of Medicine.