Fifteen people with stubborn lipid disorders got a single dose of CTX310. Their LDL cholesterol dropped by more than half. Triglycerides fell almost as much. These numbers held steady for a full year. No serious safety problems turned up during follow-up.
At the highest dose, ANGPTL3 protein levels in the blood were reduced by nearly 79%, aligning with the intended biological target of the therapy.
CTX310 sends the CRISPR machinery straight to the liver. There, it targets ANGPTL3, a gene that controls blood fats. Turning off ANGPTL3 lowers both LDL cholesterol and triglycerides. These are two major risks for heart disease. Doses ranged from 0.1 to 0.8 mg/kg. The biggest changes came at the top dose. Before the infusion, patients got corticosteroids and antihistamines to lower the risk of immune reactions. Doctors watched them closely for side effects and lab changes.
The lasting effect stands out. Earlier data from November 2025 showed strong drops in cholesterol. Now, the 12-month results confirm that one CRISPR treatment can keep these gains for at least a year. Luke Laffin, M.D., a Cleveland Clinic cardiologist and lead author, said, "Building upon the initial data presented in November 2025, the durability of the lipid-lowering effect was impressive." The team shared the results at the 2026 European Society of Cardiology meeting and in the New England Journal of Medicine.
The 12-month results were not an expansion of the trial cohort, but a confirmation of the durability of effect seen in the initial data. Long-term safety will be monitored for up to 15 years, as is standard for gene-editing interventions.
The trial is still small. Only 15 people took part. CTX310 remains experimental. Long-term safety is not yet known. Researchers will track patients for 15 years, following FDA rules for gene-editing studies. CRISPR Therapeutics AG funded the work. Dr. Laffin’s institution received research support from the company.
One thing is clear. CRISPR therapies are moving beyond rare diseases and lab tests. Here, a single infusion gave a year of real, meaningful drops in two tough heart risk factors. No serious safety issues so far. The group is small and the follow-up is just the start. Still, these results force a rethink of what’s possible in cholesterol care. If bigger, longer studies confirm the findings, treatment for hard-to-manage cholesterol could change fast. One-and-done gene editing for common diseases may be closer than anyone thought.
