A one-time CRISPR-Cas9 gene editing treatment targeting the ANGPTL3 gene maintains significant reductions in cholesterol and triglycerides for at least one year. Data presented at the European Society of Cardiology Congress 2026 confirms that the therapy, known as CTX310, remains safe and effective after 12 months of follow-up. These findings appear as a research letter in the New England Journal of Medicine.
Understanding the ANGPTL3 Approach
Researchers developed CTX310 based on evidence that the ANGPTL3 protein regulates lipid metabolism. People with natural loss-of-function variants in the ANGPTL3 gene experience lifelong lower levels of LDL cholesterol and triglycerides. By using lipid nanoparticle-encapsulated CRISPR-Cas9 to induce a permanent mutation in hepatocytes, the treatment aims to replicate this biological advantage.
This specific gene-editing formulation uses both mRNA and guide RNA to modify the target gene. The primary goal is to achieve a permanent genetic change that persists despite normal liver cell turnover. This method offers a move away from daily medication toward a potential one-time intervention for refractory dyslipidemia.
Study Findings and Long-term Data
The phase 1a clinical trial enrolled 15 adults diagnosed with hypercholesterolemia, severe hypertriglyceridemia, or mixed dyslipidemia. Participants received a single infusion of CTX310 at doses ranging from 0.1 to 0.8 mg/kg. The initial 60-day results, published in 2025, confirmed the therapy was well-tolerated with no serious adverse events.
Extended data through one year shows that lipid reductions remained durable. Patients receiving the highest dose of 0.8 mg/kg saw their ANGPTL3 levels drop by an average of 78.6%. Simultaneously, LDL cholesterol fell by 52.5%, and triglycerides decreased by 47.8%. These figures indicate that the genetic modification holds firm even as liver cells replicate over time.
Implications for Future Gene Therapy
Cleveland Clinic cardiologist Luke Laffin, MD, notes that these results suggest a one-and-done treatment approach is viable for various genetic targets. Because hepatocytes turn over at a rate of roughly 20% per year, the consistency of these results indicates high editing efficiency. The genetic change persists in daughter cells, preventing a rebound in lipid levels.
Still, the clinical path forward requires caution. The FDA mandates 15 years of patient surveillance for this trial. Steven Nissen, MD, Chief Academic Officer of the Heart, Vascular & Thoracic Institute, explains that this oversight focuses on potential long-term safety concerns, such as malignancy. This duration of monitoring will likely become a standard requirement for upcoming CRISPR-based therapies.
Next Steps in Clinical Trials
The research team is now preparing to launch a phase 1b trial. This upcoming study will move beyond the heterogeneous participant mix of the phase 1a trial. Instead, researchers will evaluate treatment efficacy within specific cohorts of patients with defined lipid disorders. All participants in the new phase will receive a standardized dosage to better assess therapeutic performance.
Public interest in the study has grown since the initial publication. Dr. Laffin reports that numerous potential patients have reached out regarding participation in future trials. As the field looks toward treating conditions like PCSK9, the data from CTX310 provides a baseline for evaluating the longevity of gene-editing interventions in cardiology.