Background

Dyslipidemia is a major risk factor for cardiovascular diseases such as angina and myocardial infarction. Previously, patients had to take statin-based medications daily or receive periodic injections of targeted therapies to regulate blood lipid levels. However, the inconvenience of daily medication often led to poor medication adherence, resulting in long-term treatment failure. Patients with familial hypercholesterolemia, a condition caused by genetic mutations, particularly struggled to control their lipid levels with existing drug therapies.

Angiopoietin-like protein 3 (ANGPTL3), produced in the liver, is a protein that regulates lipid metabolism. It has been shown that blocking the activity of this protein reduces the blood concentration of low-density lipoprotein (LDL) cholesterol and triglycerides (TG), prompting active research into therapies targeting ANGPTL3. Existing treatments, such as monoclonal antibodies or small interfering RNA (siRNA)-based therapies, required periodic administration every few months to maintain their effects. This highlighted the need for a gene therapy that could provide lifelong cholesterol control with a single injection.

Key Findings

Researchers at CRISPR Therapeutics developed CTX310, an in vivo CRISPR-Cas9 gene-editing therapy, and conducted clinical evaluations. The results were presented at the European Society of Cardiology (ESC) 2026 Annual Congress and simultaneously published in the New England Journal of Medicine (NEJM). This study is a one-year follow-up of a Phase 1a clinical trial involving 15 patients with refractory dyslipidemia, familial hypercholesterolemia, and severe hypertriglyceridemia.

Participants received a single intravenous injection of CTX310. The key focus of the study was the long-term persistence of the treatment effect. Analysis revealed a significant reduction in lipid levels in the group receiving the highest dose of 0.8 mg/kg. At the one-year mark, the average level of ANGPTL3 protein in the blood had decreased by 79%, with a maximum reduction of 89%. Levels of LDL cholesterol, a major contributor to cardiovascular disease, were reduced by an average of 53%. Triglyceride levels also decreased by an average of 48%, demonstrating that the effects of a single dose were sustained over a long period.

Patients who received the drug exhibited excellent tolerability. No dose-limiting toxicity or major adverse events related to the treatment were reported during the clinical process. Notably, no adverse effects such as a sharp increase in liver enzyme levels, which are a concern in gene-editing therapies, were observed. Some patients experienced mild infusion reactions, but symptoms resolved spontaneously without additional treatment.

Significance and Outlook

The clinical results showing that blood lipid levels can be maintained at normal levels for a long time with a single treatment herald a paradigm shift in the treatment of chronic diseases. This opens a path to address the root cause of diseases through gene correction, moving away from the traditional model of lifelong medication. This approach can fundamentally eliminate the risks associated with non-adherence to medication, such as missed treatment windows or complications, thereby improving treatment success rates. It also presents an opportunity to apply gene-editing technology to other chronic diseases requiring long-term management, such as hypertension and diabetes.

However, clear challenges remain before commercialization. This clinical trial was conducted with a very limited number of patients (15 individuals) and is in an early stage. To validate efficacy in a larger patient population and confirm potential risks such as unexpected off-target effects, long-term follow-up is necessary. Addressing high drug costs and ensuring patient access will also be critical challenges. CRISPR Therapeutics is currently advancing a Phase 1b clinical trial with a fixed dose of 0.8 mg/kg to explore the potential for commercialization.