CRISPR Therapeutics Reports Phase 1b Data for CTX310 in Severe Hypertriglyceridemia at AHA 2026

Key Takeaways

• CRISPR Therapeutics presented Phase 1b data for CTX310, an investigational in vivo CRISPR/Cas9 gene editing therapy targeting ANGPTL3, in a late-breaking oral presentation at the American Heart Association (AHA) Scientific Sessions 2026.
• In 10 patients with sHTG, a single infusion produced mean reductions at Day 30 of 65% in ANGPTL3 and 63% in triglycerides. Median baseline triglycerides were above 1,000 mg/dL.
• The company reports no treatment-related serious adverse events and no clinically relevant liver enzyme elevations. The study is small, open-label, and has short follow-up.

CRISPR Therapeutics announced clinical data from the sHTG cohort of its Phase 1b trial of CTX310, with the results presented by Ashish Sarraju, M.D., a preventive cardiologist at the Cleveland Clinic. The data build on Phase 1a results, including one-year durability findings presented at the European Society of Cardiology Congress 2026 and published in The New England Journal of Medicine. The FDA recently granted Regenerative Medicine Advanced Therapy (RMAT) designations to CTX310 for sHTG and for patients with elevated LDL cholesterol.

CTX310 uses a lipid nanoparticle delivery system to edit the ANGPTL3 gene in the liver. ANGPTL3 is a protein involved in regulating lipid metabolism. The Phase 1b portion is a multicenter, open-label study at sites in New Zealand, Australia, the United Kingdom, and the United States. In the sHTG cohort, 10 participants with fasting triglycerides above 500 mg/dL received a single intravenous infusion of 40 mg (for body weight under 85 kg) or 50 mg (85 kg or more). The flat dosing was designed to approximate the 0.8 mg/kg dose studied in Phase 1a, and the cohort includes one Phase 1a participant who received 56.5 mg. All participants had diabetes, three (30%) had a history of pancreatitis, and two (20%) had clinical atherosclerotic cardiovascular disease.

At Day 30, mean reductions from baseline were 65% for circulating ANGPTL3 protein and 63% for triglycerides. The mean reductions in non-HDL cholesterol and apolipoprotein B were 51% and 23%, and LDL cholesterol fell by a mean 16% from a low baseline of 60 mg/dL. The company says the reductions in ANGPTL3 and triglycerides were maintained in participants followed for at least 90 days, which was seven of the 10 at the data cutoff. No acute pancreatitis events were reported on study.

On safety, the company reports no serious adverse events related to CTX310, no clinically relevant elevations in AST or ALT, and no related adverse events of Grade 3 or higher. One participant had a Grade 2 infusion-related reaction that resolved, and the infusion was completed. Chief Medical Officer Naimish Patel, M.D., said sHTG carries a higher risk of acute pancreatitis and cardiovascular disease, and that many patients still have elevated triglycerides on current therapies.

The data come from 10 participants, with no comparison group, and the follow-up period reported is short. The results are company-reported, from a press release, so the figures haven’t been peer reviewed. The trial is also designed first to assess safety, with the lipid changes as exploratory measures. CRISPR Therapeutics says additional Phase 1b cohorts are ongoing, and CTX310 is also in development for familial hypercholesterolemia and mixed dyslipidemias. The company, based in Zug, Switzerland, and Boston, also has programs targeting angiotensinogen (CTX340) and lipoprotein(a) (CTX321), and it markets the first approved CRISPR-based therapy, Casgevy, with Vertex.