In a small initial test in people, researchers have shown that a single infusion of a novel gene-editing treatment can reduce cholesterol, the fatty substance that clogs and hardens arteries over time.

The experiment was carried out in 10 participants with an inherited condition that causes extremely high LDL, or “bad,” cholesterol levels, which can lead to heart attack at an early age. Despite being on cholesterol-lowering medications, the volunteers were already suffering from heart disease. They joined a trial in New Zealand and the United Kingdom run by Verve Therapeutics, a Cambridge, Massachusetts–based biotech company.