A single dose of an experimental jab has been found to cut “bad” cholesterol levels by half within six months of treatment in a small Chinese gene-editing trial, a new study reveals.
The therapy is being developed for the treatment of familial hypercholesterolemia, a life-threatening hereditary disease that causes abnormally high levels of fats in the blood.
Patients with the condition face a heart attack risk 10 to 20 times higher than normal and need lifelong medication.
Researchers at China’s Shanghai Jiao Tong University tested the therapy in six volunteers aged 34 to 62 with a confirmed diagnosis and found the patients showed a significant reduction in their “bad” cholesterol levels within six months of starting treatment.
The experimental treatment also did not cause dangerous side effects, they say.
Low-density lipoprotein cholesterol (LDL-C) in the body, also called “bad” cholesterol, is a key driver of heart disease, along with fat molecules called triglycerides.
Currently, most people across the world take daily statin pills to keep these molecules at manageable levels in the body.
In recent years, scientists have been exploring gene-editing methods to control levels of these fat molecules.
One pioneering approach targets the PCSK9 gene in the liver, which, when overactive, can drastically weaken the liver’s ability to remove bad cholesterol. Chinese scientists developed an enzyme from the bacterium Hafnia paralvei, which targets specific genetic sequences to neutralise viruses.
They modified the bacterial enzyme to target human DNA, particularly the PCSK9 gene in liver cells, to weaken its cholesterol production ability.
Three patients who took the highest dose showed a significant reduction in the activity of the PCSK9 enzyme (by 74 per cent) and a 52 per cent decrease in “bad” cholesterol levels within six months of starting treatment.
Some participants said they experienced mild side effects like fever and muscle aches, which resolved within 24 hours, and no other adverse events were reported.
Patients are also expected to undergo long-term follow-up for up to 15 years, according to the trial protocol.
In another recent gene-editing trial conducted by the Cleveland Clinic in the US, four volunteers who received the highest dose saw their bad cholesterol drop by 52 per cent and triglycerides fell by 48 per cent.
This therapy targeted a gene named ANGPTL3, which regulates how much fat circulates in the blood.
The experimental treatment is based on previous research, which showed that those born with a mutation inhibiting ANGPTL3 have extremely low cholesterol and triglycerides and rarely develop any heart disease.
Scientists hope the new gene-editing jabs could be further developed to cover more patients with other kinds of lipid disorders.