Not only did the system work in 13 monkeys, the researchers reported, but it appeared that every liver cell had been altered. After gene editing, the monkeys’ LDL levels dropped 59% in two weeks. Editing the ANGPTL3 gene resulted in a 64% drop in triglyceride levels.
One of the dangers of gene editing is that the process can lead to a change in DNA that scientists do not expect. “You can never have off-target effects,” warned Dr. Deepak Srivastava, president of the Gladstone Institutes in San Francisco.
By treating a condition as common as heart disease, he added, even an uncommon side effect can mean that many patients are affected. So far, however, the researchers say they have seen no unintended changes to other genes.
Another question is how long will the effect on cholesterol and triglyceride levels last, said Dr. Davidson. “We hope it will be done and done, but we have to validate it with clinical trials,” he said.
Jennifer Doudna, biochemist at the University of California at Berkeley and discoverer of Crispr, the revolutionary gene editing system, said: “In principle, Verve’s approach could be better because it is a treatment unique.”
But it is far too early to say whether it will be safe and durable, she added.
If the strategy works in humans, its greatest impact could be in poor countries that cannot afford expensive injections for people at high risk for heart disease, said Dr. Daniel Rader, chair of the genetics department. from the University of Pennsylvania and a member of the Verve Scientific Advisory Board.
Dr. Kathiresan of Verve noted that half of all first heart attacks end in sudden death, so protecting people at high risk is imperative.