Now a cousin of CRISPR can prove himself. Recently, a team tested for the first time in humans whether a genome editing method related to the CRISPR-Cas9 system can be used safely. With base editing, one wants to precisely change a genetic sequence in a cholesterol-regulating gene without first destroying both DNA strands, as CRISPR-Cas9 would do.
The experiments are to be followed by another base-editing study in which researchers want to treat a genetic blood disease – sickle cell anemia. The test series is scheduled to start in 2022.
Results from both studies are expected to be available in 2023, while additional base-editing therapies are pending approval for initial clinical trials. “It’s very exciting that the first clinical trials are starting with CRISPR-Cas9 and now also with base editing,” says Gerald Schwank, who studies genome editing to treat diseases at the University of Zurich. »We still have a lot to learn.«
Lower cholesterol with base editing
Announced in mid-July 2022, the study will use a base editor to convert an adenine (A) base to a guanine (G) base in DNA encoding a protein called PCSK9, a key regulator of cholesterol levels. The approach, developed by Verve Therapeutics in Cambridge, Massachusetts, aims to reduce the amount of functional PCSK9 in people with heterozygous familial hypercholesterolemia, which causes high cholesterol and can lead to heart disease. PCSK9 deactivation has been shown to lower cholesterol and heart disease risk, and several therapies already on the market reduce PCSK9 activity.