Genetic test could predict success of injectable weight-loss drugs, a step toward precision medicine for obesity

CNN
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One of the great mysteries of popular GLP-1 weight loss drugs is why some people will lose 20 percent or more of their initial body weight on these drugs, while for others the scale will barely budge.

One study found that about 1 in 7 people who used semaglutide – which is approved for weight loss under the brand name Wegovy – for more than a year did not lose at least 5% of their initial weight, which which indicates that the medicine has not been lost. works well for them.

Now, research suggests the answer may lie in a person’s genes.

The study shows that a new test assigning a genetic risk score could help people determine whether they are likely to succeed with injected weight loss drugs.

“We believe the test will be able to explain who will be able to lose weight, and we can predict with 95% accuracy who will lose more than 5% with this genetic test,” said gastroenterologist Dr. Andres Acosta. and researcher. at the Mayo Clinic who helped develop the test.

Acosta points out that these drugs are not cheap. They are not always covered by insurance, and if they are, they may have high co-pays. Being able to predict whether medications will work could save people a lot of frustration and money.

The test, MyPhenome, was developed by researchers at the Mayo Clinic and was licensed last year by a company called Phenomic Sciences. It costs $350 and must be ordered by a health care provider.

It looks for 6,000 changes in 22 genes that are in the GLP-1 hormone signaling pathway, and uses the results to assign each person a risk score that classifies them as either “hungry gut” – positive or “hungry gut” – negative.

People who have positive gut hunger have normal responses to hormonal signals in the brain, while people who have negative gut hunger do not seem to respond as well to hormonal signals from the stomach that tell the brain to stop eating. eat. Acosta says the test classifies these people as having a starving brain and they may need different types of interventions to lose weight, such as bariatric surgery.

In a recent small study of 84 people enrolled in a weight loss registry at the Mayo Clinic, researchers performed the test on stored blood or saliva samples. After nine months of treatment with semaglutide, people classified as having positive gut hunger had lost significantly more weight than those with negative gut hunger.

After a year, people classified as hungry had lost an average of 19% of their starting weight, almost twice as much, on average, as the 10% of total body weight lost by people classified as hungry. hungry for the test. negative hungry gut.

The study is expected to be presented Monday at the Digestive Disease Week conference in Washington, DC. It has not been reviewed by outside experts or published in a medical journal, so its findings are considered preliminary.

“We need to test them in a randomized, double-blind, placebo-controlled trial, as we have done with other drugs. It’s the highest gold standard,” Acosta said.

“But at this point we can say that these results were for patients who did not know the results or the investigation,” he added, meaning they did not know if they had intestinal hunger positive or negative while they were being fed. using the medicine.