Science magazine has selected the new obesity drugs as “Breakthrough of the Year 2023”, the distinction that designates the most notable scientific advance of the year.
The publication assesses that the benefits of these drugs have extended beyond obesity, since this year they have been shown to reduce cardiovascular mortality and kidney disease. He also values that they help combat the stigma associated with obesity, by showing that it is due to biochemical causes and not a lack of will.
But Science warns that these drugs pose a challenge for doctors and researchers, since they open new scientific questions, and also for health systems, which face the challenge of promoting equitable access to expensive treatments.
“GLP-1 agonists have opened more questions than they have answered, a hallmark of a real breakthrough,” says Holden Thorp, editor of Science, in an editorial.
In a clinical trial with 17,000 participants presented in August, semaglutide has reduced heart attacks, strokes and cardiovascular deaths by 20%. Another clinical trial with more than 3,500 participants has shown that it slows the progression of kidney disease, as reported in October by the Danish company Novo Nordisk.
With sales of more than a billion dollars a month, Novo Nordisk has reached a value greater than the GDP of all of Denmark this year. The company markets the drug as Wegowy for obesity and as Ozempic and Rybelsus for diabetes.
A second agonist of the GLP-1 hormone, tirzepatide from the company Eli Lilly, is already approved in Europe for the treatment of diabetes and is expected to be approved in the coming months for obesity. The results of clinical trials indicate that tirzepatide achieves greater weight loss than semaglutide. Other pharmaceutical multinationals such as Pfizer or AstraZeneca are developing their own GLP-1 agonists.
One of the questions that have arisen with the arrival of this new family of drugs is what indications they will have beyond the treatment of diabetes and obesity. Following the results presented this year, its potential for cardiovascular and kidney diseases will be assessed. There are also clinical trials underway for addiction treatment after some users have reported that it reduces their urge to use tobacco or alcohol, which is attributed to the drugs blocking receptors in the brain related to seeking rewards. Other clinical trials are exploring its possible effectiveness for the treatment of Alzheimer's and Parkinson's, which would be explained by its anti-inflammatory effect on the brain.
In the field of obesity, the questions awaiting answers are whether treatment should be for life; what the side effects of long-term treatment may be; and how to prevent weight gain again if treatment is stopped, something that no pharmaceutical company has shown interest in investigating.
But the big question in the short term is how to make it easier for these treatments to reach all the people for whom they will be indicated. With a cost per person of more than a thousand dollars per month in the United States for semaglutide, and about 310 euros per month in Germany, and waiting for the price to be set in Spain, it will be difficult for health systems to cover the cost of the treatment for the entire obese population, which will force prioritization of the groups that can benefit most from it.
“These drugs are forcing important discussions about how we view obesity,” notes Holden Thorp, the editor of Science. “There is now compelling evidence that a biochemical difference, not poor willpower, is responsible for weight gain. This could reduce stigma and judgment about weight. And this would really be a breakthrough.”
