A new diabetes drug helped people lose a quarter of their body weight

But can the pocket afford it?
Ameya Paleja

In May this year, the U.S. Food and Drug Administration approved a new drug called Tirzepatide to fight Type 2 diabetes. A Phase 3 clinical trial of the same drug to test its effect on weight loss in obese and overweight people has shown some promising results.

According to the Centers for Disease Control and Prevention, obesity is a serious disease in the U.S. affecting as many as 42 percent of the population. It also increases the risk of other illnesses such as cardiovascular conditions, type 2 diabetes, and some types of cancer. 

While some take the slow way of eating a balanced diet and an increase in physical activity to bring their weight under control, others opt for surgical interventions to see a substantial loss in weight. A once-a-week skin injection could also deliver weight loss results similar to surgical intervention. 

What is this new weight-loss drug? 

Developed by U.S. pharmaceutical company Eli Lilly, the drug Tirzepatide combines two synthetic incretins, GLP-1 and GIP. Incretins are naturally occurring hormones in the body involved in food digestion and help lower blood sugar after we consume a meal.

GLP-1 stands for glucagon-like peptide-1, while GIP stands for the glucose-dependent insulinotropic polypeptide. Both these incretins work on controlling insulin levels in the body, whose inefficient production is the cause of diabetes. By ensuring sufficient insulin levels, these incretins help control diabetes and have also been approved by the FDA. 

In 2021, the FDA also approved a GLP-1-based drug, semaglutide, as a weight-loss drug after encouraging results in clinical trials. Since Eli Lilly's tirzepatide uses GLP-1, researchers wanted to know if it could be used as a weight-loss medication too.

Phase 3 clinical trial

The researchers enrolled 2,539 participants who were either overweight or obese for the study to investigate. For 72 weeks, the participants either received tirzepatide or a placebo while also being provided with support to follow a low-calorie diet and increase physical activity. 

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The drug was administered as a weekly injection. Individuals receiving the drug were categorized into three dose groups; 5 mg, 10 mg, and 15 mg. Preliminary results of the trial that is still ongoing came out in April this year and have now undergone peer review and have been published in the New England Journal of Medicine

According to the researchers, all three groups of patients who received the drug showed significant weight loss. On average, patients who received the 15 mg dose showed a 22.5 percent (52 lb, 24 kg) reduction in weight, while those who received the 10 mg dose showed a 21.4 percent (49 lb, 22 kg) weight reduction. Individuals who received a 5 mg dose also demonstrated a 16 percent (35 lb, 16 kg) weight reduction on average, while those on the placebo lost only 2.4 percent (5 lb, 2 kg) of their body weight. 

The results of the 15 mg dose are comparable to bariatric surgery, which has been reported to show 25 to 30 percent weight reduction in patients.  

"Almost 40% of individuals lost a quarter of their body weight," said coauthor Dr. Ania Jastreboff, codirector of the Yale Center for Weight Management.

Can this be used to treat obesity? 

While the results are promising, there is also the issue of side effects of the drug that need to be taken into account. As many as a third of participants in the trial who received the drug felt nauseous; diarrhea was also commonly reported, which FDA will look into before approving the drug. 

Even if the drug were approved, Eli Lilly's price for tirzepatide as a diabetes drug is $974.33 a week. It is unlikely that health insurance will cover these drugs, Science Alert reported. So, even if science were to bring a cure for obesity, economics would block it from being accessible to those who need it.