Liraglutide, a medication that we currently use to treat type 2 diabetes, will soon become available in Canada as a treatment for obesity. Hot off the presses, the biggest clinical trial to study liraglutide as an obesity treatment has just been published this week in the New England Journal of Medicine.
This SCALE obesity trial enrolled just over 3700 participants, and evaluated the effect of liraglutide 3.0mg vs placebo on body weight, with both groups receiving counselling on lifestyle modification. To participate in the study, patients had to have a BMI of at least 30, or a BMI of 27 plus high blood pressure or high cholesterol (treated or untreated). After a year, patients on liraglutide lost 8.4kg of body weight, compared to 2.8kg in the placebo group.
We generally consider a weight loss of 5% to be clinically important, in that a 5% loss of body weight has been shown to be associated with a decreased risk of developing many complications of obesity. In the SCALE trial, 63% of patients lost at least 5% body weight, compared with 27% in the placebo group.
While patients with type 2 diabetes were not included in this study, patients with prediabetes were included, and were equal between groups receiving medication vs placebo at the start of the study. After a year on liraglutide, 70% of patients who had prediabetes at the start of the study had normal blood sugar levels; after a year on placebo, only a third of patients with prediabetes at the start of the study had normal blood sugar levels.
In terms of side effects, the most common side effect in the liraglutide group was gastrointestinal side effects (such as nausea or vomiting); 94% of these symptoms were mild to moderate in nature. Gallbladder related side effects were also more common on liraglutide. Pancreatitis occurred in 0.4% of patients on liraglutide vs less than 0.1% of patients on placebo; the majority of these cases were related to gallstone disease.
Liraglutide will become available as an obesity treatment in Canada later this summer, and is already available in USA. As the first obesity medication approved by Health Canada in 19 years, it will provide a useful tool in our toolbox to treat obesity, in addition to permanent lifestyle changes. Our next challenge is now to convince payors (both provincial and private insurance companies) of the need to truly consider obesity as a chronic disease, and accordingly provide financial coverage for obesity medications.
Disclaimer: I was involved in the research trials of liraglutide as an obesity treatment. I receive honoraria as a continuing medical education speaker and consultant from the makers of liraglutide (Novo Nordisk). I am involved in research of medications similar to liraglutide for the treatment of type 2 diabetes.