Tirzepatide, an antidiabetic drug currently used to treat type 2 diabetes, was found to be effective in helping individuals who are overweight or have obesity and without diabetes lose weight in combination with other lifestyle changes, according to a recent clinical trial published in Nature Medicine.
“It suggests that a combination of intensive lifestyle therapy followed by medication, rather than intensive lifestyle therapy alone, is more effective in achieving and maintaining weight loss,” said Robert Kushner, MD, ‘82 GME, professor of Medicine in the Division of Endocrinology, Metabolism and Molecular Medicine, and a co-author of the study.
Note: On Nov. 8, tirzepatide was approved by the FDA for weight-related medical problems in patients who are clinically overweight or have obesity. The approval was based on results from the current clinical trial and others.
Currently, more than 40 percent of Americans are clinically overweight or have obesity, according to the Centers for Disease Control and Prevention. Obesity is associated with multiple health complications including type 2 diabetes, hypertension and certain types of cancer, among others.
The current clinical trial suggests that tirzepatide could be added to a list of medications already approved by the FDA to help individuals lose weight, including semaglutide, which was shown in a recent landmark study led by Kushner to be twice as effective as other weight-loss drugs currently on the market.
In comparison to semaglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist, tirzepatide is a “dual agonist,” in that it combines glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 receptor agonism to suppress appetite and reward-seeking behaviors from food in the brain.
In the current study, 579 adults who were clinically overweight or had obesity — having a body mass index between 27 and 30 kg/m2 — and with at least one obesity-related complication (excluding diabetes) were randomized to receive the maximum tolerated dose of tirzepatide (10 or 15 mg) or placebo once a week for a total of 72 weeks (18 months).
All patients had also previously completed a 12-week intensive supervised lifestyle intervention program (changes in diet and exercise) that reduced their baseline body weight by an average of 6.9 percent.
By the end of the trial period, adults who received once-weekly tirzepatide saw an additional 18 percent reduction in weight compared to a 2.5 percent weight gain in the placebo group. Additionally, 87.5 percent of tirzepatide participants attained at least 5 percent weight loss compared with only 16.5 percent of placebo participants.
The findings suggest that once-weekly tirzepatide could be effective in helping adults with overweight or obesity lose weight in combination with supervised or self-directed diet and exercise interventions.
“Either front-loading or adding a more intensive lifestyle therapy is likely to help individuals lose more weight at the end than not receiving that intensive therapy upfront,” said Kushner, who is also a professor of Medical Education.
This work was supported by Eli Lilly and Company.