A new study revealed that patients who stopped taking Eli Lilly's weight-loss drug, Zepbound, experienced substantial weight regain nearly a year after ending treatment. The findings, which were published in the Journal of the American Medical Association (JAMA), showed that obese patients without diabetes saw a 14% increase in weight after switching from Zepbound to a placebo following an eight-month course of treatment.
In contrast, those patients who continued using Zepbound during the 52-week period experienced an additional 5.5% reduction in weight. These results emphasize the importance of long-term treatment with Zepbound for sustained weight loss.
Eli Lilly's tirzepatide, marketed as Zepbound for weight loss, is also used as Mounjaro for type 2 diabetes. Alongside other drugs like Novo Nordisk's Wegovy and Ozempic, these medications belong to a class of treatments that target the GLP-1 hormone, which induces the feeling of fullness after eating.
However, discontinuing the use of weight-loss drugs, including Wegovy, poses the risk of patients regaining their original body weight within five years, as indicated by a statement made by a Novo Nordisk official earlier this year. These findings underscore the significance of consistent and long-term therapy for sustainable weight loss.
Although Eli Lilly had previously shared some details from this trial in July, the recently published full results provide more comprehensive insights. Analysts noted that the study outcomes highlight the necessity for patients to continue therapy with GLP-1 drugs for an extended duration.
Goldman Sachs analysts emphasized the need for further data to evaluate the effects of tirzepatide and other similar therapies over multiple years of continuous treatment. They stressed the risk of a diminishing response to these drugs, making it crucial to monitor long-term effects and efficacy.
Throughout the entire 88-week treatment period, patients who remained on Eli Lilly's drug achieved a remarkable 25.3% weight loss. On the other hand, those who switched to a placebo after 56 weeks experienced an overall weight reduction of 9.9% during the entire study period.
These findings shed light on the critical role of consistent therapy with Zepbound or similar GLP-1 agonists in achieving and maintaining substantial weight loss. The study further underscores the importance of long-term evaluation to understand any potential diminishing response to these medications over extended periods of use.