In the phase 3 SURMOUNT-3 trial, tirzepatide recipients saw some of the most impressive weight loss results among trials of GLP-1 drugs, including most notably semaglutide. In the study, participants’ total mean weight loss was 26.6% over 84 weeks following a 12-week intensive lifestyle intervention and subsequent tirzepatide treatment. In all, participants who received tirzepatide lost an additional 18.4% of their body weight compared to a weight gain of 2.5% in the placebo group.
In SURMOUNT-3, some 87.5% of participants who received tirzepatide achieved an additional weight reduction of 5% or more, compared to 16.5% of those in the placebo group.
While it is difficult to compare data from separate studies, the highest weight loss percentage for tizepatide, 26.6%, was 53% higher than the highest percentage, 17.4%, for semaglutide (OASIS 1).
More possible momentum for tirzepatide
The data could drive more momentum for tirzepatide, a glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) dual agonist that generated $1.55 billion in sales in the first half of 2023. The Wall Street consensus is roughly $15 billion in peak sales with UBS foreseeing peak sales of $25 billion. Some analysts project that the drug could fetch up to $50 billion annually.
The FDA approved the drug with a brand name of Mounjaro (tirzepatide) to treat type 2 diabetes in May 2022. In October, the drug received an FDA Fast Track designation for adults with obesity or overweight with weight-related comorbidities.
Tirzepatide safety profile in SURMOUNT-3
In SURMOUNT-3, the safety profile was in line with data from the previously shared SURMOUNT and SURPASS studies. The most common adverse events were gastrointestinal in nature, including nausea (39.7% vs. 14.0%), diarrhea (31.0% vs. 9.2%), constipation (23.0% vs. 6.8%), and vomiting (18.1% vs. 1.4%). COVID-19 diagnoses were common among both tirzepatide and placebo recipients (23.0% vs. 25.3%).
Most adverse events were mostly mild to moderate and occurred mainly during the dose escalation phase of the study. A total of 5.9% tirzepatide recipients experienced serious adverse events compared to 4.8% in the placebo group.
The table below summarizes weight loss outcomes and details from various trials of semaglutide and tirzepatide:
Cost-effectiveness could drive tirzepatide adoption
A 2022 article in Diabetes, Obesity and Metabolism concluded that tirzepatide could be a potent competitor to semaglutide in terms of weight loss, especially among individuals with type 2 diabetes. The analysis explored the cost needed to treat for a 1% body weight reduction using both drugs, concluding, ultimately, that tirzepatide was more economical. The 52-week analysis found a cost-needed-to-treat value of $683.49 for tirzepatide versus $1,350.97 for semaglutide, underscoring tirzepatide's cost-effectiveness despite a higher upfront cost.
The article also simulated therapy group weight reduction costs per 1% of body weight reduction, concluding that tirzepatide would cost $1,196.90 compared to semaglutide's $1,511.17. The analysis, however, cited a need for head-to-head trials to corroborate its findings.
Filed Under: Metabolic disease/endicrinology, Uncategorized
