Abstract
Tirzepatide, a dual GIP/GLP-1 receptor agonist, has shown unprecedented efficacy in weight loss and improving metabolic parameters in clinical trials. However, the durability of these benefits after treatment cessation remains poorly understood. This study aimed to investigate the effect of tirzepatide cessation on body weight change in people with obesity or overweight. This real-world, observational 26-week follow-up study included participants who completed 52 weeks' study treatment during SURMOUNT-CN (NCT05024032). The analysis excluded participants who received anti-obesity medications or bariatric procedures during the 26-week follow-up. Key outcomes were the changes in body weight and waist circumference after 26 weeks, from treatment cessation (Week 52) and trial baseline (Week 0), by the SURMOUNT-CN treatment groups (tirzepatide 10 or 15 mg, or placebo). Overall, 152 participants were included (tirzepatide 10 mg: n = 57; tirzepatide 15 mg: n = 51; placebo: n = 44). Following treatment cessation (Week 52), the mean (SD) percentage changes in body weight at Week 78 were 9.1% (7.4), 12.3% (9.9), and 1.8% (5.2), and the absolute changes in waist circumference were 2.9 cm (7.5), 5.5 cm (6.5) and -0.5 cm (5.6), in tirzepatide 10 and 15 mg, and placebo groups, respectively. From trial baseline to Week 78, the mean (SD) net percentage weight changes were -8.7% (6.9), -10.6% (10.2), and -2.5% (7.0), and the changes in waist circumference were -10.5 cm (8.1), -10.6 cm (9.3) and -4.0 cm (7.2), in the tirzepatide 10 and 15 mg, and placebo groups, respectively. At Week 78, residual improvements in multiple cardiometabolic indicators were evident in the tirzepatide groups. Despite weight gain following tirzepatide cessation, participants achieved a large net weight loss and reduction in waist circumference from trial baseline to Week 78, with residual improvements in several cardiometabolic indicators.