SURMOUNT-1 results published in The New England Journal of Medicine show tirzepatide achieved between 16.0% and 22.5% weight loss in adults with obesity or overweight.- Eli Lilly.

Tirzepatide met both co-primary endpoints of superior mean percent change in body weight from baseline and greater percentage of participants achieving body weight reductions of at least 5% compared to placebo for both estimands.

For the efficacy estimand, participants taking tirzepatide achieved average weight reductions of 16.0% (35 lb. or 16 kg on 5 mg), 21.4% (49 lb. or 22 kg on 10 mg) and 22.5% (52 lb. or 24 kg on 15 mg), compared to placebo (2.4%, 5 lb. or 2 kg). Additionally, 89% (5 mg) and 96% (10 mg and 15 mg) of people taking tirzepatide achieved at least 5% body weight reductions compared to 28% of those taking placebo.

All three doses of tirzepatide achieved all key secondary endpoints at 72 weeks of treatment for the efficacy estimand, including: i. Percentage of participants achieving at least 10% body weight reductions: 73% (5 mg, not controlled for type 1 error), 86% (10 mg) and 90% (15 mg) compared to 14% with placebo. ii. Percentage of participants achieving at least 15% body weight reductions: 50% (5 mg, not controlled for type 1 error), 74% (10 mg) and 78% (15 mg) compared to 6.0% with placebo. iii. Percentage of participants achieving at least 20% body weight reductions: 32% (5 mg, not controlled for type 1 error), 55% (10 mg) and 63% (15 mg) compared to 1.3% with placebo. iv. Change in waist circumference from baseline: -14.6 cm (5 mg, not controlled for type 1 error), -19.4 cm (10 mg) and -19.9 cm (15 mg) compared to -3.4 cm with placebo.

All three doses of tirzepatide achieved an additional secondary endpoint at 72 weeks of treatment , measuring the percentage of participants achieving at least 25% body weight reductions (not controlled for type 1 error): 16.5% (5 mg), 35% (10 mg) and 39.7% (15 mg) compared to 0.3% with placebo. Participants taking tirzepatide also achieved an approximately three times greater percent reduction in fat mass versus lean mass (33.9% fat mass reduction compared to a 10.9% lean mass reduction).

"Obesity is a chronic, treatable disease, and individuals living with obesity deserve effective and safe treatment options that can help restore their weight to levels that support optimal health," said Ania Jastreboff, MD, Ph.D., Associate Professor of Medicine & Pediatrics, Endocrinology & Metabolism, at Yale School of Medicine; Director, Weight Management & Obesity Prevention at the Yale Stress Center; and co-Director of the Yale Center for Weight Management. "In SURMOUNT-1, participants taking tirzepatide on average lost up to one fifth of their body weight – and notably, about nine out of ten participants taking tirzepatide lost weight. These results are significantly higher than the placebo arm and underscore the importance of this study."

Tirzepatide also met the co-primary and all key secondary endpoints for the treatment-regimen estimand , including : i. Average body weight reductions: 15.0% (5 mg), 19.5% (10 mg) and 20.9% (15 mg) compared to 3.1% with placebo. ii.Percentage of participants achieving body weight reductions of greater than 5%: 85% (5 mg), 89% (10 mg) and 91% (15 mg) compared to 35% with placebo. iii. Percentage of participants achieving greater 10 % body weight reductions: 69% (5 mg, not controlled for type 1 error), 78% (10 mg) and 84% (15 mg) compared to 19% with placebo. ivi Percentage of participants achieving greater than 15% body weight reductions: 48% (5 mg, not controlled for type 1 error), 67% (10 mg) and 71% (15 mg) compared to 9% with placebo. v. Percentage of participants achieving body weight reductions of greater than 20%: 30% (5 mg, not controlled for type 1 error), 50% (10 mg), and 57% (15 mg) compared to 3.1% with placebo. v. Change in waist circumference from baseline: -14.0 cm (5 mg, not controlled for type 1 error), -17.7 cm (10 mg) and -18.5 cm (15 mg) compared to -4.0 cm with placebo. vi. Percentage of participants taking tirzepatide achieving greater than 25% body weight reductions (not controlled for type 1 error): 15.3% (5 mg), 32.3% (10 mg) and 36.2% (15 mg) compared to 1.5% with placebo.

The overall safety and tolerability profile of tirzepatide was similar to other incretin-based therapies approved for the treatment of obesity . The most commonly reported adverse events were gastrointestinal-related and generally mild to moderate in severity, usually occurring during the dose escalation period. For those treated with tirzepatide (5 mg, 10 mg and 15 mg, respectively), nausea (24.6%, 33.3%, 31.0%), diarrhea (18.7%, 21.2%, 23.0%), constipation (16.8%, 17.1%, 11.7%), and vomiting (8.3%, 10.7%, 12.2%) were more frequently experienced compared to placebo (9.5% [nausea], 7.3% [diarrhea], 5.8% [constipation], 1.7% [vomiting]).

Treatment discontinuation rates due to adverse events were 4.3% (5 mg), 7.1% (10 mg), 6.2% (15 mg) and 2.6% (placebo). The overall treatment discontinuation rates were 14.3% (5 mg), 16.4% (10 mg), 15.1% (15 mg) and 26.4% (placebo). The overall trial completion rates were 89% (5 mg), 88% (10 mg), 90% (15 mg) and 77% (placebo).

See-"Tirzepatide Once Weekly for the Treatment of Obesity"- Ania M. Jastreboff, M.D., Ph.D., Louis J. Aronne, M.D., Nadia N. Ahmad, M.D., M.P.H.et al.,. for the SURMOUNT-1 Investigators. June 4, 2022. DOI: 10.1056/NEJMoa2206038.