NCT07481747

Efficacy and Safety of Tirzepatide Once Weekly Versus Placebo in Participants Who Are Either Obese or Overweight With Weight-Related Comorbidities (SURMOUNT-1)

Efficacy and Safety of Tirzepatide Once Weekly in Participants Without Type 2 Diabetes Who Have Obesity or Are Overweight With Weight-Related Comorbidities: A Randomized, Double-Blind, Placebo-Controlled Trial (SURMOUNT-1)

• Status: Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 2,539 (estimated)
• Sponsor: Hudson Biotech · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This Phase 3 study evaluates the efficacy and safety of once-weekly subcutaneous tirzepatide (a dual GIP and GLP-1 receptor agonist) at 5 mg, 10 mg, or 15 mg versus placebo, each used with a reduced-calorie diet and increased physical activity, in adults without type 2 diabetes who have obesity or are overweight with weight-related comorbidities. The primary efficacy assessment is at Week 72. Participants with prediabetes at randomization may continue in an additional long-term treatment period to assess progression to type 2 diabetes and longer-term weight outcomes.

Detailed description

After screening, eligible participants are randomized in a 1:1:1:1 ratio to receive tirzepatide 5 mg, 10 mg, 15 mg, or placebo once weekly by subcutaneous injection using an autoinjector. All participants receive lifestyle counseling focused on a reduced-calorie diet and increased physical activity. The main treatment period is 72 weeks. Participants identified with prediabetes at randomization can continue study treatment for up to 176 weeks (plus follow-up), allowing evaluation of longer-term weight management and time to onset/progression to type 2 diabetes. Safety is monitored throughout, including adverse events and laboratory testing.

Conditions

• Obesity
• Overweight (Without Type 2 Diabetes) With Weight-related Comorbidities

Interventions

Type	Name	Description
DRUG	Tirzepatide	(once-weekly SC injection; doses 5/10/15 mg)
DRUG	Placebo	(once-weekly SC injection)
BEHAVIORAL	Reduced-calorie diet	increased physical activity counseling

Timeline

• Start date: 2026-02-02
• Primary completion: 2027-02-14
• Completion: 2028-03-17
• First posted: 2026-03-19
• Last updated: 2026-03-19

Locations

1 site across 1 country: China