NCT06803888

Bariatric Surgery vs. Semaglutide vs. Tirzepatide

Efficacy and Safety of Bariatric Surgery, Semaglutide Once Weekly, and Tirzepatide Once Weekly in Patients With Obesity

• Status: Recruiting
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 125 (estimated)
• Sponsor: Ali Aminian · Academic / Other
• Sex: All
• Age: 18 Years – 70 Years
• Healthy volunteers: Not accepted

Summary

The recent introduction of the new generation of anti-obesity medications (AOMs) will change the future of obesity treatment. These highly effective medications, such as high-dose semaglutide and tirzepatide, are hormone analogues that augment the incretin function and exert multiple physiological effects by activating glucagon-like peptide-1 (GLP-1) and/or glucose-dependent insulinotropic polypeptide (GIP) distributed in various organs. These medications provide an average of 15-22% weight reduction in one-year trials, which had not been seen in the past with medical therapy. While the literature suggests that bariatric surgery is superior to these new highly effective medications, there is no head-to-head comparison between the most common bariatric operations (Roux-en-Y gastric bypass \[RYGB\] and sleeve gastrectomy \[SG\]) with semaglutide (once weekly) and tirzepatide (once weekly). The goal of this Randomized Clinical Trial (RCT) is to compare these effective therapies in patients with severe obesity to provide the best evidence to inform clinical decisions in treating patients with obesity.

Detailed description

This is a randomized, non-blinded, controlled efficacy/safety study with 3 parallel groups who will either receive bariatric surgery (RYGB or SG), semaglutide, or tirzepatide. The study has 2 phases: the first 12 months for the assessment of the primary endpoint ( mean percentage weight loss) and the second 12 months as the extension phase of the study to mimic the real-life setting. Findings at the end of each phase will be separately reported. A randomized trial of 125 patients with a BMI of 35-65 kg/m2 who sought treatment for obesity at Cleveland Clinic will be performed. Patients who meet the ASMBS/IFSO 2022 guidelines for bariatric surgery will be invited for possible enrollment. Interested and eligible patients will be randomized to receive their already chosen bariatric surgery (RYGB or SG), tirzepatide. or semaglutide in 2:2:1 ratio. The study is not intended to compare RYGB vs SG head-to-head. RYGB and SG constitute one group as a bariatric surgery group. The assignment of RYGB or SG is not based on a randomized design. Each patient and surgical team will make a shared decision about the most appropriate surgical procedure. The study is also not intended to compare semaglutide vs tirzepatide head-to-head. In the second or extension phase of the study, participants are followed from month 12 to month 24, regardless of the treatment that they receive. In this phase, the study medications (semaglutide and tirzepatide) will not be provided by the study. The goal of this phase is to provide valuable insights into A) access to AOMs and the durability of effects in the real-life setting, B) cross-over from AOMs to bariatric surgery, and C) adjuvant pharmacotherapy after bariatric surgery.

Conditions

• Obesity and Obesity-related Medical Conditions

Interventions

Type	Name	Description
PROCEDURE	Bariatric Surgery	Patients receive either RYGB or SG. The surgical risk, the differential impact of each procedure on body weight and other obesity-related diseases, presence of other medical and mental problems, patient's behavioral factors (e.g., postoperative compliance, active smoking), medications, and goals will be considered when the patient and local medical team make a shared decision about the most appropriate surgical procedure.
DRUG	Semaglutide	Semaglutide will be initiated at a dose of 0.25 mg once weekly and will be increased during the dose-escalation period to reach a maintenance dose of up to 2.4 mg once weekly by week 16. If patients do not tolerate a dose during dose escalation, we will consider delaying dose escalation until next visit (for 4 weeks). Dosing for Semaglutide is the FDA-approved dosing schedule. The maintenance dose is 2.4 mg injected subcutaneously once-weekly. The protocol allows for dose reductions in case a participant does not tolerate the recommended target dose of 2.4 mg and may stay at the lower maintenance dose level (e.g., 1.7 mg once weekly), if needed.
DRUG	Tirzepatide	Tirzepatide will be initiated at a dose of 2.5 mg once weekly and will be increased by 2.5 mg every week during the dose-escalation period to reach a maintenance dose of up to 15 mg once weekly by week 20. If patients do not tolerate a dose during dose escalation, we will consider delaying dose escalation until next visit (for 4 weeks). Dosing for Tirzepatide is the FDA-approved dosing schedule. The maintenance dose is 15 mg injected subcutaneously once-weekly. The protocol allows for dose reductions in case a participant does not tolerate the recommended target dose of 15 mg and may stay at the lower maintenance dose level (e.g., 10 mg once weekly), if needed.

Timeline

• Start date: 2025-01-29
• Primary completion: 2027-07-01
• Completion: 2027-12-01
• First posted: 2025-01-31
• Last updated: 2026-04-02

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study