A Study of Tirzepatide (LY3298176) Versus Semaglutide Once Weekly as Add-on Therapy to Metformin in Participants With Type 2 Diabetes

NCT03987919 · Completed

Last updated 2026-05-28

This clinical trial is comparing the effects of tirzepatide and semaglutide, both taken once a week alongside metformin, in adults with type 2 diabetes.

Status Completed The study has finished.

Phase Phase 3 Confirms effectiveness in a large group before approval.

Type Interventional (clinical trial)

Design Randomized, open-label (no blinding) treatment study

Participants 1,879 people

Who can join Ages 18+ · all sexes

Timeline Started 2019-07 · est. completion 2021-02

Where 127 sites · Argentina, Australia, Brazil, Canada, Israel, Mexico, Puerto Rico, United Kingdom, United States

What this study is testing ClinicalTrials.gov NCT03987919 ↗

Description as written by the study sponsor.

The reason for this study is to compare the effect of the study drug tirzepatide to semaglutide on blood sugar levels in participants with type 2 diabetes. The study will last approximately 47 weeks and may include about 12 visits.

Treatments tested

Tirzepatide also known as LY3298176 Drug

Administered SC
Semaglutide Drug

Administered SC

Main thing measured	Change From Baseline in Hemoglobin A1c (HbA1c) (10 mg and 15 mg)
Sponsor	Eli Lilly and Company
Conditions studied	Type 2 Diabetes
GLP-1 drugs	semaglutide, tirzepatide

Full protocol, eligibility, and contacts on ClinicalTrials.gov NCT03987919 ↗