Efficacy and Safety of GZR18 Every 2 Weeks Versus Tirzepatide and Placebo in Obese or Overweight Participants

What Was Tested

This registered phase 2 trial tested Tirzepatide.

The study will evaluate weight management in participants with obesity (BMI ≥30 kg/m2) or who are overweight (BMI ≥27 kg/m2) with weight-related comorbidities (excluding type 2 diabetes mellitus).

It had four arms (groups): one (experimental), one (experimental), one (experimental) and Tirzepatide group (active comparator).

The registry classes the interventions as drug.

More on the Plan

Approximately 285 participants will be randomized at Week 0 into 1 of 4 groups, stratified by sex.

The study will be partially-blinded (intragroup blinded); treatment in the GZR18 groups will be blinded (GZR18 vs placebo), but GZR18 vs tirzepatide will be unblinded.

Who Took Part

Enrollment: 326 actual participants took part.

It was open to people of any sex aged from 18 years up to 75 years.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: 18 to 75 years of age (both inclusive) at the time of signing the informed consent form (ICF). History of failing to lose sufficient weight with lifestyle/dietary modification. Hypertension: defined as taking blood pressure (BP) lowering medication or have a systolic blood pressure (SBP) of ≥130 mmHg or a diastolic blood pressure (DBP) of ≥80 mmHg at screening. Obstructive sleep apnea. Cardiovascular disease: defined as having eg, ischemic cardiovascular disease or New York Heart Association (NYHA) Functional Classification Class I to II heart failure.

The full record lists 91 inclusion and 0 exclusion criteria.

How the Study Was Run

Design: randomized, parallel-group and quadruple-blind.

Because people in this Tirzepatide study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Groups ran in parallel: each of the participants stayed in one arm throughout.

Neither the participants nor the staff measuring them knew who was on Tirzepatide, so expectations could not easily colour the readings.

Those kept unaware of assignments: participant, care provider, investigator and outcomes assessor.

It started in 2025-02-24 with completion listed for 2026-02-27.

It ran at 20 sites in United States (20).

Its stated primary purpose is treatment.

What Was Measured

The main thing measured (primary outcome): Primary Objective (time frame: 36 weeks).

What This Means in Plain Language

Put simply, this is a phase 2, randomized trial of Tirzepatide in 326 people.

The trial is marked completed; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Tirzepatide compound page, all human trials.