ClinicalTrials.gg
CompletedNCT06737042Updated Jul 16, 2026

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

A Phase 2 interventional study of GZR18 and Tirzepatide in Obesity and Overweight, sponsored by Gan and Lee Pharmaceuticals, USA. Completed at 20 sites in United States. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-07-16.

Sponsored by Gan and Lee Pharmaceuticals, USA · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
326
Allocation
Randomized
Ages
18 Years to 75 Years
Sex
All
01

Study summary

This is a Phase 2 study to evaluate the safety and efficacy of 24, 36, and 48 mg GZR18 (Q2W) compared with placebo and 15 mg tirzepatide (QW). 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).

Read the detailed description

This is a Phase 2 multicenter, randomized, parallel-group, partially-blinded, placebo and tirzepatide-controlled study of the safety and efficacy of 24, 36, and 48 mg GZR18 (Q2W) compared with placebo and 15 mg tirzepatide (QW). 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).

The study will comprise a 2-week screening period (Days -14 to -1), a 36-week treatment period (Weeks 0 to 36), which includes a titration period and a maintenance dose period, and a safety follow-up period of 2 weeks after the primary endpoint assessment (ie, 4 weeks after the last GZR18 dose and 3 weeks after the last tirzepatide dose).

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.

02

Conditions studied

  • Obesity and Overweight

Keywords

  • GLP-1, Obesity, Overweight, Weight loss
03

In context

Obesity

11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.

This study's enrollment of 326 is above the median of 67 across 9,006 interventional studies indexed under Obesity.

Browse Obesity studies →

Lead sponsor

Gan and Lee Pharmaceuticals, USA is the lead sponsor of 29 studies on the registry; 5 are open to participants now.

Of its 8 completed or terminated interventional studies of FDA-regulated products, 2 (25%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 75 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. 18 to 75 years of age (both inclusive) at the time of signing the form (ICF).
  2. History of failing to lose sufficient weight with lifestyle/dietary modification.

≥30.0 kg/m2, or

BMI ≥27.0 kg/m2 with at least 1 of the following:

  • 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.
  • Dyslipidemia: defined as taking lipid-lowering medication or have LDL ≥160 mg/dL (4.1 mmol/L) or triglycerides ≥150 mg/dL (1.7 mmol/L), or high-density lipoprotein (HDL) \<40 mg/dL (1.0 mmol/L) for men or HDL \<50 mg/dL (1.3 mmol/L) for women at screening.
  • Obstructive sleep apnea.
  • Cardiovascular disease: defined as having eg, ischemic cardiovascular disease or (NYHA) Functional Classification Class I to II heart failure.

    4. In the investigator's opinion, are well motivated, capable, and willing to:

  • Learn how to self-inject the IP as required for this protocol (visually impaired persons who are not able to perform the injections must have the assistance of a sighted individual trained to inject the IP; persons with physical limitations who are not able to perform the injections must have the assistance of an individual trained to inject the IP).
  • Inject the IP (or receive an injection from a trained individual if visually impaired or with physical limitations).
  • Follow study procedures for the duration of the study, including, but not limited to, lifestyle advice (eg, dietary changes and physical activity plan), complete the electronic diary (eDiary), and complete required questionnaires.
  • Identify the biological sex for the study stratification. 5.Capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the ICF and in this protocol.

Exclusion criteria

Exclusion Medical Conditions Related to Obesity

  1. A self-reported change (increase or decrease) in body weight >5 kg within 3 months prior to screening.
  2. Prior or planned surgical treatment for obesity (excluding liposuction or abdominoplasty, if performed >1 year prior to screening).
  3. Have or plan to have endoscopic and/or device-based therapy for obesity or have had device removal within the last 6 months prior to screening, including but not limited to:

    • Mucosal ablation
    • Gastric artery embolization
    • Intragastric balloon
    • Duodenal-jejunal endoluminal liner Related to Diabetes
  4. History of type 1 or T2DM, history of ketoacidosis, or hyperosmolar state/coma.
  5. At least 1 laboratory value suggestive of diabetes during screening, including 1 or more of ≥6.5% (48 mmol/mol), fasting serum glucose ≥126 mg/dL (7.0 mmol/L), or random glucose ≥200 mg/dL (11.1 mmol/L).

    Other Medical Conditions

  6. Renal impairment measured as estimated (eGFR) \<60 mL/min/1.73 m2, calculated by chronic kidney disease-epidemiology collaboration (CKD-EPI) as determined by central laboratory during screening.
  7. Known gastric emptying abnormality (eg, severe gastroparesis or gastric outlet obstruction) or chronically take drugs that directly affect GI motility.
  8. History of acute or chronic pancreatitis. A participant with a history of acute pancreatitis caused by gallstones may be included in the study if the participant has a cholecystectomy to resolve the problem.
  9. Thyroid-stimulating hormone (TSH) outside of the range of 0.4 to 6.0 mIU/L at screening.

    Note: Participants receiving treatment for hypothyroidism may be included, provided their thyroid hormone replacement dose has been stable for at least 6 months.

    Note: TSH values above the normal range can, in some participant, suggest subclinical hypothyroidism. If, in the investigator's opinion, the participant has subclinical hypothyroidism and may require initiation of thyroid hormone replacement during the study, the participant should be excluded from the study.

  10. Obesity induced by other endocrinologic disorders (eg, Cushing's syndrome) or diagnosed monogenetic or syndromic forms of obesity (eg, melanocortin 4 receptor deficiency or Prader-Willi syndrome).
  11. History of significant active or unstable major depressive disorder (MDD) or other severe psychiatric disorder (eg, schizophrenia, bipolar disorder, or other serious mood or anxiety disorder) within the last 2 years.

    Note: Participants with MDD or generalized anxiety disorder whose disease state is considered stable for the past 2 years and expected to remain stable throughout the course of the study, in the opinion of the investigator, may be considered for inclusion if they are not on excluded medications.

  12. A history of suicide attempt.
  13. Patient health questionnaire-9 (PHQ-9) score of 15 or more at screening.
  14. On the Columbia Suicide Severity Rating Scale (C-SSRS) prior to randomization:

    • a "yes" answer to Question 4 (active suicidal ideation with some intent to act, without specific plan) on the "suicidal ideation" portion of the C-SSRS or
    • a "yes" answer to Question 5 (active suicidal ideation with specific plan and intent) on the "suicidal ideation" portion of the C-SSRS or
    • a "yes" answer to any of the suicide-related behaviors (actual attempt, interrupted attempt, aborted attempt, preparatory act, or behavior) on the "suicidal behavior" portion of the C-SSRS and
    • the ideation or behavior occurred within the past month
  15. Uncontrolled hypertension (SBP ≥160 mmHg and/or DBP ≥100 mmHg). If a participant is on antihypertensive therapies, doses must be stable for 30 days prior to screening. For participants with uncontrolled hypertension at screening, antihypertensive medication may be started or adjusted. BP must meet the protocol criterion for hypertension control with stable treatment for at least 30 days before re-screening.
  16. An elevated resting pulse rate >100 bpm at baseline.
  17. Any of the following cardiovascular conditions within 3 months prior to screening:

    • Acute myocardial infarction
    • Cerebrovascular accident (stroke)
    • Unstable angina
    • Hospitalization due to congestive heart failure (CHF)
  18. Ongoing or history of frequent intermittent or chronic tachyarrhythmia syndromes (eg, atrial fibrillation, supraventricular tachycardia, and positional orthostatic tachycardia syndrome).

    Note: Participants with a history of premature atrial contractions or premature ventricular contractions may be included.

  19. Functional Classification III or IV CHF.
  20. An (ECG) considered by the investigator indicative of active cardiac disease or with abnormalities that may interfere with the interpretation of changes in ECG intervals at screening.
  21. Acute or chronic hepatitis, or signs and symptoms of any other liver disease other liver disease except nonalcoholic fatty liver disease (NAFLD) (ie, participants with NAFLD are eligible for participation), or any of the following at screening:

    • (ALT) >3 × the (ULN)
    • alkaline phosphatase (ALP) >1.5 × ULN
    • total level >1.5 × ULN (except for cases of known Gilbert's Syndrome)
  22. Serum calcitonin level of:

    • 20 ng/L, if eGFR ≥60 mL/min/1.73 m2
    • 35 ng/L, if eGFR ≤60 mL/min/1.73 m2
  23. A family or personal history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN2).
  24. A history of an active or untreated or are in remission from a clinically significant malignancy (other than basal or squamous cell skin cancer, in situ carcinomas of the cervix, or in situ prostate cancer) for \<5 years.
  25. Any other condition not listed in this section (eg, or intolerance) that is a to GLP-1R agonists.
  26. A history of any other condition (such as known drug or alcohol abuse, diagnosed eating disorder, or other psychiatric disorder) that, in the opinion of the investigator, may preclude the participant from following and completing the protocol.
  27. Alcohol consumption >14 units/week for women and >21 units/week for men.
  28. A history of use of marijuana or tetrahydrocannabinol (THC)-containing products within 3 months of enrollment or unwillingness to abstain from marijuana or THC-containing product use during the study.

    Note: If a participant has used cannabidiol oil during the past 3 months but agrees to refrain from use for the duration of the study, the participant may be enrolled.

  29. Have had an organ transplant (corneal transplants [keratoplasty] are allowed) or are awaiting an organ transplant.
  30. Any hematological condition that may interfere with HbA1c measurements (eg,
  31. A blood donation of ≥500 mL within the previous 8 weeks of screening or a blood transfusion or severe blood loss within the prior 3 months, or have known hemoglobinopathy, hemolytic anemia, sickle cell anemia, or a value \<11 g/dL (men) or \<10 g/dL (women), or any other condition known to interfere with HbA1c methodology.
  32. A history of atopy (severe or multiple allergic manifestations) or clinically significant multiple or severe drug allergies, intolerance to topical , or severe posttreatment hypersensitivity reactions (including, but not limited to, erythema multiforme major, linear immunoglobulin A dermatosis, toxic epidermal necrolysis, anaphylaxis, angioedema, or exfoliative dermatitis).
  33. A fasting serum triglyceride level of >500 mg/dL at screening. If a participant is on lipid-lowering therapies, doses must be stable for 30 days prior to screening.

    Prior/Concomitant Therapy

  34. Are receiving or have received within 3 months prior to screening chronic (>2 weeks) systemic glucocorticoid therapy (excluding topical, intraocular, intranasal, single intraarticular injection, or inhaled preparations) or have evidence of a significant, active abnormality (eg, lupus or rheumatoid arthritis) that has required (within the last 3 months) or is likely to require, in the opinion of the investigator, concurrent treatment with systemic glucocorticoids (excluding topical, intraocular, intranasal, intraarticular, or inhaled preparations) during the course of the study.
  35. Receiving treatment with or have a history of treatment with (within 3 months prior to screening) medications that may cause significant weight gain including, but not limited to, tricyclic antidepressants, atypical antipsychotics, and mood stabilizers:

    Examples:

    • imipramine
    • amitriptyline
    • mirtazapine
    • paroxetine
    • phenelzine
    • chlorpromazine
    • thioridazine
    • clozapine
    • olanzapine valproic acid and its derivatives
    • lithium Note: Selective serotonin reuptake inhibitors other than paroxetine are permitted.
  36. Have taken within 3 months prior to screening medications (prescribed or over thecounter) or alternative remedies intended to promote weight loss.

    Examples include, but are not limited to:

    • Saxenda® (liraglutide 3.0 mg) or other GLP-1R agonists
    • Xenical®/Alli® (orlistat)
    • Meridia® (sibutramine)
    • Acutrim® (phenylpropanolamine)
    • Sanorex® (mazindol)
    • Adipex® or LomairaTM (phentermine)
    • QsymiaTM (phentermine/topiramate combination)
    • Contrave® (naltrexone/bupropion)
  37. Use of metformin or any other glucose-lowering medication, whether prescribed for polycystic ovarian syndrome or diabetes prevention is not permitted.
  38. Have started implantable or injectable (such as Depo Provera®) within 18 months prior to screening.

    Prior/Concurrent Clinical Study Experience

  39. Have known allergies to GLP-1R agonists or GZR18.
  40. Are currently enrolled in any other clinical study involving an IP or any other type of medical research judged not to be scientifically or medically compatible with this study.
  41. Within the last 30 days, participated in a clinical study and received treatment, whether active or placebo. If the study involved an IP, 5 half-lives or 30 days, whichever is longer, should have passed.
  42. Have previously completed or withdrawn from this study or any other study investigating GZR18 and have previously received GZR18.

    Other Exclusions

  43. Women of (WOCBP) who:

    • Are pregnant or intend to become pregnant (or have a positive pregnancy test at screening).
    • Are lactating/breastfeeding (including the use of a breast pump).
    • Are unwilling to remain abstinent or use acceptable birth control
Terms in these criteria, in plain language(18)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

NYHA class (heart failure)

The New York Heart Association’s four classes of how much heart failure limits physical activity.

I
No limits: ordinary activity causes no undue tiredness or breathlessness.
II
Slight limits: comfortable at rest, ordinary activity causes symptoms.
III
Marked limits: comfortable at rest, less than ordinary activity causes symptoms.
IV
Symptoms even at rest; any activity makes them worse.

Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.

HbA1c

A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.

GFR and eGFR (kidney filtering)

GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².

Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

ECG (electrocardiogram)

A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

Bilirubin

A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.

Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
326 participants (actual)

Study arms

  • Experimental
    24 mg GZR18 group

    24 mg GZR18 group: 76 participants (57 receiving GZR18 and 19 receiving placebo)

    Drug: GZR18

  • Experimental
    36 mg GZR18 group

    36 mg GZR18 group: 76 participants (57 receiving GZR18 and 19 receiving placebo)

    Drug: GZR18

  • Experimental
    48 mg GZR18 group

    48 mg GZR18 group: 76 participants (57 receiving GZR18 and 19 receiving placebo)

    Drug: GZR18

  • Active comparator
    Tirzepatide group

    Tirzepatide group: 57 participants receiving 15 mg tirzepatide

    Drug: Tirzepatide

Interventions

06

What researchers measure

Primary outcomes

  1. Primary Objective

    To demonstrate that GZR18 24 mg, 36 mg, and 48 mg is superior to placebo based on percentage change in body weight after 36 weeks of treatment

    Time frame: 36 weeks

07

Study locations

20 sites
  • KUR Research - Trinity @ Bessemer, AL Site Network
    Bessemer, Alabama 35022, United States
  • KUR Research - Trinity @ Centreville Site Network
    Centreville, Alabama 35042, United States
  • ERG - Woodland Int'l Research Group
    Little Rock, Arkansas 72211, United States
  • ERG - Woodland Research Northwest
    Rogers, Arkansas 72758, United States
  • Ark Clinical Research Ark-Fountain Valley
    Fountain Valley, California 92708, United States
  • Ark Clinical Research Ark-Long Beach
    Long Beach, California 90815, United States
  • Clinedge - Central Valley Research, LLC
    Modesto, California 95350, United States
  • Populace Health, LLC - Catalina Research Institute
    Montclair, California 91763, United States
  • East Coast Institute for Research - ECIR Jacksonville (Southside)
    Jacksonville, Florida 32216, United States
  • East Coast Institute for Research ECIR Jacksonville (Headquarters) University
    Jacksonville, Florida 32216, United States
  • 3Sync Research - PCRS Network
    Lake Worth, Florida 33460, United States
  • Clever Medical Research - PCRS Network
    Miami, Florida 33126, United States
  • KUR Research @ Columbia Site Network
    Columbia, Maryland 21045, United States
  • Populace Health, LLC - Elixia SISU
    Springfield, Massachusetts 01103, United States
  • Populace Health, LLC - Vector Clinical Trials
    Las Vegas, Nevada 89128, United States
  • Populace Health, LLC - CTI Clinical Research Center
    Cincinnati, Ohio 45212, United States
  • ERG - Ohio Clinical Trials
    Columbus, Ohio 43212, United States
  • Elligo Clinical Research Center - Austin
    Austin, Texas 78704, United States
  • Clinvax Katy Research Center
    Katy, Texas 77493, United States
  • Endeavor Clinical Trials
    San Antonio, Texas 78229, United States
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 16, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT06737042
Responsible party
Sponsor
First posted
Dec 17, 2024
Start date
Feb 24, 2025
Primary completion
Feb 27, 2026
Completion
Feb 27, 2026
Last update
Jul 16, 2026

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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