Recruiting
Phase 2

Tirzepatide

Sponsor:

University of Southern California

Code:

NCT07602699

Conditions

Smoking Cessation

Smoking Behaviors

Eligibility Criteria

Sex: All

Age: 21 - 65

Healthy Volunteers: Not accepted

Interventions

Tirzepatide

Placebo

Study Details

Brief summary:

This multi-site clinical trial will generate data on the efficacy of tirzepatide for smoking cessation and associated outcomes (e.g., post-cessation weight gain) in treatment-seeking people who smoke (PWS) with overweight or obesity. A sample of 300 treatment-seeking people who smoke with body mass index of 25 kg/m2 or greater will be recruited from four geographic sites (University of Southern California, Yale University, University of Chicago, and University of Colorado Anschutz Medical Campus) to participate in a parallel-arm, dose-escalating, placebo-controlled trial. Participants will attend weekly clinic visits to receive subcutaneous tirzepatide or placebo over 16 weeks (Visit Weeks 1-16), followed by follow-up visits at Week 17 and Week 27. Medication will be prescribed according to the standard dose titration schedule for the first 16 weeks of treatment (initial dose: 2.5mg/week; final dose: 10mg/week). All participants will also receive nicotine patches.

Conditions

Smoking Cessation

Smoking Behaviors

Study ID

NCT07602699

Start date

Jun 5, 2026

Status verified date

Jul, 2026

Completion date

Sep, 2028

Anticipated

Primary completion date

Mar, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 21 - 65

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Age 21-65 years
2. Body mass index ≥ 25kg/m2 at the baseline screening
3. Reporting ≥10 cigarettes per day, on average, for the past 6 months and > 2 year duration of smoking
4. Interest in making a long-term cessation attempt within the next 30-60 days
5. Willingness to receive study medication and standard-of-care smoking cessation supports (nicotine replacement therapy and a smoking cessation app)
6. Ability to adhere to weekly visits and study procedures over the study period (i.e., no plans to move or travel for extended periods)
7. Exhaled CO of >5ppm at baseline
8. Use of an acceptable birth control method for female participants\*
9. Ability to read and communicate in English

Exclusion Criteria:

1. BMI < 25 kg/m2 at screening
2. History of diabetes, diabetes-attributable medical conditions, or HbA1c ≥6.5% at baseline
3. Recent (past 90 days) active suicidal ideation or lifetime history of suicide attempt
4. Current treatment for psychotic disorders or mood disorders with psychotic features (e.g., schizophrenia, schizoaffective disorder, depression with psychotic features), current treatment for bipolar disorder (with or without psychotic features), or current secondary psychosis due to substance use or another medical condition
5. Meeting DSM-5 criteria for a current (past 12 months) substance use disorder other than tobacco use disorder, mild or moderate cannabis use disorder, or mild or moderate alcohol use disorder.
6. Recent (past 30 day) self-report of illicit drug use (excluding cannabis) or non-prescribed opioids; or positive urine screen for illicit drugs. A positive screen for opioids will be allowed if the participant is prescribed an opioid replacement therapy medication and can provide documentation.
7. Past 30-day initiation of psychiatric medications (e.g., SSRIs) or changes to medication dose
8. Treatment with tirzepatide or another GLP-1RA medication in the prior 6 months
9. Current (past month) treatment with other weight loss, diabetes, or smoking cessation medications (varenicline or bupropion; excluding nicotine replacement products)
10. Severe GI disease (e.g., gastroparesis, ulcerative colitis).
11. History of gastric bypass surgery or other surgeries of the stomach
12. Any health condition or treatment/medication that would preclude the use of tirzepatide or NRT, in the opinion of the study physician, including severe cardiovascular disease
13. History of chronic pancreatitis or acute pancreatitis in the last 6 months
14. Currently nursing, pregnant, or anticipating pregnancy
15. History of diabetic retinopathy, proliferative retinopathy, or maculopathy
16. Elevated serum lipase, amylase, bilirubin, or ALP, ALT, or AST (>5x upper limit of normal range)
17. History of malignant neoplasms in the last 5 years, except non-melanoma skin cancer
18. Inability to attend weekly clinic visits as scheduled (i.e., based on travel or work schedule)
19. Currently enrolled in another clinical study involving an investigational product
20. Currently living in the same household as someone taking a GLP-1 medication, or living with a current or former participant in the present trial
21. Planned surgical procedures requiring anesthesia during the planned study medication period
22. Personal or family history of medullary thyroid cancer
23. Personal or family history of multiple endocrine neoplasia syndrome type 2 (MEN 2)
24. Treatment with other weight loss (e.g., phentermine), or FDA-approved, non-NRT smoking cessation therapies (varenicline, bupropion) or FDA-approved AUD medications (naltrexone, acamprosate, disulfiram) or off-label AUD medications (e.g., topiramate) in the past 90 days
25. Any health condition or treatment/medication that would preclude use of tirzepatide or NRT, in the opinion of the site physicians including thyroid enlargement.

Study Design

Enrollment

300 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Tirzepatide

placebo comparator: Placebo

Interventions

Tirzepatide

Participants will receive tirzepatide (subcutaneous injection) at doses of 2.5mg for Weeks 1-4, 5mg for Weeks 5-8, 7.5mg for Weeks 9-12, and 10mg for Weeks 13-16

Placebo

Participants will receive placebo (saline) injections for Weeks 1-16

Primary outcome measure

  • 7-day point prevalence abstinence [ Time Frame: From baseline through 16 weeks of treatment (final assessment at Week 17 visit) and at 6 months after the target quit date (assessed at Week 27 visit) ]

Central Contacts and Locations

Locations

Keck School of Medicine, University of Southern California

Recruiting

Los Angeles, California, United States, 90033

Contacts

Principal Investigator:

Christian Hendershot, Ph.D.

University of Colorado Anschutz Medical Campus

Recruiting

Aurora, Colorado, United States, 80045

Contacts

Principal Investigator:

Joseph Schacht, PhD

Yale University School of Medicine

Recruiting

New Haven, Connecticut, United States, 06510

Contacts

Principal Investigator:

Sherry McKee, PhD

University of Chicago Pritzker School of Medicine

Recruiting

Chicago, Illinois, United States, 60637

Contacts

Principal Investigator:

Andrea King, PhD

More Information

Sponsor

University of Southern California

Last update posted

Jul 17, 2026

Last verified

Jul, 2026

Keywords

  • Addiction
  • GLP-1
  • Tirzepatide
  • Substance Use Disorder

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-12. This information was provided to ClinicalTrials.gov by University of Southern California on 2026-07-17.