E-cigarette Cessation in Adults Who Co-use Cannabis (VapeCAT)

June 10, 2026 updated by: Erin McClure, Medical University of South Carolina

A Prospective Trial of Varenicline and Incentives for E-cigarette Cessation in Adults Who Co-use Cannabis

The purpose of this study is to better understand tobacco outcomes using a commonly prescribed stop smoking medication (varenicline) and financial incentives for adults who also use cannabis. Varenicline is not FDA approved for e-cigarette cessation, but is FDA approved for cigarette cessation. Investigators are also interested in how cannabis/marijuana and tobacco interact during a tobacco quit attempt. All participants will receive e-cigarette cessation treatment for 12 weeks. To qualify, participants must be between the ages of 18-40 and use both e-cigarettes and cannabis. Participants do not need to be interested in quitting cannabis to qualify. This study is being conducted at three sites: the Medical University of South Carolina in Charleston, SC, Behavioral Health Services in Pickens, SC, and MUSC Lancaster in Lancaster, SC.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Cannabis co-use among tobacco users is exceedingly common and rates of co-use appear to be increasing among adults in the US, which is consistent with overall increases in cannabis use rates among US adults. Given the current cannabis landscape, further increases in cannabis use are likely and may result in continued increases in the co-use of cannabis and tobacco.

Despite high rates of co-use, there is little consensus regarding treatment recommendations for this population and an understanding of the impact of co-use on successful cessation. The literature on the impact of co-use on tobacco cessation outcomes specifically has been mixed and fraught with limitations, including methodological variation, lack of biochemical verification to confirm cannabis use status and severity, and variations in study samples. Currently, no prospective studies have been conducted to evaluate the impact of cannabis use on tobacco cessation outcomes. Further, no studies have collected cannabis use changes during tobacco cessation treatment to assess for concurrent reductions, abstinence, or of greater concern, compensatory (i.e., increased) use as a result of tobacco reduction/abstinence.

This study is a prospective 12-week tobacco cessation trial using established methods and outcomes typical of tobacco cessation trials, but specifically recruiting co-users of cannabis. The aims of this proposed study are to; Specific Aim 1. Compare rates of 7-day biochemically-confirmed e-cigarette abstinence with cigarette abstinence rates from the parent R37 co-use sample (as a historical controls). Specific Aim 2. Assess changes in cannabis use during e-cigarette cessation treatment among the new sample of participants enrolled in this extension.

Specific Aim 3. Assess for a dose-dependent impact of cannabis co-use severity on e-cigarette cessation. Specific Aim 4. Characterize and compare patterns of co-use among the e-cigarette sample to those using cigarettes (parent R37).

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
105

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Elizabeth Chapman, MA, LPC, LAC, AADC
  • Phone Number: 864.898.2992
  • Email: chapmanb@musc.edu

Study Locations

  • United States
    • South Carolina
      • Charleston, South Carolina, United States, 29425
        • Recruiting
        • MUSC Charleston
        • Principal Investigator:
          • Erin A McClure, PhD
        • Contact:
      • Lancaster, South Carolina, United States, 29720
        • Recruiting
        • MUSC Lancaster
        • Contact:
      • Pickens, South Carolina, United States, 29671
        • Recruiting
        • Behavioral Health Services of Pickens County
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Between the ages of 18 and 40 years old
  • Use e-cigarettes daily or near daily in the past month
  • Must submit a positive instant-read urine cotinine test at screening (≥ 200 ng/ml)
  • Be interested in quitting use of e-cigarettes
  • Must be willing to take varenicline for the standard 12-week course of treatment
  • Self-reported use of cannabis on at least 10 out of the past 30 days or must submit a positive qualitative urinary cannabinoid test at screening (> 50 ng/ml)

Exclusion Criteria:

  • Any serious or unstable medical/psychiatric disorder (including severe substance use disorders, other than cannabis or tobacco use disorders) in the past three months that may interfere with study performance
  • Use of cigarettes on 10+ days in the past 30
  • Currently pregnant or breastfeeding
  • Current use of medications with smoking cessation efficacy
  • Use of any medications that would interfere with varenicline

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Other: Co-use group
E-cigarette and cannabis co-use group
Drug: Varenicline Pill
In this study, all participants will be administered active medication for a 12 week treatment period. The standard dose titration schedule will be used, which includes 0.5 mg once per day (q.d.) on Days 1-3, 0.5 mg twice per day (b.i.d.) on Days 4-7, and 1.0 mg b.i.d. starting on Day 8. Dosing of 2.0 mg per day will be maintained for the next 11 weeks, for a total of 12 weeks of active treatment for all study participants.
Behavioral: Contingency management
Contingency management procedures will be implemented and financial incentives will be provided at weekly visits contingent on e-cigarette abstinence verified through urinary qualitative cotinine (starting at Week 2). A set amount of $20 per study visit will be delivered based on a negative qualitative urinary cotinine result.
Behavioral: Counseling
Psychosocial counseling will be administered by trained research staff leading up to the target quit date and throughout the study.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
7-day point prevalence tobacco abstinence at the end of treatment (Week 12)
Time Frame: Final 7 days of treatment (Week 12)
7-day point prevalence abstinence from e-cigarettes at the end of treatment (Week 12) will be assessed via biochemical verification (urinary cotinine; ng/ml) and will be compared to cigarette abstinence rates from the parent study (as historical controls)
Final 7 days of treatment (Week 12)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Cannabis co-use severity on e-cigarette abstinence rates
Time Frame: Final 7 days of treatment (Week 12)
Assess for a dose-dependent impact of cannabis co-use severity on e-cigarette cessation.
Final 7 days of treatment (Week 12)
Changes in cannabis use during e-cigarette cessation treatment
Time Frame: Final 4 weeks of study treatment (Weeks 8-12)
Cannabis use rates (based on urinary cannabinoids [ng/ml]) during the final 4 weeks of tobacco treatment (Weeks 8-12) will be assessed.
Final 4 weeks of study treatment (Weeks 8-12)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Medical University of South Carolina

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Cancer Institute (NCI)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Erin A McClure, PhD, Medical University of South Carolina

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 19, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 11, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 12, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 14, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 12, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 10, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Pro00136601
  • R37CA237245 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified data will be made available for retrieval and analysis of secondary outcomes, upon request to the Principal Investigator. Study datasets (de-i

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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