A Phase 2 interventional study of Varenicline (VAR) and Nicotine lozenge (NRT) in Smoking Cessation, sponsored by University of Oklahoma. Recruiting at 1 site in United States. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-09.
Sponsored by University of Oklahoma · Phase 2, Interventional, and Treatment
No published studies to date have evaluated the combined impact of varenicline and oral nicotine replacement therapy (NRT) on smoking cessation in a randomized trial. Oral NRT, such as nicotine lozenges, can provide acute relief from cravings/withdrawal, and offers individuals the flexibility to deliver nicotine quickly, in contrast with the continuous, passive, and slow-acting delivery of the nicotine patch. Nevertheless, in clinical trials of other combination pharmacotherapies, participants' adherence to of oral NRT has been suboptimal, making it difficult to determine whether there is an added benefit. Given the near-ubiquity of smartphone ownership (85% of U.S. adults), it is plausible that smartphone-based medication adherence interventions could have a positive influence on pharmacotherapy adherence and smoking cessation. This investigative team has demonstrated the feasibility and potential efficacy of using combination varenicline plus oral NRT treatment to promote smoking cessation in a pilot factorial randomized trial. Likewise, pilot findings showed that medication adherence and smoking cessation rates were higher among those who received smartphone-based medication reminders than those who did not. The proposed study will enroll 496 adults who smoke cigarettes daily. The study will employ a 2x2 factorial design in which participants will be randomized to one of four combinations of two treatment factors: 1) pharmacological treatment (varenicline + nicotine lozenges vs. varenicline alone) and 2) smartphone medication adherence intervention (smartphone-based smoking cessation app with vs. without adherence components). The primary study outcomes will be biochemically-confirmed 7-day point prevalence abstinence at 26 weeks after a scheduled quit date, and medication adherence over the 13-week treatment period. Smartphone-based daily diaries will be employed to assess daily smoking and medication adherence. Notably, the proposed study will employ entirely remote assessment and treatment delivery strategies. Exploratory analyses will evaluate the potential interaction between medication type and the smartphone adherence intervention, and compare the influences of pharmacological treatment type and the medication adherence intervention on weekly physical symptoms (e.g., withdrawal, medication side effects). The overarching goal of the proposed research is to improve smoking cessation treatment and decrease cancer risk.
Study Overview. The study will employ an efficient 2x2 factorial design in which participants are randomized to one of four combinations of two treatment factors: 1) pharmacological treatment (VAR+NRT or VAR) and 2) smartphone-based smoking cessation intervention with or without medication adherence intervention (COMBO-A [adherence] or COMBO-B [basic]). All participants will receive 13 weeks of varenicline including the standard 1-week pre-quit titration period, with half of participants additionally receiving 12 weeks of nicotine lozenges. Those assigned to the COMBO-A group will receive a smartphone intervention app that includes medication adherence components: education, medication reminders, medication tracking, and messages following a missed medication dose. Participants assigned to COMBO-B will receive a smartphone smoking cessation intervention app that does not include medication adherence components. All participants, regardless of treatment group assignment will receive telephone counseling with a Tobacco Treatment Specialist from the TTRP. The primary study outcomes will be carbon monoxide (CO)-confirmed 7-day point prevalence abstinence at 26 weeks after the scheduled quit date, and medication adherence during the 12-week treatment period (self-reported weekly). Daily smoking and medication adherence will also be assessed via smartphone.
Randomization Plan. Stratified block randomization, with a small block size, will be used to ensure balance between study arms over time. Randomization will be stratified by sex (male vs. female), race/ethnicity (White vs. minoritized race/ethnicity), and cigarettes smoked per day (\<10 vs. ≥10). Participants will be randomized following full study enrollment.
Blinding. Participant blinding is not feasible since participants will be aware of whether or not they are provided with nicotine lozenges (in addition to the varenicline provided to all participants), and they will know whether their smartphone app has medication adherence components.
Intervention Components. Counseling. All participants will be scheduled to receive 6 weekly telephone counseling sessions lasting 15-30 minutes each with an experienced tobacco treatment specialist (TTS) though the TTRP. Counseling sessions will begin one week prior to the scheduled quit date and continue weekly through 4 weeks after the quit date. Consistent with Guideline recommendations, counseling will focus on education, skill-building, and support; and will employ cognitive-behavioral and motivational strategies. Topics include benefits of quitting, mood/stress management strategies, making positive lifestyle changes, coping skills, and planning for future challenges. Several recommended strategies will be employed to maintain and evaluate treatment fidelity (e.g., counseling checklists, session duration, and total sessions completed). Participant perceptions of nonspecific counselor characteristics will be assessed. Differences between groups on counseling factors may be included in analyses as covariates.
Varenicline. All participants will be evaluated by a study physician via telephone or video conferencing for eligibility to use varenicline. If appropriate, varenicline will be prescribed and filled through a campus Pharmacy and mailed to participants. During the week prior to the scheduled quit date, participants will begin taking varenicline. Doses will be titrated during the first week of medication use (days 1-3: 0.5 mg once daily; days 4-7: 0.5 mg twice daily) and will continue at 1 mg twice daily for 12 additional weeks. Participants will be advised to continue taking varenicline, even if they return to smoking.
Nicotine Lozenges. Participants randomized to VAR+NRT will be provided with 5 boxes of nicotine lozenges (108 pieces per box; 540 pieces total) by mail. This quantity provides a supply that supports flexible ad lib dosing, while also supporting optimal dosing based on package recommendations. Participants may request additional lozenges during the first 12 weeks after the scheduled quit date, and additional supply requests will be documented. Flexible standard nicotine dosing instructions (printed on the package) will be followed. In summary, participants who smoke their first cigarette of the day >30 minutes after waking will be provided with 2 mg lozenges, and those who smoke within 30 minutes of waking will be provided with 4 mg lozenges. Participants will be encouraged to use a lozenge every 1-2 hours during the first 6 weeks after the scheduled quit date, every 2-4 hours during weeks 7-9, and every 4-8 hours during weeks 10-12. Participants will be advised to use ≥9 lozenges per day during the first 6 weeks after the quit date to maximize the likelihood of cessation.
Smartphone App. The study smartphone app will be configured via the Insight Mobile Health Platform. All participants will download the smartphone app, but only those assigned to COMBO-A will have access to the medication adherence components. The main menu screen contains treatment topic options and contact information. COMBO-A participants will receive scheduled medication reminder prompts each day. All participants will be prompted to complete daily/weekly study assessments (brief daily diaries; weekly, longer, traditional questionnaires).
Mobile Health Platform. The mHealth Technology Shared Resource at the NCI-designated Stephenson Cancer Center developed the Insight mobile health platform which empowers researchers to build, test, and launch technology-based assessment and intervention tools. Applications are developed using state-of-the-art cross-platform design tools.
Intervention Hardware. Hardware will be shipped to participants' home addresses. Participants will be asked to use their own smartphones. All participants will be provided with a portable Bluetooth breath CO monitor for remote verification of abstinence via smartphone.
Education. All participants will have access to educational topics via the main menu of the app.
Medication Reminders-Varenicline. All participants randomized to the adherence intervention (VAR+COMBO-A; VAR+NRT+COMBO-A) will receive smartphone medication reminders that correspond with the varenicline dosing schedule. Morning (AM) reminders will appear 30 minutes after participants' self-reported typical wake time. Evening (PM) reminders will appear 2 hours before bedtime. Follow-up prompts will appear 30 and 60 minutes after the initial reminder if the participant has not yet taken the dose. Following the 3rd and final follow-up prompt, participants will again be asked whether they have take their varenicline (pill). If the participant responds that they have not taken their pill, they will be asked about the main reason they have not taken their pill. Participants will then receive an adherence promotion message that corresponds with their reason for not taking their medication dose.
Medication Reminders-Nicotine Lozenges. Participants randomized to VAR+NRT+COMBO-A will receive smartphone-based medication reminders that correspond with standard NRT dosing schedules in addition to varenicline reminders.
After each reminder message, participants will be asked when they last used a nicotine lozenge. Participants who report that they have not used a lozenge in more than 8 hours will be asked about the main reason that they have not used a lozenge. Participants will then receive an adherence promotion message that corresponds with their reason for not using lozenges.
Other App Features. All participants (regardless of treatment group assignment) may also contact study staff directly by telephone. They may access study contact information (email, phone numbers) through the app main menu. This feature allows participants convenient access to study staff when they have questions or concerns about their medications or other aspects of the study. For COMBO-A participants, graphical tracking of medication adherence based on daily diary self-reports of varenicline and NRT use will be available, along with descriptive summary information.
Measures. Treatment variables will be assessed via smartphone-based daily diaries to capture the dynamics of daily medication adherence and smoking, withdrawal symptoms, and medication side effects.
Assessment Schedule. All participants will complete app-based assessments on their smartphones. At baseline, participants will complete a longer initial assessment, with weekly follow-up assessments through 12 weeks after the scheduled quit date, interim assessments at 17, 20, and 23 weeks post-quit, and a final follow-up assessment at 26 weeks after the quit date. In addition, participants will be asked to complete brief daily dairy assessments each morning (30 minutes after waking) to assess smoking and other tobacco and cannabis use during the previous day as well as medication adherence and other relevant variables. Participants will be compensated $1 per day for the completion of daily diary assessments over the first 13 weeks of the study (up to up $92). Participants will earn $50 for the completion of the baseline assessment, and an additional $10 per week over the first 13 weeks for completing weekly questionnaires and a CO breath sample submission (up to $130), and $5 for each of the 3 interim assessments. Participants will earn $50 for the completion of the final follow-up assessment. Participants may earn up to $337 total via reloadable study credit card.
Smoking Abstinence. Self-reported previous day smoking will be assessed daily from 1- week pre-quit through 12 weeks post-quit, and past 7-day smoking status will be self-reported weekly and at the final follow-up reflecting a commonly used self-report measure of abstinence. Breath sample submissions for biochemical verification of abstinence will be prompted as part of each weekly smartphone assessment and the final follow-up assessment. Participants will submit breath samples via the portable breath CO monitor that connects with their study smartphone via Bluetooth. Participants will be considered abstinent if they report complete abstinence from smoking during the past 7 days and provide a CO breath sample of ≤6 ppm consistent with abstinence. The primary outcome measure is biochemically verified, 7-day point prevalence smoking abstinence at 26 weeks post-quit-date (i.e., 12 weeks after the end of treatment) per current recommendations. E-cigarette and other tobacco product use will be assessed and considered in alternate outcomes focused on broader tobacco use abstinence, but the primary outcome will be combustible cigarette abstinence.
Treatment Adherence. An adapted 7-item version of the the Adherence to Refills and Medications Scale (ARMS) will be used to assess overall participant adherence to each smoking cessation medication during the previous week. Participants will complete one version that assesses varenicline adherence, and the subset of participants assigned to the NRT groups will also complete an NRT version of the ARMS. The ARMS will be administered weekly through 12 weeks after the scheduled quit date. In addition, participants will complete daily EMAs of their NRT and varenicline use/adherence during the previous day (i.e., daily number of lozenges used, daily varenicline adherence [0, 1, or 2 doses taken]). Finally, completed counseling sessions will be summed.
Other Measures. Measures of sociodemographic characteristics, tobacco use characteristics, health, mental health, substance use, and several hypothesized treatment mediators and moderators will be included. In addition, participants will be asked weekly to choose from a list of physical symptoms (e.g., medication side effects, withdrawal symptoms) that they have experienced during the previous week. Participants will be asked to rate the severity of any symptoms they are experiencing.
1,581 studies on the registry are indexed under Smoking Cessation; 198 are open to participants now.
This study's planned enrollment of 496 is above the median of 164 across 1,423 interventional studies indexed under Smoking Cessation.
Browse Smoking Cessation studies →University of Oklahoma is the lead sponsor of 432 studies on the registry; 100 are open to participants now.
Of its 42 completed or terminated interventional studies of FDA-regulated products, 16 (38%) have results posted.
Counted across the registry records on this site, refreshed daily.
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.
Exclusion Criteria:
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.
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.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive 13 weeks of varenicline (1 titration week + 12 weeks at full twice daily 1 mg dosing) and a smartphone-based smoking cessation intervention with medication adherence components. All participants will receive up to 6 telephone counseling calls.
Drug: Varenicline (VAR) · Behavioral: Smartphone intervention with adherence components (COMBO-A) · Behavioral: Telephone Counseling
Participants will receive 13 weeks of varenicline (1 titration week + 12 weeks at full twice daily 1 mg dosing), 12 weeks of nicotine lozenges (2 mg or 4 mg), and a smartphone-based smoking cessation intervention with medication adherence components. All participants will receive up to 6 telephone counseling calls.
Drug: Varenicline (VAR) · Drug: Nicotine lozenge (NRT) · Behavioral: Smartphone intervention with adherence components (COMBO-A) · Behavioral: Telephone Counseling
Participants will receive 13 weeks of varenicline (1 titration week + 12 weeks at full twice daily 1 mg dosing) and a smartphone-based smoking cessation intervention without medication adherence components. All participants will receive up to 6 telephone counseling calls.
Drug: Varenicline (VAR) · Behavioral: Smartphone intervention without adherence components (COMBO-B) · Behavioral: Telephone Counseling
Participants will receive 13 weeks of varenicline (1 titration week + 12 weeks at full twice daily 1 mg dosing), 12 weeks of nicotine lozenges (2 mg or 4 mg), and a smartphone-based smoking cessation intervention without medication adherence components. All participants will receive up to 6 telephone counseling calls.
Drug: Varenicline (VAR) · Drug: Nicotine lozenge (NRT) · Behavioral: Smartphone intervention without adherence components (COMBO-B) · Behavioral: Telephone Counseling
13 weeks of varenicline
12 weeks of nicotine lozenges
Smartphone-based smoking cessation intervention with adherence components
Smartphone-based smoking cessation intervention without adherence components
Up to 6 telephone counseling sessions with a tobacco treatment specialist
Smoking Abstinence (26 weeks post-quit)
Self-reported smoking abstinence over the past 7 days with breath CO≤6 ppm
Time frame: 26 weeks after the scheduled quit day
Medication Adherence (weekly)
Adapted 7-item version of the Adherence to Refills and Medications Scale (ARMS). Separate scales will be administered to assess past-week varenicline and nicotine lozenge adherence. Scores may range from 7-28, with lower scores indicating better adherence.
Time frame: Weekly starting on the quit day (for varenicline) or 1-week post-quit (for lozenges) through 12 weeks post-quit.
Medication Adherence (daily)
Smartphone daily diary assessments of previous day varenicline and lozenge adherence.
Time frame: Assessments begin 1 week before the quit day (varenicline) or on the quit day (lozenges) through 12 weeks post-quit.
Smoking Abstinence (12 weeks post-quit)
Self-reported smoking abstinence over the past 7 days with breath CO≤6 ppm
Time frame: 12 weeks after the scheduled quit day
Plan to share: Yes
Started Jul 2026 (actual). Primary completion is estimated for Jun 2029, 34 months after the start.
Of 42 non-industry phase 2 interventional studies under Smoking Cessation, half reached primary completion within 41 months of starting (the median), counting those still running; a quarter within 17 and three quarters within 61. This study's planned 34 months is below that.
Counting every sponsor, half of 51 studies reached it within 35 months; a quarter within 14 and three quarters within 60.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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