A Phase 2 interventional study of Either normal nicotine content cigarettes (15.8mg/g) or reduced nicotine content cigarettes (0.4mg/g) and E-Cigarettes in Tobacco Use Disorder, sponsored by Brown University. Completed at 2 sites in United States. Open to participants aged 18 Years to 70 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-04-01.
Sponsored by Brown University · Phase 2, Interventional, and Basic science
While the prevalence of smoking in the United States general population has declined over the past 50 years, there has been little to no decline among people with mental health conditions. Affective Disorders (ADs) are the most common mental health conditions in the US, and over 40% of people with ADs are current smokers. A national policy of reducing the nicotine content of cigarettes has the potential to reduce tobacco use, dependence, and related adverse health outcomes. Controlled trials in psychiatrically-stable smokers have shown that reducing the nicotine content in cigarettes can reduce cigarettes per day (CPD), dependence and tobacco toxicant exposure, with few adverse consequences.
The goal of the proposed trial is to experimentally model whether increasing the availability and appeal of an alternative, non-combusted source of nicotine (e-cigarettes) moderates the effect of altering the nicotine in cigarettes in smokers with ADs. Additionally, investigators will test whether allowing participants to personalize the flavor of the e-liquid alters any moderating effects their availability may have on tobacco cigarette smoking.
Daily smokers with current ADs will be recruited at Brown University and the University of Vermont.
Investigators will study two research cigarettes referred to here as Research Cigarette 1 (RC1) and Research Cigarette 2 (RC2). One of these cigarettes will be a normal nicotine content cigarette and the other will be a reduced nicotine content cigarette. Investigators will study two e-cigarette conditions referred to here as E-Cigarette Condition 1 (EC1) and E-Cigarette Condition 2 (EC2). Both e-cigarette conditions will involve the same commercially available devices and same nicotine-containing e-liquid, but in one condition that e-liquid will be available only in tobacco flavor while in the other condition that e-liquid will be available in multiple flavors from which participants can choose based on personal taste preference. Participants will be assigned to one of the following four study conditions: (1) RC1 only; (2) RC2 only; (3) RC2 + EC1; (4) RC2 + EC2.
Participants will be asked to use only their assigned study products for 16 weeks. Outcome measures include total CPD, cigarette demand assessed by behavioral economics-based purchase tasks, craving, withdrawal, psychiatric symptoms, breath carbon monoxide (CO), biomarkers of tobacco toxicant exposure, brain function and structure, and airway inflammation (fractional nitric oxide concentration in exhaled breath [FeNO]).
968 studies on the registry are indexed under Tobacco Use Disorder; 126 are open to participants now.
This study's enrollment of 326 is above the median of 89 across 851 interventional studies indexed under Tobacco Use Disorder.
Browse Tobacco Use Disorder studies →Brown University is the lead sponsor of 282 studies on the registry; 42 are open to participants now.
Of its 25 completed or terminated interventional studies of FDA-regulated products, 18 (72%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria
Research Cigarettes #1
Other: Either normal nicotine content cigarettes (15.8mg/g) or reduced nicotine content cigarettes (0.4mg/g)
Research Cigarettes #2
Other: Either normal nicotine content cigarettes (15.8mg/g) or reduced nicotine content cigarettes (0.4mg/g)
Research Cigarettes #2 plus E-cigarettes #1 (participants receive tobacco flavor only)
Other: Either normal nicotine content cigarettes (15.8mg/g) or reduced nicotine content cigarettes (0.4mg/g) · Other: E-Cigarettes
Research Cigarettes #2 plus E-cigarettes #2 (participants can choose among varying flavors)
Other: Either normal nicotine content cigarettes (15.8mg/g) or reduced nicotine content cigarettes (0.4mg/g) · Other: E-Cigarettes
1) Altering the nicotine content of the tobacco research cigarette
1) Altering the availability of e-cigarettes; 2) Altering option to personalize the e-liquid in the e-cig condition
Cigarettes Per Day
Cigarettes per day will be assessed for use of cigarettes with different nicotine content.
Time frame: 16 weeks
| Milestone | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 |
|---|---|---|---|---|
| Started | 83 | 85 | 74 | 84 |
| Completed | 67 | 66 | 57 | 70 |
| Not completed | 16 | 19 | 17 | 14 |
Cigarettes per day will be assessed for use of cigarettes with different nicotine content.
| cigarettes per day | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 |
|---|---|---|---|---|
| Cigarettes Per Day | 22.54 ± 1.59 | 14.32 ± 1.32 | 11.76 ± 1.18 | 7.63 ± 0.90 |
Collected over 16 weeks. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| RC 1 Only | 0/83 (0%) | 9/83 (10.8%) | 71/83 (85.5%) |
| RC 2 Only | 0/85 (0%) | 4/85 (4.7%) | 74/85 (87.1%) |
| RC 2 + EC 1 | 1/74 (1.4%) | 4/74 (5.4%) | 62/74 (83.8%) |
| RC 2 + EC 2 | 0/84 (0%) | 2/84 (2.4%) | 72/84 (85.7%) |
| Event | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 |
|---|---|---|---|---|
| Psychiatric disorders - OtherPsychiatric disorders | 3/83 | 0/85 | 0/74 | 0/84 |
| HypertensionVascular disorders | 1/83 | 0/85 | 1/74 | 0/84 |
| Death NOSGeneral disorders | 0/83 | 0/85 | 1/74 | 0/84 |
| Injury, poisoning, and procedural complicationsInjury, poisoning and procedural complications | 0/83 | 0/85 | 1/74 | 0/84 |
| DehydrationMetabolism and nutrition disorders | 0/83 | 0/85 | 1/74 | 0/84 |
| Esophageal perforationGastrointestinal disorders | 1/83 | 0/85 | 0/74 | 0/84 |
| IrritabilityGeneral disorders | 1/83 | 0/85 | 0/74 | 0/84 |
| Tumor PainNeoplasms benign, malignant and unspecified (incl cysts and polyps) | 1/83 | 0/85 | 0/74 | 0/84 |
| Pregnancy, puerperium, and perinatal conditionsPregnancy, puerperium and perinatal conditions | 1/83 | 0/85 | 0/74 | 0/84 |
| Surgical and medical procedures - OtherSurgical and medical procedures | 1/83 | 1/85 | 0/74 | 0/84 |
| Event | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 |
|---|---|---|---|---|
| OASIS Score IncreasePsychiatric disorders | 32/83 | 31/85 | 31/74 | 31/84 |
| BDI Category IncreasePsychiatric disorders | 29/83 | 29/85 | 26/74 | 25/84 |
| Psychiatric disordersPsychiatric disorders | 27/83 | 28/85 | 19/74 | 24/84 |
| Respiratory, thoracic and mediastinal disordersRespiratory, thoracic and mediastinal disorders | 23/83 | 27/85 | 18/74 | 18/84 |
| General disorders and administrationGeneral disorders | 18/83 | 24/85 | 16/74 | 22/84 |
| Infections and infestationsInfections and infestations | 16/83 | 23/85 | 8/74 | 10/84 |
| Nervous system disordersNervous system disorders | 7/83 | 18/85 | 15/74 | 10/84 |
| Gastrointestinal disordersGastrointestinal disorders | 9/83 | 17/85 | 14/74 | 17/84 |
| Vascular disordersVascular disorders | 10/83 | 13/85 | 8/74 | 16/84 |
| Musculoskeletal and connective tissue disordersMusculoskeletal and connective tissue disorders | 11/83 | 16/85 | 7/74 | 12/84 |
| Age, Continuous(years) | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 | Total |
|---|---|---|---|---|---|
| Mean | 39.77 ± 10.98 | 39.85 ± 9.28 | 41.51 ± 12.39 | 39.38 ± 10.59 | 40.09 ± 10.79 |
| Sex: Female, Male(Participants) | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 | Total |
|---|---|---|---|---|---|
| Female | 65 | 69 | 50 | 59 | 243 |
| Male | 18 | 16 | 24 | 25 | 83 |
| Race/Ethnicity, Customized(Participants) | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 | Total |
|---|---|---|---|---|---|
| Black, non-Latino | 9 | 6 | 9 | 9 | 33 |
| Latino | 4 | 3 | 3 | 2 | 12 |
| White, non-Latino | 66 | 68 | 60 | 68 | 262 |
| Non-Latino other or multiracial | 4 | 8 | 2 | 5 | 19 |
| Region of Enrollment(participants) | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 | Total |
|---|---|---|---|---|---|
| United States | 83 | 85 | 74 | 84 | 326 |
| Population(Participants) | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 | Total |
|---|---|---|---|---|---|
| Females with lower educational level | 20 | 23 | 16 | 21 | 80 |
| OUD | 19 | 19 | 17 | 19 | 74 |
| Affective disorders | 44 | 43 | 41 | 44 | 172 |
| Educational level(Participants) | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 | Total |
|---|---|---|---|---|---|
| <High school | 9 | 4 | 3 | 14 | 30 |
| High school graduate, equivalency, or some college | 51 | 57 | 46 | 47 | 201 |
| Associate's degree | 8 | 11 | 13 | 11 | 43 |
| ≥College graduate | 15 | 13 | 12 | 12 | 52 |
| Marital status(Participants) | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 | Total |
|---|---|---|---|---|---|
| Married | 8 | 15 | 17 | 11 | 51 |
| Never married | 49 | 47 | 36 | 48 | 180 |
| Divorced, separated, or widowed | 26 | 23 | 21 | 25 | 95 |
| Primarily smokes mentholated cigarettes(Participants) | RC 1 Only | RC 2 Only | RC 2 + EC 1 | RC 2 + EC 2 | Total |
|---|---|---|---|---|---|
| Count of participants | 32 | 35 | 31 | 33 | 131 |
7 further baseline measures are reported on the registry.
Documents are hosted by the registry — open the source record to download them.
Plan to share: Yes
This study is completed, as verified in Mar 2025. You cannot join it, but the record below documents what was studied.
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