Effects of Very Low Nicotine Content Cigarettes Among Adults Who Smoke Daily in South Korea

N/ANot Yet RecruitingNCT07755891

Sung-il Cho300 enrolled

Overview

The goal of this clinical trial is to learn how switching to very low nicotine content (VLNC) cigarettes affects smoking behavior and nicotine exposure among adults in South Korea who smoke conventional cigarettes daily. The main questions it aims to answer are: * Do participants assigned to VLNC cigarettes smoke fewer cigarettes per day during the 7 days before the Week 14 endline visit than those assigned to normal nicotine content (NNC) cigarettes? * Do participants assigned to VLNC cigarettes have more smoke-free days during the 12-week randomized intervention period than those assigned to NNC cigarettes? Researchers will compare participants assigned to VLNC cigarettes with those assigned to NNC cigarettes to evaluate differences in smoking behavior, nicotine exposure, dependence, craving, withdrawal symptoms, abstinence-related outcomes, use of other tobacco or nicotine products, product perceptions, policy support, and behavioral patterns assessed using ecological momentary assessment. Participants will: * Complete a 1-week baseline period while continuing to smoke their usual-brand cigarettes. * Be randomly assigned to receive either VLNC or NNC SPECTRUM research cigarettes for 12 weeks. * Attend scheduled study visits and complete questionnaires, daily surveys, and ecological momentary assessments. * Provide urine samples for assessment of nicotine exposure and complete other study assessments related to smoking behavior and symptoms. Up to approximately 350 individuals may be recruited and screened to obtain approximately 300 randomized participants.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Enrollment

300

Conditions

Interventions

SPECTRUM cigarettesOTHER

NRC102 non-menthol SPECTRUM research cigarettes with very low nicotine content (VLNC), containing approximately 0.4 mg nicotine per gram of tobacco. Final product specifications will follow documentation from the National Institute on Drug Abuse (NIDA) and RTI International for the lot used.

SPECTRUM cigarettesOTHER

NRC600 SPECTRUM research cigarettes with normal nicotine content (NNC), containing approximately 17.36 mg nicotine per gram of tobacco. Final product specifications will follow documentation from the National Institute on Drug Abuse (NIDA) and RTI International for the lot used.

Eligibility

Sex: ALLMin age: 19 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Age 19 years or older. * Current daily smoker of at least 10 conventional cigarettes per day for the past 12 months. Concurrent heated tobacco product use is permitted only when the participant meets the conventional-cigarette criterion and is a conventional-cigarette-dominant user. * No intention to quit smoking within the next month. * Willingness to switch entirely to the assigned study cigarettes during the trial period. * Ability to understand written Korean and complete study procedures independently. * Ability to use a smartphone for EMA data collection. * Ability to provide written informed consent. Exclusion Criteria: * Current regular use of electronic cigarettes (e-cigarettes). * Self-reported pregnancy, planning pregnancy during the study period, or breastfeeding; or positive pregnancy test at screening for participants who can become pregnant. * Current use of pharmacological smoking cessation aids, including varenicline, bupropion, or nicotine replacement therapy. * Serious psychiatric disorder that would interfere with study participation, such as psychosis or severe depression. * Any medical condition that contraindicates continued smoking, including prespecified safety thresholds such as systolic blood pressure of 160 mmHg or higher, heart rate of 105 beats/min or higher, or heart rate below 45 beats/min with symptoms. * Any other factor that may affect adherence or pose a health risk to the participant. * Inability to read and write sufficiently to complete study activities. * No reliable way for the research team to communicate with the participant by telephone or email. * Current participation in another tobacco- or nicotine-related research study. * Prior participation in a similar tobacco or nicotine intervention trial involving SPECTRUM research cigarettes or manipulation of cigarette nicotine content, if determined to affect eligibility.

Outcomes

Primary Outcomes

Mean number of cigarettes smoked per day during the 7 days preceding the Week 14 endline visit

Cigarette consumption will be assessed using brief online daily surveys, a 7-day Timeline Follow-Back questionnaire completed at the Week 14 endline visit, and returned cigarette butt counts. Daily cigarette consumption estimates from available measures will be summarized for each participant and averaged across the 7 days preceding the Week 14 endline visit. The outcome includes both study and non-study conventional cigarettes. Lower values indicate fewer cigarettes smoked per day.

Time frame: 7 days preceding Week 14 endline visit

Number of smoke-free days during the 12-week randomized intervention period

A smoke-free day is defined as a day on which the participant reports smoking no study or non-study conventional cigarettes. The outcome will be calculated by summing the number of days with zero cigarettes smoked per day during the 12-week randomized intervention period. The possible range is 0 to 84 days, with higher values indicating a greater number of smoke-free days.

Time frame: From randomization at Week 2 through the Week 14 endline visit (12 weeks)

Secondary Outcomes

Change from Week 2 baseline in urinary cotinine concentration

Urinary cotinine concentration will be assessed as a biomarker of nicotine exposure. Change from the Week 2 baseline value will be evaluated at Weeks 4, 8, 12, and 14. Because urinary cotinine concentrations are expected to be right-skewed, values may be log-transformed for analysis, and treatment effects may be reported as geometric mean ratios and corresponding percent differences between treatment groups.

Time frame: Week 2 baseline; Weeks 4, 8, 12, and 14

Change from baseline in Fagerström Test for Nicotine Dependence total score

Nicotine dependence will be assessed using the Fagerström Test for Nicotine Dependence (FTND). FTND total scores will be collected at baseline and at biweekly research-site visits during the randomized intervention period. Changes in total score over time and differences between the very low nicotine content and normal nicotine content cigarette groups will be evaluated.

Time frame: Baseline and biweekly visits through Week 14

Change from baseline in Questionnaire of Smoking Urges-Brief score

Smoking craving will be assessed using the Questionnaire of Smoking Urges-Brief (QSU-Brief). Scores will be collected at baseline and at biweekly research-site visits during the randomized intervention period. Changes in craving over time and differences in mean craving scores between the very low nicotine content and normal nicotine content cigarette groups will be evaluated.