Table 1.

Eligibility Criteria

Inclusion criteria
Provided signed informed consent and could understand the subject information sheet
Age 23–65 y
Body mass index 18.5–32 kg/m2
Japanese ethnicity
Healthy smoker, as judged by the principal investigator based on data collected at the screening visit
Smoked ≥10 mCCs per day with a maximum ISO yield of 1 mg for the previous 4 weeks (self-reported) and had smoked for ≥3 consecutive years
No plan to quit smoking in the next 3 months
Ready to stop smoking for up to 90 days
Ready to use the mTHS 2.2
Exclusion criteria
The principal investigator judged the participant to be unable to participate for any reason (medical, psychiatric, and/or social reason)
Legally incompetent, physically or mentally incapable of giving consent
Medical condition requiring smoking cessation, or clinically relevant disease
Medical condition that required or would have required in the course of the study a medical intervention (eg, start of treatment, surgery, or hospitalization), which would have interfered with study participation and/or study results
Use of nicotine-containing products (other than mCCs) or electronic cigarettes/similar devices within 4 weeks prior to enrollment
Administration of drugs likely to affect CYP1A2 or CYP2A6 activity within 14 days or five half-lives of the drug (whichever was longer) before Day −2
Administration of drugs within 14 days of Day −2 that the principal investigator thought was likely to interfere with the study objectives or the participant’s safety
Concomitant use of non-steroidal anti-inflammatory drugs (NSAIDs) or acetylsalicylic acid
Positive alcohol test and/or history of alcohol abuse that could have interfered with participation in the study
Positive urine drug test
Positive serology test for human immunodeficiency virus 1/2, hepatitis B, or hepatitis C virus
Donation/receipt of whole blood/blood products within 3 months prior to admission
Current or former employee of the tobacco industry, or of their first-degree relatives (parent, sibling, or child)
Employee of the investigational site, or any other parties involved in the study, or of their first-degree relatives (parent, sibling, or child)
Participation in a clinical study within 3 months before screening
Participation in the same study at a different time (ie, each subject could be included in the study population only once)
Pregnant/breast feeding women
Women who were unwilling to use an acceptable method of contraception

ISO = International Organization for Standardization; mCC = menthol cigarettes; mTHS = menthol Tobacco Heating System 2.2.