Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Randomized, Controlled, Open-label, 2-arm Parallel Group, Single Center Study to Demonstrate Reductions in Exposure to Selected Smoke Constituents in Healthy Smokers Switching to the Carbon Heated Tobacco Product 1.0 (CHTP 1.0) Compared to Continuing to Use Conventional Cigarettes During 5 Days in Confinement.
Brief Summary: The overall goal of the study is to demonstrate the reduction of biomarkers of exposure (BoExp) to selected harmful and potentially harmful constituents (HPHCs) in adult smokers switching for 5 days from conventional cigarette (CC) to Carbon Heated Tobacco Product 1.0 (CHTP 1.0) as compared to smokers continuing to use CC.


Options:
A: Inclusion Criteria:

Subjects must meet all of the following inclusion criteria to be eligible for enrolment into the study:

1. Able to comply with the study procedures
2. Male or female healthy smokers aged ≥19
3. Smoking at least 10 cigarettes a day
4. Smoking for at least one year
5. Not currently attempting to quit smoking or wishing to do so in the next 30 days (this will be verified at screening by the answer ''NO'' to both questions ''Do you intend to quit in the next 30 days?'' and ''Are you interested in taking part in one of our smoking cessation programs?'')
6. Female smokers not planning to become pregnant are using an acceptable form of contraception.

Exclusion Criteria:

The presence of any of the following will exclude a subject from study enrolment:

1. Use of smokeless tobacco, or any other tobacco products (including e-cigarettes, cigars, chewing tobacco, snus, etc.) within the last 3 months, at baseline and during the whole study.
2. Use of nicotine replacement therapy or other smoking cessation therapies within the last 3 months and at baseline.
3. Self-reported pregnancy, planned pregnancy or breastfeeding.
4. Tobacco industry employees and 1st degree relatives will be excluded in order to safeguard independence of the study

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B: Inclusion Criteria:

* Subject is aged ≥ 21 years.
* Subject is Caucasian.
* Subject is healthy, as judged by the Investigator.
* Subject smokes at least 10 commercially available non-menthol CCs per day (no brand restrictions) for at least the last 6 weeks prior to admission, based on self-reporting.
* Subject has smoked at least for the last 3 years.
* Subject does not plan to quit smoking in the next 3 months.

Exclusion Criteria:

* As per Investigator judgment, the subject cannot participate in the study for any reason (e.g., medical, psychiatric, and/or social reason).
* Subject has received medication within 14 days or within 5 half-lives of the medication (whichever is longer), which has an impact on cytochrome P450 1A2 (CYP1A2) or cytochrome P450 2A6 (CYP2A6) activity.
* Female subject is pregnant or breast feeding.
* Female subject does not agree to use an acceptable method of effective contraception.
C: Inclusion Criteria:

* Males or females, between 28 and 55 years of age, inclusive.
* Cigarette-only smokers who currently smoked at least 15 cigarettes daily and who smoked for at least 10 years prior to Week 0 (i.e., chronic cigarette smokers).
* Smokers not intending to quit smoking, but willing to switch their tobacco product (intent to quit was defined as intending to make or making a quit attempt within 1 month prior to Week 0).
* Non-smoking subjects who self-reported "Never-Smoker" per the American Thoracic Society Questionnaire definition, and did not have urinary cotinine levels exceeding 50 ng/mL.
* Subjects, in the opinion of the Investigators, free of clinically significant health problems and not on medication on a daily basis for chronic medical disorders deemed clinically significant by the Investigator(s).
* Subjects not regularly taking creatine supplements.
* Subjects testing negative for selected drugs of abuse at Screening (included alcohol test).
* Subjects with a negative hepatitis panel (including hepatitis B surface antigen \[HBsAg\] and hepatitis C virus antibody \[anti-HCV\]) and negative Human Immunodeficiency Virus (HIV) antibody screens (for subjects immunized against hepatitis B with documentation of this immunization, a positive test result was not exclusionary).
* Female subjects who were non-pregnant (urine pregnancy test results were negative at Screening and Weeks 0, 12, and 24), non-lactating, and either postmenopausal (as verified by Follicle Stimulating Hormone levels) for at least 1 year, surgically sterile (e.g., tubal ligation, hysterectomy) for at least 90 days, or agreed to use from the time of signing the informed consent until 30 days after Week 24 (or Study Completion) a form of contraception considered acceptable to the Investigators (such as oral, injectable or implantable contraceptives, intrauterine devices and barrier methods ).
* Subjects able to read and comprehend questionnaires in English and willing to sign an Informed Consent Form.

Exclusion Criteria:

* Smokers using any other tobacco or nicotine-containing product or device other than tobacco-burning cigarettes from 6 months prior to the study through Week 24, including cigars, pipes, chewing tobacco, snuff, snus, nicotine patch, nicotine gum, etc.
* A history or clinical manifestations of significant metabolic, hepatic, renal, hematological, pulmonary, cardiovascular, gastrointestinal, urological, neurological, or psychiatric disorders.
* A history of hypersensitivity or allergies to any drug compound unless approved by the Investigator(s).
* A history or presence of an abnormal ECG deemed clinically significant by the Investigator.
* A history of alcoholism or drug addiction within 1 year prior to Study Entry.
* Evidence of visible oral cancer, as found in an oral health examination or based on oral health questions at each visit.
* Any acute or chronic condition that, in the Investigator(s)' opinion, limited the subject's ability to complete and/or participate in the study.
* Donation of blood from 30 days prior to Screening through Week 24 (or Study Completion), inclusive, or plasma from 2 weeks prior to Screening through Week 24 (or Study Completion), inclusive.
* Receipt of blood products within 2 months prior to Study Entry.
* Subject or a relative of the subject was currently or had ever been employed by the tobacco industry.
* Subject participated in any other investigational study drug or product trial in which receipt of an investigational study drug or product occurred within 30 days prior to Check-in (inclusive).
D: Inclusion Criteria:

* Smoking, apparently healthy subject as judged by the Investigator.
* Subject smokes at least 10 commercially available mCCs per day (no brand restrictions) for the last 4 weeks, based on self-reporting.
* Subject has smoked for at least the last 3 consecutive years.
* Subject does not plan to quit smoking within the next 6 months.

Exclusion Criteria:

* As per Investigator judgment, the subject cannot participate in the study for any reason (e.g., medical, psychiatric, and/or social reason).
* The subject has received medication within 14 days or within 5 half-lives of the medication (whichever is longer), which has an impact on CYP1A2 or CYP2A6 activity.
* For women: Subject is pregnant or is breast feeding.
* For women: Subject does not agree to use an acceptable method of effective contraception.

Answer: B