Prefatory Study to Explore Changes in Nasal Mucociliary Clearance and to Standardize Nasal Scraping Procedure

Inclusion Criteria to be met at Visit 1 and Visit 2:

- Male smokers aged ≥25 to ≤45 years old.

- Male never smokers aged ≥25 to ≤40 years old.

- Subject's BMI is comprised between 18.0 kg/m2 to 32.0 kg/m2, inclusive.

- Subject is healthy, as judged by the Investigator.

Additional Inclusion Criteria to allocate subjects in one of the two groups:

- Non-menthol cigarette smokers:

- A positive urine cotinine test (≥200 ng/mL).

- Smoked at least 20 cigarettes per day for at least the past 5 years.

- eCO levels >10 parts per million (ppm).

- No plans to quit smoking in the next 3 months.

- Never smokers:

- Subject who has smoked less than 100 cigarettes throughout their lifetime and no
cigarettes in the past 3 years.

- A negative urine cotinine test (<200 ng/mL).

- eCO levels ≤ 5 ppm.

Exclusion Criteria:

- As per the Investigator's judgment, the subject cannot participate in the study for
any reason (e.g., medical, psychiatric, and/or social reason).

- Inability to taste sweet within 60 minutes in the STT test.

- Any condition the Principal Investigator or designee has cause to believe would
interfere with the procedures for upper or lower airway function. This could include,
but is not limited to, nasal/septum deviations, or nasal polyps or nasal allergies.