The study will comprise:
- A screening period of up to 28 days;
- Two treatment periods lasting a total of 17 days from admission to the Clinical Unit (Day -1) to discharge (Day 16). During each treatment period subjects will receive a single dose of AZD4635 under fasting conditions. Period 1 is designed to evaluate the pharmacokinetics (PK) of AZD4635 in healthy smokers and nonsmokers. Period 2 is designed to evaluate the effect of fluvoxamine on the PK of AZD4635 in healthy smokers and non-smokers.
- A follow-up call will take place between 6 to 9 days after the last dose of fluvoxamine, to ensure the well-being of the subjects. Completion of the last follow-up call or unscheduled follow-up visit will be considered the end of the study.
Each subject will be involved in the study for a maximum of 53 days.

