A Study to Evaluate the Safety, Tolerability and Absorption to the Blood After Administration of Single and Multiple Doses of AZD8154 in Healthy Participants.

This study is a Phase 1, first in human (FiH) study, consisting of 3 parts (Part 1, Part 2, and Part 3) in healthy male and female participants of non-childbearing potential, performed at a single study center. Part 1 of this study will be a randomized, single-blind, placebo-controlled, single ascending dose (SAD) in healthy male and female participants of non-childbearing potential. Six dose levels of AZD8154 are planned to be investigated. Depending on emerging data, 1 to 2 additional dose levels may be added at the discretion of the Sponsor. Furthermore, one dose level will be repeated using the same formulation of AZD8154 but with a larger particle size (Part 1 only). Part 2 of this study will be a single cohort, open-label, 2-period, study to compare a single inhaled dose of AZD8154 (small particle size) nebuliser suspension with a single IV dose of AZD8154. Part 3 will be a single blind placebo controlled, multiple ascending doses (MAD) sequential design study in healthy male and/or female subjects of non childbearing potential conducted at a single center. Part 3:Three (3) inhaled dose levels of AZD8154 are planned to be investigated. Depending on the emerging data, up to 2 additional inhaled dose levels may be added at the discretion of the Sponsor.