A Study to Assess the Safety, Tolerability and Pharmacokinetics of AZD7503 in Healthy Participants

This study will evaluate safety, tolerability and pharmacokinetics (PK) of AZD7503, following subcutaneous (SC) administration of single ascending doses of AZD7503 in healthy participants.

This is a Phase I, First-in-Human, study in healthy males and females (non-childbearing potential) participants. In this study up to four dose levels of AZD7503 are planned to be evaluated. The planned doses of AZD7503 are dose 1, dose 2, dose 3, and dose 4. Eligible participants will be randomised to receive either AZD7503 or placebo. The study will include four single dose cohorts with an option to include two cohorts based on emerging data from planned cohorts in the study and two additional cohorts of Japanese participants and one cohort of Chinese participants will also be included. Dosing for each ascending dose cohort will be proceeded with sentinel dosing strategy. Here, sentinel sub-cohort will be included, such that 1 participant will be randomised to receive placebo and 1 participant will be randomised to receive AZD7503. The safety data from the sentinel participants up to 24 hours post-dose will be reviewed by the Principal Investigator (PI) before the remaining participants in the cohort are dosed The study will comprise: * A Screening Period of maximum 28 days; * A Treatment Period during which participants will be resident at the Study Centre from the day before study medication administration (Day -1) until at least 72 hours after study medication administration; discharged from the Study Centre on Day 4; * Follow-up Visits on 1,2,4,6 and 8 weeks; and * A Final Follow-up Visit 10 weeks after the last study medication dose. Each participant will be involved in the study for approximately 14 weeks.