A Study to Investigate Safety, Tolerability, Pharmacokinetics, Pharmacodynamics and Immunogenicity of AZD1613 in Healthy Participants.

This is a first-in-human, randomized, single-blind, placebo-controlled, single and multiple ascending dose study in healthy participants and will be conducted at a single study center. It consists of two parts: Part A (Single Ascending Dose - SAD) and Part B (Multiple Ascending Dose - MAD).

Part A of the study is a SAD sequential group design study and will consist of Parts A1, A2, and A3. Part A1 is planned to consist of 7 cohorts, Part A2 is planned to consist of one cohort of participants of Chinese descent, and Part A3 is planned to consist of 2 cohorts of participants of Japanese descent.

Parts A1, A2, and A3 of the study will comprise of:

1. A Screening Period of maximum 28 days. 2. A Treatment Period during which each participant will receive a single subcutaneous (SC) or intravenous (IV) dose of either AZD1613 or placebo on Day 1. 3. A Follow-up Period where participants will return to the study center for non-residential visits until Day 105.

Part B of the study will be a MAD sequential group design study. Up to 3 dose levels of AZD1613 are planned to be investigated in 3 cohorts of healthy participants.

Part B of the study will comprise of:

1. A Screening Period of maximum 28 days. 2. Three Treatment Periods during which participants will receive 3 single subcutaneous (SC) or intravenous (IV) doses of AZD1613 or placebo at 28-day intervals (Day 1, Day 29, and Day 57). 3. A Follow-up Period where participants will return to the study center for non-residential visits until Day 161.