A Study to Investigate the Safety, Tolerability and Effects of AZD8630 in Healthy Subjects and Subjects With Asthma on Inhaled Corticosteroids and Long-acting Beta-agonists

The study is divided in 2 parts, A and B. Part A will be conducted in healthy adults, whereas Part B will be conducted in adult asthma patients on medium/high dose inhaled corticosteroids (ICS)/long-acting beta-agonists (LABA) to evaluate the safety, tolerability, pharmacokinetics (PK), and immunogenicity of AZD8630 by dry powder inhaler (DPI) administration. Part A includes the assessment of the PK and safety of intravenous (IV) AZD8630. Part A consists of single ascending dose (SAD) and multiple ascending dose (MAD) cohorts in sequential order and Part B will be evaluating multiple dose levels. Part A: This part will consist 4 sub-parts and will include healthy participants and healthy participants of Chinese and Japanese ethnicity. These participants will randomized to receive AZD8630 and to receive placebo. * Sub-Part A1, SAD in healthy participants (one cohort in Sub-Part A1 will receive IV AZD8630 \[IV formulation\]) * Sub-Part A2, SAD in healthy participants of Chinese and Japanese ethnicity * Sub-Part A3, MAD in healthy participants * Sub-Part A4, MAD in healthy participants of Chinese and Japanese ethnicity Part B: Adult asthma patients will be randomized to one of 3 inhaled dose levels of AZD8630 or placebo. The expected duration of study participation for each participants in the part A is up to 87 days, and each patients in the Part B is up to 70 days.