This is a Phase 1, Single Centre, Double-blind, Randomized, Placebo-controlled Parallel-group Study to Evaluate the Pharmacokinetics, Safety, Tolerability and Immunogenicity of Tezepelumab after Single-Dose Subcutaneous Administration in Healthy Chinese Subjects.

This is a Phase 1, single centre, randomized, double-blind, placebo-controlled, single dose, parallel group study in healthy Chinese male or female subjects. 48 healthy subjects will be randomly assigned to one of the three treatment cohorts (i.e. 1:1:1 to Low dose, Medium dose and High dose) to receive a single dose of tezepelumab or placebo in a 3:1 ratio. Each subject will only participate in one cohort. Dose level is unblinded and treatment (tezepelumab or placebo) will be double-blinded within each treatment cohort. Following a screening period of a maximum of 28 days, subjects will stay at the study facility for two nights starting from the day before dosing (Day -1) to Day 2. Subjects will receive a single dose of tezepelumab or placebo subcutaneously on Day 1 and safety monitoring and serial collection of blood samples for PK evaluation will be followed throughout the study period. The follow up period after the dosing will be 112 days.

Inclusion Criteria:

• Male and female healthy Chinese subjects
• Age 18 to 45
• Body weight ≥ 40 kg
• Body mass index (BMI) between 19-24 kg/m2

Exclusion Criteria:

• History or evidence of a clinically significant disorder
• History of cancer
• Smokers of > 5 cigarettes/day
• Receipt of any marketed or investigational biologic within 4 months or 5 half-lives/non-biologic agent within 30 days or 5 half-lives prior to randomization
• History of chronic alcohol or drug abuse
• Hepatitis B, C or HIV
• Pregnant or breastfeeding
• History of anaphylaxis following any biologic therapy

double-blinded