The purpose of this study is to evaluate the Pharmacokinetics, Safety, Tolerability of Nirsevimab in Healthy Chinese Adults.

This is a Phase 1, randomized, double-blind, placebo-controlled study to evaluate the PK, safety and tolerability, and ADA of nirsevimab when administered as a single fixed IM dosage to healthy Chinese adult subjects. Enrolment is planned at a single study center in China. Approximately 24 subjects will be randomly assigned in a 3:1 ratio to receive nirsevimab (n = 18) or placebo (n = 6). All subjects will be followed for approximately 150 days after dosing to assess safety, PK, and ADA response.

Inclusion Criteria:

1. Age 18 to 45 years
2. Weight ≥ 45 kg and ≤ 110 kg and Body Mass Index of 19 to 26 kg/m2
3. Healthy Chinese subjects (both male and female)
4. Normotensive
5. Normal electrocardiogram (ECG) within 28 days prior to Day 1

Exclusion Criteria:

1. Acute illness at study entry (pre-dose on Day 1)
2. Fever ≥99.5°F (37.5°C) on day of dosing
3. Any drug therapy within 14 days prior to Day 1 (except contraceptives).
4. Receipt of immunoglobulin or blood products within 6 months prior to study entry.
5. Receipt of any investigational drug therapy within 120 days prior to investigational product dosing or planned to receive any investigational drug therapy within 150 days after investigational product dosing.
6. Previous receipt of any marketed or investigational mAb.
7. Previous vaccination against RSV.
8. History of immunodeficiency or receipt of immunosuppressive medications during the prior year.
9. History of asthma.
10. History of autoimmune disorder.
11. Evidence of any systemic disease on physical examination.
12. Evidence of infection with hepatitis A, B, or C virus, syphilis, or human immunodeficiency virus.
13. Any clinically significant abnormal laboratory assessments at screening.
14. Pregnant or nursing mother.
15. Alcohol or drug abuse

Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal. All request will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.

AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

When a request has been approved AstraZeneca will provide access to the de-identified individual patient-level data in an approved sponsored tool . Signed Data Sharing Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information. Additionally, all users will need to accept the terms and conditions of the SAS MSE to gain access. For additional details, please review the Disclosure Statements at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

As-treated population included all participants who were randomized into the study and received any amount of study treatment.

Treatment emergent adverse events were collected from first date of study treatment administration (Day 1) up to 151 days.

Treatment emergent adverse events were reported for As-treated population which included all participants who were randomized into the study and received any amount of study treatment.