A Study to Assess Safety, Pharmacokinetics Anti-Drug Antibody and Anti-RSV Antibody After 2 Doses of Nirsevimab

Study Overview
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Brief Summary
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The purpose of this study is to measure the safety, PK, occurrence of ADA to nirsevimab, and anti-RSV neutralizing Ab in Japanese children with certain health conditions or pre-term infants aged ≤12 months. Study details include The study duration is approximately 21 months with a 2-month enrollment period. Study intervention is 2 doses administered 5- 6 months apart. The study has 5 or 6 site visits and several telephone contacts with a 2 or 4 week interval

Official Title
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A Phase III Single-Arm Open-Label Study to Evaluate the Safety PK ADA and Anti RSV nAb Following Administration of 2 Doses of Nirsevimab Given 5 to 6 Months Apart in Infants With CHD, CLD, Immunocompromise, Down Syndrome, or Born Pre-Term in Japan

Conditions
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Respiratory Syncytial Virus Infections

Intervention / Treatment
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* Drug: Nirsevimab


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent and any locally required authorization obtained from the participant's parent(s)/legally authorized representative(s) before performing any protocol-related procedures, including screening evaluations Japanese infants of ≤12 months of age eligible to receive palivizumab in accordance with national or local guidelines and those who must meet at least one of the following conditions at the time of informed consent. Immunodeficiency Chronic Lung Disease Congenital Heart Disease Down syndrome Born pre-term ≤28 wks Gestation age and aged ≤12 months, or born pre-term >28 wks and ≤35 wks Gestation age and aged ≤6 months The participant's parent(s)/legally authorized representative(s) can understand and comply with the requirements of the protocol including follow-up visits as judged by the investigator. The participant is available to complete the follow-up period for approximately 19 months, which will be approximately 1 year after receipt of 2nd dose of nirsevimab Exclusion Criteria: Requirement for mechanical ventilation, extracorporeal membrane oxygenation, continuous positive airway pressure (CPAP), or other mechanical respiratory or cardiac support at the time of enrollment A current, active RSV infection at the time of screening and investigational product administration Any fever (≥100.4°F [≥38.0°C], regardless of route) or acute illness at the time of prior to investigational product administration Any serious concurrent medical condition (except those resulting in an immune deficiency condition), including: Known renal impairment Known hepatic dysfunction including known or suspected active or chronic hepatitis infection Any seizure disorder or evolving or unstable neurological condition Anticipated cardiac surgery within 5-6 months after enrollment Prior history of a suspected or actual acute life-threatening event Receipt or intended use of palivizumab in the current enrollment season Any known allergy or history of allergic reaction to any component of nirsevimab Any known allergy or history of allergic reaction to immunoglobulin products, blood products, or other foreign proteins Concurrent enrollment in another interventional study, or prior receipt of any investigational agent Anticipated survival of less than 1 year at the time of informed consent Any condition that, in the opinion of the investigator, would interfere with the evaluation of the investigational product or interpretation of study results Children of employees of the Sponsor, clinical study site, or any other individuals involved with the conduct of the study, or immediate family members of such individuals

Ages Eligible for Study
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Minimum Age: 0 Years
Maximum Age: 1 Year

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: MEDI8897<br>Anti-RSV monoclonal antibody | Drug: Nirsevimab<br>* Participants in the first year of life will receive the 1st dose of nirsevimab as a single, fixed intramuscular (IM) dose of 50 mg if body weight is <5 kg or 100 mg if body weight is ≥5 kg. A 2nd fixed IM dose of 50 mg if body weight is <5 kg or 100 mg if body weight is ≥5 kg will be administered 5 to 6 months following the 1st dose.<br>* Other names: MEDI8897;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of all TEAEs, TESAEs, AESIs, and NOCDs | The number and percentage of participants with TEAEs, TESAEs, AESIs, and NOCDs will be summarized by SOC and PT overall. | 360 days after the 2nd or last dose administered in the study | 
| Study discontinuations prior to Day 151 post 2nd dose. | The number and percentage of subject discontinuations will be summarized. | 360 days after the 2nd or last dose administered in the study | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pharmacokinetics (PK) - Nirsevimab serum concentrations |  | 360 days after the 2nd or last dose administered in the study | 
| ADA - Occurrence of ADA to nirsevimab in serum |  | 360 days after the 2nd or last dose administered in the study | 
| Anti-RSV neutralizing Ab - Anti-RSV neutralizing Ab levels (IU/mL) in serum |  | 360 days after the 2nd or last dose administered in the study |