A Study to Learn About the Drug-drug Interactions of Sisunatovir in Healthy Adult Participants

An Adaptive, Part Open-label, Part Randomised Phase 1 Clinical Trial in Healthy Volunteers to Study Drug Interactions With RV521 Including Those Mediated by CYP3A4 and P-glycoprotein

The purpose of this clinical trial is to learn about the interaction of sisunatovir with four medications (midazolam, itraconazole, rifampicin, and verapamil). These medications are known to have specific effects on enzymes and proteins that could influence drug absorption.

This study will be conducted in 4 Cohorts:

• Cohort 1 will receive midazolam and sisunatovir or placebo,
• Cohort 2 will receive Itraconazole and sisunatovir,
• Cohort 3 will receive verapamil and sisunatovir,
• Cohort 4 will receive rifampicin and sisunatovir. A placebo looks like sisunatovir but does not contain any active medicine in it.

This study is looking for health adult participants that meet the following criteria:

1. Caucasians age 18 to 45 years
2. All fertile participants must agree to the use of highly effective contraception
3. Body mass index (BMI) of 18-25.0 kg/m2
4. Male and female participants who are overtly healthy as determined by medical evaluation. This includes medical history, physical examination, blood pressure, pulse rate, standard 12-lead ECG (electrocardiogram), and laboratory tests.

This study consists of 2 parts, Part A and Part B. Part A will enroll up to 104 participants. The design of Part B will be determined after the completion of Part A.

Inclusion Criteria:

• Age 18 to 45 years, inclusive
• Willing to comply with protocol defined contraception requirements
• In good health with no history of major medical conditions
• A body mass index (BMI) of 18 - 25 kg/m2

Exclusion Criteria:

• Evidence of any clinically significant or currently active major medical condition
• Positive test for Hepatitis B surface antigen (HBsAg), Hepatitis C antibody (HCV Ab), or human immunodeficiency virus antibody (HIV Ab)
• Not willing to comply with protocol defined restrictions for intake of drugs of abuse, alcohol, nicotine-containing products, medication (prescription, OTC, herbal, vitamins/minerals etc) and specified food and drink products