Safety, Pharmacokinetics,and Antiviral Activity of RV299 Against Respiratory Syncytical Virus (RSV)

The purpose of the study is to learn about the safety, pharmacokinetics and antiviral activity of the study medicine (RV299) for the potential treatment of respiratory syncytial virus (RSV). RSV is a highly contagious virus that can lead to serious lung infections in patients with reduced ability to fight infection. Most vulnerable populations include babies, the elderly and patients that have received a bone marrow transplant.

This study is seeking healthy participants who are: Healthy adult male and female participants aged between 18 to 55 years, with a total body weight ≥50 kg and body mass index (BMI) ≥18 kg/m2 and ≤35kg/m2 and who have been screened to be sero-suitable for infection with the RSV-A Memphis 37b virus challenge virus. A total of 80 participants is planned: 40 participants on RV299 and 40 participants on placebo. The study is divided into 3 phases: * Screening phase: from Day -90 to Day-3 pre-human viral challenge (HVC). * Inpatient phase: Participants will be resident in the quarantine unit for approximately 15 days (from Day -2 to Day 12). * Post RSV-A Memphis 37b virus inoculation on Day 0, participants will be randomized to receive RV299 or matched placebo. * Administration of RV299 or placebo will be twice daily (\~12 hours interval) for 5 consecutive days and will start on confirmation of RSV infection. * Outpatient phase: Day 28 (±3 days)