Anti-RSV Study in Chinese Patients (ASCENT)

Inclusion Criteria: * Age 18 - 75 years, inclusive. * Confirmed with RSV infection by rapid diagnostic testing. * New onset with documentation of the following symptoms within 72 hours prior to the start of screening: Respiratory symptoms: runny nose, stuffy nose, sneezing, sore throat, earache, cough, shortness of breath; Systemic symptoms: headache, fatigue / lethargy, fever, and muscle and / or joint ache. The patient must have four symptoms of above, and at least one of these must be respiratory symptom in nature. * Able and willing to provide written informed consent and to comply with the study protocol. Exclusion Criteria: * The patient has taken, is taking or needs to take any antiviral medication (e.g. ribavirin, Chinese medicine or herbs with effects of treating respiratory tract infection) within the 72 hours prior to screening. * Awareness of concomitant infections of respiratory viruses (eg, influenza A, B), bacterial or fungal infections, including systemic bacterial or fungal infections within 7 days prior to screening or during the screening period. * Patient frailty was evaluated as "Vulnerable" or worse according to the Clinical Frailty Scale with a score ≥ 4 at screening. * Awareness of having positive results on HBsAg or HCV antibody or HIV (HIV 1 or HIV 2). * Patient with active tuberculosis or is taking antituberculosis treatment. * Patient with severe gastrointestinal disease which could impact drug absorption, eg, vomiting, malabsorption syndrome, o…