A Phase III, Multicenter, Randomized, Double-blind, Placebo-controlled, Clinical Efficacy and Safety Study of GP681 Tablets for Post-exposure Prophylaxis Against Influenza in Adults and Adolescents
Index patients who are infected with influenza virus (Q-PCR positive) can be treated with anti-influenza drugs if their influenza symptoms onset was within 48 hours of screening. Their eligible households will be randomized to either GP681 tablets or placebo if at least 1 household contacts have not received influenza vaccine with 6 months of screening and if all household contacts screen negative for influenza infection. The main endpoints are assessed based on multiple respiratory swabs, obtained from household contacts up to Day 10, and through the assessment of symptoms.
⁃ Index patients(IPs)
• Male or female patients aged≥2 years at the time of signing the informed consent form.
• The first patient in a household with a diagnosis of influenza virus infection confirmed by all of the following in the influenza season:
• Positive Influenza rapid antigen test or Polymerase chain reaction (PCR), and;
• Fever (axillary temperature ≥37.3℃) in the predose examinations or \> 4 hours after dosing of antipyretics if they were taken.
• Patients with onset of fever within 48 hours or less at informed consent.
• Patients live in a household where all household contacts are expected to meet the key household contacts inclusion criteria (criteria 2, 3, \& 4).
• Patients and/or their guardian who are willing to provide written informed consent and consent to participate in the study, able to understand the study and comply with all study procedures.
⁃ Household contacts of index patients:
• Male or female patients aged≥12 years at the time of signing the informed consent form.
• Household contacts who are able to provide informed consent within 24 hours or less from informed consent in index patients.
• Subjects who had lived with the index patient for 3 months or more prior to informed consent.
• Subjects who meet all of the following criteria and are judged not to have influenza virus infection by the investigator.
• Negative Influenza rapid antigen test or Polymerase chain reaction (PCR), and;
• Subjects who have a body temperature (axillary) \< 37.3°C at Screening, and;
• Subjects who have no influenza like symptoms (cough, sore throat, headache, nasal discharge/nasal congestion, feverishness or chills, muscle or joint pain, and fatigue) at Screening.
• Household contacts intended for full study have not received influenza vaccine within 6 months prior to screening;
• Subjects and/or their guardian who are willing to provide written informed consent and consent to participate in the study, able to understand the study and comply with all study procedures, including patient health diary records.