Study to Assess the Efficacy and Safety of GP681 Versus Placebo for Postexposure Prophylaxis Against Influenza
NCT Number: NCT06574503
Status: NOT_YET_RECRUITING
Study Type: INTERVENTIONAL
Phases: PHASE3
Conditions: Influenza
Interventions: DRUG: GP681 40mg|DRUG: GP681 Simulant
Sponsor: Jiangxi Qingfeng Pharmaceutical Co. Ltd.
Sex: ALL
Age: CHILD, ADULT, OLDER_ADULT
Enrollment: 748
Study Design: Allocation: RANDOMIZED|Intervention Model: PARALLEL|Masking: DOUBLE (PARTICIPANT, INVESTIGATOR)|Primary Purpose: TREATMENT
Start Date: 2024-09-30
Completion Date: 2027-12-30

Summary:
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.

Primary Outcome Measures: Proportion of household members who are infected with influenza virus (Q-PCR positive), and present with fever and at least one influenza symptom with severity of moderate or severe in the period from Day 1 to Day 10., Defined as the proportion of household members having body temperature (axillary)≥37.3°C, having symptom of influenza (respiratory symptoms or systemic symptoms) with a severity of "2, Moderate" or "3, Severe" assessed in the subject diary, and influenza virus positive assessed by Q-PCR., up to Day 10
Secondary Outcome Measures: Proportion of household members who are infected with influenza virus (Q-PCR positive), and present with fever or at least one influenza symptom with severity of moderate or severe in the period from Day 1 to Day 10., Defined as the proportion of household members having body temperature (axillary)≥37.3°C, or having symptom of influenza (respiratory symptoms or systemic symptoms) with a severity of "2, Moderate" or "3, Severe" assessed in the subject diary, and influenza virus positive assessed by Q-PCR., up to Day10|Proportion of household members with influenza virus infection in the period from Day 1 to Day 10, Defined as the proportion of subjects having influenza virus positive assessed by RT-PCR regardless of body temperature or influenza symptoms., up to Day10|Time from study treatment to the time when fever, at least one influenza symptom with severity of moderate or severe, and influenza virus infection were observed., Defined as the later timepoint of the following (1) and (2):

1. Timepoint when body temperature (axillary) rises first to " 37.3°C
2. Timepoint when an influenza symptom was first assessed as"2, Moderate" or "3, Severe" in the subject diary.

If a household member does not have a body temperature (axillary) of "37.3°C or influenza symptom was not assessed as"2, Moderate" or "3, Severe" in the period from Day 1 to Day 10, the subject will be handled as a censored case., up to Day10|Time from study treatment to the time when fever or at least one influenza symptom (respiratory symptom or systemic symptom), and influenza virus infection are observed., Defined as the timepoint of the following (1) and (2), whichever is earlier:

1. Timepoint when body temperature (axillary) rises first to " 37.3°C
2. Timepoint when an influenza symptom was first assessed as"2, Moderate" or "3, Severe" in the subject diary.

If a subject does not have a body temperature (axillary) of "37.5°C and influenza symptoms (respiratory symptoms and systemic symptoms) were not assessed as 2, Moderate or 3, Severe in the period from Day 1 to Day 10, the subject will be handled as a censored case., up to Day10|Proportion of asymptomatic influenza-infected (Q-PCR positive) household members in the period from Day 1 to Day 10, Defined as the proportion of household members having body temperature (axillary) \< 37.5°C, influenza symptoms all assessed as 0, Absent or 1, Mild , and influenza virus positive assessed by Q-PCR., Up to Day 10|Proportion of household members who are not infected with influenza virus (Q-PCR negative) and present with fever and at least one influenza symptom with severity of moderate or severe in the period from Day 1 to Day 10, Defined as the proportion of household members having body temperature (axillary) "37.3°C, having symptom of influenza (respiratory symptoms or systemic symptoms) with a severity of "2, Moderate" or "3, Severe" assessed in the subject diary, and influenza virus negative at all time points assessed by Q-PCR., Up to Day 10|Proportion of household members who are infected with influenza virus (Q-PCR positive) in the period from Day 1 to Day 10, with virus subtype consistent with index patient, Defined as the proportion of household members who are infected with influenza virus (Q-PCR positive) in the period from Day 1 to Day 10，and the virus subtype of household members are consistent with index patient, Up to Day 10