Influenza Influenza
Conditions
Interventions
Sponsors
Eligibility
Inclusion criteria
Inclusion criteria: (1) Patients whose nasopharyngeal swab specimen tested positive for influenza virus by nucleic acid amplification test (NAAT) or antigen test. (2) Patients with influenza symptoms who can initiate protocol treatment within 2 days after symptom onset (e.g., if symptoms begin on June 1, treatment may be initiated up to June 3). (3) Patients aged 65 years or older (at the time of consent). (4) Patients with influenza symptoms* requiring hospitalization. (5) Patients who can understand the details of this clinical trial and are able to provide written informed consent themselves or through a legally authorized representative. *Symptoms include: Fever, feeling of warmth, chills, cough, sore throat, nasal discharge, nasal congestion, myalgia, generalized pain, headache, fatigue, vomiting, diarrhea, dyspnea, shortness of breath, chest pain, abdominal pain, dizziness, altered consciousness, convulsions, decreased urine output, muscle weakness.
Exclusion criteria
Exclusion criteria: (1) Patients with coexisting respiratory viral infections other than influenza. (2) Patients expected to die within 48 hours. (3) Patients unable to take oral capsule formulations. (4) Patients who have been administered anti-influenza drugs within 30 days prior to enrollment. (5) Patients receiving treatment for severe liver dysfunction equivalent to Grade C in the Child-Pugh classification. (6) Patients requiring regular hemodialysis or continuous ambulatory peritoneal dialysis (CAPD) (7) Patients whose creatinine clearance is 10 mL per minute or less. (8) Patients with a history of gout attacks or with uric acid levels exceeding the reference range. (9) Patients with hereditary xanthinuria. (10) Patients diagnosed with hypouricemia (less than 1 mg/dL) or a history of xanthine urolithiasis. (11) Patients with a history of alcohol dependence or drug abuse. (12) Patients with hypersensitivity to concomitant medication (oseltamivir phosphate). (13) Patients with hypersensitivity to favipiravir. (14) Pregnant or lactating patients or patients who may be pregnant. (15) Premenopausal female patients who are unable to use contraceptive methods such as oral contraceptives, intrauterine devices, or barrier methods (e.g., diaphragm, condom) or combine these methods from the start of the investigational drug administration until 10 days after the end of the administration. (16) Patients who have received any investigational drug within the past 90 days. (17) Patients deemed by the principal investigator or sub-investigator to be unsuitable for appropriate efficacy evaluation or adverse event assessment due to underlying diseases (e.g., advanced dementia) or complications.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Time to Recovery from Enrollment/Randomization [Evaluation Method] The principal investigator or sub-investigator will use a 7-point ordinal scale for clinical evaluation. The patient's condition will be assessed daily from enrollment/randomization through Day 29 of hospitalization. The highest score representing the patient's condition on each day will be recorded as that day's value. Recovery will be defined as the point at which the patient remains in a discharge-eligible state (score 1 or 2) for three consecutive days or is discharged. The time to recovery will be calculated up to the first day on which recovery is confirmed. | — |
Secondary
| Measure | Time frame |
|---|---|
| Clinical Endpoints (1) Percentage of Patients Over 29 Days Based on a 7-Point Scale [Evaluation Method] The principal investigator or sub-investigator will use a 7-point scale for clinical evaluation. From enrollment/randomization through Day 29 of hospitalization, the highest score for each day will be recorded. The percentage of patients according to the 7-point scale will be calculated daily until Day 29. (2) Worsening Rate Over 15 Days and 29 Days Based on a 7-Point Scale [Evaluation Method] The investigator will use a 7-point scale. From enrollment/randomization through Day 29 of hospitalization, the highest score for each day will be recorded. Worsening is defined as a decline of at least one level from baseline. The percentage of patients who experienced worsening by Day 15 and Day 29 will be calculated. (3) Time to Defervescence [Evaluation Method] The investigator will assess the patient's highest body temperature daily from enrollment/randomization through Day 15. Defervescence is defined as a temperature below 37.5 C for two consecutive days, regardless of antipyretic use. The time to first defervescence will be calculated. Evaluation after defervescence is not required. (4) 29-Day Mortality Rate [Evaluation Method] The percentage of patients who died within 29 days, regardless of cause, will be calculated. (5) 29-Day ICU Admission Rate [Evaluation Method] The percentage of patients admitted to intensive care units within 29 days will be calculated. (6) 15-Day Incidence of Pneumonia Complications [Evaluation Method] After enrollment and randomization, the incidence of pneumonia requiring initiation of new antibiotic treatment during hospitalization through Day 15 will be calculated. Virological Endpoints (1) Influenza Virus Titer (Day 1, 2, 3, 7) [Evaluation Method] Using the provided viral transport medium container and swab, nasopharyngeal samples will be collected on Day 1 (before the first dose), Day 2 (before the third dose), Day 3 (before th | — |
Contacts
National Center for Global Health and Medicine, Japan Institute for Health Security