Study to Assess the Efficacy of Baloxavir Marboxil Versus Placebo to Reduce Onward Transmission of Influenza A or B in Households

A Phase IIIB, Multicenter, Randomized, Double-Blind, Placebo-Controlled, Clinical Efficacy Study of Baloxavir Marboxil for the Reduction of Direct Transmission of Influenza From Otherwise Healthy Patients to Household Contacts

Otherwise healthy index patients (IP) are randomized to either baloxavir marboxil or placebo if their influenza symptoms onset was within 48 hours of screening. Their households are enrolled within 24 hours of randomization if at least 1 household contacts (HHC) have not received influenza vaccine within 6 months of screening and if all HHC screen negative for influenza infection. The main endpoints are assessed based on multiple respiratory swabs, obtained from both IP and HHC up to 9 (+/-1) days post IP randomization, and through the assessment of symptoms.

Study Overview

• Status: Completed
• Conditions: Influenza
• Intervention / Treatment: Drug: Baloxavir Marboxil; Drug: Placebo

• Study Type: Interventional
• Enrollment (Actual): 4138
• Phase: Phase 3

Contacts and Locations

Study Locations

• Bulgaria
  • Dupnitsa, Bulgaria, 2600
    • Medical Centre "Asklepii", OOD
  • Montana, Bulgaria, 3400
    • Medical Center Hera EOOD
  • Pleven, Bulgaria, 5800
    • MHAT Sveta Paraskeva
  • Sevlievo, Bulgaria, 5400
    • Medizinski Zentrar-1-Sevlievo EOOD
  • Sliven, Bulgaria, 8800
    • MHAT Sliven - Military Medial Academy
  • Sofia, Bulgaria, 1510
    • Medical Center Hera Sofia
  • Sofia, Bulgaria, 1618
    • MHAT Sveta Sofia
• China
  • Beijing, China, 10029
    • China-Japan Friendship Hospital
  • Beijing, China, 100069
    • Beijing You An Hospital
  • Beijing City, China, 102218
    • Beijing Tsinghua Changgung Hospital
  • Beijing City, China, 100010
    • Capital Medical University Beijing Hospital of Traditional Chinese Medicine
  • Chengdu, China, 610041
    • West China Hospital, Sichuan University
  • Sansha City, China, 572000
    • The Third People's Hospital of Hainan Province
  • Shenzhen, China, 510852
    • ShenZhen People's Hospital
  • Shenzhen City, China, 518038
    • Shenzhen Children's Hospital
  • Taizhou City, China, 225309
    • Taizhou People's Hospital
  • Wenzhou, China, 325000
    • The First Affiliated Hospital of Wenzhou Medical College
  • Yinchuan, China, 750004
    • General Hospital of Ningxia Medical University
  • Zhengzhou, China, 450003
    • Henan Provincial People's Hospital
• Costa Rica
  • San José, Costa Rica, 10108
    • ICIMED Instituto de Investigación en Ciencias Médicas
• Greece
  • Athens, Greece, 115 27
    • Sotiria General Hospital of Athens
  • Athens, Greece, 115 27
    • Laiko General Hospital - Uni of Athens
  • Chaidari, Greece, 124 62
    • Attikon University General Hospital
• Hungary
  • Budapest, Hungary, 1036
    • Obudai Egeszsegugyi Centrum Kft.
  • Hosszúhetény, Hungary, 7694
    • II. Háziorvosi Körzet
  • Nyíregyháza, Hungary, 4400
    • Gyermekháziorvosi rendel?- Dr. Újhelyi János
  • Zalaegerszeg, Hungary, 8900
    • OEC Clinical Research
• India
  • Karnataka
    • Mysuru, Karnataka, India, 570004
      • JSS Hospital
• Israel
  • Kiryat Motzkin, Israel
    • Kiryat Motzkin Maccabi Medical Center
  • Tel Aviv, Israel, 6789140
    • Maccabi health services - Moked Hashalom
• Japan
  • Akashi, Japan, 674-0081
    • Toda Internal Medicine & Neurology Clinic
  • Chikushino, Japan, 818-0024
    • Medical Corporation Houmankai?Umezu?Clinic
  • Fukuoka, Japan, 800-0057
    • Shin Komonji Hospital
  • Fukuoka, Japan, 812-0053
    • Irie Naika Syounika Iin
  • Fukuoka, Japan, 819-0022
    • Kimura Siro Clinic
  • Fukuyama, Japan, 720-0825
    • Iguchi Clinic
  • Hanno, Japan, 357-0024
    • Mashiba Clinic
  • Ichikawa, Japan, 272-0143
    • Fujimaki Ent Clinic
  • Ichikawa, Japan, 272-0805
    • Hisaki Family Clinic
  • Kagoshima, Japan, 890-0063
    • Kamoike ENT Allergy Clinic
  • Kagoshima, Japan, 890-0034
    • Moriyama Otolaryngology
  • Kashiwa, Japan, 277-0882
    • Clinic Kashiwanoha
  • Kasugai, Japan, 486-0817
    • Kamezawa Clinic
  • Kasuyagun, Japan, 811-2310
    • Oishi Clinic
  • Kawasaki, Japan, 211-0041
    • Takahashi naika
  • Kawasaki, Japan, 216-0006
    • Kanagawa Himawari Clinic
  • Kitakyushu, Japan, 802-0083
    • Osaki Internal and Respiratory Clinic,
  • Kitakyushu, Japan, 807-0072
    • Morizono Medical Clinic
  • Kitakyushu, Japan, 807-0856
    • Sato ENT Clinic
  • Kodaira, Japan, 187-0044
    • Kiheibashi Otolaryngology
  • Musashino, Japan, 180-0022
    • Medical corporation Shirayurikai Swing Nozaki Clinic
  • Naha, Japan, 900-0032
    • Yaesu Clinic
  • Nonoichi, Japan, 921-8801
    • Horikawa Clinic
  • Oita, Japan, 870-0021
    • Funai Ear Nose Throat Clinic
  • Osaka, Japan, 538-0044
    • Kitada Clinic
  • Osaka, Japan, 531-0073
    • Lee's Clinic
  • Osaka, Japan, 538-0044
    • Sunami Internal medicine Clinic
  • Saga, Japan, 849-0917
    • Saga Memorial Hospital
  • Saitama, Japan, 355-0328
    • Segawa Hospital
  • Sapporo, Japan, 006-0031
    • Uehara Clinic
  • Sapporo, Japan, 064-0804
    • Aiiku Hospital
  • Shinagawa, Japan, 140-8522
    • Tokyo Shinagawa Hospital Medical Corporation Association Tokyokyojuno-kai
  • Tokorozawa, Japan, 359-1151
    • Wakasa Clinic
  • Tokyo, Japan, 123-0845
    • Seiwa Clinic
  • Tokyo, Japan, 145-0071
    • Denenchofu Family Clinic
  • Tokyo, Japan, 150-0013
    • Sato Clinic
  • Toshima, Japan, 171-0014
    • Sekino Hospital
  • Toyohashi, Japan, 440-0834
    • Takeru CLINIC
  • Tsuchiura, Japan, 300-0062
    • Tsuchiura Beryl Clinic
  • Tsuru, Japan, 402-0025
    • Medical corporation Seijinkai Takei Clinic
  • Urasoe, Japan, 901-2102
    • Gushiken-Cardiology and Internal medicine
  • Urasoe, Japan, 901-2104
    • Uranishi Clinic
  • Yotsukaido, Japan, 284-0032
    • Yotsukaido Tokushukai Medical Center
• Mexico
  • Jalisco
    • Guadalajara, Jalisco, Mexico, 44130
      • Centro de Investigacion Medico Biologico y Terapia Avanzada, S.C.
  • Mexico CITY (federal District)
    • Mexico, Mexico CITY (federal District), Mexico, 14050
      • Centro Respiratorio de Mexico
  • Queretaro
    • Querétaro, Queretaro, Mexico, 76000
      • Centro de Estudios Clínicos de Querétaro (CECLIQ)
  • Yucatan
    • Mérida, Yucatan, Mexico, 97125
      • Merida | Investigacion Clinica
    • Mérida, Yucatan, Mexico, 97000
      • EME RED
• Poland
  • Bialystok, Poland, 15-704
    • KLIMED
  • Chojnice, Poland, 89-600
    • Centrum Medyczne Lukamed Joanna Luka
  • Pulawy, Poland, 24-100
    • KO-MED Centra Kliniczne Sp. z o.o.
  • Zabrze, Poland, 41-807
    • CLINHOUSE Sp z o.o.
• Puerto Rico
  • San Juan, Puerto Rico, 00927
    • Fundacion de Investigacion de Diego
• South Africa
  • Groenkloof, South Africa, 0181
    • Into Research
  • Johannesburg, South Africa, 2113
    • Newtown Clinical Research
  • Kraaifontein, South Africa, 7570
    • Langeberg Clinical Trials
  • Midrand, South Africa, 1685
    • Midrand Medical Centre
• Spain
  • Madrid, Spain, 28044
    • Centro de Salud Las Aguilas
• Turkey
  • Ankara, Turkey, 6100
    • Hacettepe University Medical Faculty
  • Ankara, Turkey, 06100
    • Ankara Bilkent City Hospital
  • Ankara, Turkey, 65000
    • Gazi University Medical Faculty
  • Ankara, Turkey, 06590
    • Ankara University Faculty of Medicine Cebeci Hospital
  • Antalya, Turkey, 07059
    • Akdeniz University Medical Faculty
  • Istanbul, Turkey, 34303
    • Atakent Acibadem Private Hosptial Halkali Merkez Mh.,
  • Izmir, Turkey, 35100
    • Ege University Medical Faculty
  • Izmir, Turkey, 35340
    • Dokuz Eylul University Medical Faculty
  • Kocaeli, Turkey, 41380
    • Kocaeli University Medical Faculty
  • Trabzon, Turkey, 61080
    • Karadeniz Technical Uni School of Medicine
• United Kingdom
  • Harrow, United Kingdom, HA3 9SN
    • Preston Hill Surgery
• United States
  • Alabama
    • Birmingham, Alabama, United States, 35235
      • Cahaba Research, Inc.
    • Pelham, Alabama, United States, 35124
      • Cahaba Research, Inc
  • Arizona
    • Phoenix, Arizona, United States, 85032
      • Precision Trials
  • California
    • Canoga Park, California, United States, 91303
      • HOPE Clinical Research
    • Long Beach, California, United States, 90806
      • Long Beach Clinical Trials
    • Los Angeles, California, United States, 90017
      • Downtown LA Research Center
    • Riverside, California, United States, 92501
      • Probe Clinical Research
    • San Diego, California, United States, 92119
      • MD Strategies Research Centers
  • Colorado
    • Denver, Colorado, United States, 80246
      • Cherry Creek Family Practice
  • Florida
    • Fort Lauderdale, Florida, United States, 33308
      • Proactive Clinical Research, LLC
    • Kissimmee, Florida, United States, 34744
      • Helios Clinical Research, Inc (former Ventavia Research Group)
    • Miami, Florida, United States, 33135
      • South Florida Research Center, Inc.
    • Miami, Florida, United States, 33155
      • Cordova Research Institute, LLC
    • Miami, Florida, United States, 33173
      • Research Institute of South Florida Inc
    • South Miami, Florida, United States, 33185
      • Kendall South Medical Center Inc.
  • Georgia
    • Atlanta, Georgia, United States, 30328
      • Agile Clinical Research Trials
  • Idaho
    • Idaho Falls, Idaho, United States, 83404
      • Clinical Research Prime
  • Indiana
    • Mishawaka, Indiana, United States, 46544
      • Mishawaka Osteopathic Clinic
  • Missouri
    • Saint Louis, Missouri, United States, 63110
      • Washington University School of Medicine
  • Montana
    • Butte, Montana, United States, 59701
      • Mercury Street Medical Group
    • Missoula, Montana, United States, 59808
      • Montana Medical Research LLC
  • Nevada
    • Las Vegas, Nevada, United States, 89109
      • Excel Clinical Research
    • Las Vegas, Nevada, United States, 89104
      • Accent Clinical Trials
  • North Carolina
    • Charlotte, North Carolina, United States, 28277
      • OnSite Clinical Solutions LLC
    • Morganton, North Carolina, United States, 28655
      • Burke Primary Care
  • Ohio
    • Cincinnati, Ohio, United States, 45215
      • Hometown Urgent Care and Occupational Health - Springdale
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19114
      • Tristar Clinical Investigations
    • Scottdale, Pennsylvania, United States, 15683
      • Frontier Clinical Research
    • Smithfield, Pennsylvania, United States, 15478
      • Frontier Clinical Research
    • Smithfield, Pennsylvania, United States, 26505
      • Frontier Clinical Research
  • South Carolina
    • Greer, South Carolina, United States, 29651
      • Jedda Enterprises dba Galen Clinical Research
  • Tennessee
    • Chattanooga, Tennessee, United States, 37421
      • AFC Urgent Care-Gunbarrell
    • Jackson, Tennessee, United States, 38305
      • Helios Clinical Research, Inc (former Ventavia Research Group)
  • Texas
    • Dallas, Texas, United States, 75235
      • Southwest Family Medicine Associates
    • Dallas, Texas, United States, 75204
      • City Doc Urgent Care-Dallas/Ft. Worth
    • Denison, Texas, United States, 75020
      • Premier Pulmonary Critical Care and Sleep Medicine
    • Houston, Texas, United States, 77017
      • Vilo Research Group
    • Houston, Texas, United States, 077099
      • Pioneer Research Solutions
    • Houston, Texas, United States, 77087
      • Fairway Medical Clinic
    • Houston, Texas, United States, 77087
      • Mercury Clinical Research
    • McAllen, Texas, United States, 78501
      • Family Practice Center
    • San Antonio, Texas, United States, 78215
      • Sun Research Institute
  • West Virginia
    • Kingwood, West Virginia, United States, 26537
      • Frontier Clinical Research

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 5 years to 64 years (Child, Adult)
• Accepts Healthy Volunteers: No

Description

INCLUSION CRITERIA:

Index Patients (IPs):

• Able to comply with the study protocol per investigator judgment.
• Diagnosed with acute influenza infection by investigator.
• Polymerase chain reaction [PCR] (+) or Rapid Influenza Diagnostic Test [RIDT] (+) for influenza A/B based on cobas® SARS-CoV-2 and influenza A/B or other point-of-care / local laboratory results.
• PCR (-) or antigen test (-) for SARS-CoV-2 based on cobas® SARS-CoV-2 and Influenza A/B test or other point-of-care / local laboratory result
• Presence of (a) fever (>=38.0 °C per tympanic or rectal thermometer; >=37.5 °C per axillary, oral or forehead/temporal thermometer) or (b) any influenza symptoms (cough, sore throat, nasal congestion, headache, feverishness or chills, muscle or joint pain, fatigue).
• The time interval between the onset of fever or influenza symptoms and the pre-dose examinations is 48 hours or less.
• IP lives in a household where: (1) No HHC is known to have been diagnosed with influenza or SARS-CoV-2 infection by a healthcare professional (HCP) in the past 4 weeks; (2) All HHCs are expected to meet the key HHC inclusion criteria; (3) >=1 HHCs are expected to participate in the full study who have not received the influenza vaccine within 6 months prior to screening.
• Women of childbearing potential: Agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures specified in the protocol

All HHCs (Part 1):

• PCR (-) or RIDT (-) based on cobas® SARS-CoV-2 and influenza A/B or other local point-of-care / local laboratory result.
• PCR (-) or antigen test (-) for SARS-CoV-2 based on cobas® SARS-CoV-2 and Influenza A/B or other POC / local laboratory result.
• HHC lives with no HHC who will be present in the home at any time during the study and who meets any HHC exclusion criteria.
• HHC lives with no HHC who does not meet HHC inclusion criteria (part 1).
• HHC lives in a household where ≥1 HHCs meet all of the following: Start screening within 24 hours after IP randomization; Have NOT received the influenza vaccine within 6 months prior to screening; and Fulfill full study HHC inclusion criteria part 2.

Full study HHCs (part 2) intended for full study must meet the following additional criteria for study entry:

• Agree to participate in the full study.
• Able to comply with the study protocol per investigator judgment
• No influenza symptoms within 7 days prior to screening. Alternatively, mild symptoms are permissible if determined by the investigator to be due to a preexisting condition.
• Temperature <38.0 °C (tympanic).
• Will reside in the index patient's house for at least 7 of the next 9 days and will be present for scheduled study visits.
• Willing and able to measure and record temperature, or have another household member perform the task on his or her behalf. Furthermore, a responsible adult will assume responsibility to oversee or perform this task on behalf of minors.
• In the 6 months prior to screening: a) Has not been diagnosed with influenza by a healthcare professional b) Has not received BXM, peramivir, laninamivir, oseltamivir, zanamivir, rimantadine, umifenovir, favipiravir or amantadine.
• Does not have a moderate or worse active infections OR infections requiring systemic (e.g., oral or intravenous) or otherwise internally administered (e.g., inhaled, intrathecal) antibiotic/antiviral/antifungal therapy, (topical therapies for mild external infections allowed).

EXCLUSION CRITERIA:

IPs:

• IPs with severe influenza virus infection requiring inpatient treatment.
• IPs judged by the investigator to be at high risk for complications of influenza.
• IP is ≥12 years old and unable to swallow tablets (not applicable to IPs 5 to 11 year olds who will receive oral suspension).
• Women who are breastfeeding or have a positive pregnancy test in the pre-dose examinations.
• IPs with concurrent (non-influenza) infections requiring systemic antimicrobial and/or antiviral therapy at the pre-dose examinations.
• IPs who have received baloxavir marboxil, peramivir, laninamivir, oseltamivir, zanamivir, rimantadine, umifenovir, favipiravir or amantadine, or an investigational drug, within 30 days or 5 drug-elimination half-lives, whichever is longer, prior to screening.
• IPs who have received an investigational monoclonal antibody for a viral disease in the last year.
• Known hypersensitivity to baloxavir marboxil or the drug product excipients.
• IP previously included in the study
• IP lives with an HHC who, based on available information, meets the HHC exclusion criteria

HHC:

• Pregnant or within 2 weeks post-partum at screening.
• Immunocompromised.
• Less than 2 years old.
• Who have received an investigational therapy within the 30 days or 5 drug elimination half-lives, whichever is longer, prior to screening.
• Diagnosed with influenza or SARS-CoV-2 infection by a healthcare professional in the past 4 weeks.
• HHC who plans to arrive home after 24 hours post IP randomization to Day 9 and is not willing to be consented as soon as possible upon arrival.
• HHC previously included in the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Baloxavir Marboxil; Participants who are IPs will receive a single oral dose of baloxavir marboxil. HHCs of the IPs will not receive study medication.	Drug: Baloxavir Marboxil; IPs less than 12 years old will receive either 2 mg/kg (if weight less than 20 kg) or 40 mg (if weight more than or equal to 20 kg) of Baloxavir Marboxil as oral suspension. IPs more than or equal to 12 years old will receive either 40 mg (if weight less than 80 kg) or 80 mg (if weight more than or equal to 80 kg) of Baloxavir Marboxil as tablets. HHCs of IPs will not receive study medication.; Other Names: Xofluza
Placebo Comparator: Placebo; Participants who are IPs will receive a single oral dose of placebo. HHCs of the IPs will not receive study medication.	Drug: Placebo; IPs less than 12 years old will receive placebo oral suspension and those above 12 years will receive placebo tablets. HHCs of IPs will not receive study medication.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of HHCs With Virological Influenza Transmission by Day 5	The virological transmission was determined based on Polymerase Chain Reaction Positive (PCR+) influenza test results. The adjusted incidence (cumulative proportion of events by Day 5) rate is reported here. This is defined as percentage of HHCs who tested PCR+ for influenza by Day 5 post IP randomization with virus subtype matching with that of the respective IP, irrespective of being symptomatic or asymptomatic. The adjusted incidence rates presented were estimated using a generalized estimating equations (GEE) approach.	Baseline (Day 1) to Day 5

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of HHCs With Symptomatic Influenza Transmission by Day 5	The adjusted incidence (cumulative proportion of events by Day 5) rate is reported here. This is defined as percentage of HHCs who tested PCR+ for influenza by Day 5 post IP randomization with virus subtype matching with that of respective IP, & developed symptoms at any time during the study. The adjusted incidence rates presented were estimated using a GEE approach. HHCs ≥12 years old were symptomatic if 1. Presence of temperature ≥38.0 Celsius (C) and 1 respiratory symptom (cough, sore throat, nasal congestion) or 2. Presence of 1 respiratory symptom and 1 general systemic symptom (headache, feverishness or chills, muscle or joint pain, fatigue), with/without a fever. HHCs ≥2 and <12 years old were symptomatic if the presence of temperature was ≥38.0°C and had upper respiratory tract infection signs or symptoms (cough, nasal congestion, or rhinorrhea). Symptoms must be either new or have worsened versus baseline in HHC with baseline symptoms due to a preexisting comorbidity.	Baseline (Day 1) to Day 5
Percentage of Households (HHs) With Virological Influenza Transmission at Household Level by Day 5	Percentage of households with at least one HHC who met the primary endpoint of virological transmission by Day 5 are reported here. 'Number of participants analyzed' is the number of IPs in the PAS-IP set.	Baseline (Day 1) to Day 5
Percentage of HHs With Symptomatic Influenza Transmission at Household Level by Day 5	Percentage of HHs with at least one HHC who meets the symptomatic transmission by Day 5 endpoint are reported here. 'Number of participants analyzed' is the number of IPs in the PAS-IP set.	Baseline (Day 1) to Day 5
Percentage of HHCs With Virological Influenza Transmission by Day 9	The adjusted incidence (cumulative proportion of events by Day 9) rate is reported here. This is defined as percentage of HHCs who tested PCR+ for influenza by Day 9 post IP randomization with virus subtype matching with the respective IP, irrespective of being symptomatic or asymptomatic including: 1. all HHC meeting primary endpoint, AND 2. all HHC cases detected after Day 5 meeting the following criteria: 2a. included HHC case was in an HH where another HHC had already met the primary endpoint OR 2b. included HHC case was PCR+ bearing an amino acid substitution of isoleucine for another amino acid at position 38 (I38X) in the polymerase acidic (PA) protein (PA/I38X substitution) or amino acid substitution of threonine to lysine at position 20 in the PA protein for influenza B only (PA/T20K). The adjusted incidence rates presented were estimated using a GEE approach.	Baseline (Day 1) to Day 9
Percentage of HHCs With Symptomatic Influenza Transmission by Day 9	The adjusted incidence (cumulative proportion of events by Day 9) rate is reported here. This is defined as percentage of HHCs who met the virological transmission by Day 9 endpoint and developed symptoms at any time during the study. The adjusted incidence rates presented were estimated using a GEE approach. HHCs ≥12 years were symptomatic if they had 1. temperature ≥38.0°C and one respiratory symptom (cough, sore throat, nasal congestion) or 2. one respiratory and one general systemic symptom (headache, feverishness or chills, muscle or joint pain, fatigue), with or without fever. HHCs ≥2 and <12 years were symptomatic if the presence of temperature was ≥38.0°C and had upper respiratory symptoms (headache, feverishness or chills, muscle or joint pain, fatigue). Symptoms must be either new or have worsened versus baseline in HHC with baseline symptoms due to a preexisting comorbidity.	Baseline (Day 1) to Day 9
Percentage of HHCs With Any Virological Infection by Day 9	Virological infection was defined as HHCs who tested PCR+ for influenza by Day 9 post IP randomization based on PCR influenza test results. The adjusted incidence (cumulative proportion of events by Day 9) rate is reported here. This is defined as percentage of HHCs who met the virological infection by Day 9 endpoint. The adjusted incidence rates presented were estimated using a GEE approach.	Baseline (Day 1) to Day 9
Percentage of HHs With Any Virological Infection at HH Level by Day 9	Virological infection at the HH level was defined as the HHs with at least one HHC who met the endpoint of any virological infection by Day 9. 'Number of participants analyzed' is the number of IPs in the PAS-IP set.	Baseline (Day 1) to Day 9
Percentage of HHCs With Any Symptomatic Infection by Day 9	The adjusted incidence (cumulative proportion of events by Day 9) rate is reported here. This is defined as percentage of HHCs who tested PCR+ for influenza by Day 9 post IP randomization and developed symptoms at any time during the study. The adjusted incidence rates presented were estimated using a GEE approach. HHCs ≥12 years were symptomatic if they had (1) a temperature ≥38.0°C and one respiratory symptom (cough, sore throat, nasal congestion) or (2) one respiratory and one systemic symptom (headache, chills, muscle/joint pain, fatigue), with or without fever. HHCs ≥2 and <12 years were symptomatic if the presence of temperature was ≥38.0°C and had upper respiratory symptoms (cough, nasal congestion, rhinorrhea). Symptoms must be either new or have worsened versus baseline in HHC with baseline symptoms due to a preexisting comorbidity.	Baseline (Day 1) to Day 9
Percentage of HHs With Any Symptomatic Infection at HH Level by Day 9	Percentage of HHs with at least one HHC who meets the endpoint of any symptomatic infection by Day 9 are reported here. HHCs ≥12 years were symptomatic if they had 1. a temperature ≥38.0°C &1 respiratory symptom (cough, sore throat, nasal congestion) or 2. 1 respiratory & 1 systemic symptom (headache, chills, muscle/joint pain, fatigue), with/without fever. HHCs ≥2 & <12 years were symptomatic if the temperature was ≥38.0°C & had upper respiratory symptoms (cough, nasal congestion, rhinorrhea). Symptoms must be new or have worsened versus baseline in HHC with baseline symptoms due to preexisting comorbidity. 'Number of participants analyzed' is the number of IPs in the PAS-IP set.	Baseline (Day 1) to Day 9
Number of IPs With Adverse Events (AEs)	An AE is any untoward medical occurrence in a participant administered a pharmaceutical product and regardless of causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not considered related to the medicinal (investigational) product.	Baseline up to Day 9 (for IPs ≥12 years old) and Day 21 (for IPs <12 years old)
Number of IPs With Serious Adverse Events (SAEs)	A SAE is any significant hazard, contraindication, side effect that is fatal or life-threatening, requires hospitalization or prolongation of an existing hospitalization, results in persistent or significant disability or incapacity, is a congenital anomaly or birth defect, is medically significant or requires intervention to prevent one or other of the outcomes listed above.	Baseline up to Day 9 (for IPs ≥12 years old) and Day 21 (for IPs <12 years old)

Collaborators and Investigators

• Sponsor: Hoffmann-La Roche
• Investigators: Study Director: Clinical Trials, Hoffmann-La Roche

Publications and helpful links

General Publications

• Komeda T, Takazono T, Hosogaya N, Ogura E, Fujiwara M, Miyauchi H, Ajisawa Y, Iwata S, Watanabe H, Honda K, Kitanishi Y, Hara K, Mukae H. Comparison of Household Transmission of Influenza Virus From Index Patients Treated With Baloxavir Marboxil or Neuraminidase Inhibitors: A Health Insurance Claims Database Study. Clin Infect Dis. 2021 Jun 1;72(11):e859-e867. doi: 10.1093/cid/ciaa1622.

Study record dates

Study Major Dates

• Study Start (Actual): October 10, 2019
• Primary Completion (Actual): May 10, 2024
• Study Completion (Actual): May 10, 2024

Study Registration Dates

• First Submitted: May 29, 2019
• First Submitted That Met QC Criteria: May 29, 2019
• First Posted (Actual): May 31, 2019

Study Record Updates

• Last Update Posted (Actual): July 4, 2025
• Last Update Submitted That Met QC Criteria: July 3, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Orthomyxoviridae Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Influenza, Human; Anti-Infective Agents; Molecular Mechanisms of Pharmacological Action; Enzyme Inhibitors; Antiviral Agents; Baloxavir
• Other Study ID Numbers: MV40618; 2018-004056-37 (EudraCT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Qualified researchers may request access to individual patient level data through the clinical study data request platform (www.vivli.org). Further details on Roche's criteria for eligible studies are available here (https://vivli.org/ourmember/roche/). For further details on Roche's Global Policy on the Sharing of Clinical Information and how to request access to related clinical study documents, see here (https://www.roche.com/research_and_development/who_we_are_how_we_work/clinical_trials/our_commitment_to_data_sharing.htm)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No