Last updated on February 2020

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

Are you eligible to participate in this study?

You may be eligible for this study if you meet the following criteria:

  • Conditions: Influenza Vaccine | Influenza
  • Age: Between 12 - 64 Years
  • Gender: Male or Female


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 influenza A/B Assay or other point-of-care / local laboratory results.
  • 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: No household contact (HHC) known to have been diagnosed with influenza by a healthcare professional, all HHCs are expected to meet the key HHC inclusion criteria and none of the HHC exclusion criteria, >=2 HHCs are expected to participate in the full study who have not received the influenza vaccine within 6 months prior to screening.

All HHCs:

  • Willing to undergo screening visit as a scheduled/unscheduled visit after they return to the home if not at home at Day 0 Visit.
  • PCR (-) or RIDT (-) based on cobas influenza A/B Assay or other local point-of-care / local laboratory result at Day 0 Visit.

HHC intended for full study must meet the following additional criteria for study entry:

  • No influenza symptoms within 7 days prior to screening. Alternatively, mild symptoms are permissible if determined by the investigator to be due to a pre-existing 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.
  • 2 HHC who have not been vaccinated within 6 months prior to screening are needed for household to be included)


  • IPs with severe influenza virus infection requiring inpatient treatment.
  • IPs judged by the investigator to be at high risk for complications of influenza.
  • IPs unable to swallow tablets.
  • IPs weighing less than 40 kg.
  • 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 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.
  • 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.

Recruitment Status: Open

Brief Description Eligibility Contact Research Team

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