CENTERSTONE
Trial question
What is the effect of baloxavir marboxil for the prevention of influenza virus transmission?
Study design
Multi-center
Double blinded
RCT
Population
Characteristics of study participants
53.0% female
47.0% male
N = 1092
1092 patients (578 female, 514 male).
Inclusion criteria: influenza-positive index patients 5-64 years of age.
Key exclusion criteria: high risk for influenza-related complications; severe influenza virus infection requiring inpatient treatment; pregnancy or breastfeeding; concurrent infections requiring systemic antimicrobial and/or antiviral therapy; receipt of investigational monoclonal antibody for a viral disease in the last year; hypersensitivity to baloxavir marboxil.
Interventions
N=548 baloxavir marboxil (a single oral dose within 48 hours after symptom onset).
N=544 placebo (matching placebo within 48 hours after symptom onset).
Primary outcome
Rate of transmission of influenza virus from an index patient to a household contact by day 5
9.5%
13.4%
13.4 %
10.1 %
6.7 %
3.4 %
0.0 %
Baloxavir
marboxil
Placebo
Significant
decrease ▼
NNT = 25
Significant decrease in the rate of transmission of influenza virus from an index patient to a household contact by day 5 (9.5% vs. 13.4%; OR 0.68, 95% CI 0.5 to 0.93).
Secondary outcomes
No significant difference in the rate of transmission of influenza virus by day 5 that resulted in symptoms (5.8% vs. 7.6%; OR 0.75, 95% CI 0.5 to 1.12).
No significant difference in the rate of transmission of influenza virus by day 9 that resulted in symptoms at the household level (6.2% vs. 8.3%; OR 0.73, 95% CI 0.49 to 1.09).
Significant decrease in the rate of any infection with influenza virus by day 9 at the household level (14% vs. 18.7%; OR 0.71, 95% CI 0.54 to 0.94).
Safety outcomes
No significant difference in ≥ 1 adverse events.
Conclusion
In influenza-positive index patients 5-64 years of age, baloxavir marboxil was superior to placebo with respect to the rate of transmission of influenza virus from an index patient to a household contact by day 5.
Reference
Arnold S Monto, Klaus Kuhlbusch, Corrado Bernasconi et al. Efficacy of Baloxavir Treatment in Preventing Transmission of Influenza. N Engl J Med. 2025 Apr 24;392(16):1582-1593.
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