Preventive levofloxacin found to reduce drug-resistant TB in household contacts
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Two studies published yesterday in the New England Journal of Medicine show that 6 months of preventive treatment with levofloxacin in children and adults with household exposure to multidrug-resistant tuberculosis (TB) resulted in statistically non-significant reductions in TB incidence compared with placebo.
But an additional analysis of individual data from the two trials, which were conducted in Vietnam and South Africa, found that preventive levofloxacin led to a much larger relative reduction in cumulative incidence of TB than was initially observed.
Data from the two phase 3 randomized controlled trials have already been used by the World Health Organization (WHO) to update its recommendations for TB preventive treatment (TPT).
MDR-TB develops in an estimated 400,000 people globally each year, according to the WHO, including approximately 30,000 children. While new, shorter treatment regimens have been introduced in recent years, MDR-TB treatment is longer and more expensive than drug-susceptible TB treatment, and treatment outcomes are worse.
Because TB is an airborne disease, people who share a household or have close contact with an infectious TB patient are considered a high risk for infection. TPT for both drug-susceptible and MDR-TB is therefore a cornerstone of the WHO efforts to reduce global TB incidence. But while the WHO has recommended preventive treatment for selected high-risk household contacts of MDR-TB patients since 2017, the original recommendation was based on low-quality evidence and didn’t specify use of any particular drug.
The two trials were designed to investigate whether levofloxacin, which is a component of some MDR-TB treatment regimens and has shown promise for reducing TB incidence among close contacts of people who have MDR-TB, is a safe and effective preventive treatment for household contacts in countries with high MDR-TB incidence.