A recent clinical trial has revealed that levofloxacin, an oral antibiotic, can significantly reduce the risk of developing multidrug-resistant tuberculosis (MDR-TB). The study, published in the New England Journal of Medicine, offers a promising strategy for preventing the spread of this challenging disease, which affects an estimated 400,000 people globally each year.
The VQUIN trial, conducted in Vietnam, a country with a high rate of drug-resistant TB, enrolled 2,041 family members of individuals with MDR-TB. These participants had early TB infection but had not yet developed the active form of the disease. Participants were given either a daily oral dose of levofloxacin or a placebo for six months, and monitored for 30 months.
Key Findings from the VQUIN Trial
The trial demonstrated that levofloxacin reduced the risk of MDR-TB in adults and adolescents by 45 percent. "We now have a way of stopping people with early TB infection from becoming sick and spreading their infection to other people," said Professor Gregory Fox, who led the VQUIN trial at the University of Sydney's Woolcock Institute of Medical Research.
Meta-Analysis with TB-CHAMP Trial
The findings from the VQUIN trial were combined with data from the TB-CHAMP trial, a separate study conducted in South Africa that assessed the same treatment in children. A meta-analysis of individual patient data from the two trials showed that levofloxacin led to a relative reduction of approximately 60% in the cumulative incidence of tuberculosis as compared with placebo.
Safety and Tolerability
The study also addressed the long-term safety of taking levofloxacin for six months. Ori Solomon, who sequenced the genomes of the bacteria from patients with MDR TB and their contacts, explained, "Fortunately, it was well tolerated and not associated with any major adverse effects. We also found no new acquired resistance to the antibiotic. Together, this shows the treatment is both safe to the patient and poses a low risk of driving antibiotic resistance in TB."
Implications for Global TB Control
The results of the VQUIN trial have significant implications for global TB control efforts. MDR-TB is notoriously difficult to treat, and current medications often have significant side effects. The availability of a safe and effective preventive treatment like levofloxacin could substantially reduce the burden of this disease, particularly among vulnerable populations such as household contacts of MDR-TB patients.
In September 2024, the World Health Organisation issued new guidelines for MDR-TB preventive therapy based on the findings of the VQUIN trial. These guidelines are expected to influence clinical practice and public health policy worldwide.
Increased TB Cases in Montreal
In Montreal, cases of tuberculosis (TB) have increased by 54% in 2024 compared to the average from 2010 to 2023, according to a recent call for vigilance issued by Montreal’s public health department, reminding us that even in low-incidence countries, the disease remains an important threat, exacerbated by multidrug-resistant (MDR) TB.
