Despite the availability of life-saving vaccines and antibiotics, tuberculosis (TB) remains a highly deadly infectious disease worldwide. A recent international clinical trial has identified three new and effective drug regimens for treating antibiotic-resistant strains of TB. The findings of this study were published on January 30 in the New England Journal of Medicine.
Why is tuberculosis still dangerous?
TB is a bacterial infection that primarily affects the lungs and spreads through air droplets released during talking or coughing. It is highly infectious and can linger in the air for several hours. However, TB only spreads when a person is symptomatic.
Once the bacterium infects a person, it can take on two forms. Active TB manifests with a persistent cough, bloody phlegm, fever, and night sweats, while latent TB involves the bacterium lying dormant in the body without causing symptoms or being contagious.
According to the Cleveland Clinic, approximately 10 million people fell ill with TB and 1.5 million died from it globally in 2020, with around 7,860 reported cases in the United States in 2021.
An ongoing outbreak in the Kansas City area has led to two deaths since January, with 67 active TB cases and 79 latent TB cases being treated, as reported by the Kansas Department of Health and Environment.
The World Health Organization’s (WHO) Global Tuberculosis Report 2024 highlighted an increase in reported cases from 7.5 million in 2022 to 8.2 million in the previous year, citing disruptions to vaccination schedules due to the COVID-19 pandemic and the rise of drug-resistant strains as contributing factors.
Antibiotic resistance is a growing concern with TB, as some strains are already resistant to rifampin, the most effective first-line antibiotic. Treatment regimens involving rifampin and other drugs can be lengthy, require daily injections, and may have severe side effects due to the toxic nature of the medications.
The endTB trials
This recent research is part of the endTB trial, a collaborative effort involving Harvard Medical School, Partners In Health, Médecins Sans Frontières, and Interactive Research and Development.
The endTB trial, one of four randomized controlled trials focusing on new, shorter, and less toxic treatment regimens for drug-resistant TB, utilizes two relatively new drugs—bedaquiline and delamanid, introduced to the market in 2012 and 2013 as the first new TB medications in nearly half a century.
The trial, initiated in 2017 with 754 patients across multiple countries, aims to enhance treatment for individuals with rifampin-resistant TB, affecting approximately 410,000 people annually. According to the World Health Organization (WHO), only 40 percent of these cases are diagnosed and treated, with a 65 percent success rate.
In the trial, endTB evaluated five new all-oral regimens combining bedaquiline and delamanid with other drugs over a nine-month period. Although pretomanid, a third drug, received emergency FDA approval in 2019, it was not part of these trials.
Three out of the five new regimens demonstrated success rates of between 85 and 90 percent in patients with this treatment-resistant TB strain, compared to an 81 percent success rate in the control group receiving longer treatments.
The trial regimens were deemed effective based on their performance compared to the control group, which received a standard of care in line with WHO recommendations.
A step towards more accessible care
Two of the three new endTB regimens, along with another WHO-recommended regimen, are priced below $500, aligning with a target set over a decade ago. These advancements could make shorter, all-oral regimens more accessible to a broader population.
Carole Mitnick, trial co-principal investigator and Harvard Medical School epidemiologist, emphasized the significance of these findings in expanding access to life-saving care and simplifying treatment for tuberculosis patients.
Mitnick highlighted the challenges posed by poor treatment options and insufficient evidence in preventing TB-related deaths, underscoring the potential of these new regimens to streamline treatment, reduce side effects, and offer pill-based alternatives to daily injections. The endTB trials have concluded, marking a significant step forward in combating TB.
