Clinical trial finds three new ways to treat drug-resistant tuberculosis

Despite having life-saving vaccines and antibiotics, tuberculosis (TB) remains one of the deadliest infectious diseases globally. A recent international clinical trial has identified three safe and effective drug regimens to treat antibiotic-resistant strains of TB. The findings were published in a study in the New England Journal of Medicine on January 30.

Why is tuberculosis still dangerous?

TB is a bacterial infection that primarily affects the lungs and spreads through air droplets released when talking or coughing. It can remain in the air for several hours and is highly infectious, but only spreads when a person is symptomatic.

Once the bacterium infects a person, it can take on two forms. Active TB presents with symptoms like a long-standing cough, bloody phlegm, fever, and night sweats, while latent TB remains dormant in the body without causing symptoms or being contagious.

In 2020, approximately 10 million people fell ill with TB, resulting in around 1.5 million deaths worldwide. The United States reported about 7,860 cases of tuberculosis in 2021.

An ongoing outbreak in Kansas City, Kansas, has claimed two lives since January last year. The Kansas Department of Health and Environment reported that 67 people are undergoing treatment for active TB, while 79 have latent TB.

Dr. Dana Hawkinson, an infectious disease doctor at the University of Kansas Health System, noted that the high case counts in the current outbreak serve as a “stark warning” given the usual low number of cases seen annually.

The World Health Organization’s Global Tuberculosis Report 2024 highlighted a rise in reported cases, potentially due to disruptions in vaccination schedules during the COVID-19 pandemic and the emergence of drug-resistant strains.

Antibiotic resistance is a growing concern with TB, as some strains are already resistant to key antibiotics. Treatment regimens often involve long durations, daily injections, and potentially toxic medications with severe side effects.

The endTB trials

The endTB trial, a collaborative effort involving Harvard Medical School, Partners In Health, Médecins Sans Frontières, and Interactive Research and Development, is part of ongoing research to test new, shorter, and less toxic treatments for drug-resistant TB.

Using newer drugs like bedaquiline and delamanid, the trial aims to improve treatment outcomes for patients with rifampin-resistant TB, a condition affecting around 410,000 individuals annually, of whom only 40% are diagnosed and treated successfully.

[ Related: How infectious diseases killed Victorian children at alarming rates. ]

The trial tested five new oral regimens over nine months, with three of them showing success rates between 85-90% for patients with drug-resistant TB. The control group, receiving longer treatments, had a success rate of 81%.

The trial regimens were considered effective if they performed at least as well as the control group, which followed the WHO recommendations for standard care.

A step towards more accessible care

Two of the three successful endTB regimens, along with another WHO-recommended regimen, are cost-effective, making lifesaving care more accessible. These regimens utilize approved drugs to simplify treatment, reduce side effects, and offer pill-based alternatives to daily injections.

Carole Mitnick, trial co-principal investigator and Harvard Medical School epidemiologist, emphasized that these new regimens address previous limitations in treatment options and evidence quality, potentially preventing more tuberculosis-related deaths.

By leveraging existing drugs, the regimens aim to expand treatment options, shorten durations, and improve outcomes for TB patients across the globe.

The endTB trials have now concluded.