1 Month of Rifapentine/Isoniazid Noninferior to Current HIV-Related TB Prevention Therapy

Tuberculosis (TB) is the leading cause of death for people infected with HIV, but a new study offers hope, suggesting that a short course of daily rifapentine plus isoniazid could provide benefits over current treatment regimens.

"One of the major problems with currently available treatments for TB infection is that they take too long, and people just stop taking them after a while," lead author Susan Swindells, MBBS, professor and medical director, HIV Clinic, Department of Internal Medicine at the University of Nebraska Medical Center, told Contagion^®. "We identified an ultra-short course of treatment (only 1 month) and tested it against the conventional 6-month course of treatment.”

"Our main findings were that the new short course was just as effective as the standard 6-month course, more patients taking the short course completed their treatment, and they had less adverse effects," she continued.

The randomized, open-label, phase 3 noninferiority trial, published in The New England Journal of Medicine, followed 3000 patients with HIV for an average of 3.3 years. Participants were placed in 1 of 2 groups, with 1 group receiving daily rifapentine plus isoniazid for 1 month and the other taking isoniazid alone for 9 months.

Treatment completion was 97% in the 1-month group, compared with 90% in the 9-month group. In both groups, the primary endpoint of first diagnosis of tuberculosis or death from tuberculosis or an unknown cause was reported in 2% of patients. Adverse events occurred in 6% of patients in the 1-month group and in 7% of patients in the 9-month group.

The study found that a 1-month course of daily rifapentine plus isoniazid is noninferior to 9 months of isoniazid to prevent TB, which has been is limited by factors including concerns over adherence, drug toxicity, and drug resistance.

TB is of particular concern among patients infected with HIV. A recent study found that Latin Americans infected with HIV were twice as likely to die within 10 years of being diagnosed with TB than those with HIV who did not have TB. HIV-associated TB killed about 300,000 people in 2017, according to the World Health Organization.

Although such outcomes highlight the importance of prevention, only about 1 million patients with HIV received preventive treatment in 2017 out of 30 million who were eligible, the UNMC study noted.

More broadly, TB is among the top 10 causes of death globally, killing a total of 1.6 million people in 2017.

"Our study was only in adults and adolescents with HIV infection, so we would recommend study in people without HIV, in children and also in pregnant women to make sure it also works for these populations," Swindells told Contagion^®.

A new initiative aims to accelerate the response to TB. Announced ahead of World TB Day on March 24, the initiative called "Find. Treat. All. #EndTB" aims to ensure patients have access to treatment for the disease, which kills 5000 people every day, with 10 million new cases around the world in 2017.

"TB is still an enormous problem globally, and often ignored," Swindells said. "Treatment for latent infection works well, but not enough people have access to it, and many of those who have access do not complete the whole course. This new ultrashort course of therapy is much more likely to be completed and could have a major impact on the global epidemic."