Simpler Combination Therapy as Good as Old Regimen to Prevent Full-Blown TB in People with and without HIV

Johns Hopkins and South African scientists have further compelling evidence that new, simpler and shorter treatments with antibiotic drugs could dramatically help prevent tens of millions of people worldwide already infected with the bacterium responsible for tuberculosis, and especially those co-infected with HIV, from developing full-blown TB. That population includes as many as 22 million in sub-Saharan Africa who are already HIV positive and at high risk of also picking up TB, which is endemic to the region, plus another 50,000 in the United States who are similarly HIV positive and at high risk of catching the lung infection.

Results of a study, to be published in The New England Journal of Medicine online July 7, by the international team of scientists found the most streamlined combination - a high-dose pairing of 900 milligrams each of the newer antibiotic rifapentine and traditional isoniazid once weekly for three months - worked just as well or even better than 300 milligrams of isoniazid taken daily for six months or longer, and widely considered the gold standard of care.

“This new, simpler treatment regimen with rifapentine and isoniazid is highly effective and could transform therapy for latent tuberculosis in both those co-infected with HIV and those not,” says study senior author Richard Chaisson, M.D., a professor of infectious diseases at the Johns Hopkins University School of Medicine and founding director of its Center for Tuberculosis Research.

“New treatment options are urgently needed to help control TB globally, and simpler regimens will substantially increase the number of people receiving therapy,” says Chaisson, who points out that fewer than 1 percent of those infected and most likely to develop full-blown TB are receiving drug treatment because of inconvenience, drug side effects and difficulty finding health clinics close to where they live.

Chaisson says the latest study in 1,148 South African men and women co-infected with HIV, and another recent study, in which he was also involved, in more than 8,000 men and women in the United States, Canada, Spain and Brazil who mostly were HIV free, show success for the first new treatment option since rifapentine, marketed as the drug Priftin, was approved for use in the United States in 1998. He adds that the results represent the most significant advance in preventing the disease since isoniazid was first proven effective in treating the disease in the 1950s.

TB is the leading cause of death among people co-infected with HIV, the virus that causes AIDS, leading to some half-million deaths annually among those co-infected.

Chaisson says the streamlined, weekly regimen is much easier for patients to follow, with 95 percent having completed treatment in this study, while traditional daily and longer isoniazid therapy shows a compliance rate of about 60 percent or less in other studies and in practice. This is important, he notes, because isoniazid does not work if treatment is interrupted and people stop taking it as prescribed.