Humans

A new FDA-approved drug takes aim at a deadly form of tuberculosis

The antibiotic, paired with two others, works against highly drug-resistant TB

DEADLY RESISTANCE Tuberculosis is caused by Mycobacterium tuberculosis (shown). A drug newly approved by the U.S. Food and Drug Administration could help combat a highly drug-resistant form of the disease.

NIAID

By Aimee Cunningham

August 16, 2019 at 6:00 am

An especially dangerous type of tuberculosis may have met its match.

The U.S. Food and Drug Administration announced August 14 that it has approved the antibiotic pretomanid to help tackle what’s called extensively drug-resistant tuberculosis. This form of the disease is resistant to at least four of the main TB drugs, and treatment often fails: Only around 34 percent of infected patients typically survive, the World Health Organization says.

Becoming ill with this type of TB “can be a death sentence — until now,” says William Bishai, a tuberculosis researcher at the Johns Hopkins University School of Medicine, who was not involved in the drug’s development.

The current treatment requires patients to take as many as eight antibiotics orally, and sometimes by injection, for 18 months or more. By contrast, the new antibiotic is paired with two other previously approved drugs, bedaquiline and linezolid, in a six-month course of pills. Ninety-five of 107 patients who had the highly resistant disease and took this drug regimen recovered, according to the TB Alliance, the nonprofit organization that developed pretomanid. The drug is only the third since the 1960s to be approved for tuberculosis, which is caused by Mycobacterium tuberculosis.

Tuberculosis sickened an estimated 10 million people in 2017 (SN: 10/27/18, p. 15). Around 458,000 cases were multidrug-resistant, unresponsive to the two most powerful TB drugs (SN Online: 4/30/14). Of those cases, about 8.5 percent, or roughly 39,000, were extensively drug-resistant, according to WHO.

Pretomanid has been tested only in patients with highly resistant TB. More research is needed to determine whether the drug could be useful for the vast majority of patients who have TB that’s more receptive to treatment, says Bishai. Perhaps the standard regimen of multiple drugs taken for six months could be shortened by including the new antibiotic, he says. “We’re delighted to have this new drug pretomanid, but there’s a lot more to do.”