U.S. regulators have approved a new tuberculosis medicine that shortens and improves treatment for the hardest-to-treat cases, a worsening problem in many poor countries.

It’s the first TB drug developed by a nonprofit group, the TB Alliance, which was formed to come up with better treatments. RTI International also assisted in the effort.

The Food and Drug Administration approved pretomanid (preh-TOH’-meh-nihd) for use with two other drugs for TB, which attacks the lungs. In testing, the three-pill combo cured about 90% of patients with very drug-resistant TB, usually within 6 months. It also appears to stop patients spreading the deadly bacterial infection after just a few days’ treatment.

Until now, the best option cured about two-thirds of patients and took 18 to 30 months, according to the TB Alliance.

The new drug was developed to treat Extensively Drug-Resistant Tuberculosis (XDR-TB) and treatment intolerant/non-responsive Multidrug-Resistant (MDR) TB.

Helping lead efforts to develop it was RTI International scientist Dr. Doris Rouse, who is vice president of RTI’s Center for Global Health. She and “her team have collaborated closely with TB Alliance on the development of pretomanid for almost 20 years,” RTI notes.

RTI and Rouse helped form the TB Alliance in 2000 and it has negotiated license agreements enabling an affordable cost of pretomanid in low resource countries, according to RTI

“We are seeing an increase in XDR-TB, and we need new weapons to attack it,” Rouse said in a statement. “I’ve been in wards with patients that are so emaciated, they won’t eat anything, they have fevers, they can’t sleep. But with pretomanid, in a regimen that includes two other drugs, bedaquiline and linezolid, we see improvement within a few weeks. This new treatment will help people who have no other good option for a cure.”