(Newser) – Good news for those with the deadliest strain of tuberculosis: It no longer has to mean a death sentence. Scientists have discovered a cure for extensively drug-resistant TB, or XDR-TB, and on Wednesday, the FDA "effectively endorsed" it, the New York Times reports. Just a small percentage of people who get tuberculosis—which is now the leading infectious cause of death in the world, having surpassed AIDS—get the XDR strain, but very few survive if they do. XDR is resistant to all four families of antibiotics typically used to fight TB, and the existing treatment regimen is difficult and can result in severe side effects—including death. The new regimen is easier, shorter, has less severe side effects, and the preliminary trial results show a 90% success rate against XDR.

The three-drug regimen, known as Nix-TB, includes two previously approved drugs (bedaquiline and linezolid) plus pretomanid, which the FDA on Wednesday approved for XDR-TB patients as long as it is used in conjunction with the other two. The WHO typically adopts FDA approvals, so the regimen could soon be used worldwide. One of the trial's 109 patients, Tsholofelo Msimango, is now tuberculosis-free and went from 57 pounds when she joined the trial to 103 pounds. Another, Innocent Makamu, said patients on the standard regimen discouraged him from joining the trial—but within a month, he could tell he would be cured. "Then the patients who called us 'guinea pigs'—they wished they had taken the research pills," he says. (See the full Times story here.)

