New Rx for Hard-to-Treat TB

Sirtura approved by FDA to treat multi-drug resistant tuberculosis

(RxWiki News) In the United States, most people recover from tuberculosis (TB), a type of lung infection. In some people, however, the drugs used to treat TB don't work. A recently approved drug could help fix this problem.

The FDA has approved Sirturo (bedaquiline) to treat adults with multi-drug resistant TB. Sirturo is part of a combination treatment for TB patients who have no other drug options.

Sirturo was approved through the FDA's accelerated approval program. This means that patients will have earlier access to a drug that treats this serious disease.

"Ask your doctor about your TB exposure risk."

TB is a bacterial infection that affects the lungs but can spread to other organs. The infection is highly contagious and is one of the world's deadliest diseases. In 2011, more than 10,000 Americans became sick with TB.

Multi-drug resistant TB develops when the bacteria that causes TB becomes resistant to isoniazid and rifampin - two of the most common TB drugs. In other words, isoniazid and rifampin do not have an effect on patients with multi-drug resistant TB.

Sirturo is the first FDA-approved drug to treat multi-drug resistant TB in combination with other drugs.

"Multi-drug resistant tuberculosis poses a serious health threat throughout the world, and Sirturo provides much-needed treatment for patients who don’t have other therapeutic options available," said Edward Cox, MD, MPH, director of the Office of Antimicrobial Products in the FDA's Center for Drug Evaluation and Research.

"However, because the drug also carries some significant risks, doctors should make sure they use it appropriately and only in patients who don't have other treatment options," he said.

The approval of Sirturo is important for a few reasons. First, it may fill an unmet medical need. That is, patients with multi-drug resistant TB previously had no other drug option. Second, Sirturo may offer safe and effective treatment to patients with no other option. Third, it is meant to treat a rare disease.

As promising as Sirturo may be, it also carries some risks. The Boxed Warning that comes Sirturo alerts patients that taking the drug may affect the electrical activity of the heart, which could lead to a potentially deadly heart rhythm. The Boxed Warning also notes that some patients taking Sirturo have died. In clinical trials, nine patients taking Sirturo died, compared to two patients taking placebo. While all of the deaths among placebo patients were linked to TB, only five of the deaths among Sirturo patients were linked to TB. Researchers could not identify a consistent reason explaining the other four deaths among Sirturo patients.

In addition, researchers found that common side effects of Sirturo included nausea, joint pain and headache.

The safety and effectiveness of Sirturo was tested in 440 patients in two Phase II clinical trials. In the first trial, patients were assigned to take Sirturo plus other TB drugs or placebo plus other TB drugs. In the second trial, all patients took Sirturo plus other TB drugs. The second trial is still ongoing.

Sirturo was approved by the FDA on December 28. Sirturo is manufactured by Janssen Therapeutics.

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Review Date: 
December 31, 2012