The U.S. Food and Drug Administration has approved Sirturo (bedaquiline) as part of combination therapy to treat adults with multi-drug resistant pulmonary tuberculosis (TB) when other alternatives are not available.
Tuberculosis (TB) is considered to be one of the world’s deadliest diseases affecting nearly 9 million people around world. Caused by Mycobacterium, tuberculosis is spread from person to person through the air and usually affects the lungs, but it can also affect other parts of the body such as the brain and kidneys. According to the Centers for Disease Control and Prevention 10,528 people in the United States became sick with TB in 2011.
While only about 10% of people infected with M. tuberculosis ever develop tuberculosis disease. Many of those who suffer TB do so in the first few years following infection, but the bacillus may lie dormant in the body for decades.
Multi-drug resistant TB occurs when M. tuberculosis becomes resistant to isonazid and rifampin, two powerful drugs most commonly used to treat TB. Sirturo is the first drug approved to treat multi-drug resistant TB and should be used in combination with other drugs used to treat TB. Sirturo works by inhibiting an enzyme needed by M. tuberculosis to replicate and spread throughout the body.
“Multi-drug resistant tuberculosis poses a serious health threat throughout the world, and Sirturo provides much-needed treatment for patients who have don’t have other therapeutic options available,” said Edward Cox, M.D., M.P.H, 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.”
While common side effects identified in the clinical trials include nausea, joint pain, and headache, Sirturo carries a Boxed Warning alerting patients and health care professionals that the drug can affect the heart’s electrical activity (QT prolongation), which could lead to an abnormal and potentially fatal heart rhythm. The Boxed Warning also notes deaths in patients treated with Sirturo. Nine patients who received Sirturo died compared with two patients who received placebo. Five of the deaths in the Sirturo group and all of the deaths in the placebo arm seemed to be related to tuberculosis, but no consistent reason for the deaths in the remaining Sirturo-treated patients could be identified.