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 when other alternatives are not available.
According to the Centers for Disease Control and Prevention, nearly 9 million people around the world and 10,528 people in the United States became sick with TB in 2011.
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 dont have other therapeutic options available,” Edward Cox, MD, MPH, director of the Office of Antimicrobial Products in the FDAs Center for Drug Evaluation and Research, said in a news release.
“However, because the drug also carries some significant risks, doctors should make sure they use it appropriately and only in patients who dont have other treatment options.”
Sirturo carries a Boxed Warning alerting patients and healthcare professionals that the drug can cause QT prolongation, which could lead to an abnormal and potentially fatal heart rhythm. The warning also notes deaths in patients treated with Sirturo. Nine patients who received Sirturo died in clinical studies, 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.
Sirturos manufacturer, Janssen Therapeutics, will distribute the drug from a single source and will provide educational materials to help ensure the drug is used appropriately.
Sirturos safety and effectiveness were established in 440 patients in two Phase 2 clinical trials. Patients in the first trial were randomly assigned to be treated with Sirturo plus other drugs used to treat TB, or a placebo plus other drugs used to treat TB. All patients in the second trial, which is ongoing, received Sirturo plus other TB drugs. Both studies were designed to measure the length of time needed for sputum culture conversion.
Results from the first trial showed patients treated with Sirturo combination therapy achieved SCC in a median time of 83 days, compared with 125 days in patients treated with placebo combination therapy. Results from the second trial showed the median time to SCC was 57 days, supporting the efficacy findings of the first trial.
Common side effects identified in the clinical trials were nausea, joint pain and headache.