New Drug Attacks Resistant TB

By: Margaret A. Hamburg, M.D.

Having seen first-hand the threat to public health posed by multi-drug resistant tuberculosis (MDR TB), which cannot be cured by many of the most powerful drugs usually used to treat the disease, I’m pleased that another weapon has been added to the arsenal for fighting this deadly, contagious disease.

Margaret Hamburg, M.D.TB is a disease caused by germs that are spread from person to person through the air. TB usually affects the lungs, but it can also affect other parts of the body, such as the brain, the kidneys, or the spine. A person with TB can die if they do not get treatment.

The critical need for new interventions is real and fortunately we now have a new drug—approved in only six months through an expedited pathway — to treat this. Bedaquiline, sold under the brand name Sirturo, is the first drug developed specifically to treat multi-drug resistant tuberculosis involving the lungs — Mycobacterium tuberculosis. It will be used in combination with other drugs when other TB drug treatment regimens will not be effective.

Sirturo has a new mechanism of action: It inhibits an enzyme needed for replication of the M. tuberculosis bacteria and represents an important new development for some patients with particularly difficult to treat forms of tuberculosis

TB is one the world’s deadliest diseases, and is more prevalent now than at any time in history. Last year, nearly 9 million people worldwide became sick with TB, and 1.4 million died. A total of 10,528 cases were reported in the U.S. last year, according to the Centers for Disease Control and Prevention.

People with active TB must take several drugs on a regular basis for 6 to 12 months; for drug resistant TB the treatment regimens are longer and more complicated. If treatment is inadequate or incomplete, the disease can become resistant to certain drugs, meaning those medications don’t work anymore. It then becomes more difficult or sometimes impossible to treat or cure these patients, putting them and others at serious health risk.

Of course, drugs have risks too. Given the significant potential risks of Sirturo, a boxed warning will be included in the label for the drug alerting patients and health care professionals about the increased rate of mortality observed in patients who received bedaquiline compared to patients who received treatment of their resistant TB with other drugs. The boxed warning will also describe the risk of Sirturo’s effects on the heart that can infrequently result in abnormal heart rhythms, leading in some instances, to death.

There is no question that we need more and better treatments for drug-resistant TB. And we’ll continue to need new drugs as the disease mutates or changes.  Meanwhile, Sirturo is a welcome addition to the drugs that we have available to treat patients who have multi-drug resistant TB who need this drug as part of their treatment regimen.

 Margaret A. Hamburg, M.D., is Commissioner of the U.S. Food and Drug Administration.