The Food and Drug Administration said Monday that it had approved a new treatment for multidrug-resistant tuberculosis that can be used as an alternative when other drugs fail.
The drug, to be called Sirturo, was discovered by scientists at Janssen, the pharmaceuticals unit of Johnson & Johnson, and is the first in a new class of drugs that aims to treat the drug-resistant strain of the disease.
Tuberculosis is a highly infectious disease that is transmitted through the air and usually affects the lungs but can also affect other parts of the body, including the brain and kidneys. It is considered one of the world’s most serious public health threats.
Although rare in the United States, multidrug-resistant tuberculosis is a growing problem elsewhere in the world, especially in poorer countries. About 12 million people worldwide had tuberculosis in 2011, according to J&J, and about 630,000 had multidrug-resistant TB.
“This is quite a milestone in the story of therapy for TB,’’ said Paul Stoffels, the chief scientific officer at J&J.
Sirturo works by inhibiting an enzyme needed by the tuberculosis bacteria to replicate and spread throughout the body.
Sirturo, also known as bedaquiline, would be used on top of the standard treatment, which is a combination of several drugs. Patients with drug-resistant tuberculosis often must be treated for 18 to 24 months.
Even as it disclosed the approval, however, the FDA also issued some words of caution.
‘‘Multidrug-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,’’ Edward Cox, director of the office of antimicrobial products in the FDA’s center for drug evaluation and research, said in a statement. ‘‘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.’’
The consumer advocacy group Public Citizen opposed approval in a letter to the FDA in mid-December, saying that the results of a limited clinical trial showed that patients using bedaquiline were five times as likely to die than those on the standard drug regimen to treat the disease.
Sirturo carries a so-called black box warning alerting patients and health care professionals that the drug can affect the heart’s electrical activity, which could lead to an abnormal and potentially fatal heart rhythm.