Johnson & Johnson's pill Sirturo has been approved to fight tuberculosis.(Photo: Daniel Hulshizer, AP)
WASHINGTON -- The Food and Drug Administration on Monday approved
a Johnson & Johnson tuberculosis drug that is the first new
medicine to fight the deadly infection in more than four decades.
The
agency approved J&J's pill, Sirturo, for use with older drugs to
fight a hard-to-treat strain of tuberculosis that has not responded to
other medications. However, the agency cautioned that the drug carries
risks of potentially deadly heart problems and should be prescribed
carefully by doctors.
Roughly one-third of the world's population
is estimated to be infected with the bacteria causing tuberculosis. The
disease is rare in the U.S., but kills about 1.4 million people a year
worldwide. Of those, about 150,000 succumb to the increasingly common
drug-resistant forms of the disease. About 60% of all cases are
concentrated in China, India, Russia and Eastern Europe.
Sirturo,
known chemically as bedaquiline, is the first medicine specifically
designed for treating multidrug-resistant tuberculosis. That's a form of
the disease that cannot be treated with at least two of the four
primary antibiotics used for tuberculosis.
The standard drugs used to fight the disease were developed in the 1950s and 1960s.
"The
antibiotics used to treat it have been around for at least 40 years and
so the bacterium has become more and more resistant to what we have,"
said Chrispin Kambili, global medical affairs leader for J&J's
Janssen division.
The drug carries a boxed warning indicating that
it can interfere with the heart's electrical activity, potentially
leading to fatal heart rhythms.
"Sirturo provides much-needed
treatment for patients who have don't have other therapeutic options
available," said Edward Cox, director of the FDA's antibacterial drugs
office. "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."
Nine patients taking
Sirturo died in company testing compared with two patients taking a
placebo. Five of the deaths in the Sirturo group seemed to be related to
tuberculosis, but no explanation was apparent for the remaining four.
Despite
the deaths, the FDA approved the drug under its accelerated approval
program, which allows the agency to clear innovative drugs based on
promising preliminary results.
Last week, the consumer advocacy group Public Citizen criticized that approach, noting the drug's outstanding safety issues.
"The
fact that bedaquiline is part of a new class of drug means that an
increased level of scrutiny should be required for its approval," the
group states. "But the FDA had not yet answered concerns related to
unexplained increases in toxicity and death in patients getting the
drug."
The FDA said it approved the drug based on two mid-stage
studies enrolling 440 patients taking Sirturo. Both studies were
designed to measure how long it takes patients to be free of
tuberculosis.
Results from the first trial showed most patients
taking Sirturo plus older drugs were cured after 83 days, compared with
125 days for those taking a placebo plus older drugs. The second study
showed most Sirturo patients were cured after 57 days.
Associated Press