The U.S. Food and Drug Administration on Mondayapproved a Johnson & Johnson tuberculosis drug that is the first newmedicine to fight the deadly infection in more than four decades.
The agency approved J&J's pill, Sirturo, for use witholder drugs to fight a hard-to-treat strain of tuberculosis that has notresponded to other medications. However, the agency cautioned that the drugcarries risks of potentially deadly heart problems and should be prescribedcarefully by doctors.
Roughly one-third of the world's population is estimated tobe infected with the bacteria causing tuberculosis. The disease is rare in theU.S., but kills about 1.4 million people a year worldwide. Of those, about150,000 succumb to the increasingly common drug-resistant forms of the disease.About 60 percent of all cases are concentrated in China, India, Russia andEastern Europe.
Sirturo, known chemically as bedaquiline, is the firstmedicine specifically designed for treating multidrug-resistant tuberculosis.That's a form of the disease that cannot be treated with at least two of thefour primary antibiotics used for tuberculosis.
The standard drugs used to fight the disease were developedin the 1950s and 1960s.
"The antibiotics used to treat it have been around forat least 40 years and so the bacterium has become more and more resistant towhat we have," said Chrispin Kambili, global medical affairs leader forJ&J's Janssen division.
The drug carries a boxed warning indicating that it caninterfere with the heart's electrical activity, potentially leading to fatalheart rhythms.
"Sirturo provides much-needed treatment for patientswho don't have other therapeutic options available," said Edward Cox,director of the FDA's antibacterial drugs office. "However, because thedrug also carries some significant risks, doctors should make sure they use itappropriately and only in patients who don't have other treatmentoptions."
Nine patients taking Sirturo died in company testingcompared with two patients taking a placebo. Five of the deaths in the Sirturogroup seemed to be related to tuberculosis, but no explanation was apparent forthe remaining four.
Despite the deaths, the FDA approved the drug under itsaccelerated approval program, which allows the agency to clear innovative drugsbased on promising preliminary results.
Last week, the consumer advocacy group Public Citizencriticized that approach, noting the drug's outstanding safety issues.
"The fact that bedaquiline is part of a new class ofdrug means that an increased level of scrutiny should be required for itsapproval," the group states. "But the FDA had not yet answeredconcerns related to unexplained increases in toxicity and death in patientsgetting the drug."
The FDA said it approved the drug based on two mid-stagestudies enrolling 440 patients taking Sirturo. Both studies were designed tomeasure how long it takes patients to be free of tuberculosis.
Results from the first trial showed most patients takingSirturo plus older drugs were cured after 83 days, compared with 125 days forthose taking a placebo plus older drugs. The second study showed most Sirturopatients were cured after 57 days.