The FDA approved Levaquin (levofloxacin), an antibacterial, to treat plague and to reduce the risk for acquiring it after exposure on April 27 under a priority review. Levaquin is manufactured by J&J's Janssen Pharmaceuticals.
About 10 to 15 people contract plague in the U.S. each year, according to the Centers for Disease Control and Prevention. Plague is a rare and potentially deadly bacterial infection, according to the FDA. Other drugs approved to treat plague include streptomycin, doxycycline and tetracycline.
The approval was based on results of a randomized trial of African green monkeys. The monkeys were infected with Yersinia pestis, the plague bacterium. Survival was 94 percent among the monkeys that received 10 days of levofloxacin within six hours of the onset of fever and 0 percent among the group that received a placebo.
For more info, read the FDA press release on the approval of Levaquin.