On April 27, 2012, the U.S. Food and Drug Administration (“FDA”) approved Levaquin (levofloxacin), a drug used to treat those afflicted with plague. In addition to treating those with the deadly infection, Levaquin is also approved to reduce the risk of contracting plague after exposure to Yersinia pestis, the bacteria responsible for causing the disease. Although the FDA estimates that only 1,000 to 2,000 people worldwide contract the infection each year, the Agency is interested in expanding available treatment options for the disease based on its belief that it could potentially be used as a bioterrorism agent in the future. More information about Levaquin may be accessed here.
Interestingly, Levaquin was approved based on a single efficacy study conducted with African green monkeys. As discussed in the Agency’s announcement of the approval, Levaquin was approved through the application of the FDA’s Animal Efficacy Rule. Found at 21 C.F.R. § 314.610, the Rule allows the FDA to grant marketing approval for new drug products for which safety has been demonstrated using animal studies alone. The Rule allows for FDA approval based solely on animal studies only when the effect demonstrated in the animal species is a predictive result for humans and it is not otherwise feasible or ethical to test the safety and effectiveness of the drug with human subjects. In addition to other postmarketing requirements, all human recipients of drugs approved under the Animal Efficacy Rule must be notified, via product labeling, that the drugs’ approval was based solely on animal efficacy studies.