Establishing efficacy of human products using animals: the US food and drug administration's "animal rule".

In 2002, the US Food and Drug Administration issued regulations to allow the approval of human drugs and biological products based on animal efficacy studies when human efficacy studies would be unethical or not feasible. These regulations are intended to assist in the approval process for products aimed at preventing or treating human diseases caused by nuclear, radiological, biological, and chemical agents that have the potential to harm a significant percentage of the US population. This article discusses the criteria that must be met to use the Animal Rule to demonstrate efficacy in place of human clinical trials.