Implementation of the principles of the 3Rs of animal testing at CDER: Past, present and future.

The safety testing of pharmaceutical candidates has traditionally relied on data gathered from studies in animals, and these sources of information remain a vital component of the safety assessment for new drug and biologic products. However, there are clearly ethical implications that attend the use of animals for safety testing, and FDA fully supports the principles of the 3Rs, as it relates to animal usage; these being to replace, reduce and refine. We provide an overview of some of the events and activities (legal and programmatic) that have had, and continue to have, the greatest impact on animal use in pharmaceutical development, and highlight some ongoing efforts to further meet the challenge of achieving our mission as humanely as possible.