FDA perspective on antivirals against biothreats: communicate early and often.

Development of antiviral products for certain highly pathogenic viruses with limited available treatments, such as viruses that may have biothreat potential, is critically important and challenging. The mission of the FDA is to protect the public health by assuring the safety, efficacy and quality of such products. Human clinical trials are critically important whenever relevant naturally occurring diseases can appropriately be studied. In selected situations when clinical studies are not ethical and field efficacy studies are not feasible, the Animal Rule (67 FR 37988, 2002) introduces the possibility of drug/biologic approval/licensure based on efficacy studies in animals, and appropriate human safety and pharmacokinetic information. This approach necessitates the development of well-delineated animal models predictive of human disease and treatment responses, and plans for adding human information if suitable circumstances arise. Efficient development of therapeutics against these agents requires collaborative efforts among industry, academia and federal agencies.