cologists (particularly those who can integrate the field of molecular biology with clinical investigation), the increasing number of drugs available for testing, and the limited capacity to conduct clinical trials with children may still result in the prescription of too many drugs for children in the absence of good evidence for their safety and efficacy in that population. Additionally, on the basis of a lack of experience, there are concerns about the new FDA regulations that permit a drug to be prescribed for a pediatric patient on the basis of adequate and well-controlled studies with adults if the course of the disease and the effects of the drug are sufficiently similar in the pediatric and adult populations. Comparison of the pediatric and adult populations needs to take several factors into account, including pathophysiology and natural history of diseases common to both groups and the host reactions to disease and therapeutic agents (including pharmacodynamics and toxic reactions).

The workshop summarized in this report explored how scientists in industry, academia, and the government can develop a research strategy to gather the needed information to facilitate the development process for therapeutic drugs and biologics designed for use in the pediatric population. The workshop focused on four major areas of importance for improving understanding of the development and testing of drugs and biologics in studies with pediatric populations, as well as facilitating future planning in this area:

• how children are similar or dissimilar to adults with regard to physiology, drug metabolism, immunology, cognitive effects, and response to disease states and therapy;

• the identification of new advances in biomedical science that are uniquely applicable to children and that could be applied to the development and testing of drugs and biologics in studies with children;

• the special requirements in evaluating drugs and biologics in studies with pediatric populations, including an assessment of when and how safety and efficacy data can be used for children; and

• an examination of the many legal and regulatory issues in evaluating new drugs and biologics in studies with pediatric populations, as well as interrelated social and ethical concerns.

The following sections highlight major themes discussed in the workshop presentations.

The pediatric population often responds to drugs and biologics differently than adults do. Generally, the drug prescription guidelines that practitioners use