(a) Definitions As used in this section, the term "pediatric studies" or "studies" means at least one clinical investigation (that, at the Secretary's discretion, may include pharmacokinetic studies) in pediatric age groups (including neonates in appropriate cases) in which a drug is anticipated to be used, and, at the discretion of the Secretary, may include preclinical studies. (b) Market exclusivity for new drugs (1) In general Except as provided in paragraph (2), if, prior to approval of an application