ABSTRACT
Classical drug development programs usually are referred to those for the treatment of chronic diseases. In most of the programs, Phase I clinical trials recruit healthy normal volunteers to study pharmacokinetics (PK), pharmacodynamics (PD), and the maximally tolerated dose (MTD) for the drug candidate. Patients with the target disease under study are recruited in Phase II. Therefore, under these development programs, drug efficacy cannot be studied at Phase I, and the first efficacy trial is designed in Phase II. One important step in early clinical development of a new drug is to draft a clinical development plan (CDP). Various clinical studies are designed and carried out according to this plan, and such a CDP is updated over time based on newly available information. Understanding of dose-response relationship should be one of the central components in CDP. Since dose finding is mainly addressed in Phase II, this chapter focuses on clinical trials to be designed during the Phase II clinical development.
