The purpose of this chapter is to describe key aspects of the design and analysis of phase III clinical trials focusing on the treatment of breast cancer. Phase III clinical trials are 1 of 5 basic hierarchical phases of human research activity designed to ascertain information regarding the biological processing, safety, and efficacy of a new treatment.1,2 Details regarding phase III trials are provided later in the chapter. To provide a perspective from which to understand the relative importance of the type of information that is gained from a phase III clinical trial, before we begin our presentation on the design and analysis of phase III trials, we present a synopsis of all of the different phases of clinical trial research. We use the term "new treatment" as a general term to refer to the use of one or several methods for treating a disease or condition with a new surgical technique, a new medical device, or a new form of chemical, physical, or biological agent.
Phase 0 trials are a relatively newly defined type of trial involving the administration of a subtherapeutic dose of a new treatment to a single group of usually 10 to 15 human subjects. The purpose of this type of trial is to determine early in the development process if a new treatment has the pharmacokinetic and pharmacodynamic properties in humans as would be anticipated from the findings from laboratory and animal studies. Because the dosing is subtherapeutic, these trials are also referred to as microdosing trials. Due to the subtherapeutic nature of the dosing, phase 0 trials are not intended to provide relevant information on safety or efficacy. Discussions on the methodology and issues in phase 0 trials are presented by Takimoto, Murgo and associates, and others.2-5
Phase I trials also involve the administration of a new treatment to a single group of human subjects in the range of 20 or more, but rarely over 100. The purpose of this phase of research is to obtain some initial information regarding the therapeutic dosing of the treatment. Until the point of initiating a phase 1 trial, information has been limited to that from laboratory investigations, studies among animals, and perhaps the pharmacokinetics in humans of subtherapeutic doses. The objectives of a phase I trial can include obtaining information on the best mode of treatment delivery, determining adequate dosing levels, describing the nature of side effects from treatment and detecting some signal that the new treatment has activity on the disease or condition for which the treatment is planned to be used. Eisenhauer and coworkers, Miller, Horstmann and colleagues, and others present discussions regarding methodology and issues in phase1 trials.6-11
If the findings from phase I research show some promise and are within safety parameters, phase II trial ...