ABSTRACT
The clinical performance of Companion Diagnostics in selecting patients to receive or avoid a particular therapy can only be provided by data from clinical trials. This chapter provides an overview of trial designs for assessing the ability of a biomarker. In the enrichment design, only patients who are positive for the biomarker are included in a study evaluating the effect of an experimental therapy. It is also called a targeted, enriched, or selection design. When there is insufficient evidence of a biomarker’s ability to predict a treatment effect to justify exclusion of a subpopulation from randomization, the marker-stratified design is a reasonable alternative. In this design, all patients are randomized to experimental or control treatments; however, patients are first stratified by marker status and then randomized to a treatment arm within their given marker cohort. Only individuals with valid biomarker results enter the trial.
