ABSTRACT
In this chapter, the authors assume that biological characterization is accomplished by use of biomarker-based tests, although the principles discussed apply also to other methods of biological characterization such as imaging. They begin with a brief discussion of some considerations in the evaluation of analytical performance of a biomarker-based test; a biomarker assay should meet some minimal analytical performance criteria before being used in a clinical trial where it might influence the therapy a patient receives. Biomarker-stratified designs provide full information about the relative treatment efficacy in each biomarker-defined subgroup and in the overall patient population. An approach that is sometimes used to analyze biomarker-stratified designs is to test the treatment in the biomarker-positive and overall population. An example of a trial using a biomarker-strategy design with a binary biomarker was a trial of docetaxel/cisplatin versus a biomarker-directed treatment arm for patients with metastatic non-small cell lung cancer.
