Ziad Taib: Signs of the unseen: Biomarkers and Surrogate Endpoint

Biomarkers are biological features used to indicate biological processes, disease processes, or responses to therapy. A surrogate endpoint is defined as "a biomarker intended to substitute for a clinical endpoint".

Biomarkers play a very important role in personalized medicine, in drug development etc. The simplest familiar example is blood pressure. Another one is prostate specific antigen which is a molecular biomarker for prostate cancer diagnosis.

To be really useful, a biomarker has to be validated, an issue that is very statistical in nature. The naïve thought that it suffices that a biomarker is strongly correlated to the clinical endpoint is not always true. I will discuss the problem of biomarker validation and in particular how to establish that a biomarker can in fact be used as a surrogate endpoint. There is quite some work done in this area recently but still more can be done.