Drug-biomarker co-development in oncology - 20 years and counting.

Predictive biomarkers for oncology are necessary to accurately identify patients who will benefit from anticancer treatment. Recently approved oncology drugs target discrete molecular aberrations or pathways in tumor cells and consequently are active on a subset of patient population, yet clinical studies have shown that not all biomarker-positive patients respond. The advancement of predictive biomarkers needs to detect novel and evolving drug resistance mechanisms, not only to guide the selection of patient subsets for specific treatments, but to identify new therapeutic targets. Going beyond the "one marker, one drug" model to incorporate genomics, transcriptomics, and receptor status assessments during biomarker-drug co-development can aid in the successful application of molecular marker-based cancer therapy. This review provides the latest update of biomarker-based cancer therapeutics approved by the US Food and Drug Administration. We provide case studies of therapeutics selectively targeting HER2, EGFR, or PD-1/PD-L1 signaling pathways. We also discuss the challenges and promising future directions in the co-development of targeted cancer therapeutics and paired predictive biomarkers.