[Current landscape of biomarker development for immune checkpoint inhibitors targeting PD-1/PD-L1 pathway in...

The immune checkpoints inhibitors targeting PD-1 or PD-L1 represent a new paradigm in the cancer treatment strategy. However, some populations of patients do not benefit from these agents. The identification of predictive biomarkers appears as an essential step for the treatment pathway, to guarantee the access to an evidence-based medicine accounting for the potential toxicity profile, the cost for the healthcare system and the clinical benefit eventually provided by these new drugs. In this review, we propose, based on scientific literature and industrial communications, an overview of the current landscape of predictive biomarkers related to PD-1 or PD-L1 inhibitors efficacy, validated or under development, their evidence level, and limits accounting for identified or potential confounding factors. Our paper shows that, despite the important amount of work performed in this field, there is not yet a validated and efficient solution for the prediction of the activity and/or the toxicity of anti-PD-1 and anti-PD-L1 antibodies.