Commentary: PD-L1 Expression as a Predictive Biomarker: Is Absence of Proof the Same as Proof of Absence?

JAMA Network - full text

.... Identifying the subset of patients who are most likely to respond to anti–PD-L1 therapy is the first step toward individualized therapy. As a biomarker, however, PD-L1 immunohistochemistry offers poor sensitivity and reproducibility, and as a result, these patients may be unfairly excluded from clinical trials. To offer this potentially life-saving personalized immune-based therapy to as many patients as possible, we need to develop a multifaceted predictive biomarker system that integrates checkpoint inhibitors such as PD-L1, tumor mutations, and inflammatory cells.