Eve M Segal, PharmD, BCOP

The frontline treatment paradigm for patients with advanced or metastatic non−small cell lung cancer (NSCLC) has changed dramatically in the past decade amid efforts to tackle this leading cause of cancer-related mortality. Immune checkpoint inhibitors (ICIs) targeting the programmed cell death protein 1 (PD-1) receptor and its ligand PD-L1 are an important therapeutic option for patients whose tumors lack genetic alterations that dictate response to molecularly targeted therapies. With a growing number of FDA-approved ICI monotherapy and combination therapy options for first-line therapy, the use of biomarkers such as PD-L1 expression has become increasingly important in guiding therapeutic decision making. Presently, PD-L1 expression remains a key biomarker in this setting, in spite of its limitations. This article will evaluate the current and evolving clinical trends in the use of ICIs in the frontline management of metastatic NSCLC, as well as the challenges associated with PD-L1 expression analysis and biomarker implementation.