Immune checkpoint inhibitors in metastatic NSCLC: challenges and future directions

The treatment metastatic non-small cell lung cancer (NSCLC) is largely influenced by the incorporation of immune checkpoint inhibitors (ICI) in the frontline setting. There are several ICI approved for the management of NSCLC based on the PD-L1 expression of the tumors. PD-L1 is a controversial biomarker with various inconsistencies in expression owing to temporal and spatial heterogeneity. Tumor mutational burden is another much studied biomarker associated with its own challenges and questionable concordance with tumor PD-L1 expression. In this article, we aim to discuss the challenges associated with the existing biomarkers, highlighting the need for emerging biomarkers that can help with decision making in the management of this there where several therapeutic options exist. There are emerging “me too” PD-1/PD-L1 drugs which may serve its purpose in many counties where there is limited access to current approved ICIs. What is increasingly apparent is the need to move the needle forward in the treatment of NSCLC and we will discuss the challenges associated with the current therapeutic landscape and the emerging checkpoints and the future directions that are being explored in the management of metastatic NSCLC.