Pembrolizumab for the treatment of nonsmall cell lung cancer: Current status and future directions

The development of inhibitors of immune checkpoints has revolutionized the treatment for a subset of patients with advanced nonsmall cell lung cancer (NSCLC), resulting in promising clinical outcomes and durable responses. Pembrolizumab, a humanized anti-programmed cell death-1 (PD-1) antibody, has been approved as a first-line treatment for patients with advanced NSCLC with PD-L1 expression of >= 50% and as a second-line treatment for PD-L1 expression of >= 1%. Pembrolizumab in combination with standard chemotherapy has shown better clinical outcomes than chemotherapy as a first-line therapy in patients with advanced NSCLC without targetable mutations, regardless of PD-L1 expression. In this review, we summarized the current indications of pembrolizumab for NSCLC, briefly described immune-relevant pneumonitis and discussed potential biomarkers to predict clinical efficacy.