Pembrolizumab: The Nut Cracker

Anti-programmed cell death-1 (PD-1)/PD ligand-1 immune checkpoint inhibitors (ICIs) are the newest class of drugs approved for various advanced cancers. Pembrolizumab, an anti-PD1 inhibitor, is approved for treating advanced-stage solid malignancies and refractory lymphomas. Recently, it has been approved as tumor agnostic therapy for microsatellite instability-high advanced-stage disease. In all these studies, pembrolizumab has shown dramatic efficacy with lesser Grade3/4 immune-related adverse events. Contemporarily, immunotherapy paved the way for diagnostic assays and immunotherapy-related response assessment criteria definitions. No published Indian experience with ICIs exists other than isolated case reports. This article aims to review on pembrolizumab mechanism, its indications, and safety. The description of other ICIs is beyond the scope of this review.