PD-1 BLOCKADE IN CANCER IMMUNOTHERAPY

There is increasing evidence demonstrating the important role that the programmed cell death protein 1/programmed cell death 1 ligand 1 (PD-1/PD-L1) pathway plays in mediating tolerance in the setting of malignancy. Exciting results from clinical studies demonstrating durable clinical responses following treatment with PD-1 and PD-L1 blocking antibodies in patients with refractory malignancies has heightened interest in immunotherapy and in immune checkpoint blockade. Future directions will focus on identifying biomarkers that predict response to therapy, and on evaluating PD-1 blockade in combination with blockade of cytotoxic T-lymphocyte protein 4 (CTLA-4), tumor vaccines and chemotherapy.