Combination of checkpoint inhibitors with other agents as a strategy to improve anti-cancer effect – a glimpse to the future

In the last years, a remarkable progress has been made in the clinical application of novel immunotherapy agents, the so called 'checkpoint inhibitors,' that has revolutionized the treatment of many malignant tumors. Their design has been based on the immune-mediated mechanisms of antitumor activity circle, such as antigen release and presentation, activation and trafficking of T-cells into tumors, depletion of immunosuppression, and immunogenic cell death. Various combinations of checkpoint inhibitors are being designed and/or tested, such as double checkpoint blockade, combination with chemotherapy, radiotherapy, molecularly targeted agents, and other immune-directed strategies.