Immunotherapy has made a significant impact on the survival of patients with different tumor. However, it has become clear that they are not sufficiently active durable responses for many tumor patients, but only in a fraction of tumor patients. In order to improve this, combination regimens revealed impressive synergistic effects by combination of doublet or triplet immune agents. In this article, we will summarize the cancer-immunity cycle (CIC) and propose a rationale for the design of synergistic antitumor combinations. In addition, key issues in the development of these strategies are further discussed. Overall, we wish to highlight the backbone principles of combination regimens design at different points of the CIC, with the ultimate goal to guide better designs for future cancer combination therapies.
Keywords: Immunotherapy; antitumor immunity; checkpoint inhibitors; chemotherapy; combination; radiotherapy.