Abstract:  In recent years, immune checkpoint inhibitors (ICIs) have been approved for the treatment of various malignant tumors. However, the objective response rate of ICIs monotherapy is relatively low (only 10% to 20% in specific populations). Improving clinical benefit in patients receiving ICIs has always been the focus of immune-related clinical research. Recent studies have demonstrated that combining ICIs of different mechanisms might increase the response rates as well as prolong the duration of response. And using appropriate dosage regimens could reasonably balance efficacy and safety of ICIs. We aimed to summarize the mechanism, pharmacokinetics, and efficacy and safety results from clinical trials for combination therapy with ICIs.

Key words: Immunotherapy, Programmed death-1, Cytotoxic T-lymphocyte-associated protein 4, Melanoma, Gastrointestinal neoplasms, Lung neoplasms