Table 2.

Immune checkpoint inhibitors used in melanoma treatment.

Drug Name	Therapeutic Target and Effect
Ipilimumab	Human monoclonal IgG1 anti-CTLA-4 antibody blocking inhibitory signaling based on CTLA-4 [27].
Nivolumab	Human monoclonal IgG4 anti-PD-1 antibody binding to PD-1, thereby preventing interaction between this receptor and its ligands present in the tumor niche [28].
Pembrolizumab	Fully humanized monoclonal IgG4 antibody directed against PD-1, which prevents it from interacting with PD-L1 [28].
Atezolizumab	Fully humanized monoclonal IgG1 antibody, interfering with the binding of PD-L1 ligand to its receptors, PD-1 and B7.1 [29].

Abbreviations: CTLA-4— cytotoxic T-lymphocyte associated protein 4; PD-1—programmed cell death protein 1; PD-L1—programmed cell death-ligand 1.