Tremelimumab is a fully humanized IgG2 anti-CTLA-4 (Cytotoxic T-Lymphocyte Antigen-4) monoclonal antibody with indirect antitumor activity. The monoclonal antibody is an immunotherapeutic agent approved in tumor diseases that targets the CTLA-4 antigen, which plays a central role in regulating the body's immune response. Tremelimumab blocks the immunoinhibitory interaction between CTLA-4 and its ligands(CD80/CD86), which is associated with increased activation and proliferation of T cells (immune checkpoint blockade). Ipilimumab thus enhances the body's own T-cell-mediated immune response and may act indirectly against immunogenic tumors. Tremelimumab has been tested in several human trials for the treatment of different types of cancer(melanoma, mesothelioma; non-small cell lung cancer), but has not received approval for any.