Opdivo 100 mg injection Opdivo contains nivolumab, a human immunoglobulin G4 (IgG4) monoclonal antibody that binds to the programmed death-1 (PD-1) receptor and blocks its interaction with PD-L1 and PD-L2. Binding of the PD-1 ligands to the PD-1 receptor found on T cells inhibits T-cell proliferation and cytokine production. Upregulation of PD-1 ligands occurs in some tumors, and signaling through this pathway can contribute to inhibition of active T-cell immune surveillance of tumors. Nivolumab blocks PD-1 receptor activity, releasing PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response. Opdivo is indicated for the treatment of various malignancies, including advanced melanoma, non-small cell lung cancer (NSCLC), renal cell carcinoma (RCC), classical Hodgkin lymphoma, squamous cell carcinoma of the head and neck, urothelial carcinoma, MSI-H/dMMR metastatic colorectal cancer, hepatocellular carcinoma, esophageal cancer, and gastric cancer.