The Anti-CTLA-4 / CD152 Reference Antibody (nurulimab) is a recombinant monoclonal antibody serving as a reference standard that mimics the investigational therapeutic nurulimab. Nurulimab targets CTLA-4 (cytotoxic T-lymphocyte-associated protein 4), a key immune checkpoint receptor. By blocking CTLA-4, nurulimab enhances T-cell activation and promotes anti-tumor immune responses. It is primarily developed for cancer immunotherapy, particularly in solid tumors where immune evasion plays a critical role. The antibody is being studied in clinical trials either as monotherapy or in combination with other immune checkpoint inhibitors, such as anti-PD-1/PD-L1 antibodies, to improve response rates in cancers like melanoma, non-small cell lung cancer, and renal cell carcinoma. Its mechanism supports sustained immune surveillance against tumor cells, making it a potential option for patients who do not respond to existing immunotherapies.