IBI-325 is a humanized monoclonal antibody inhibitor targeting CD73. It completely inhibits CD73 enzymatic activity without causing a hook effect. IBI-325 can reverse adenosine monophosphate-mediated immunosuppression and significantly inhibits T cell proliferation and the release of cytokines (IL-2, IFN-γ, and TNF-α). In both hPBMC-reconstituted mouse models and hCD73 knock-in mouse models, IBI-325 demonstrates potent antitumor activity. This compound is applicable for cancer immunotherapy research.