Abstract: Provided is an isolated antigen-binding protein, which contains a first binding domain and a second binding domain, wherein the first binding domain is capable of binding to a CD39 protein, and the second binding domain is capable of binding to a CD73 protein. Also provided are a nucleic acid molecule encoding the isolated antigen-binding protein, a vector and a cell containing the nucleic acid molecule, a pharmaceutical composition containing the isolated antigen-binding protein, a method for preparing the isolated antigen-binding protein, and the use of the isolated antigen-binding protein.

Abstract: A PD-L1 antigen binding protein and an application thereof. The antigen binding protein has one or more of the following properties: binding to a PD-L1 protein at an EC50 value of 0.07 ?g/ml or above; blocking binding between the PD-L1 protein and a PD-1 protein; promoting the activation of a T cell; and inhibiting the volume increase of the in vivo tumor. An application of the antigen binding protein in the preparation of a drug for treating tumor.

Abstract: Provided in the present application is a multispecific antibody, which includes a first targeting moiety capable of specifically binding to the TIGIT protein and a second targeting moiety capable of binding to a tumor-associated antigen, and the multispecific antibody can be used to treat a tumor. Further provided in the present application is the use of the multispecific antibody as a drug.