This disclosure relates to a monoclonal antibody directed against CD73 or an antigen-binding fragment thereof, and the use of such antibody or antigen-binding fragment thereof in the treatment of tumors. The disclosure also relates to methods for the treatment of tumors comprising administering to a patient in need thereof an anti-CD73 antibody or antigen-binding fragment thereof in combination with a monoclonal antibody directed against programmed death-ligand 1 (PD-L1) also known as B7 homolog 1 (B7-H1), or an antigen-binding fragment thereof. The disclosure also relates to methods for the treatment of tumors comprising administering to a patient in need thereof an anti-CD73 antibody or antigen-binding fragment thereof in combination with a PD-L1 antibody or an antigen-binding fragment thereof and chemotherapy.
