An antibody-drug conjugate (ADC) composed of an immunoglobulin G1 (IgG1) monoclonal antibody directed against the tumor-associated antigen (TAA) trophoblast cell surface protein 2 (trophoblast antigen 2; calcium signal transducer 2; TROP2; TROP-2; TACSTD2; GA733-1; M1S1) conjugated, via a cleavable linker, to the exatecan derivative and topoisomerase-1 inhibitor SHR9265, with potential antineoplastic activity. Upon intravenous administration, the monoclonal antibody moiety of anti-TROP-2 ADC SHR-A1921 targets and binds to TROP-2 expressed on tumor cells. Upon binding, internalization and linker cleavage, SHR9265 is released and inhibits DNA topoisomerase I activity, thereby inhibiting DNA replication and resulting in cell cycle arrest and apoptosis in tumor cells expressing TROP-2. TROP-2 is a transmembrane protein overexpressed in various tumors. Its expression is associated with enhanced tumor aggressiveness, metastasis, drug resistance and increased tumor cell survival.