An antibody-drug conjugate (ADC) composed of a Fc-silenced, humanized immunoglobulin G1 (IgG1) monoclonal antibody targeting folate receptor alpha (FRa; FolRa; FOLR1) linked, via a dipeptide cleavable linker and a polysarcosine hydrophobicity masking agent, to the camptothecin analog and topoisomerase 1 inhibitor exatecan, with potential antineoplastic activity. Upon administration of anti-FRalpha/exatecan ADC LY4170156, the antibody moiety targets and binds to FRa expressed on tumor cells. Upon binding, cellular uptake and linker cleavage, exatecan is released. Exatecan inhibits DNA topoisomerase I activity, thereby inhibiting DNA replication and generating DNA single- and double-strand breaks. This leads to cell cycle arrest and tumor cell apoptosis. In addition, exatecan is able to induce a bystander effect on neighboring cells in the tumor environment. This inhibits the proliferation of FRa-expressing tumor cells. FRa is a glycosylphosphatidylinositol linked cell-surface glycoprotein that is widely expressed in certain cancers while its expression is limited in normal tissues.