Definition

An antibody-drug conjugate (ADC) composed of an antibody directed against the immunosuppressive ligand programmed cell death-1 ligand 1 (PD-L1; cluster of differentiation 274; CD274), conjugated to the cytotoxic agent monomethyl auristatin E (MMAE) via a protease-cleavable peptide linker, with potential antineoplastic activity. Upon administration of the anti-PD-L1 ADC SGN-PDL1V, the anti-PD-L1 antibody specifically targets and binds to PD-L1 expressed on tumor cells. Following internalization, enzymatic cleavage and release of MMAE, MMAE targets and binds to tubulin, and inhibits microtubule polymerization. This results in G2/M phase cell cycle arrest and apoptosis in PD-L1-expressing tumor cells. PD-L1, a transmembrane protein, is expressed on the surface of certain immune cells and on many cancer cell types. PD-L1 binding to PD-1, a negative regulator of the immune system on activated T cells, limits the expansion and survival of CD8-positive T cells, suppresses the immune system and results in immune evasion.