Sacituzumab govitecan

Sacituzumab govitecan is an antibody-drug conjugate (ADC) targeting TROP-2-expressing cancer cells to induce DNA-damage-mediated cell death. The conjugate comprises a humanized anti-TROP-2 monoclonal antibody (RS7-3G11, also known as RS7) chemically linked by a hydrolyzable CL2A linker to the cytotoxic drug SN-38.

The proposed mechanism of action first involves the binding of the RS7 component to TROP-2, which is highly expressed on the cell surface of multiple cancers. Binding of RS7 to TROP-2 results in rapid internalization of bound antibody, and the likely intracellular release of SN-38 via hydrolysis of the CL2A linker. SN-38 is an active metabolite of the anti-cancer drug irinotecan, which is thought to work primarily through inhibition of DNA topoisomerase I, leading to DNA damage and eventual cell death. In addition, recent work has identified a possible secondary mechanism of action for SN-38 by disrupting the binding of Far Upstream Binding Protein 1 (FUBP1) to the FUSE elements regulating oncogene expression.

In addition to SN-38-mediated cell death, there is also some evidence that the RS7 component of the conjugate drug possesses antibody-directed cellular toxicity.