CX-2051

CX-2051 is a masked, conditionally activated antibody-drug conjugate (ADC) developed by CytomX Therapeutics. It targets the epithelial cell adhesion molecule (EpCAM), a tumor-associated antigen highly expressed in various epithelial cancers but also present on normal tissues, making it historically challenging to drug safely. The ADC uses CytomX’s Probody technology to mask the antibody and reduce off-tumor toxicity, enabling selective activation in the tumor microenvironment. The payload is a next-generation topoisomerase-1 inhibitor (CAMP59), based on camptothecin chemistry and licensed from AbbVie, designed for potent cytotoxicity against EpCAM-expressing tumors such as colorectal cancer. The linker between the antibody and payload is cleavable to promote bystander killing of neighboring tumor cells. As of 2024–2025, CX-2051 is in Phase 1 clinical trials for advanced solid tumors with high EpCAM expression, particularly metastatic colorectal cancer[1][2][3][4][5][6][7][8].

Other names

conditionally-activated anti-EpCAM antibody-drug conjugate CX-2051