CytomX Therapeutics doses first patient in CX-2051 Phase 1 study

CytomX Therapeutics announced the first patient has been dosed in a Phase 1 dose escalation study of CX-2051 in patients with advanced solid tumors. CX-2051 is a masked PROBODY antibody drug conjugate directed toward epithelial cell adhesion molecule, a cell-surface target that is highly expressed across many cancer types including colorectal, gastric, endometrial, and ovarian cancers. The cytotoxic payload utilized in CX-2051 is a derivative of camptothecin, a topoisomerase-1 inhibitor, a class of drug that has shown potent clinical anti-cancer activity and demonstrated significant clinical benefit as an approved ADC in multiple cancers. The CX-2051 Phase 1 dose escalation is designed to efficiently test the safety and preliminary anti-tumor activity of CX-2051, to provide initial clinical proof of concept to inform a potential decision to move into dose expansions in 2025.