SOUTH SAN FRANCISCO, CA, USA I April 08, 2024 I CytomX Therapeutics, Inc. (Nasdaq: CTMX), a leader in the field of conditionally activated, localized biologics, today announced the first patient has been dosed in a Phase 1 dose escalation study (NCT06265688) of CX-2051 in patients with advanced solid tumors. CX-2051 is a masked PROBODY® antibody drug conjugate (ADC) directed toward epithelial cell adhesion molecule (EpCAM), 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.

“EpCAM is a high potential ADC target present at high levels on many solid cancers. CX-2051 has been optimized using our tailored masking strategies and possesses a potent cytotoxic payload ideally suited to specific EpCAM positive tumor types, including colorectal cancer. The successful initiation of the Phase 1 dose escalation study for CX-2051 is an important clinical milestone for CytomX as we continue to advance our multi-modality PROBODY therapeutic pipeline to address areas of significant unmet medical need,” said Wayne Chu, M.D., chief medical officer of CytomX Therapeutics.

About CytomX Therapeutics
CytomX is a clinical-stage, oncology-focused biopharmaceutical company focused on developing novel conditionally activated biologics designed to be localized to the tumor microenvironment. By pioneering a novel pipeline of localized biologics, powered by its PROBODY® therapeutic platform, CytomX’s vision is to create safer, more effective therapies for the treatment of cancer. CytomX’s robust and differentiated pipeline comprises therapeutic candidates across multiple treatment modalities including antibody-drug conjugates (“ADCs”), T-cell engagers, and immune modulators such as cytokines. CytomX’s clinical-stage pipeline includes CX-904, CX-2051 and CX-801. CX-904 is a conditionally activated T-cell-engaging bispecific antibody targeting the epidermal growth factor receptor (EGFR) on tumor cells and the CD3 receptor on T cells. CX-904 is partnered with Amgen in a global co-development alliance. CX-2051 is a conditionally activated ADC directed toward epithelial cell adhesion molecule, EpCAM, with potential applicability across multiple EpCAM-expressing epithelial cancers. CX-2051 was discovered in collaboration with Immunogen, now part of AbbVie. CX-801 is an interferon alpha-2b PROBODY® cytokine with broad potential applicability in traditionally immuno-oncology sensitive as well as insensitive (cold) tumors. CytomX has established strategic collaborations with multiple leaders in oncology, including Amgen, Astellas, Bristol Myers Squibb, Regeneron and Moderna. For more information about CytomX and how it is working to make conditionally activated treatments the new standard-of-care in the fight against cancer, visit and follow us on LinkedIn and X (formerly Twitter).

SOURCE: CytomX Therapeutics