CytomX Therapeutics Inc. is a clinical-stage, oncology-focused biopharmaceutical company developing novel conditionally activated biologics designed to be localized to the tumor microenvironment. The company's proprietary PROBODY® therapeutic platform creates masked molecules that remain inactive in circulation and normal tissues but become activated within tumors, aiming to enhance anti-cancer efficacy while minimizing effects on healthy tissues. CytomX's clinical pipeline includes varsetatug masetecan, a masked antibody-drug conjugate targeting EpCAM for colorectal cancer, and CX-801, an interferon alpha-2b cytokine for melanoma and other oncology indications. The company also develops T-cell engagers and other immune-modulating therapies across multiple treatment modalities. CytomX maintains strategic research collaborations with major biopharmaceutical partners including Amgen, Astellas, Bristol Myers Squibb, Regeneron, and Moderna, focusing on advancing its platform technology across various cancer types. Based in South San Francisco, California, CytomX operates as a clinical-stage developer with a focus on expanding the therapeutic window for targets previously considered difficult to drug due to expression on normal tissues.