CytomX Therapeutics (CTMX) investor relations material

Key technology and platform insights

• Pioneered the Probody therapeutic platform, a masking strategy to improve the therapeutic window for antibody modalities in oncology, including ADCs, T-cell engagers, and cytokines.

• Masking technology enables selective activation of therapeutics in tumor tissue, reducing off-target effects in normal tissues.

• The EpCAM ADC (CX-2051) leverages a high-affinity antibody, a topo I inhibitor payload (CAMP59), and a cleavable peptide linker optimized for bystander effect.

• Learnings from previous clinical programs informed the optimized design and clinical strategy for 2051.

Clinical data and program progress

• Phase one data for CX-2051 in late-line colorectal cancer (CRC) showed a 28% confirmed response rate and 5.8 months progression-free survival, outperforming standard of care.

• Disease control rate reached 94% with a favorable safety profile and low hematologic toxicity.

• Enrollment expanded from 70 to an anticipated 100 patients for further data robustness, with next data disclosure expected in Q1 2026.

• Activity observed across diverse patient subgroups, suggesting pan-CRC potential and broad market opportunity.

• Plans to move from late-line to earlier-line CRC therapy, with vision to potentially replace irinotecan.

Differentiation and future strategy

• Differentiation driven by target selection, validated abundance of EpCAM, and focused clinical design enrolling only CRC patients.

• Masking technology enables systemic dosing of EpCAM-targeted ADCs, overcoming historical toxicity barriers.

• Prophylactic loperamide introduced to manage grade 3 diarrhea, with ongoing evaluation of mitigation strategies.

• Robust phase one data package intended to support FDA discussions for a registrational path in 2026.

• Strong financial position with nearly $150 million in cash, funding operations into Q2 2027, and ongoing business development activities.