CytomX Therapeutics (CTMX) Cantor Global Healthcare Conference 2025 summary

Key clinical developments and data

• CX-2051 EpCAM ADC showed a 28% overall response rate in late-line metastatic CRC, with 42% ORR at the highest dose, significantly outperforming current standards.

• Expansion phase enrollment is complete, with over 70 patients across three dose levels; next data update expected in Q1 2026.

• Safety profile includes manageable GI toxicity, with Grade 3 diarrhea in 20% of patients; prophylactic measures like loperamide have been implemented.

• A patient death due to GI toxicity was transparently disclosed and assessed as an outlier, with no changes to enrollment criteria.

• Ongoing dialogue with FDA and safety review committee confirmed trial continuation and alignment with regulatory expectations.

Platform technology and pipeline strategy

• Probody therapeutic platform uses peptide-based masking with protease-cleavable linkers, enabling tumor-specific activation and minimizing off-target effects.

• ADCs are prioritized for their ability to target broadly expressed tumor antigens like EpCAM, but the platform is also applied to T-cell engagers and cytokines.

• T-cell engager programs with partners like Regeneron and Astellas are advancing, showing reduced cytokine release syndrome and EGFR toxicities.

• CX-801, a masked interferon alpha-2b, is in clinical trials for metastatic melanoma, with initial biomarker data expected by year-end and clinical data in 2026.

Forward-looking plans and financial position

• Next steps include selecting optimal dose(s) for registrational studies, with potential for both monotherapy and combination trials in third and fourth-line CRC.

• Regulatory strategy will be data-driven, with PFS likely as the primary endpoint for accelerated approval; studies are expected to be relatively small.

• Fourth-line CRC market in the US is estimated at 12,000 patients annually, with significant revenue potential; expansion to earlier lines and other tumor types is planned.

• Strong cash position of $158 million provides runway into Q2 2027, with ongoing business development and partnership discussions.

• Corporate goal is to become a commercial-stage company, with partnerships considered to support global development and commercialization.