PDSB · PDS Biotechnology Corporation

This disclosure reports interim clinical results from Stage 1 (N=9) of a non-randomized, open-label, single-center Phase 2 trial evaluating PDS01ADC — a tumor-targeted IL-12 immunocytokine — in combination with hepatic artery infusion pump (HAIP) therapy for MSS/pMMR metastatic colorectal cancer with liver metastases. The trial, led by the NCI under protocol NCT05286814, enrolled patients who had failed at least one prior line of chemotherapy. The reported 77.8% objective response rate (ORR) and ~85% 24-month survival rate represent substantial improvements over comparator data from a parallel trial without PDS01ADC (35% ORR, ~40% 2-year survival), though the filing explicitly notes no head-to-head trials have been performed. These findings are particularly significant because MSS/pMMR mCRC constitutes ~95% of metastatic colorectal cancer cases and has shown consistent resistance to immune checkpoint inhibitors — creating a major unmet medical need. The mechanism of action — using the NHS76 antibody to deliver IL-12 selectively to sites of tumor cell death — appears to enable potent anti-tumor immunity while avoiding the dose-limiting toxicities historically associated with systemic IL-12. Management highlights that these early data support PDS Biotech’s strategy of enhancing HAIP therapy with targeted immunostimulation, and position PDS01ADC as a potential backbone for future combinations, including ongoing evaluation in triple-combination regimens with checkpoint inhibitors. Given the magnitude of the observed clinical signals in a refractory population and the absence of randomized confirmation, investors should view these results as highly promising but preliminary — with definitive validation dependent on completion of the full 22-patient trial and progression to later-stage development.