Dual-Target HER2/CEA CAR-NK Cells in Advanced Biliary Tract Cancer

Overview

This example phase 1/2, open-label, biomarker-selected study evaluates EB-HC01, an allogeneic dual-target CARNK product composed of a 1:1 mixture of HER2-CAR-NK and CEACAM5-CAR-NK cells, in adults with unresectable or metastatic cholangiocarcinoma or other biliary tract cancers after standard therapy. Part A determines safety, dose-limiting toxicities (DLTs), and the recommended phase 2 dose (RP2D) after reduced-intensity lymphodepletion. Part B evaluates preliminary anti-tumor activity, CAR-NK persistence, and biomarker-response associations.

Biliary tract cancers remain highly lethal after progression on gemcitabine/platinum-based therapy, and only a biomarker-defined minority have actionable cell-surface targets. HER2 has the strongest clinical validation among the antigens under consideration, including active HER2-targeted drug development and prior HER2 CAR-T experience in advanced BTC. CEACAM5 is retained as a complementary second target because it may reduce antigen escape and improve coverage of heterogeneous disease; however, it is treated conservatively because prior CEA-directed cell therapy has shown gastrointestinal and pulmonary toxicity in other solid tumors. EpCAM is not used for enrollment in this example because physiologic expression in the biliary tree may narrow the safety window for a first systemic study. EB-HC01 is designed as an off-the-shelf cord bloodderived NK-cell product manufactured as a fixed 1:1 mixture of HER2-CAR-NK and CEACAM5-CAR-NK cells. After fludarabine/cyclophosphamide lymphodepletion, participants receive intravenous EB-HC01 on Days 0 and 7 of a 28-day cycle. In Part A, a standard 3+3 doseescalation design evaluates 3 flat-dose levels to identify the RP2D. In Part B, an expansion cohort at RP2D better defines safety and preliminary activity in biomarkerconfirmed dual-positive BTC. Key correlative studies include central HER2 and CEACAM5 testing, ctDNA analysis, serum CA19-9 and CEA,and serial blood assessments of CAR-NK persistence and cytokine kinetics. EpCAM testing is retained as an exploratory biomarker to inform future protocol amendments but is not used to determine eligibility.