Abpro Holdings, Inc. and Celltrion unveiled preclinical data for ABP-102/CT-P72 in an oral presentation at the American Association for Cancer Research® (AACR) Annual Meeting 2025, in the New Drugs on the Horizon session. ABP-102/CT-P72, a tetravalent bispecific HER2 x CD3 T-cell engager co-developed with Celltrion, is engineered to selectively target HER2-overexpressing tumors while reducing the risk of on-target, off-tumor toxicity in normal tissues. Preclinical findings presented at AACR suggest the potential of ABP-102/CT-P72 to surpass existing HER2-targeted therapies in both efficacy and safety.
Key Findings: Highly Selective Tumor Killing: ABP-102/CT-P72 achieves potent cytotoxicity in HER2-overexpressing breast and gastric cancer models while significantly reducing activity against HER2-low cells, addressing a key limitation of prior HER2-targeted T-cell engagers. Enhanced Tumor Growth Inhibition: In vivo studies showed ABP-102/CT-P72 had up to a two-fold increase in tumor suppression compared to a biosimilar of runimotamab, a benchmark HER2 x CD3 bispecific antibody. Reduced Cytokine Release: Engineered for functionally monovalent CD3 binding, ABP-102/CT-P72 minimizes cytokine-related toxicities, as demonstrated by reduced cytokine release in HER2-low cell models while maintaining potent cytotoxicity in HER2-high models.
Improved Tolerability: Dose escalation studies in cynomolgus monkeys confirmed that ABP-102/CT-P72 was well tolerated, even at doses exceeding 180 times the maximum tolerated dose observed with the parental antibody, suggesting a broader therapeutic window. The combination of HER2-selective T-cell activation, reduced cytokine release in HER2-low environments, and high tolerability in non-human primates underscores how ABP-102/CT-P72?s functionally monovalent CD3 binding strategy successfully mitigates on-target off-tumor toxicity. These attributes position ABP-102/CT-P72 as a potentially safer alternative to previous HER2-targeting T-cell engagers, paving the way for a broader therapeutic window in clinical trials, which are planned to start in the first half of 2026.
