ABP-102 (CT P72) is a tetravalent IgG1-[L]-scFv bispecific t-cell adduct (BiTE) that acts as a CD3 modulator and selective HER2 modulator for the selective targeting of HER2 overexpressing tumors. ABP-102 showed cytotoxicity in HER2-overexpressing models of breast and gastric cancers, while significantly decreasing activity against HER2 low level cells, twice as effective as rununmotamab.

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[1]. ABP-102/CT-P72 achieved up to twice the tumor suppression compared to a biosimilar of runimotamab (a benchmark HER2 x CD3 bispecific antibody)[1].By engineering functionally monovalent CD3 binding, ABP-102/CT-P72 significantly reduced cytokine release in HER2-low models while maintaining strong cytotoxicity in HER2-high models[1].

Dose escalation studies in cynomolgus monkeys showed that ABP-102/CT-P72 was well tolerated even at doses over 180 times higher than the maximum tolerated dose of the parental antibody [1].