A phase I study of the bispecific antibody T-cell engager GBR 1302 in subjects with HER2-positive cancers.

TPS3091 Background: GBR 1302, a bispecific antibody based on Glenmark’s BEAT platform, is designed to recruit cytotoxic T-cells (independent of their specificity) to HER2-positive cancer cells where they are activated by the CD3e-specific domain of the molecule. Preclinically, GBR 1302 has demonstrated potent killing of HER2-positive human cancer cells (HER2 3+ or 2+ by IHC HercepTest), as well as growth suppression of the trastuzumab-resistant cell line JIMT-1. In contrast, the GBR 1302 concentration required to kill primary cardiomyocytes with normal HER2 levels was up to 1000 times greater than the concentration needed to kill HER2 3+ tumor cell lines. This study will determine safety a…