Alpha-radioimmunotherapy with At211-trastuzumab against peritoneal metastasis of HER2-overexpressing gastric cancer.Alpha-radioimmunotherapy with At211-trastuzumab against peritoneal metastasis of HER2-overexpressing gastric cancer.
Peritoneal metastasis of gastric cancer (PMGC) has extremely poor prognosis, however, there is no effective therapeutics has been established. Trastuzumab, a humanized anti-HER2 monoclonal antibody, has been used for the treatment for HER2-overexpressed (HER2+) GC since about 20% of GC is reported as HER2+. Radioimmunotherapy (RIT), the internal radiotherapy using antibody as the carrier to deliver radioisotope (RI) to cancer specifically, has huge advantage in targeting metastatic cancer. Recently, alpha-RIT, using alpha emitting RI, is getting higher attention, because the high cell cytotoxicity and short range of alpha particle can prevent damages to untargeted tissues with effective cell killing effect. Astatine 211 (At211) is one of the useful alpha-RI.In this study, we investigated the cell cytotoxicity and therapeutic efficacy of RIT with At211-trastuzumab against HER2+ PMGC both in vitro and in a preclinical mouse model. We will discuss the possibility of alpha-RIT with At211-trastuzumab as a new effective therapeutic for HER2+ PMGC. International Symposium on Immune Diversity and Cancer Therapy Kobe 2017