0000000000352503
AUTHOR
Christopher Stroh
Clinical outcome according to tumor HER2 status and EGFR expression in advanced gastric cancer patients from the EXPAND study.
4021 Background: In the EXPAND study adding cetuximab to first-line capecitabine and cisplatin chemotherapy (CT) failed to improve clinical outcome in patients (pts) with advanced gastric or gastroesophageal junction cancer. This analysis assessed treatment outcome according to tumor HER2 status (a pre-defined subgroup) and EGFR expression in EXPAND study pts. Methods: Tumor HER2 status was determined primarily by immunohistochemistry (IHC), HER2 +ve tumors were IHC 3+ or IHC 2+ and fluorescence in situ hybridization (FISH) +ve. EGFR expression was assessed by IHC. A continuous scoring system (scale of 0–300) was used to determine the level of EGFR expression. Biomarker status was correlat…
IgG1 anti-epidermal growth factor receptor antibodies induce CD8-dependent antitumor activity
Anti-EGFR monoclonal antibodies (mAb) like Cetuximab are commonly used for treatment of EGFR+ solid tumors mainly by exerting their therapeutic effect through inhibition of signal transduction. Additionally, IgG1 is a potent mediator of antibody-dependent cytotoxicity (ADCC). In case of the IgG1, Cetuximab induction of ADCC in vivo is controversially discussed. In our study, we investigated the efficiency of Cetuximab-mediated ADCC in a humanized mouse tumor model in vivo and analyzed the contribution of immunologic processes toward antitumor activity. Therefore, we used immunodeficient NOD/Scid mice transgenic for human MHC class I molecule HLA-A2 and adoptively transferred human HLA-A2+ P…