Detection of soluble EpCAM in malignant ascites to predict overall survival in patients treated with catumaxomab.

e15173 Background: The EpCAM-specific antibody catumaxomab has been approved for intraperitoneal treatment of patients suffering from malignant ascites. New prognostic markers are necessary to select patients that mostly benefit from catumaxomab. This exploratory retrospective analysis was performed on ascites samples to evaluate the predictive role of soluble EpCAM (sEpCAM) in catumaxomab-treated patients. Methods: Sixty-six patients with an available archived ascites sample were included in this study and tested for sEpCAM by an in-house developed and validated ELISA. All probes were sampled before the start of treatment and all patients received at least one catumaxomab infusion. Overall survival and puncture-free survival were compared between sEpCAM-positive and -negative patients. Antibody-dependent cell-mediated cytotoxicity assay (ADCC) was performed to investigate the interaction between sEpCAM and catumaxomab. Results: The ELISA showed a high specificity, accuracy and reproducibility for sEpCAM ...