Intraoperative Immunotherapy With The Trifunctional Antibody Catumaxomab In Patients With Ovarian Cancer: Results From A Phase Ii Study

5039 Background: Despite recent improvements in cytoreductive surgery followed by chemotherapy in patients (pts) with advanced ovarian cancer the relapse and mortality rates are still too high. In previous studies with pts suffering from malignant ascites due to ovarian cancer the trifunctional antibody catumaxomab has demonstrated the ability to kill EpCAM-positive tumor cells in the peritoneal cavity and to control the malignant ascites in recurrent ovarian cancer. This study was conducted to investigate the tolerability and feasibility of catumaxomab administered directly into the peritoneal cavity during primary cytoreductive surgery and post-operatively prior to standard chemotherapy with paclitaxel and platinum. Methods: Ovarian cancer pts undergoing radical surgery received one intraoperative (10 μ g) followed by four subsequent intraperitoneal (i.p.) dosages (10, 20, 50 and 150 μ g) of catumaxomab over 3 hours on days 7, 10, 13, and 16, respectively. Analysis of the safety endpoints evaluable after subjects completed 1 month of follow-up are presented. Results: Of the 58 screened pts 41 were evaluable for the safety analysis. All 41 pts experienced at least one treatment-emergent adverse event, for a total of 871 events. Most common adverse events were pyrexia, nausea, abdominal pain, and vomiting due to cytokine release. The complications decreased continuously down to zero up to the fourth and fifth infusion. The observed post-operative complication rate was 51.2% including anastomosis insufficiencies (3 pts), infections (8 pts), and pleural effusions (10 pts). Conclusions: The safety data reflect the mode of action of catumaxomab. We can therefore conclude that the intra-operative treatment approach is feasible but its potential role with regard to postoperative complications especially for anastomosis insufficiencies needs to be further investigated. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Fresenius Biotech GmbH, TRION Pharma GmbH Fresenius Biotech, GlaxoSmithKline TRION Pharma GmbH Fresenius Biotech