MULTICENTER, OPEN-LABEL PHASE II STUDY TO EVALUATE THE EFFICACY OF A 2-CYCLE IMMUNOTHERAPY WITH THE TRI FUNCTIONAL BISPECIFIC ANTIBODY CATUMAXOMAB (ANTI EPCAM X ANTI-CD3) IN ADDITION TO SYSTEMIC CHEMOTHERAPY IN PATIENTS WITH PERITONEAL CARCINOMATOSIS FROM GASTRIC OR COLORECTAL ADENOCARCINOMA

Primary objectives: • Decrease of the incidence of clinically significant malignant ascites (defined by one paracentesis of > 1500 ml or a cumulative amount of 1500 ml by multiple paracentesis within 10 days) from 40% (estimated value from the literature) to 15% within 9 months after first catumaxomab therapy. The event will be counted on the day of 2nd paracentesis
• Decrease of the incidence of intestinal obstruction with the indication of surgery or parenteral nutrition (> 14 days, > 70% of calorie intake) from to 40% (estimated value from literature and local database) to 20 % within 9 months after first Catumaxomab therapy
• Decrease of the incidence of ECOG deterioration from ECOG 1 or 2 to ECOG 3 in within 9 months after first Catumaxomab therapy
• decrease of the incidence of death from 60 % to 35% within 9 months after first Catumaxomab therapy
Primary endpoints: Symptom- and progression free survival, defined by the primary end-points:
• Incidence of clinically significant malignant ascites (defined by one paracentesis of > 1500 ml or a cumulative amount of 1500 ml by multiple paracentesises within 10 days)• Incidence of intestinal obstruction with the need of surgical in-tervention or parenteral nutrition (>14 days, > 70% of calorie intake)• Increase from ECOG 1 or 2 to ECOG 3• Death
Each parameter will be analyzed separately with reference to previous patient data. The first day of cumulative ascites paracentesis or intestinal obstruction and parenteral nutrition will be assessed.