This phase II single arm, open-label study investigate the safety of a second cycle of catumaxomab in patients with malignant ascites due to carcinoma, requiring their first therapeutic puncture after treatment in the CASIMAS study.

Up to 30 evaluable patients from the CASIMAS study will be enrolled. Catumaxomab will be infused intraperitoneally with 3hour constant-rate infusions 4 times within 11 days with ascending dosages (10 - 20 - 50 - 150 µg).

Inclusion Criteria:

• patients who have completed 4 infusions of catumaxomab in the CASIMAS study
• age >= 18 years
• Karnofsky index >= 60 %
• patients with malignant ascites requiring their first therapeutic ascites paracentesis after at least 60days following last catumaxomab infusion in the CASIMAS study
• Patients where standard therapy is either not available or no longer feasible

Exclusion Criteria:

• acute or chronic infection
• concomitant treatment with investigational products other than catumaxomab, cancer, chemo- or radiotherapy
• previous treatment with entirely murine monoclonal antibodies other than catumaxomab
• liver metastases with volume >70 % of liver metastasized tissue