Safety data of the completed pivotal phase II/III trial, IP-REM-AC-01, in which catumaxomab was administered as 6 hour i.p. infusion showed that most reported AEs were cytokine release-related symptoms such as fever, nausea, and vomiting (based on the pharmacodynamic mode of action of catumaxomab) and abdominal pain. In order to make the catumaxomab treatment more convenient for the patient and the hospital praxis the current trial was designed to determine whether tolerability of the 3 hour infusion of catumaxomab with and without premedication of prednisolone. Prednisolone was chosen as additional premedication with the objective to reduce cytokine release related symptoms which might change with the switch from 6 to 3 h infusion time.