Treatment Of Ovarian Cancer Patients With Malignant Ascites Using The Trifunctional Antibody Catumaxomab: Results Of A Phase Ii/Iii Study

5520 Background: Malignant ascites in ovarian carcinoma patients (pts.) is associated with a poor prognosis and reduced quality of life. Catumaxomab (anti-EpCAM × anti-CD3) is known to effectively eliminate tumor cells within ascites by simultaneously activating T cells and Fc gamma-receptor positive cells and redirecting them against the tumor. Methods: A total of 129 ovarian cancer pts. with recurrent symptomatic malignant ascites containing EpCAM+ tumor cells were enrolled in the study; 85 were randomized to treatment with catumaxomab (paracentesis plus intraperitoneal infusions of 10, 20, 50 and 150 μg for 11 days), and 44 to the control arm (paracentesis alone). The primary endpoint was puncture free survival (time to first need for paracentesis after treatment or time to death, which ever occurred first). Results: Pts. characteristics were well balanced in both arms. Median puncture free survival was 52 days for catumaxomab vs. 11 days for control (p<0.0001) whereas the median time to first need for paracentesis was 71 days vs. 11 days l (p<0.0001). There was a pronounced decrease of tumor cell load accompanied by a distinct increase of leukocyte count during catumaxomab treatment within the ascites fluid. Overall and progression free survival data suggest longer survival for catumaxomab-treated pts. compared to control. Follow-up data will be presented. The most frequent AEs were symptoms related to cytokine release (pyrexia, nausea, vomiting). These were generally mild to moderate in intensity, and fully reversible. Transient increases in liver enzymes and bilirubin, and transient WBC abnormalities such as leukocytosis, neutrophilia and a decrease in peripheral lymphocyte were regularly observed as abnormal laboratory values but rarely considered clinically significant. Conclusions: Intraperitoneal therapy with catumaxomab resulted in a significant and clinically relevant improvement of puncture-free survival time, tumor cell load, and time to first need for puncture compared to the control group of best available treatment. The safety profile reflects catumaxomabs mode of action and reveals a low and acceptable toxicity. No significant financial relationships to disclose.