First surgical experience of intraperitoneal treatment with the trifunctional antibody catumaxomab (anti-EpCam x anti-CD3) for epithelial ovarian cancer.

Aim: Intraperitoneal (i.p.) treatment with the trifunctional antibody catumaxomab is a novel promising option in the clinical management of advanced or recurrent epithelial ovarian cancer (EOC). As yet, no data exists sregarding the surgical experience after i.p. catumaxomab application. Therefore we analyzed the surgical outcome of EOC patients, previously treated with i.p. catumaxomab, with special focus on the effect on adhesion formation and morbidity.
Patients and Methods: We conducted a retrospective evaluation of patients with EOC, who were previously treated with catumaxomab, either at time of primary cytoreduction (n=6) or due to malignant ascites in the recurrent situation (n=4), and who underwent surgery due to various indications between 01/2007 and 03/2010. Surgical outcome, grade of adhesions and operative morbidity were analyzed based on surgical reports and a validated intraoperative documentation tool 'Intraoperative Mappinf of Ovarian Cancer'.
Results: Ten patients with EOC (FIGO stage III-IV; median age 68 years; range: 45-77 years) were evaluated. The mean time between catumaxomab treatment and surgery was 187 days (range: 8-481 days). Mean operation-time was 185 minutes (range:69-32). The indications for surgery were as follows: 3 patients due to anastomotic insufficiency after primary tumor debulking; 2 patients due to secondary tumor debulking; 4 patients due to ileus in recurrent EOC; and 2 patients for restoring intestinal continuity. At the post-catumaxomab surgery 7 patients presented massive intraoperative adhesion grade 3 (score system 0-3), while 3 patients developed repeated abscesses. Four out of the six patients operated due to recurrent EOC, presented extensive tumor load with severe peritoneal carcinosis. Nevertheless, none of the relapsed patients had at surgery ascites >500 ml.
Conclusion: Surgery after i.p. catumaxomab appears feasible, however, larger prospective evaluations are warranted to assess its true impact on adhesion formation and postoperative morbidity.