In the past, treatment for malignant
ascites focussed on symptomatic relief or treatment of the underlying disease. A promising option evolved with
catumaxomab (
Removab(®)) in 2009. Since
catumaxomab is a bispecific, trifunctional antibody with mouse-rat origin, so far repeated treatment cycles were not an option due to the occurrence of human anti-
drug antibodies (HADA). Nevertheless, the good results obtained so far raised the question whether a repeated treatment cycle with
catumaxomab could be feasible and effective. We report on a 74-year-old female patient with
breast cancer and
peritoneal carcinomatosis. To our knowledge, this is the first patient world-wide to be treated with a repeated cycle of
catumaxomab. HAMA (human anti-mouse
antibodies) values were identified in blood and
ascites samples.
Ascites samples were also stained to identify and quantify cells, positive for
EpCAM (
epithelial cell adhesion molecule) and CD45. The patient tolerated the second cycle without unexpected side effects and remained
puncture-free for another 45 days. Analysis of blood and
ascites revealed a quick increase in HAMA values in the blood samples after 1 week, but considerably lower HAMA values and delayed increase in the
ascites samples. Also a distinct and continuous decrease of
EpCAM-positive cells was observed in the
ascites samples under treatment. A strong increase in CD45-positive cells was detected after the beginning of the second cycle, with a consecutive decline toward the end. This first experience suggests that a repeated cycle of
catumaxomab might be feasible and effective. As a consequence, a phase II trial (SECIMAS) was initiated.