Catumaxomab: malignant ascites: unjustified marketing authorisation.
The only treatment for malignant ascites in patients with refractory cancer is paracentesis, a procedure to relieve symptoms. Catumaxomab, a monoclonal antibody, is now authorised in the European Union for intraperitoneal administration to patients with epithelial cancers that overexpress epithelial cellular adhesion molecule (EpCAM) and provoke ascites unresponsive to chemotherapy. Clinical evaluation of catumaxomab in this setting is based on a comparative, randomised but unblinded trial including 258 patients. Patients in the catumaxomab group had four paracenteses over a 10-day period, followed by a 6-hour intraperitoneal catumaxomab infusion, while patients in the control group had a single paracentesis. Catumaxomab did not extend median survival time, which was about two months. Methodological biases rule out any conclusions as to whether catumaxomab reduced the number of paracenteses needed during this short survival period. In this trial, 80% of patients treated with catumaxomab experienced serious adverse events, versus 29% of controls, resulting in hospitalisation in respectively about 29% versus 16% of patients. Two-thirds of patients had reactions linked to intraperitoneal catumaxomab infusion. Gastrointestinal disorders were frequent, and included abdominal pain, nausea and vomiting. Catumaxomab is hepatotoxic. In addition, most patients develop anti-catumaxomab antibodies, although the clinical consequences are unclear. Catumaxomab therapy is inconvenient: it lasts 10 days and requires 4 intraperitoneal infusions that last 6 hours each and require 24-hour monitoring. In practice, catumaxomab has more harms than benefits. It is better to focus on individually tailored palliative care for these terminally ill patients.