Catumaxomab: A Comprehensive Dossier on a Pioneering Trifunctional Antibody for Malignant Ascites

Executive Summary

Catumaxomab is a first-in-class, rat-mouse hybrid, trifunctional bispecific antibody that represents a significant milestone in the field of cancer immunotherapy. This report provides an exhaustive analysis of its molecular characteristics, unique mechanism of action, clinical development, and complex commercial lifecycle. The active substance, Catumaxomab, has been marketed under the brand names Removab® and, more recently, Korjuny®.

The antibody’s innovative design enables it to simultaneously bind three distinct cellular targets: the Epithelial Cell Adhesion Molecule (EpCAM) on tumor cells, the CD3 antigen on T-cells, and activating Fc-gamma (Fcγ) receptors on accessory immune cells such as macrophages and natural killer cells. This unique trifunctionality orchestrates a potent, multi-pronged anti-tumor attack within the local microenvironment, leading to highly effective tumor cell destruction through T-cell-mediated lysis, antibody-dependent cell-mediated cytotoxicity (ADCC), and phagocytosis.

Clinically, Catumaxomab has demonstrated profound and statistically significant efficacy in the intraperitoneal treatment of malignant ascites, a debilitating condition with high unmet medical need. In a pivotal Phase II/III clinical trial, Catumaxomab therapy resulted in a four-fold increase in puncture-free survival compared to standard paracentesis alone, establishing a clear clinical benefit in a palliative care setting.