Novel monoclonal antibodies for cancer treatment: the trifunctional antibody catumaxomab (removab)

Abstract

THE TRIFUNCTIONAL ANTIBODY (TRAB) CATUMAXOMAB IS CHARACTERIZED BY A UNIQUE ABILITY TO BIND THREE DIFFERENT CELL TYPES: tumor cells; T-cells; and accessory cells. It binds to epithelial cell adhesion molecule (EpCAM) on tumor cells, the CD3 antigen on T-cells, and to type I, IIa, and III Fcγ receptors (FcγRs) on accessory cells (e.g. natural killer cells, dendritic cells, and macrophages). Catumaxomab exerts its anti-tumor effects via T-cell-mediated lysis, antibody-dependent, cell-mediated cytotoxicity, and phagocytosis via activation of FcγR-positive accessory cells. Catumaxomab represents a self-supporting system, as no additional immune cell activation is required for tumor eradication. The efficacy and safety of catumaxomab have been demonstrated in a pivotal phase II/III study in malignant ascites (MA) and supporting phase I/II studies. It is administered as four intraperitoneal (i.p.) infusions of 10, 20, 50, and 150 µg on days 0, 3, 7, and 10, respectively. Catumaxomab was approved for the i.p. treatment of MA in patients with EpCAM-positive carcinomas where standard therapy is not available or no longer feasible in the European Union in April 2009. It is the first trAb and the first drug in the world approved specifically for the treatment of MA. Catumaxomab was awarded the Galen of Pergamon Prize, which recognizes pharmacological research for developing new and innovative drugs and diagnostics, in the specialist care category in 2010. The use of catumaxomab in other indications and additional routes of administration are currently being investigated to further exploit its therapeutic potential in EpCAM-positive carcinomas.

Keywords: anti-EpCAM × anti-CD3; catumaxomab; epithelial cell adhesion molecule (EpCAM); malignant ascites; targeted cancer immunotherapy; trifunctional antibody.

Figure 1

Catumaxomab mechanism of action. ADCC = antibody-dependent cell-mediated cytotoxicity, CK = cytokine, DC = dendritic cell, EpCAM = epithelial cell adhesion molecule, Fcγ R = Fcγ receptor, GM-CSF = granulocyte-macrophage colony-stimulating factor, IL = interleukin, IFN = interferon, LFA = lymphocyte function-associated antigen, NK = natural killer, TNF = tumor necrosis factor.

Figure 2

Pathophysiology of malignant ascites.

Figure 3

Puncture-free survival in the pooled intent-to-treat population in the pivotal phase II/III study.

Figure 4

Ascites-related symptoms in the pivotal phase II/III study.

Figure 5

Overall survival in HAMA-positive versus HAMA-negative patients* in the pooled population in the pivotal phase II/III study. *Assessed 8 days after last catumaxomab infusion.