anti-TfR-PE immunotoxin

This experimental immunotoxin, developed at the National Cancer Institute (NCI) in the 1980s, is a first-generation antibody-drug conjugate (ADC) consisting of a monoclonal antibody (typically HB21) targeting the human transferrin receptor (TfR) chemically conjugated to Pseudomonas exotoxin (PE). The transferrin receptor is frequently overexpressed on the surface of rapidly dividing cancer cells, such as ovarian carcinoma, to meet increased iron requirements. Upon binding to the receptor, the immunotoxin is internalized via receptor-mediated endocytosis. Once inside the cell, the Pseudomonas exotoxin component is translocated to the cytosol, where it catalyzes the ADP-ribosylation and subsequent inactivation of elongation factor 2 (EF-2). This action halts protein synthesis, leading to cell death via apoptosis. This agent was evaluated in vitro and in preclinical models by researchers including Ira Pastan and David FitzGerald, serving as a precursor to later recombinant single-chain immunotoxin constructs like anti-TFR(Fv)-PE40.

Other names

anti-transferrin receptor-Pseudomonas exotoxin immunotoxinanti-TFR-PEanti-transferrin receptor-Pseudomonas exotoxin conjugate