A recombinant, chimeric toxin composed of human transforming growth factor alpha (TGF-alpha) fused to a fragment of Pseudomonas exotoxin (PE38) without its cell-binding domain. The TGF-alpha moiety of the agent attaches to tumor cells expressing the epithelial growth factor receptor (EGFR); the exotoxin induces caspase-mediated apoptosis of tumor cells via a mechanism involving mitochondrial damage; it also catalyzes the transfer of ADP ribose from nicotinamide adenine dinucleotide (NAD) to elongation factor-2 in eukaryotic cells, thereby inactivating elongation factor 2 and inhibiting protein synthesis.
