Proxinium

Proxinium (VB4-847) is a targeted immunotoxin developed by Viventia Biotech for the treatment of late-stage or recurrent squamous cell carcinoma of the head and neck (SCCHN). The drug is a recombinant fusion protein consisting of a humanized single-chain antibody fragment (scFv) that targets the Epithelial Cell Adhesion Molecule (EpCAM), fused to a truncated version of Pseudomonas exotoxin A (ETA). EpCAM is highly expressed on the surface of most head and neck tumor cells but has limited expression in normal tissues. Upon binding to EpCAM, Proxinium is internalized into the cancer cell via receptor-mediated endocytosis. Once inside, the toxin payload is released into the cytosol, where it enzymatically inhibits protein synthesis by ADP-ribosylating elongation factor-2 (EF-2), ultimately leading to apoptosis. Proxinium has received Fast Track and Orphan Drug designations from the FDA and Orphan Drug status from the EMA.

Brand names

Proxinium

Other names

VB4-847VB-4-847VB 4-847