L49-Fab'-bL

**L49-Fab'-bL** is an experimental, chemically assembled antibody-enzyme conjugate developed for antibody-directed enzyme prodrug therapy. It comprises the Fab' fragment of the L49 monoclonal antibody, which recognizes the tumor-associated p97 antigen, also called melanotransferrin, covalently coupled through a heterobifunctional cross-linker to *Enterobacter cloacae* beta-lactamase. After tumor localization, the enzyme was intended to activate cephalosporin-containing anticancer prodrugs at antigen-positive tumor-cell surfaces. It was evaluated in preclinical melanoma, renal carcinoma, and lung carcinoma models as a chemically prepared comparator to the recombinant L49-sFv-bL fusion protein; no clinical development program, marketed product, or regulatory approval has been identified. ([europepmc.org](https://europepmc.org/article/MED/10563779))

Other names

L49-Fab'-bLL49-Fab′-bL