NCI Drug Dictionary

The NCI Drug Dictionary contains technical definitions and synonyms for drugs/agents used to treat patients with cancer or conditions related to cancer. Each drug entry includes links to check for clinical trials listed in NCI's List of Cancer Clinical Trials.

anti-CD20 B9E9 scFv-streptavidin fusion protein
An Escherichia coli periplasm-expressed tetrameric fusion protein composed of four single-chain variable regions (scFv) of the murine immunoglobulin (Ig) G2a anti-CD20 monoclonal antibody B9E9 fused to the streptavidin (SA) gene of Streptomyces avidinii (scFv-SA), with potential use in pretargeted radioimmunotherapy (PRIT). Upon intravenous administration of the anti-CD20 B9E9 scFv-SA fusion protein, this agent targets and binds to CD20-expressing tumor cells. Subsequently, a biotinylated N-acetylgalactosamine-containing clearing agent is administered, which binds to the streptavidin moiety of the unbound fusion protein and promotes its hepatic excretion. In turn, radiolabeled DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid)-biotin is administered and, due to its small size, quickly distributes. The biotin moiety efficiently binds to the SA moiety of the bound fusion protein, which localizes the biotin-conjugated radionuclide to the tumor site. CD20, a tumor-associated antigen (TAA), is overexpressed on B-cell malignancies. PRIT increases both tumor uptake and renal elimination of the radionuclide conjugate as compared to conventional radioimmunotherapy (RIT), where the radioisotope is bound to the antibody before administration; this increases the dose of radionuclide delivered to the tumor while limiting radiation exposure for normal, healthy tissues. Check for active clinical trials using this agent. (NCI Thesaurus)

Synonym:anti-CD20 B9E9 scFv-SA fusion protein
anti-CD20 B9E9-SA fusion protein
B9E9 scFvSA fusion protein
recombinant anti-CD20 B9E9 scFvSA fusion protein
scFv B9E9-streptavidin fusion protein