PSMA specific antibodies and their diagnostic and therapeutic use

Prostate-specific membrane antigen (PSMA) is a membrane-bound glycoprotein highly restricted to prostatic epithelial cells. PSMA expression is increas ed in association with prostatic cancer, particularly in hormone refractory disease. Given its membrane-bound character, PSMA is an ideal sentinel mol ecule Fur use in targeting prostatic cancer cells. Monoclonal antibodies sp ecific for PSMA are available, beginning with the antibody 7E11.C5 which or iginally defined PSMA and which has been developed for use in cancer detect ion via immunoscintiscanning in the ProstaScint(TM) test. Newer second gene ration antibodies specific for both linear amino acid sequence epitopes and protein conformational epitopes on the extracellular domain of PSMA has be en reported. Although most of these are murine antibodies, both humanised a nd fully human examples have been dec-eloped, These antibodies are beginnin g to work their cc;ay into clinical applications for potential improved dia gnostic and therapeutic uses. Results to date suggest that antibodies speci fic: for extracellular epitopes are significantly better for clinical uses ill vivo than the 7E11.C5 antibody that is specific For an intracellular ep itope. Current knowledge relating to PSMA-specific antibodies and their cli nical uses and potential is described and evaluated.