BIODISTRIBUTION OF NEOCARZINOSTATIN CONJUGATED TO CHIMERIC FAB FRAGMENTS OF THE MONOCLONAL-ANTIBODY A7 IN NUDE-MICE BEARING HUMAN PANCREATIC-CANCER XENOGRAFTS

In this study, we conjugated chimeric Fab fragments of the monoclonal antibody (MAb) A7, which reacts with pancreatic cancers, to the antitu mor drug neocarzinostatin (chA7Fab-NCS) and intravenously injected I-1 25-labeled chA7Fab-NCS into nude mice bearing a human pancreatic cance r xenograft. We compared the tumor localization of I-125-labeled chA7F ab-NCS with that of conventional I-125-labeled A7-NCS, which was produ ced by conjugation of MAb A7 and NCS. I-125-Labeled chA7Fab-NCS accumu lated in the tumor earlier than I-125-labeled A7-NCS, and significantl y larger amounts of I-125-labeled chA7Fab-NCS had accumulated in the t umor 1 hour after injection. The results suggest that chA7Fab may be a suitable carrier for NCS in immunotargeting therapy against pancreati c cancer.