INTRATUMORAL INJECTION OF AN ADRIAMYCIN IMMUNOCONJUGATE AGAINST HUMANPANCREATIC-CANCER XENOGRAFTS

We have evaluated the effect of an adriamycin conjugate of monoclonal antibody Nd2 (ADM-Nd2) on the growth rate of SW1990 xenografts grown s ubcutaneously in athymic nude mice. Intravenous or intraperitoneal adm inistration of radiolabeled Nd2 resulted in a maximum tumor accumulati on of approximately 45% of the initial dose/g of tumor 3-7 days after administration. However, administration into the tumor produced retent ion of 1200%ID/g 1 day after, with 50% of this high value remaining ev en at 7 days after administration. In contrast, intratumoral administr ation of a non-specific immunoglobulin showed a lower initial retentio n and rapid loss of label. Both intravenously and intratumorally admin istered ADM-Nd2 reduced the growth rate of SW1990 xenografts. While a single intravenous administration arrested growth for about two weeks, a single intratumoral injection prevented any increase in tumor size even 45 days after administration. Xenografts treated with ADM-Nd2 sho wed degenerative changes at the histological level. Neither Nd2 alone nor Adriamycin atone inhibited growth when administered at the same do se as the conjugate.