An immunochemotherapy protocol for enhanced tumoricidal activity: in vivo treatment with IL-2 prior to chemotherapy

Protective effects of rIL-2 modulation on immune tumoricidal activity (cytolytic activity as expressed in LU/spleen) as well as tumor mass was examined in a murine malignant tumor model. Using rIL-2 and Adriamycin both separately and concurrently to treat an established in vivo murine tumor, we demonstrate immune cytolytic function associated with drug treatment is rescued with pretreatment of IL-2 prior to administration of cytotoxic drug (i.e., to have greater tumoricidal activity as determined by lytic units/spleen than either rIL-2 or Adriamycin treatment alone). Reduction of tumor mass was observed whenever IL-2 was administered. A significant inflammatory response was observed in animals with drug and IL-2 pretreatment. This data suggests a more effective approach to the treatment of this tumor model is pretreatment of IL-2 prior to administration of chemotherapy versus either IL-2 or chemotherapy alone.