A PILOT-STUDY EVALUATING INTERLEUKIN-2-ACTIVATED HEMATOPOIETIC STEM-CELL TRANSPLANTATION FOR HEMATOLOGIC MALIGNANCIES

Cytotoxic effector cells are generated when autologous hematopoietic c ells (HSC) are cultured with IL-2 for 24 h. Infusion of these cells fo llowed by IL-2 administration may moderate a graft-versus tumor (GvT) effect in vivo. Sixteen patients-7 with non-Hodgkin's lymphoma (NHL), 2 with AML, 4 with multiple myeloma (MM), and 3 with Hodgkin's disease (HD)-received busulfan (4 mg/kg/day for 4 days) and cyclophosphamide (60 mg/kg/day for 2 days) or cyclophosphamide/TBI (1320 cGy). Autologo us HSC were activated by culturing with IL-2 for 24 h before reinfusio n. Subcutaneous administration of IL-2 began after engraftment at 1.8 x 10(6) IU/m(2)/day for 1-4 weeks. Neutrophil engraftment occurred on day 13.1 (median) (range 9-45 days), and platelet engraftment occurred on day 19.3 (median) (range 7-54 days) for 15 patients, with delayed engraftment observed in 3 patients. One patient experienced a fatal ca rdiac arrhythmia. Five patients developed transient skin rashes with h istologic evaluation demonstrating findings consistent with GvHD. At 1 7 months (median) (range 7-23 months), 9 patients are alive, with 6 pa tients remaining disease free. This pilot trial demonstrates mild to m oderate toxicities and a possible delay in platelet engraftment. Furth er trials mill determine the optimal dose and duration of IL-2 therapy and possible impact of this therapy on survival. Laboratory investiga tions are evaluating the presence of autologous GvHD and a possible Gv T effect.