High-dose systemic interleukin-2 therapy in stage IV neuroblastoma for one year after autologous bone marrow transplantation: pilot study.

Despite intensified chemotherapy protocols, including autologous bone marrow transplantation (ABMT), stage IV neuroblastoma has a poor prognosis, and modern therapeutic trends are aimed at the eradication of minimal residual disease, which is though to be the main factor leading to relapse. In this pilot study, we report the systemic administration of high doses of interleukin-2 after ABMT in four patients. Five day cycles of IL-2 at a dose of 18 x 10(6) IU/m2/day were administered at variable time intervals as frequent as it was necessary to maintain the levels of natural killer (NK) cytotoxic activity higher than the median control value (40 LU/ml blood) throughout 1 year from the start of first IL-2 treatment. After IL-2 infusion, NK and LAK activities increased significantly (median 742 x 10(-3) LU/ml blood and 186.8 x 10(-3) LU/ml blood, respectively). Toxicities were transient and no life-threatening complications were observed. Fever, anorexia, skin rash and enlarged liver were always present. Anaemia, thrombocytopenia, leukocytosis, lymphocytosis and and eosinophilia occurred following most of the IL-2 courses. Although the small number of patients does not allow an estimation of the immunomodulatory-antineoplasic effects of IL-2, the results seem promising for the management of neuroblastoma patients.