One year immunotherapy with high doses of interleukin-2 after autologous bone marrow transplantation in neuroblastoma stage IV childhood patients. I. Monitoring the parameters of toxicity and clinical response

The aim of this study was to maintain the levels of Natural Killer (NK) activity higher than control values for one year, by the systemic administration of interleukin-2 (IL2), in patients with stage IV neuroblastoma after autologous bone marrow transplantation. We administered IL2 treatment at a dose of 18 x 10 6 UI/m 2 /day given by continuous infusion over a five day period. The toxicity and clinical response to 17 cycles of treatment was analyzed in 3 patients. At the start of each new cycle, the periodicity of IL2 administration was adapted according to the levels of NK. All cycles were followed by fever, asthenia, skin lesions and liver enlargement. Anaemia, thrombopenia, leucocytosis with an excess of eosinophils were the major hematological modifications. All types of toxicity were transient and no life-threatening complications were observed under intensive care conditions. We conclude that IL2 can be administered safely and could be a way to eliminate the minimal residual tumoral disease in these patients.