Purpose: To combine the benefits of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on neutrophil recovery and recombinant human interleukin-3 (rhIL-3) on platelet recovery, we applied standard-dose chemotherapy with the combined administration of IL-3 and GM-CSF to investigate their efficacy and toxicity.
Patients and methods: Thirty-six patients with advanced malignancies were treated with etoposide (VP16) 500 mg/m2, ifosfamide 4 g/m2, and cisplatin 50 mg/m2 (VIP), followed by the sequential administration of IL-3 (days 1 to 5 subcutaneously [SC]) and GM-CSF (day 6 to 15 SC). Control patients received GM-CSF alone or were treated without hematopoietic growth factors.
Results: Subcutaneous IL-3 and GM-CSF treatment was well tolerated; low-grade fever (World Health Organization grade 1 to 2) was the only consistent clinical symptom. Neutrophil recovery documented that the duration of neutropenia less than 0.1 x 10(9)/L or less than 0.5 x 10(9)/L was identical in GM-CSF as well as IL-3 and GM-CSF-treated patients, but was shortened significantly when compared with patients who were treated without cytokines. Overall platelet recovery was not different significantly in the three treatment groups. The biologic activity of IL-3 in this cytokine combination was reflected in a variety of effects, which included an increase in basophil and eosinophil counts and the induction of circulating hematopoietic progenitor cells.
Conclusion: We conclude that after conventional-dose VIP chemotherapy, a shortened treatment course of IL-3 (5 days) sequentially followed by GM-CSF (10 days) combines the benefits of prolonged single GM-CSF treatment on WBC count recovery in all patients and an accelerated platelet recovery only in some intensively pretreated patients.