Purpose: This study assessed the efficacy of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) or recombinant human granulocyte colony-stimulating factor (rhG-CSF) in ameliorating the extent and duration of hematologic toxicity after high-dose etoposide cancer therapy.
Patients and methods: Thirty-two non-Hodgkin's lymphoma and myeloma patients were treated with 2 to 2.4 g/m2 etoposide infused intravenously (IV) during a 10- to 12-hour period, followed 72 hours later by subcutaneous administration of rhGM-CSF or rhG-CSF. Hematologic toxicity was compared with that observed in 29 patients who were treated with high-dose etoposide without growth factors.
Results: The median duration of grade 4 neutropenia in growth factor-treated patients was 3 days, and granulocyte counts never decreased to less than 100/microL in approximately half of the patients. The corresponding figures in the control patients were 8 and 3 days, respectively (P < .0001). No effect was observed in platelet and RBC recovery. Growth factor-treated patients became eligible to receive additional myelotoxic chemotherapy a median of 5 days earlier than controls. Nonhematologic toxicity was minimal. Grade 1 mucositis was observed in two of 61 patients (3%). Antitumor activity assessed within 1 month after etoposide administration was documented in 58% of 38 assessable patients. Finally, high-dose etoposide expanded and mobilized the pool of peripheral-blood hematopoietic progenitors.
Conclusion: The use of rhGM-CSF or rhG-CSF makes high-dose etoposide a safe outpatient regimen and should encourage the inclusion of this highly effective and well-tolerated drug in novel treatment strategies that use high-dose therapy early in the clinical course of chemosensitive tumors.