A prospective randomized phase II trial of GM-CSF priming to prevent topotecan-induced neutropenia in chemotherapy-naive patients with malignant melanoma or renal cell carcinoma

We conducted a phase II randomized trial of recombinant granculocyte-macrophage colony-stimulating factor (GM-CSF) administered before topotecan chemotherapy to determine whether it could prevent myelosuppression and to determine the antitumor activity of this topoisomerase I inhibitor in 53 patients with metastatic malignant melanoma and renal cell cancer. All patients received GM-CSF after topotecan at a dose of 250 μg/m² daily for at least 8 days. Patients randomly assigned to receive GM-CSF priming were treated with GM-CSF at 250 μg/m² twice daily for 5 days before treat ment. Twenty-five patients were randomly assigned to receive GM-CSF priming and 28 to receive topotecan without priming. The primary analysis was restricted to the protective effects seen during the first cycle of therapy. Grade 4 neutropenia occurred in 8 of 23 patients (35%) and grade 3 neutropenia in 5 of 23 patients (22%) randomized to GM-CSF priming, whereas 18 of 26 (69%) and 5 of 26 (19%) patients experienced grade 4 or 3 neutropenia, respectively, without GM-CSF priming (P = .0074). The mean duration of neutropenia was reduced by GM-CSF priming: grade 3 neutropenia from 5.2 ± 0.7 to 2.8 ± 0.7 days (P = .0232) and grade 4 neutropenia from 2.7 ± 0.6 to 1.1 ± 0.4 days (P = 0.0332). The protective effects of GM-CSF extended to the second cycle of treatment. The incidence of febrile neutropenia was also reduced. Chemotherapy-induced anemia and thrombocytopenia were similar in both groups. One partial response was seen in a patient with melanoma, and one patient with renal cell cancer had complete regression of pulmonary metastases and was rendered diseasefree by nephrectomy.