Fludarabine, cyclophosphamide and rituximab plus granulocyte macrophage colony-stimulating factor as frontline treatment for patients with chronic lymphocytic leukemia.

Fludarabine, cyclophosphamide and rituximab (FCR), the standard of care for the frontline treatment of patients with chronic lymphocytic leukemia (CLL), is associated with a high rate of neutropenia and infectious complications. Granulocyte macrophage colony-stimulating factor (GM-CSF) reduces myelosuppression and can potentiate rituximab activity. We conducted a clinical trial combining GM-CSF with FCR for frontline treatment of 60 patients with CLL. Eighty-six percent completed all six courses and 18% discontinued GM-CSF for toxicity: grade 3-4 neutropenia was observed in 30% of cycles, and severe infections in 16% of cases. The overall response rate was 100%. Both median event-free survival (EFS) and overall survival (OS) have not been reached. Longer EFS was associated with favorable cytogenetics. GM-CSF led to a lower frequency of infectious complications than in the historical FCR group, albeit similar EFS and OS.