Combination of GM-CSF With Fludarabine-Containing Regimens in Chronic Lymphocytic Leukemia and Indolent Non-Hodgkin Lymphoma.

Background: Granulocyte-monocyte colony stimulating factor (GM-CSF) is a hematopoietic cytokine with immunomodulatory activity that has preclinical evidence for enhancement of antitumor immunity when administered in combination with chemotherapy. We evaluated the utility of GM-CSF with chemoimmunotherapy in patients with indolent non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) in a pilot study.

Patients And Methods: Patients with previously untreated, relapsed, or refractory indolent NHL or CLL were treated with GM-CSF, rituximab, fludarabine, and cyclophosphamide or mitoxantrone for a maximum of 6 cycles.

Results: Sixteen patients were enrolled, including 1 patient who did not receive study therapy. Of the 15 remaining patients, 6 received cyclophosphamide and 9 received mitoxantrone in combination with fludarabine, rituximab, and GM-CSF. The overall response rate for all patients was 87%. Nine patients have subsequently had relapse of their disease, and 6 remained in remission at last study contact. There were no toxic deaths during the study.

Conclusion: GM-CSF-based chemoimmunotherapy was well-tolerated and resulted in a high response rate and warrants evaluation in larger studies.