Fludarabine and granulocyte colony-stimulating factor (G-CSF) in patients with chronic lymphocytic leukemia.

The study was designed to determine whether administration of granulocyte colony-stimulating factor (G-CSF) following fludarabine would reduce the incidences of myelosuppression and infections. Twenty-five previously treated patients with Rai stage III-IV chronic lymphocytic leukemia (CLL) received fludarabine 30 mg/m2 daily for 5 days each month. G-CSF was given at 5 microg/kg subcutaneously starting 1 day after chemotherapy (day 6) and continued until the next course unless the granulocyte count was > or =10000/microl. The incidences of myelosuppression and infection were compared with those seen in an historical control population of 145 previously treated patients with Rai stage III-IV CLL who were given the same schedule of fludarabine without growth factor. There was a significant decrease in myelosuppression; patients receiving G-CSF developed neutropenia at a neutrophil count <1000/microl or 500/microl in 45% and 15% of courses vs 79% (P=0.002) and 63% (P < 0.001) of historical controls. Twenty percent of G-CSF-treated patients had therapy delayed by >35 days per course, vs 50% of historical controls (P=0.005). The incidence of pneumonia was 8% with G-CSF and 37% without in historical controls. Other infection rates (sepsis, fever of undetermined origin, minor infections) were similar. This decrease in pneumonia was noted even in high-risk groups such as patients older than 60 years and patients with hypogammaglobulinemia. The use of G-CSF following fludarabine in high-risk patients with CLL resulted in a significant decrease in myelosuppression and pneumonia. Larger trials to verify these results and to compare costs are indicated.