Low-dose fludarabine and cyclophosphamide in elderly patients with B-cell chronic lymphocytic leukemia refractory to conventional therapy

Abstract

BACKGROUND AND OBJECTIVES: In recent years fludarabine alone or in combination with other drugs has been reported to be effective in the treatment of B-cell chronic lymphocytic leukemia (B-CLL), both as first line and salvage therapy. Among the different combination regimens, the association of fludarabine and cyclophosphamide has shown a considerable therapeutic efficacy, although a relevant number of infectious complications have been described, particularly in elderly patients. The aim of this work was to evaluate the efficacy, the toxicity, and the incidence of infectious episodes of a regimen combining lower doses of fludarabine and cyclophosphamide in elderly patients with B-CLL refractory to conventional therapy. DESIGN AND METHODS: Twenty patients with progressive B-CLL with a median age of 75 years (4 in stage B and 16 in stage C) and refractory to conventional therapy were enrolled in this study. The combination regimen was as follows: fludarabine 15 mg/m2/day i.v. [max 25 mg] and cyclophosphamide 200 mg/m2/day i.v. for four days. RESULTS: All patients enrolled were evaluable for response. Three out of 20 (15%) patients achieved a complete remission (CR), 14/20 (70%) a partial response (PR) with an overall response rate (CR+PR) of 85%, according to National Cancer Institute-Working Group response criteria. Three patients were considered resistant. In four out of 20 patients (20%), a severe neutropenia (neutrophils < 0.5x10(9)/L) occurred and one of them developed an infectious complication which required treatment with systemic antibiotics and granulocyte colony- stimulating factor (G-CSF). Non-hematologic toxicity was negligible in all patients but one, who despite a adequate therapy with allopurinol and hydration, experienced a tumor lysis syndrome with transient but severe renal impairment. INTERPRETATION AND CONCLUSIONS: The association of low-dose fludarabine and cyclophosphamide appeared to be effective in this subset of B-CLL patients, reproducing a similar overall response rate obtained with other fludarabine-based combination therapies. In addition, in this group of elderly patients, toxic side effects were negligible and infectious complications remarkably low.