Filgrastim for cladribine-induced neutropenic fever in patients with hairycell leukemia

Cladribine treatment of hairy cell leukemia (HCL) is complicated by neutrop enic fever in 42% of patients despite documented infections being relativel y uncommon. We performed a study of priming filgrastim followed by cladribi ne and then filgrastim again to determine if filgrastim would lead to a red uction of neutropenia and febrile episodes. Thirty-five patients received f ilgrastim and cladribine and were compared with 105 historic controls treat ed with cladribine alone. Cladribine was administered at 0.1 mg/kg/d by con tinuous infusion for 7 days. Filgrastim was administered at 5 mu g/kg/d sub cutaneously on days -3, -2, and -1 and then again after the completion of c ladribine until the absolute neutrophil count (ANC) was greater than or equ al to 2 x 10(9)/L on 2 consecutive days (days +8, +9, etc). After filgrasti m priming, the median ANC increased from 0.9 x 10(9)/L to 2.26 x 10(9)/L (2 .5-fold increase), and after cladribine, the median nadir ANC in the filgra stim-treated group was 0.53 x 10(9)/L compared with 0.29 x 10(9)/L among hi storic controls (P = .04). The median number of days to an ANC greater than 1.0 x 10(9)/L was 9 days in the filgrastim-treated group versus 22 days am ong historic controls (P < 10(-5)). The percentage of febrile patients, num ber of febrile days, and frequency of admissions for antibiotics were not s tatistically different in the two groups. Filgrastim regularly increases th e ANC in patients with HCL and shortens the duration of severe neutropenia after cladribine. This phase II study, with comparison to historical contro ls, failed to detect any clinical advantage from the use of filgrastim and cladribine in the treatment of HCL.. Accordingly, the routine adjunctive us e of filgrastim with cladribine in the treatment of HCL cannot be recommend ed. (C) 1999 by The American Society of Hematology.