Role of interferon-alpha administration after 2-deoxycoformycin in the treatment of hairy cell leukemia patients

BACKGROUND AND OBJECTIVE: Hairy cell leukemia (HCL) is a rare chronic B-cell lymphoproliferative disorder which is treated effectively by interferon-alpha (IFN-alpha), deoxycoformycin (DCF) and 2-clorodeoxyadenosine (2-CdA). As a third of patients treated with DCF do not achieve a complete remission (CR) and many of them tend to relapse, we evaluated the potential role of IFN-alpha, randomly administered after DCF, in increasing the number of patients attaining CR and/or duration of CR. METHODS: From March 1997 to December 2000, 167 previously untreated HCL patients, from 37 Italian institutions, were enrolled in the study. A total of 138 males and 29 females, with a median age of 55 yr were included in the study. All patients received six courses of DCF 4 mg/m(2) i.v. every other week and then two additional courses once a month. Complete and partial responders were randomly assigned to receive or not receive IFN-alpha at a dose of 3 MU s.c. three times a week for 6 months. RESULTS: Of the 167 patients enrolled in the study, 145 (86.8%) obtained a CR or a partial remission (PR) and were therefore suitable for randomization. One hundred and thirty-five patients were successively randomized to receive IFN-alpha (63 cases; arm A) or not (72 cases; arm B). Progression of disease was observed in eight (arm A) and 12 (arm B) patients with a median time of 27.8 and 26.9 months, respectively. As far as the improvement in response was concerned, no significant difference in the two subgroups was observed. In fact, five patients in arm A and six patients in arm B showing a good PR at the end of DCF therapy, subsequently attained a late CR. CONCLUSIONS: From our data there does not appear to be any significant role for IFN-alpha in improving the proportion and the duration of CR in HCL patients previously treated with DCF.