Sustained long-term remissions with weekly interferon maintenance therapy in hairy cell leukemia

Aim: This study evaluates the efficacy of weekly α‐interferon (IFN) maintenance therapy in hairy cell leukaemia (HCL), a disease that remains incurable. Method: Nine patients (six male, three female, aged 41–69 yrs) with hairy cell leukaemia (HCL) received IFN 3mU s.c. once weekly as long‐term maintenance therapy after achieving optimal clinical and hematological response to initial therapy with thrice weekly IFN. Results: Eight of the nine patients are in a state of sustained response at 3–17 years (median 12 years). Conclusion: Our results are similar to those from three previous studies using long‐term IFN maintenance therapy, bringing the total number of patients in sustained remission to 118. We hope these reports will lead to a multi‐centre, phase III study of IFN maintenance therapy (including pegylated IFN, given less frequently) in HCL patients achieving optimal response to initial therapy, be it IFN or a purine analogue.