[Treatment of hairy cell leukemia with cladribine]

Hairy cell leukemia is a chronic B-cell lymphoproliferative disorder characterized by clonal proliferation of hairy cells. Treatments of choice are purine analogues, particularly cladribine. We treated thirty patients with cladribine either by continuous 7-day infusion at a daily dose of 0.1 mg/kg or by 2-h infusion for 5 consecutive days at a daily dose of 0.14 mg/kg. Remission was achieved in 90% of the patients. After a median follow-up of 44 months overall survival is 93% and time to treatment failure more than 6 years. Two patients did not respond, one patient died of infection shortly after the treatment. Side-effects resulted mainly from hematological toxicity, 23% of the patients had neutropenic fever while 20% required platelets or packed red cell transfusions. Our results show that cladribine is safe and effective in the treatment of hairy cell leukemia. There were no significant differences in toxicity and response between 7-day continuous infusion and 5-day intermittent infusions of the drug.