[Successful ambulatory treatment of patients with hairy-cell leukemia using one cycle of the purine analog cladribine. 'Hemato-oncologic volwassen Nederland' (HOVON) Study Group].

OBJECTIVE

To study the efficacy of a single cycle of 2-chlorodeoxyadenosine (2-CDA) given as a 2-hour infusion on 5 consecutive days, in patients with hairy cell leukaemia (HCL).

DESIGN

Non-randomised phase II study in an unselected population.

SETTING

20 centres in the Netherlands and Belgium.

METHODS

Response to treatment was evaluated in 23 patients with a minimum follow-up of 6 months. All patients had proven HCL, were untreated or pretreated with splenectomy and (or) IFN alpha, and had at least one of the following criteria: Hb < 7.3 mmol/l, neutrophils < 1.0 x 10(9)/l, platelets < 100 x 10(9)/l, systemic symptoms or symptomatic splenomegaly. Patients with an active infection were ineligible. Treatment consisted of one cycle of 2-CDA (2-hour i.v. infusion days 1-5, dosage 0.1 mg/kg/day).

RESULTS

Sixteen patients had received no prior treatment. At the 4-week evaluation, most patients (17/23) had improvement in one or two haematological parameters. After 6 months, 6/23 (26%) patients were in haematological remission and 13/23 (57%) were in complete remission. No patient developed progressive disease. Febrile neutropenia developed in 12/23 (52%) patients, with documented infection in three of them. A generalised rash was seen in 9/23 (39%) patients.

CONCLUSION

2-CDA appears to be the treatment of choice in patients with HCL. With a single 5-day cycle, over 80% of patients achieved remission.