Treatment of hairy cell leukemia with cladribine (2-chlorodeoxyadenosine)

Hairy cell leukemia is a rare lymphoproliferative disorder resistant to con ventional chemotherapeutic agents. Recently, the purine analogue cladribine (2-chlorodeoxyadenosine, 2-CdA) was introduced for the treatment of this d isease. We report on 14 patients with hairy cell leukemia who were treated with 2-CdA at our department between 1993 and 1997. The patients received a single cycle of 2-CdA at a dose of 0.07 or 0.09 mg/kg/day by continuous in fusion, over a seven-day period. Five patients were previously untreated, w hile the others had received prior treatment with interferon-alpha (seven p atients), interferon-alpha and splenectomy (one patient) or interferon-alph a, splenectomy and pentostatin (one patient). Six patients achieved complet e remission, three a good partial response and three partial remission. Two patients did not respond to treatment and one of them died from septicemia in aplasia. Relapse of the disease occurred in two patients. Side effects such as fever (WHO grade 2) and/or neutropenia (WHO grade 4) were noted in eight patients. Thus, 2-CdA is an effective treatment of hairy cell leukemi a that can induce long lasting remissions in both, previously treated and u ntreated patients.