Annals of Oncology 13:1641-1649, 2002
© 2002 European Society for Medical Oncology
Original Paper |
Treatment of hairy cell leukemia with cladribine (2-chlorodeoxyadenosine) by subcutaneous bolus injection: a phase II study
1 Institute of Medical Oncology, Inselspital, Bern; 2 SIAK Coordinating Center, Bern; 3 Division of Hematology, Kantonsspital, Basel; 4 Department of Internal Medicine, Kantonsspital, St Gallen; 5 Department of Internal Medicine, Hôpital des Cadolles, Neuchâtel; 6 Department of Internal Medicine, Kantonsspital, Aarau, Switzerland; 7 Department of Internal Medicine, University Hospital, Ulm, Germany; 8 Department of Internal Medicine, University Hospital, Innsbruck, Austria; 9 Department of Internal Medicine, University Hospital, Geneva; 10 Oncology Institute of Southern Switzerland, Bellinzona; 11 Central Hematology Laboratory, University Hospital, Bern, Switzerland
Received 8 January 2002; revised 11 April 2002; accepted 24 April 2002
Background:
To assess the activity and toxicity of 2-chlorodeoxyadenosine (cladribine, CDA) given by subcutaneous bolus injections to patients with hairy cell leukemia (HCL).
Patients and methods:
Sixty-two eligible patients with classic or prolymphocytic HCL (33 non-pretreated patients, 15 patients with relapse after previous treatment, and 14 patients with progressive disease during a treatment other than CDA) were treated with CDA 0.14 mg/kg/day by subcutaneous bolus injections for five consecutive days. Response status was repeatedly assessed according to the Consensus Resolution criteria.
Results:
Complete and partial remissions were seen in 47 (76%) and 13 (21%) patients, respectively, for a response rate of 97%. All responses were achieved with a single treatment course. Most responses occurred early (i.e. within 10 weeks) after start of CDA therapy, but response quality improved during weeks and even months after treatment completion. The median time to treatment failure for all patients was 38 months. Leukopenia was the main toxicity. Granulocyte nadir (median 0.2 x 109/l) was strongly associated with the incidence of infections (P = 0.0013). Non-specific lymphopenia occurred early after CDA treatment, and normal lymphocytes recovered slowly over several months. No significant associations were found between infections and nadir count of lymphocytes or any lymphocyte subpopulation. No opportunistic infections were observed.
Conclusions:
One course of CDA given by subcutaneous bolus injections is very effective in HCL. The subcutaneous administration is more convenient for patients and care providers, and has a similar toxicity profile to continuous intravenous infusion. The subcutaneous administration of CDA is a substantial improvement and should be offered to every patient with HCL requiring treatment with CDA.
Key words: 2-chlorodeoxyadenosine, cladribine, hairy cell leukemia