Treatment of hairy cell leukemia with 2-chlorodeoxyadenosine via the Group C protocol mechanism of the National Cancer Institute: a report of 979 patients.
OBJECTIVE
To provide cladribine (CdA) to physicians for the treatment of patients with previously treated or untreated hairy cell leukemia (HCL), and to determine the response rate, response duration, survival, and toxicity with this agent.


METHODS
This Group C phase II study was open to all eligible patients whose primary physician obtained written permission from the National Cancer Institute (NCI) to register patients onto this protocol. Of 979 patients registered, 861 were assessable for response and 895 for toxicity.


RESULTS
The complete remission (CR) rate was 50% and the partial remission (PR) rate was 37%. At a median follow-up of 52 months, 12% of patients were reported to have progressed and 62 (7%) have died of disease.


CONCLUSIONS
This large experience confirms the excellent response rates and remission duration of CdA in patients with HCL. Nevertheless, the response rates in this setting, which approximates general clinical practice, were lower than in other series. In general, CdA was well tolerated, but the potential increased risk for secondary malignancies requires additional follow-up evaluation. CdA can now be considered as one of the best agents for the treatment of HCL.
Cheson
B D
BD
National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. chesonb@ctep.nih.gov
Sorensen
J M
JM
Vena
D A
DA
Montello
M J
MJ
Barrett
J A
JA
Damasio
E
E
Tallman
M
M
Annino
L
L
Connors
J
J
Coiffier
B
B
Lauria
F
F
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D017338:Cladribine / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007943:Leukemia, Hairy Cell / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000175:diagnosis; D016019:Survival Analysis
D000970:Antineoplastic Agents; D017338:Cladribine