Major activity of cladribine in patients with de novo B-cell prolymphocytic leukemia.
OBJECTIVE
De novo B-cell prolymphocytic leukemia (B-PLL) is a distinct clinicopathologic entity usually characterized by marked lymphocytosis, massive splenomegaly, an aggressive course, and refractoriness to therapy. Cladribine (2-chlorodeoxyadenosine [2-CdA]; Ortho Biotech, Raritan, NJ) is a newer purine analog with potent activity against indolent lymphoproliferative disorders.


METHODS
We treated eight patients with cladribine 0.1 mg/kg/d for 7 days by continuous infusion or 0.14 mg/kg/d over 2 hours for 5 days, every 28 to 35 days, for a median of three courses (range, two to five). There were five men and three women, with a median age of 62 years and a median pretreatment duration of 6 months; four patients were previously untreated.


RESULTS
All eight patients were assessable: five achieved a complete response with a median response duration of 14 months (range, 1+ to 55+), and three achieved a partial response with a median duration of 3 months (range, 1 to 3). Of four patients who achieved a complete response and in whom a peripheral-blood immunophenotypic analysis was performed, two had no circulating B-PLL cells and one had no residual disease on Southern blot analysis. Myelosuppression and infection were the major toxicities: three patients developed grade 3 or 4 myelosuppression, four had bacterial infections, and two had herpes zoster infections.


CONCLUSIONS
In this small study of patients with de novo B-PLL, cladribine was an active agent that induced a high overall and complete response rate. These results require confirmation in larger numbers of B-PLL patients.
Saven
A
A
Department of Pathology, Ida M. and Cecil H. Green Cancer Center, Scripps Clinic and Research Foundation, La Jolla, CA 92037, USA.
Lee
T
T
Schlutz
M
M
Jacobs
A
A
Ellison
D
D
Longmire
R
R
Piro
L
L
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*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D015463:Leukemia, Prolymphocytic / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging
D000970:Antineoplastic Agents; D017338:Cladribine