Phase 2 study of rituximab in the treatment of cladribine-failed patients with hairy cell leukemia.
Hairy cell leukemia (HCL) is an indolent B-cell neoplasm, strongly expressing CD20. Despite initial very high response rates following cladribine, many patients (pts) ultimately relapse. Having relapsed after prior treatment with cladribine, 24 HCL pts (21 male, 3 female) with a median age of 53.5 years were treated with rituximab at 375 mg/m2 intravenously weekly for 4 weeks. Of the pts, 3 (13%) achieved complete remissions and 3 (13%), partial responses. Thus, 6 (25%) of 24 pts achieved a response following rituximab. At a median follow-up of 14.6 months, 2 responders have relapsed; median time to relapse was not yet reached. The only grade III or IV toxicities demonstrated were culture-negative febrile neutropenia, transient and reversible disseminated intravascular coagulation related to rituximab administration, and a diverticular abscess, each in single patients. Of 18 nonresponders, 9 pts subsequently received other treatments; 5 pts were retreated with cladribine, 3 underwent splenectomy, and 1 received pentostatin. Follow-up data are available on 7 of these 9 patients; all 7 patients achieved improvements in hematologic parameters. Rituximab, administered at this dose and schedule, has only modest single-agent activity in cladribine-failed HCL patients when compared with other agents active in this disease.
Nieva
Jorge
J
Division of Hematology/Oncology and Department of Pathology, Scripps Clinic, La Jolla, CA, USA.
Bethel
Kelly
K
Saven
Alan
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000633:toxicity; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000633:toxicity; D001772:Blood Cell Count; D017338:Cladribine / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007943:Leukemia, Hairy Cell / Q000150:complications / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000166:cytology; D012074:Remission Induction / Q000379:methods; D000069283:Rituximab; D016879:Salvage Therapy / Q000379:methods*; D017211:Treatment Failure; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D017338:Cladribine; D000069283:Rituximab