Eradication of minimal residual disease in hairy cell leukemia.
Although the nucleoside analogs cladribine and pentostatin produce high response rates in patients with hairy cell leukemia (HCL), a significant number of patients eventually relapse. Several studies have demonstrated that patients with complete remission (CR) have a longer disease-free survival. Therefore, strategies to improve on the initial response to nucleoside analog therapy are likely to be beneficial, at least for a proportion of patients. We have treated 13 patients with newly diagnosed HCL (n = 11) or after failure of one prior chemotherapy (n = 2) with cladribine (5.6 mg/m(2) given intravenously over 2 hours daily for 5 days) followed by 8 weekly doses of rituximab (375 mg/m(2)). All patients achieved a CR and minimal residual disease (MRD) assessed by consensus primer polymerase chain reaction (PCR) or flow cytometry was eradicated in 11 (92%) of 12 and in 12 (92%) of 13 of patients, respectively. There was no decline in the absolute CD4 and CD8 lymphocyte number after rituximab. We conclude that eradication of MRD in HCL is possible. Whether this leads to a reduced risk of relapse would need to be evaluated in a larger number of patients and with longer follow-up. Disease characteristics may potentially be used to identify patients that are more likely to benefit from such additional therapy.
Ravandi
Farhad
F
Department of Leukemia, University of Texas, M.D. Anderson Cancer Center, Houston, TX 77030, USA. fravandi@mdanderson.org
Jorgensen
Jeffrey L
JL
O'Brien
Susan M
SM
Verstovsek
Srdan
S
Koller
Charles A
CA
Faderl
Stefan
S
Giles
Francis J
FJ
Ferrajoli
Alessandra
A
Wierda
William G
WG
Odinga
Shirley
S
Huang
Xuelin
X
Thomas
Deborah A
DA
Freireich
Emil J
EJ
Jones
Dan
D
Keating
Michael J
MJ
Kantarjian
Hagop M
HM
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D018791:CD4 Lymphocyte Count; D017338:Cladribine / Q000008:administration & dosage; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007943:Leukemia, Hairy Cell / Q000097:blood / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual; D016133:Polymerase Chain Reaction; D012008:Recurrence; D012074:Remission Induction; D000069283:Rituximab
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D017338:Cladribine; D000069283:Rituximab