Phase III trial of fludarabine plus cyclophosphamide compared with fludarabine for patients with previously untreated chronic lymphocytic leukemia: US Intergroup Trial E2997.
OBJECTIVE
The combination of fludarabine and cyclophosphamide is an effective regimen for patients with chronic lymphocytic leukemia (CLL). However, it may be accompanied by increased toxicity compared with fludarabine alone. E2997 is a phase III randomized Intergroup trial comparing fludarabine and cyclophosphamide (FC arm) versus fludarabine (F arm) alone in patients receiving their first chemotherapy regimen for CLL.


METHODS
Symptomatic, previously untreated patients with CLL were randomly assigned to receive either fludarabine 25 mg/m2 intravenously (IV) days 1 through 5 or cyclophosphamide 600 mg/m2 IV day 1 and fludarabine 20 mg/m2 IV days 1 through 5. These cycles were repeated every 28 days for a maximum of six cycles.


RESULTS
A total of 278 patients were randomly assigned in this Intergroup study. Treatment with fludarabine and cyclophosphamide was associated with a significantly higher complete response (CR) rate (23.4% v 4.6%; P < .001) and a higher overall response (OR) rate (74.3% v 59.5%, P = .013) than treatment with fludarabine as a single agent. Progression-free survival (PFS) was also superior in patients treated with fludarabine and cyclophosphamide than those treated with fludarabine (31.6 v 19.2 months, P < .0001). Fludarabine and cyclophosphamide caused additional hematologic toxicity, including more severe thrombocytopenia (P = .046), but it did not increase the number of severe infections (P = .812).


CONCLUSIONS
Fludarabine and cyclophosphamide produced an increase in OR and CR, and it improved PFS in patients with previously untreated CLL compared with fludarabine alone and was not associated with an increase in infectious toxicity.
Flinn
Ian W
IW
Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins, Baltimore, MD, USA. iflinn@tnonc.com
Neuberg
Donna S
DS
Grever
Michael R
MR
Dewald
Gordon W
GW
Bennett
John M
JM
Paietta
Elisabeth M
EM
Hussein
Mohamad A
MA
Appelbaum
Frederick R
FR
Larson
Richard A
RA
Moore
Dennis F
DF
Tallman
Martin S
MS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D003520:Cyclophosphamide / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000188:drug therapy* / Q000401:mortality; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology; D011379:Prognosis; D014740:Vidarabine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use
D003520:Cyclophosphamide; D014740:Vidarabine; C024352:fludarabine