Fludarabine and Monoclonal Antibody Therapy in Treating Patients With Untreated B-cell Chronic Lymphocytic Leukemia

OBJECTIVES: I. Determine the response rate and toxicity profile of concurrent and
consolidative chimeric anti-CD20 monoclonal antibody IDEC-C2B8 (rituximab) therapy compared
to consolidative rituximab therapy in patients with chronic lymphocytic leukemia treated
with fludarabine. II. Assess the complete response (CR) rate in patients receiving
concurrent therapy with rituximab and fludarabine. III. Assess the frequency of conversion
of a partial response (PR) to a CR or stable disease to either PR or CR in patients
receiving consolidative therapy with rituximab. IV. Follow the effects of rituximab and
fludarabine on the immunologic markers CD4, CD8, IgG, IgA, and IgM. V. Assess the
progression-free and overall survival of these patients.

OUTLINE: This is a randomized study. Patients are stratified according to stage (I and II vs
III and IV). Patients are assigned to 1 of 2 treatment arms. Arm I consists of fludarabine
and chimeric anti-CD20 monoclonal antibody IDEC-C2B8 (rituximab) induction, and arm II
consists of fludarabine induction. Arm I: Rituximab is administered IV over 4 hours on day
1, on day 3, and over 1 hour on day 5 of week 1. Subsequent doses are given over 1 hour on
day 1 every 4 weeks for a total of 6 courses. Fludarabine IV is administered over 10-30
minutes daily for 5 days during weeks 1, 5, 9, 13, 17, and 21 for a total of 6 courses.
Following the sixth course of fludarabine, patients undergo clinical staging and are then
observed for an additional 2 months, after which they undergo repeat clinical staging,
including bone marrow aspiration. Patients achieving a complete or partial response or
stable disease then proceed to consolidation therapy consisting of weekly intravenous
infusions of rituximab once weekly for 4 weeks. Arm II (Fludarabine Induction): Patients
receive fludarabine IV over 10-30 minutes daily for 5 days during weeks 1, 5, 9, 13, 17, and
21 for a total of 6 courses. Patients then proceed as in arm I. Patients are followed every
3 months for 1 year, and then every 6 months thereafter.

PROJECTED ACCRUAL: A maximum of 100 patients will be accrued for this study within 12
months.

DISEASE CHARACTERISTICS: Histologically proven B-cell chronic lymphocytic leukemia Stage I
or II with evidence of active disease as defined by: Massive or progressive splenomegaly
and/or lymphadenopathy Weight loss of greater than 10% within 6 months CALGB grade 2 or 3
fatigue Fevers of greater than 100.5 C or night sweats for over 2 weeks and no evidence of
infection Progressive lymphocytosis Stage III or IV Patient registration on CALGB 9665
required

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: CALGB 0-3 Life expectancy:
Not specified Hematopoietic: Not specified Hepatic: Not specified Renal: Creatinine no
greater than 1.5 times upper limit of normal Other: No medical condition requiring chronic
use of oral corticosteroids Direct antiglobulin test or direct Coombs test negative Not
pregnant Effective contraception required of all fertile patients

PRIOR CONCURRENT THERAPY: Biologic: No prior biologic therapy for disease No concurrent
erythropoietin Chemotherapy: No concurrent chemotherapy No prior chemotherapy for disease
Endocrine: No concurrent chronic oral corticosteroids No prior corticosteroids for
autoimmune complications developing since diagnosis No concurrent hormone therapy for
disease related conditions No concurrent dexamethasone or other corticosteroid-based
antiemetics Radiotherapy: No concurrent palliative radiotherapy Surgery: Not specified
Other: No prophylactic therapy for viral, bacterial, or fungal infections