Rituximab With or Without Yttrium Y-90 Ibritumomab Tiuxetan in Treating Patients With Untreated Follicular Lymphoma

PRIMARY OBJECTIVES:

I. Test the hypothesis that a single dose of Zevalin (yttrium Y-90 ibritumomab tiuxetan)
rituximab immunotherapy (RIT) will increase the complete remission (CR) rate over that
achieved with standard rituximab in patients with untreated asymptomatic follicular lymphoma
(FL).

SECONDARY OBJECTIVES:

I. Test the hypothesis that Zevalin RIT will improve progression-free survival. II. Test the
hypothesis that Zevalin RIT will improve time to next (any) therapy and time to next
chemotherapy.

TERTIARY OBJECTIVES:

I. Study the incidence of exon 2 B-cell leukemia/lymphoma 2 protein (bcl2) mutations in
patients with asymptomatic follicular lymphoma (AFL).

II. Measure regulatory T cells (Tregs) and tissue monocytes in on-study FL tumor tissue.

III. Measure serum cytokines and vitamin D at on study and month 6. IV. Evaluate beta-2
microglobulin plus lactate dehydrogenase (LDH) score as a prognostic factor.

V. Measure absolute lymphocyte count (ALC), absolute monocyte count (AMC), and ALC/AMC ratio
at on study and after treatment.

VI. Compare quality of life as measured by the Functional Assessment of Cancer Therapy
(FACT)-Lymphoma (Lym) between arms.

OUTLINE: Patients are randomized to 1 of 2 treatment arms.

ARM A: Patients receive rituximab intravenously (IV) on days 1, 8, 15, and 22.

ARM B: Patients receive rituximab IV on days 1 and 8 and yttrium Y-90 ibritumomab tiuxetan
over 10 minutes on day 8.

After completion of study treatment, patients are followed up at 3, 6, 9, 12, 18, 24, 30, 36,
48, and 60 months and then every 12 months for 5 years.

Inclusion Criteria:

- Histological confirmation of follicular lymphoma grades I, II diagnosed within 12
months (365 days) prior to registration; NOTE: the day of biopsy should be used as day
1 of diagnosis for this calculation

- Stage I, II, III, or IV disease; NOTE: stage I disease are eligible only if the
disease is not amenable to external beam radiation therapy

- No indication for chemotherapy; candidate for observation

- Measurable disease by tumor imaging with at least one lesion >= 1.5 cm in at least one
dimension

- Previously untreated; NOTE: this includes any chemotherapy or immunotherapy or RIT;
patients who received corticosteroids for diseases other than lymphoma are eligible as
long as prednisone dose is =< 10 mg/day

- Low tumor burden as defined by Groupe d'Etudes des Lymphomes Folliculaires (GELF)
criteria (2):

- No tumor mass (nodal or extranodal) >= 7 cm in one dimension on computed
tomography (CT)

- Fewer than 3 (2 or less) nodal masses > 3 cm

- No systemic or B symptoms

- No splenomegaly greater than 16 cm by CT scan

- No risk of organ compression - ureteral, orbital, neurological, gastrointestinal

- No leukemic phase (> 5.0 x 10^9/L circulating FL cells in the blood as detected
by complete blood count [CBC] with differential and smear)

- No cytopenias - absolute neutrophil count (ANC) < 1000 or platelets < 100,000

- Meet standard criteria for RIT:

- < 25% marrow involvement with FL

- No evidence of myelodysplasia

- Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0, 1, or 2

- Absolute neutrophil count (ANC) >= 1500/mm^3

- Platelet count >= 100,000/mm^3

- Hemoglobin > 10.0 g/dL

- Total bilirubin =< 1.5 x upper limit of normal (ULN) or if total bilirubin is > 1.5 x
ULN, the direct bilirubin must be =< ULN

- Alkaline phosphatase =< 3 x ULN

- Aspartate transaminase (AST) =< 3 x ULN

- Creatinine =< 2 x ULN

- Negative pregnancy test done =< 7 days prior to registration, for women of
childbearing potential only

- Provide informed written consent

- Willing to travel to a radioimmunotherapy site for Zevalin, if necessary

- Willing to return to the enrolling institution for follow-up (during the Active
Monitoring Phase of the study); Note: during the Active Monitoring Phase of a study
(i.e., active treatment and observation), participants must be willing to return to
the consenting institution for follow-up

- Willing to provide blood samples at baseline for correlative research purposes and
tissue for central pathology review

- < 25% bone marrow involvement of cellular marrow with lymphoma as determined by
bilateral bone marrow aspirate and biopsy; NOTE: the percent involvement should be
estimated by the hematopathologist using all of the biopsy material

- Has insurance coverage or is willing to pay for protocol therapy (rituximab x 4 or
Zevalin x 1)

Exclusion Criteria:

- Any of the following:

- Pregnant women

- Nursing women

- Men or women of childbearing potential who are unwilling to employ adequate
contraception for at least three months after completing study treatment

- Co-morbid systemic illnesses or other severe concurrent disease which, in the judgment
of the investigator, would make the patient inappropriate for entry into this study or
interfere significantly with the proper assessment of safety and toxicity of the
prescribed regimens

- Patients known to be human immunodeficiency virus (HIV) positive and currently
receiving antiretroviral therapy

- Uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris,
uncontrolled cardiac arrhythmia, or psychiatric illness/social situations that would
limit compliance with study requirements

- Receiving any other investigational agent that would be considered as a treatment for
the lymphoma

- Active other malignancy requiring treatment that would interfere with the assessments
of response of the lymphoma to protocol treatment and would interfere with follow-up
assessments through year 5

- Presence of central nervous system (CNS) lymphoma

- Known to have lymphoma related to HIV or acquired immune deficiency syndrome (AIDS)

- Abnormal renal function (serum creatinine > 2 x ULN)

- Received prior external beam radiation therapy for another reason to > 25% of active
bone marrow

- Serious non-malignant disease such as active infection or other condition which in the
opinion of the investigator would compromise other protocol objectives

- Major surgery other than diagnostic surgery =< 4 weeks prior to registration

- Any evidence of myelodysplastic syndrome or marrow chromosomal changes suggesting
myelodysplasia (-7, -5 etc)

- Corticosteroid therapy at the time the patient enters the protocol; NOTE: patients
using prednisone or its equivalent for adrenal failure or using =< 10mg of
prednisone/day for other benign causes are accepted

- Follicular grades IIIA or IIIB are not eligible

- Marrow cellularity =< 15% (as determined on all bone marrow samples)

- Seropositive for or active viral infection with hepatitis B virus (HBV):

- Hepatitis B surface antigen (HBsAg) positive

- HBsAg negative, anti-hepatitis B surface antibody (HBs) positive and/or
anti-hepatitis B core antibody (HBc) positive and detectable viral
deoxyribonucleic acid (DNA)

Notes:

- Subjects who are HBsAg negative, anti-HBs positive, and/or anti-HBc positive, but
viral DNA negative are eligible

- Subjects who are seropositive because of HBV vaccination are eligible (HBV surface
antibody positive, HBV core antibody negative, and HBV surface antigen negative)

- Active infection with hepatitis C virus (HCV)