Inclusion Criteria:

- Untreated or relapsed/refractory follicular, SLL or MZL (i.e. no limit to number of
prior treatments as long as patients meet other study criteria)

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

- Measurable tumor size (at least one node measuring 4 cm^2 in bidimensional
measurement)

- Expected survival of > 6 months

- Prior rituximab or other monoclonal immunotherapy permitted and eligible for
rituximab monotherapy

- Full recovery from any significant toxicity associated with prior surgery, radiation
therapy, chemotherapy, or immunotherapy

- Absolute neutrophil count > 1.0 x 10^9/L

- Platelets > 50 x 10^9/L

- Patients may receive erythropoietin growth factors to maintain adequate hemoglobin
levels (>= 8.0 mg/dl)

- Creatinine < 1.5 x upper normal levels (UNL)

- Total bilirubin < 1.5 mg/dL (> 25.65 umol/L)

- Aspartate aminotransferase < 5 x UNL

- Alkaline phosphatase < 5 x UNL

- Informed consent approved in institutional review board (lRB)

- CD20+ B-cell lymphoma

Exclusion Criteria:

- Prior history of human immunodeficiency virus (HIV)-positivity (routine HIV testing
is required pretreatment)

- Serious non-malignant disease (e.g. active uncontrolled bacterial, viral, or fungal
infections) or other conditions which, in the opinion of the principal investigator
would compromise other protocol objectives

- Presence of central nervous system (CNS) lymphoma

- Chemotherapy within 4 weeks of the first scheduled study treatment

- Another primary malignancy (other than squamous or basal cell carcinoma of the skin
or in-situ carcinoma of the cervix) for which the patient has not been disease-free
for at least five years

- Major surgery, other than diagnostic surgery, within four weeks

- Patients with non-Hodgkin lymphoma (NHL) other than relapsed/refractory follicular,
MZL or SLL

- Patients must not have a history of cardiac disease, defined as New York Heart
Association Class II or greater or clinical evidence of congestive heart failure

- Concurrent use of other investigational agents

- Pregnant or breast feeding

- Subjects of reproductive potential who are not using adequate contraceptive
precautions, in the judgment of the investigator

- Known hypersensitivity to any recombinant E coli-derived product, murine proteins, or
any components of the study medications

- Concerns for the subject's compliance with the protocol

- Any premalignant myeloid condition or any malignancy with myeloid characteristics
(e.g. myelodysplastic syndromes, acute or chronic myelogenous leukemia)

- Patient is currently enrolled in, or has not yet completed at least 30 days since
ending another investigational device or drug trial