INCLUSION CRITERIA

   - Histologically confirmed low grade CD20+ B cell non-Hodgkin lymphoma (NHL) patients
   who have relapsed after chemotherapy or are chemotherapy resistant and have one or
   more sites of disease measuring more than 5 cm.

   - The patients must have failed at least one chemotherapy regimen

   - No anticancer treatment for three weeks prior to study initiation (six weeks if
   Rituximab, nitrosourea or Mitomycin C)

   - Fully recovered from all toxicities associated with prior surgery, radiation,
   chemotherapy or immunotherapy

   - An institutional review board- (IRB)-approved signed informed consent

   - Age 19 years or older

   - Expected survival of at least 6 months

   - Prestudy Performance Status of 0, 1 or 2 according to the World Health Organization
   (WHO)

   - Absolute neutrophil count (ANC) of at least 1,500/mm³

   - Platelet count at least 100,000/mm³

   - Hct > 30%

   - Hgb > 9.0 gm

   - Bilirubin ≤ 2.0

   - Creatinine ≤ 2.0

   - Bone marrow involvement with lymphoma less than 25% (bilateral bone marrow) within 6
   weeks of enrollment

   - Acceptable birth control method for men and women

EXCLUSION CRITERIA

   - Disease progression within 3 months of last chemotherapy

   - Prior myeloablative therapies with bone marrow transplantation or peripheral stem cell
   rescue

   - Platelet count less than 100,000/mm³

   - Hypocellular bone marrow (≤ 15% cellularity)

   - Marked reduction in bone marrow precursors of one or more cell lines

   - History of failed stem cell collection

   - Prior treatment with fludarabine

   - Prior radioimmunotherapy

   - Presence of central nervous system (CNS) lymphoma

   - HIV or AIDS-related lymphoma

   - Evidence of myelodysplasia on bone marrow biopsy

   - Abnormal bone marrow cytogenetics

   - Patients who have received prior external beam radiation therapy to more than 25% of
   active bone marrow

   - Patients who have received filgrastim

   - Sargramostim therapy within 3 weeks prior to treatment

   - Presence of human anti-mouse antibody (HAMA) reactivity in patients with prior
   exposure to murine antibodies or proteins

   - Serious nonmalignant disease or infection, which, in the opinion of the investigator
   and/or sponsor, would compromise other protocol objectives

   - Another primary malignancy (other than squamous cell and basal cell cancer of the
   skin, in situ carcinoma of the cervix, or treated prostate cancer with stable
   prostate-specific antigen, PSA) for which the patients has not been disease free for
   at least 3 years

   - Major surgery, other than diagnostic surgery within 4 weeks

   - Pleural effusion

   - Pregnant

   - Lactating