Tositumomab and Iodine I 131 Tositumomab in Treating Patients With Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma in First Remission

PRIMARY OBJECTIVES:

I. To estimate the progression-free survival at 2 years following administration of
131I-tositumomab (tositumomab and iodine I 131 tositumomab) in patients with CLL/SLL who
achieve a complete remission (CR) or partial remission (PR) with prior therapy.

II. To improve the response rate by administering 131I-tositumomab to patients who have
achieved a PR not a CR after any prior therapy.

III. To eliminate residual disease (documented by flow cytometry or polymerase chain reaction
[PCR]) using 131I-tositumomab in patients who have achieved a CR after any prior therapy.

SECONDARY OBJECTIVES:

I. To evaluate the toxicities of 131I-tositumomab in 1st remission patients with previously
treated CLL/SLL.

OUTLINE:

Patients receive tositumomab and iodine I 131 tositumomab intravenously (IV) over 90 minutes
on day 0 and then again 7-14 days later over 30-60 minutes.

After completion of study treatment, patients are followed up weekly for 3 months, every 3
months for 2 years, every 6 months for 3 years, and then annually thereafter.

Inclusion Criteria:

- Patients with a diagnosis of cluster of differentiation (CD)20+ CLL/SLL; prior to the
first treatment patients with CLL must have been either Rai stage III/IV disease or
Rai stage I/II with evidence of disease activity as defined by the National Cancer
Institute (NCI) 1996 guidelines, and patients with SLL must have been Stage III or IV
per Ann Arbor staging system

- Patient has received prior therapy and is in 1st remission with a partial or complete
response to treatment

- Patients must have no more than 25% of the intratrabecular marrow space involved by
leukemia in bone marrow biopsy specimens as assessed microscopically after completion
of treatment; bilateral posterior iliac crest core biopsies are required if the
percentage of intratrabecular space involved exceeds 10% on a unilateral biopsy; the
mean of bilateral biopsies must be no more than 25%

- Patient must have consented to participate in the study and signed and dated an
appropriate institutional review board (IRB)-approved consent form that conforms to
federal and institutional guidelines

- Patient must have a Eastern Cooperative Oncology Group (ECOG) performance status of 0,
1 or 2 (0 = fully active, able to carry on all pre-disease performance without
restriction; 1 = restricted in physically strenuous activity but ambulatory and
ambulatory and able to carry out work of a light or sedentary nature, e.g., light
house work, office work; 2 = ambulatory and capable of all self-care but unable to
carry out any work activities and is up and about more than 50% of waking hours)

- Patient must have an anticipated survival of at least 3 months

- Granulocytes >= 1,500/uL within 14 days of planned dosimetric infusion

- Platelets >= 100,000/uL within 14 days of planned dosimetric infusion

- White blood count =< 20,000/mm^3

- Serum creatinine < 2 times upper limit of normal

- Total bilirubin < 2 times upper limit of normal

- Aspartate aminotransferase (AST) < 5 times upper limit of normal

- Males and females must agree to use a contraceptive method from enrollment to 6 months
after receiving I-131 labeled tositumomab

Exclusion Criteria:

- Patients who have received prior radiolabeled antibody

- Patients with active hemolysis

- Patients must not require sustained transfusion support of blood products

- Patients in 2nd remission or beyond

- Patients who have undergone treatment with either stem cell or bone marrow transplant

- Patients with active obstructive hydronephrosis

- Patients with evidence of any significant systemic illness, active hepatitis B
infection or other active infection at the time of study entry

- Patients with New York Heart Association class III or IV heart disease or other
serious illness that would preclude evaluation

- Patients with known human immunodeficiency virus (HIV) infection

- Patients who are pregnant or nursing

- Patients with prior malignancy other than CLL/SLL, except for adequately treated skin
cancer (basal cell or squamous cell carcinoma), in situ cervical cancer, or other
cancer for which the patient has been disease-free for 5 years unless approved by the
principal investigator (PI)

- Patients with active brain or leptomeningeal involvement by malignancy

- Patients who have, in the opinion of the investigator, other medical, social, or
psychosocial factors that may negatively impact compliance or their safety by
participation in this study