Ofatumumab for Minimal Residual Disease (MRD) and Maintenance Therapy

The Study Drug:

Ofatumumab is designed to bind to the surface of some white blood cells (B-cells) and to kill
these cells. It can destroy cancer cells that come from B-cells, and can be used to treat
cancers of B-cells such as B-CLL.

Study Drug Administration:

If you are found to be eligible to take part in this study, you will receive ofatumumab up to
20 times during this study. You will receive 8 weekly infusions and then an infusion every 2
months for 2 years or until the disease gets worse. You will receive ofatumumab by vein over
about 6 ½ hours the first time and over 4 hours for all the following infusions. The first
infusion will be the smallest dose. The second and later infusions will be 3 times larger
than the first.

Before you receive the study drug each time, you will receive Tylenol (acetaminophen) by
mouth to reduce the risk of fever. You will receive Benadryl (diphenhydramine) by mouth or
vein and prednisolone (a steroid) by vein over about 30 minutes to reduce the risk of an
allergic reaction or an infusion reaction.

During the infusions, you will be monitored closely. You will be expected to stay in clinic
for about 71/2 hours on the day of the first infusion and 5 hours for all other infusions.

You will be seen at MD Anderson for mandatory visits for enrollment, ofatumumab infusions,
for response assessment after 8 weekly ofatumumab doses (Month 3), during maintenance every 6
months and for follow-up at least once a year. Your local doctor may perform other visits and
laboratory studies.

If you decide to have your local doctor perform study visits and laboratory studies, a letter
will be sent to your doctor, describing your participation in this study and asking for your
doctor's agreement to help manage your care.

Study Visits:

The following tests and procedures will be performed every other week during Weeks 1- 8
(Weeks 1, 3, 5 and 7):

- You will have a complete physical exam including measurement of your vital signs.

- Your medical history will be recorded.

- Blood (about 2 teaspoons) will be drawn for routine tests.

Starting at Month 3, you will have the following tests and procedures every 2 Months:

- You will have a complete physical exam including measurement of your vital signs.

- Your medical history will be recorded.

- Blood (about 2 teaspoons) will be drawn for routine tests.

Starting at Month 3, you will also have the following tests and procedures every 6 months, in
addition to the ones performed every 2 months:

- Blood (about an additional 1 teaspoon) will be drawn for other routine tests.

- You may have CT scans to check the status of the disease, if your doctor thinks that
this test is needed (at Month 3 only).

- You will have a bone marrow aspirate/biopsy to check the status of the disease.

Length of Study:

You may continue taking the study drug for up to 20 doses (up to 24 months). You will no
longer be able to take the study drug if the disease gets worse or intolerable side effects
occur.

Your participation on the study will be over once you have completed the follow-up visits,
which will last until you begin receiving any other treatment.

Follow Up Visits:

Every 3 Months:

- You will have a complete physical exam including measurement of your vital signs.

- Your medical history will be recorded.

- Blood (about 2 teaspoons every 3 months, about 1 teaspoon every 6 months) will be drawn
for routine tests.

- If your doctor thinks it is needed, blood (about 2 teaspoons) will be drawn for
hepatitis testing.

Every 6 Months, you will have a bone marrow aspirate/biopsy to check the status of the
disease.

This is an investigational study. Ofatumumab is FDA approved for CLL resistant to standard
chemotherapy. Ofatumumab's use in patients with residual CLL or SLL is investigational.

Up to 42 patients will take part in this study. All will be enrolled at MD Anderson.

Inclusion Criteria:

1. Diagnosis of CD20+ chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma
(SLL) treated with chemotherapy or chemoimmunotherapy: Post-frontline therapy,
patients must have non-progressing disease and be 4 months to 1 year post treatment.
Post-treatment for relapsed CLL, eligible patients must have non-progressing disease
and be 3 months to 1 year post treatment.

2. Patients (CR, nPR, or PR at enrollment) must have measurable disease, which may
include MRD by 4-color flow cytometry.

3. Adequate renal and hepatic function (creatinine < 2 mg/dL, bilirubin < 2 mg/dL).
Patients with renal or liver dysfunction due to organ infiltration by lymphocytes may
be eligible after discussion with the study chairman. Patients with Gilbert's syndrome
are eligible.

4. Age >/= 18 years.

5. ECOG performance status of 0-2.

6. Provide informed consent indicating patient is aware of the investigational nature of
this study according to the policies of the MDACC IRB.

7. Patients of childbearing potential (females who have not been postmenopausal for at
least 12 consecutive months or who have not undergone previous surgical sterilization
or males who have not been surgically sterilized) must be willing to practice birth
control during the study.

Exclusion Criteria:

1. Positive serology for Hepatitis B virus (HB) defined as a positive test for HBsAg. In
addition, if negative for HBsAg but HBcAb positive (regardless of HBsAb status), a HB
DNA test will be performed and if positive the subject will be excluded.

2. Concurrent chemotherapy, radiotherapy, or immunotherapy, including other monoclonal
antibodies. Localized radiotherapy to an area not comprising bone marrow function does
not apply.

3. Active infection or significant medical illness, including current active hepatic or
biliary disease (with exception of patients with asymptomatic gallstones, liver
involved with CLL or stable chronic liver disease per investigator assessment).

4. Pregnant and breastfeeding females are excluded.