An Open-Label, Single-Arm, Phase I Study to Evaluate the Effect of Ofatumumab on Cardiac Repolarization (QTc Duration) in Patients With Fludarabine-Refractory B-cell Chronic Lymphocytic Leukemia

Inclusion Criteria:

- Confirmed diagnosis of Chronic Lymphocytic Leukemia (CLL).

- Active CLL disease and indication for treatment.

- Previous treatment with fludarabine-containing treatment that did not achieve at
least a partial response or, disease progression occurred in responders within six
months of the last dose of a fludarabine-containing treatment regimen.

- Fully active at a minimum, or fully capable of self-care and up and about more than
50% of waking hours.

- Age 18 years or older.

- Signed written informed consent.

- Acceptable levels of laboratory chemistry tests of potassium and magnesium.

- Males and female subjects must agree to use contraception (if fertile) from the time
of the first dose of study medication until one year following last dose of
ofatumumab.

Exclusion Criteria:

- Any abnormal electrocardiogram (ECG) or cardiac conduction findings .

- Certain heart problems, chronic infections, or serious significant diseases.

- Known transformation of CLL.

- CLL central nervous sytem involvement.

- Abnormal/inadequate blood values, liver, or kidney function.

- Past or current malignancy besides CLL, unless you have been free of malignancy for
at least two years, have a history of completely resected non-melanoma skin cancer,
or have been successfully treated.

- Lactating women or women with a positive pregnancy test.

- Use of medications known to prolong the heart rhythm.