Pegasys in Patients With Chronic Myeloid Leukemia (CML)

Study Drug Administration:

If you are found to be eligible to take part in this study, you will receive Pegasys through
a needle under the skin 1 time each week while you are on study. You will be taught how to
use the study drug at the first visit and will administer it to yourself at all future
doses.

You will continue receiving the TKI you are already taking at the dose and frequency you
have been receiving it when you began taking part in this study.

Study Visits:

At every study visit, you will be asked about any side effects you may have had and to list
any drugs you may be taking.

Every 1-2 weeks for 8 weeks, then every 6-8 weeks after that, blood (about 1-2 teaspoons)
will be drawn for routine tests.

Every 3 months for 6 months, then every 6-12 months after that, you will have a complete
physical exam, including measurement of your vital signs.

Every 3-6 months for 1 year, you will have a bone marrow aspirate to check the status of the
disease and to check for changes in your chromosomes.

Every 3-6 months for 1 year, then every 6-12 months after that, blood (about 1 teaspoon)
will be drawn to check the levels of leukemia in the blood.

Length of Study:

You may continue taking Pegasys for as long as the doctor thinks it is in your best
interest. You will no longer be able to take the study drug if the disease gets worse, if
intolerable side effects occur, or if you are unable to follow study directions.

This is an investigational study. Pegasys is FDA approved and commercially available for
the treatment of CML. TKIs (imatinib, nilotinib, and dasatinib) are FDA approved and
commercially available for the treatment of CML. The combination of these drugs to treat CML
is investigational.

Up to 50 patients will take part in this study. All will be enrolled at MD Anderson.

Inclusion Criteria:

1. Patients 16 years or older with Philadelphia chromosome (Ph)-positive or
BCR-ABL1-positive CML (as determined by cytogenetics, FISH, or PCR).

2. Patients are receiving an FDA-approved TKI for the management of CML.

3. Patients must have received TKI therapy for at least 24 months and not have increased
their TKI dose in the last 6 months.

4. Patients must be in complete cytogenetic remission.

5. Patients must have detectable BCR-ABL1 transcript levels meeting at least one of the
following criteria: 1. The patient has received therapy for at least 2 years and does
not have a sustained major molecular response, or 2. The patient has received therapy
for at least 5 years and does not have a sustained complete molecular response.

6. Patients must not have had a known continuous interruption of TKI therapy of greater
than 14 consecutive days or for a total of 6 weeks in the 6 months prior to
enrollment.

7. Patients must sign an informed consent indicating that they are aware of the
investigational nature of this study.

8. ECOG performance status
9. Adequate organ function defined as: bilirubin < 2x upper limit of normal (ULN)
(unless associated with Gilbert's syndrome), creatinine sGOT
10. Men and women of childbearing potential should practice effective methods of
contraception. Women of childbearing potential must have a negative serum or urine
pregnancy test within 1 week of enrollment.

Exclusion Criteria:

1. Patients receiving any non-FDA approved TKI.

2. Patients who are pregnant or breast-feeding.

3. Patients with clinically significant heart disease (NYHA Class III or IV).