PEG Interferon Alpha 2B and Low-Dose Ara-C in Early Chronic Phase CML

If you agree to take part in this study, during treatment, you will have blood tests every 1
to 4 weeks. After 10 years, blood tests are recommended 2 times per year. Bone marrow
samples will be taken every 3 months during the first year and then every 3 to 6 months. If
you are on this study for 10 years or longer, the bone marrow collections will only be
performed if the doctor thinks it is needed. To collect a bone marrow biopsy, an area of the
hip is numbed with anesthetic, and a small amount of bone marrow and bone is withdrawn
through a large needle.

During treatment, you will receive PEG-Intron once a week. You will also receive Ara-C
injections under the skin. You will be taught to inject yourself, or a family member or
friend can be taught how to give injections. Treatment will be given to you in the
outpatient clinic at MD Anderson or in a clinic close to you.

You will receive treatment as long as it is helping to control the disease. Treatment will
go on for about 5 to 20 years.

This is an investigational study. The FDA has approved PEG-Intron only for research studies.
About 100 patients will take part in this study. All will be enrolled at MD Anderson.

Inclusion Criteria:

1. Patients age 12 years or older with a diagnosis of Ph-positive or bcr-positive CML in
early chronic phase CML (diagnosis < 12 months).

2. Serum bilirubin less than 2mg%, serum creatinine less than 2mg%, and a performance
status of 2 or less on Zubrod scale.

3. Patients under age 55 years should have HLA A,B,C, and DR typing performed on
themselves and their siblings. Patients under age 20 years and patients with late
chronic phase, accelerated phase or blastic phase will be offered allogeneic bone
marrow transplantation from a matched sibling as the first priority.

Exclusion Criteria:

1. Severe heart disease (Class III, IV) Psychiatric disability (psychosis) Pregnant or
lactating females

2. Women of pregnancy potential must practice birth control methods because of the
potential risk of fetal teratogenecity with these agents.

3. Patients must sign an informed consent indicating they are aware of the
investigational nature of this study, in keeping with the policies of the hospital.

4. Definition of CML Phases: a. Early chronic phase: time from diagnosis to therapy < 12
months Late chronic phase: time from diagnosis to therapy > 12 months b. Blastic
phase: presence of 30% blasts or more in the peripheral blood or bone marrow. c.
Accelerated phase CML: presence of any of the following features: - Peripheral or
marrow blasts 15% or more - Peripheral or marrow basophils 20% or more -
Thrombocytopenia < 100 x 109L unrelated to therapy - Documented extramedullary
blastic disease outside liver or spleen

5. Continuation of # 4 d. Clonal evolution defined as the presence of additional clones
other than the Ph chromosome is part of accelerated phase CML. Ph chromosome variants
or complex Ph chromosome translocations are not considered to indicate disease
acceleration. We have recently found clonal evolution to have a variable prognostic
impact and may be suppressed with IFN-A therapy (22,23). Hence these patients will be
eligible if no other therapy (22,23). Hence these patients will be eligible if no
other accelerated phase signs are present.