Chemotherapy, Filgrastim and Peripheral Stem Cell Transplantation in Patients With Chronic Myelogenous Leukemia

OBJECTIVES:

- Assess clinical outcomes, survival, and morbidity of transplantation therapy in patients
with chronic myelogenous leukemia when treated with high dose chemotherapy and
filgrastim (G-CSF) followed by autologous retrovirally transduced peripheral blood stem
cell (PBSC) transplantation.

- Determine whether this priming treatment can increase the fraction of benign
Philadelphia chromosome (Ph) negative hematopoietic progenitors in PBSC and reduce the
incidence of persistent or recurrent leukemia after autologous transplantation with
mobilized PBSC in these patients.

- Assess whether retroviral transduction of mobilized PBSC progenitors determines the
contribution of malignant Ph positive progenitors contaminating the graft to relapse
after transplantation in these patients.

- Determine whether this priming treatment can expand the benign progenitor population in
the PBSC collections from these patients.

OUTLINE: In the priming phase, patients receive cyclophosphamide IV over 2 hours on day 1 and
filgrastim (G-CSF) subcutaneously (SQ) daily beginning on day 4 and continuing until the
completion of leukapheresis. Peripheral blood stem cells (PBSC) are harvested 4-7 times
between days 10 and 21 beginning when blood counts recover (CD34+ cells are selected from 2
of these PBSC collections and transduced with the LN NEO virus prior to cryopreservation).

In the transplant phase, patients who have not received prior radiotherapy receive
cyclophosphamide IV over 2 hours daily on days -7 and -6 and total body irradiation on days
-4 through -1. Autologous PBSC and LN NEO transduced CD34+ cells are reinfused on day 0.
Patients also receive G-CSF IV daily beginning on day 0 and continuing until blood counts
recover.

Patients who have received prior radiotherapy receive oral busulfan every 6 hours on days -10
through -7 and cyclophosphamide IV daily on days -6 through -3. Autologous PBSC and LN NEO
transduced CD34+ cells are reinfused on day 0. Patients also receive G-CSF IV daily beginning
on day 0 and continuing until blood counts recover.

All patients then receive interferon alfa SQ daily until disease progression or unacceptable
toxicity.

Patients are followed at 3 weeks; at 3, 6, 9, 12, 18, and 24 months; and then annually
thereafter.

PROJECTED ACCRUAL: A total of 4-26 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

- Histologically confirmed chronic or accelerated phase chronic myelogenous leukemia

- Philadelphia chromosome positive OR

- BCR/ABL rearrangement

- No blast crisis or post blast crisis

- No moderate to severe fibrosis defined by bilateral trephine biopsies

- Not eligible for or refused to participate in allogeneic marrow transplant protocols

- No splenomegaly (below umbilicus) that does not respond to chemotherapy and/or
radiotherapy

PATIENT CHARACTERISTICS:

Age:

- 18 to 65

Performance status:

- Karnofsky 90-100%

Life expectancy:

- Not specified

Hematopoietic:

- Not specified

Hepatic:

- Not specified

Renal:

- Not specified

Other:

- Normal organ function (except bone marrow)

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Prior interferon alfa allowed

Chemotherapy:

- Prior hydroxyurea allowed

- At least 2 months since prior busulfan (at time of PBSC harvest)

Endocrine therapy:

- Not specified

Radiotherapy:

- Not specified

Surgery:

- Not specified