Overall Approach to this Pilot Study 
Patients with metastatic breast cancer will receive 4-5 cycles of 
induction chemotherapy and GM-CSF or G-CSF on one of the ongoing 
Medicine Branch protocols. Patients achieving at least a partial 
response will undergo bone marrow harvest when hematologic 
recovery has occurred. Patients who have not achieved a PR, but who 
are responding to therapy, may be treated with additional cycles of 
therapy in an attempt to achieve a PR. Such patients will be eligible 
for transplant if a PR is obtained. 70% of the bone marrow will be 
cryopreserved. The CD34+ subpopulation from the remaining 30% of 
the bone marrow harvest will be obtained using an anti-CD34+ 
antibody and immunoabsorption column. These cells will be 
transduced with the GINa retroviral vector bearing the neomycin 
resistance marker gene and reinfused along with the non-transduced 
bone marrow cells into patients following high dose ICE 
chemotherapy. Serial peripheral blood and bone marrow samples 
will be obtained to study the persistance of the neo -marked stem 
cells and progeny and the time course of marrow recovery. Patients 
with residual or progressive disease after ABMT will be treated 
with vinblastine with and without G-CSF. Peripheral blood and bone 
marrow samples will be obtained to study whether chemotherapy 
and G-CSF increase the number of neo -bearing hematopoietic cells. 
Patients' bone marrow and other sites of relapsed tumor will be 
biopsied to test for the presence of the neo gene by PCR. 
3. Patient Eligibility : 
3.1 Histologically-documented metastatic breast cancer. 
3.2 Patients must have achieved at least a partial response to 
induction chemotherapy. Patients achieving a complete 
response are eligible for study . 
3.3 Age: 18-M 
3.4 No history or clinical evidence of metastatic CNS disease. 
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Recombinant DNA Research, Volume 16 
