RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells. PURPOSE: Randomized phase II trial to compare the effectiveness of paclitaxel with or without PSC 833 in treating patients with metastatic breast cancer.
OBJECTIVES: I. Evaluate the response rate and time to treatment failure of paclitaxel with and without the P-glycoprotein (Pgp) antagonist PSC 833 in advanced breast cancer. II. For each treatment arm, relate paclitaxel AUC (area under curve), and/or time above .05 um/L, to myelosuppression and/or response. III. To obtain preliminary estimates of MDR in this group of patients by measuring MDR1-Pgp immunostaining in pretreatment biopsies in 20 patients and biopsies taken at the time of progression. OUTLINE: This is a randomized study. Patients are stratified according to three criteria: 1) treatment within 2 years of adjuvant chemotherapy vs. progression on chemotherapy for advanced disease 2) measurable vs. evaluable disease 3) institution. Patients receive paclitaxel alone or paclitaxel plus PSC 833. In the first arm, paclitaxel alone is administered by continuous infusion over 3 hours once every 3 weeks. In the second arm, PSC 833 is administered PO four times a day for 3 days; paclitaxel is administered by continuous infusion over 3 hours on day 2. Courses repeat every 3 weeks. PROJECTED ACCRUAL: Approximately 70 patients will be accrued per year in this study.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Enrollment
70
Beckman Research Institute, City of Hope
Duarte, California, United States
USC/Norris Comprehensive Cancer Center
Los Angeles, California, United States
University of California Davis Cancer Center
Sacramento, California, United States
Toronto Sunnybrook Regional Cancer Centre
Toronto, Ontario, Canada
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