Mobilization of peripheral blood stem cells with docetaxel and cyclophosphamide (CY) in patients with metastatic breast cancer: a randomized trial of3 vs 4 g/m(2) of CY

The purpose of this study was to develop a regimen of docetaxel, cyclophosp hamide (CY) and filgrastim for mobilization of peripheral blood stem cells CPBSC) in patients with metastatic breast cancer (n = 66), A phase I trial of CY 2, 3 or 4 g/m(2) with docetaxel 100 mg/m(2), in consecutive cohorts o f four patients each, did not reveal any dose-limiting toxicities and subse quent patients were randomized to receive 3 or 4 g/m(2) of CY, The median y ield of CD34(+) cells from all patients was 11.06 x 10(6)/kg (range, 0.03-8 4.77) from a median of two aphereses (range, 1-7); 6.52 x 10(6) CD34(+) cel ls/kg/apheresis (range, 0.01-52.07), Target CD34(+) cell doses greater than or equal to 2.5 and greater than or equal to 5.0 x 10(6)/kg were achieved in 89% and 79%, respectively, There mere no statistically significant diffe rences in CD34(+) cell yields or target CD34(+) cell doses achieved followi ng 3 or 4 g/m2 of CY, Patients with only one prior chemotherapy regimen yie lded a median of 12.82 x 10(6) CD34(+) cells/kg/ apheresis compared to 5.85 for those receiving greater than or equal to 2 regimens (P = 0.03), It was concluded that the combination of docetaxel, 100 mg/m(2), CY 3 g/m(2) with out mesna could be administered with acceptable toxicity with collection of adequate quantities of PBSC from the majority of patients.