High-dose paclitaxel in combination with doxorubicin, cyclophosphamide and peripheral blood progenitor cell rescue in patients with high-risk primary and responding metastatic breast carcinoma: Toxicity profile, relationship to paclitaxel pharmacokinetics and short-term outcome

We assessed the feasibility and pharmacokinetics of high-dose infusional paclitaxel in combination with doxorubicin, cyclophosphamide, and peripheral blood progenitor cell rescue. Between October 1995 and June 1998, 63 patients with high-risk primary [stage II with ≥ 10 axillary nodes involved, stage IIIA or stage IIIB inflammatory carcinoma (n = 53)] or with stage IV responsive breast cancer (n = 10) received paclitaxel 150-775mg/m² infused over 24 hours, doxorubicin 165mg/m² as a continuous infusion over 96 hours, and cyclophosphamide 100 mg kg^-1. There were no treatment-related deaths. Dose-limiting toxicity was reversible, predominantly sensory neuropathy following administration of paclitaxel at the 775 mg/m² dose level. Paclitaxel pharmacokinetics were non-linear at higher dose levels; higher paclitaxel dose level, AUC, and peak concentrations were associated with increased incidence of paraesthesias. No correlation between stomatitis, haematopoietic toxicities, and paclitaxel dose or pharmacokinetics was found. Kaplan-Meier estimates of 30-month event-free and overall survival for patients with primary breast carcinoma are 65% (95% CI; 51-83%) and 77% (95% CI; 64-93%). Paclitaxel up to 725 mg/m² infused over 24 hours in combination with with doxorubicin 165 mg/m² and cyclophosphamide 100 mg kg^-1 is tolerable. A randomized study testing this regimen against high-dose carboplatin, thiotepa and cyclophosphamide (STAMP V) is currently ongoing.