Paclitaxel by 3-hour infusion in combination with bolus doxorubicin in women with untreated metastatic breast cancer: high antitumor efficacy and cardiac effects in a dose-finding and sequence-finding study.

PURPOSETo define the maximum-tolerated dose (MTD) and better tolerated sequence of paclitaxel by 3-hour infusion plus bolus doxorubicin (DOX) and to evaluate antitumor efficacy.PATIENTS AND METHODSThirty-five women with metastatic breast cancer (dominant visceral metastases in 56%, and involvement of > or = three sites in 67%) who never received chemotherapy of any type were studied. Paclitaxel every 3 weeks (125 mg/m2 starting dose) was increased by 25-mg/m2 steps in subsequent cohorts of patients. DOX (60 mg/m2 fixed dose) was administered 15 minutes before the start of or after the end of paclitaxel for a maximum of eight cycles. Subsequently, patients in continuous response could receive single-agent paclitaxel (175 to 200 mg/m2 every 3 weeks). The drug sequence was alternated in consecutive patients and in the first two cycles.RESULTSSevere neutropenia that lasted greater than 7 days (n = 4), febrile neutropenia (n = 7) and grade III oral mucositis (n = 6) defined the MTD of paclitaxel at 200 mg/m2 i...