A phase II study of three-weekly docetaxel and weekly trastuzumab in HER2-overexpressing advanced breast cancer

Background: To test safety and activity of 3- weekly doses of docetaxel and a weekly dose of trastuzumab in women with HER2- overexpressing advanced breast cancer. Patients and Methods: Forty- two women, median age 53 years ( range 36 - 73 years), with HER2- overexpressing advanced breast cancer were enrolled in a study of docetaxel, 75 mg/ m(2) q3w for 6 cycles, and trastuzumab, 4 mg/ kg loading dose, 2 mg/ kg weekly thereafter. Thirty- four patients ( 81%) had visceral metastatic involvement. Thirty-five patients had received prior chemotherapy as part of their treatment: adjuvant/ neoadjuvant ( 26), metastatic ( 2) and both ( 7). Thirty- one patients had been previously exposed to an anthracycline and 11 to paclitaxel. Four patients had previously received high- dose chemotherapy followed by autologous stem cell transplant. Results: 226 cycles ( median 6, range 1 - 6) were administered. The median delivered dose intensity for docetaxel was 24 mg/ m(2)/ week ( range 16 - 25 mg/ m(2)/ week). The intent to treat overall response rate was 67% ( 95% confidence interval, 52 - 79%). Median progression- free survival, time to treatment failure, and duration of response were 9, 8 and 12 months, respectively. Symptomatic cardiotoxicity ( grade 3) occurred in 1 patient. The most common grade 3/ 4 toxicity was neutropenia ( 76% of the patients), although febrile neutropenia did not occur. Conclusions: Three- weekly doses of docetaxel and a weekly dose of trastuzumab is an active and safe combination in patients with HER2- overexpressing advanced breast cancer. Copyright (C) 2004 S. Karger AG, Basel.