A phase I/II trial of non-pegylated liposomal doxorubicin, docetaxel and trastuzumab as first-line treatment in HER-2-positive locally advanced or metastatic breast cancer.

Aim: To assess the activity and safety of non-pegylated liposomal doxorubicin (Myocet®) in combination with docetaxel and trastuzumab as first-line treatment of patients with HER-2/neu-positive metastatic breast cancer (MBC).

Patients And Methods: The maximum tolerated dose of the combination was defined in the phase I part of the study. In the phase II part, 45 HER-2/neu-positive MBC patients were enrolled to receive 6-8 cycles of Myocet® 50 mg/m2 (day 1), docetaxel 30 mg/m2 (days 2 and 9) plus trastuzumab (day 2, 4 mg/kg followed by 2 mg/kg/week) every 21 d until unacceptable toxicity or progression occurred. Objective response (primary end-point) and treatment tolerability were assessed according to World Health Organisation criteria. Cardiotoxicity was defined as signs and/or symptoms of congestive heart failure and/or a decrease in left ventricular ejection fraction (LVEF).

Results: The overall response rate was 55.6% (complete response 8.9%, partial response 46.7%), with a median time-to-progression of 10.9 months (C.I. 8.7-15.0). Median overall survival was not reached. The most frequent grade 3-4 adverse events were granulocytopaenia (60.0%), leukocytopenia (43.2%) and alopecia (35.6%). Grade 3-4 diarrhoea, pain, oral and skin toxicity (4.4%, each) and nausea/vomiting, thrombocytopenia and elevated alkaline phosphatase (2.2%, each) were also reported. In 2 patients LVEF fell to <50%, with a decrease from baseline>15%. LVEF median values remained stable from baseline to the end of the study (60%).

Conclusions: The combination of Myocet®, docetaxel and trastuzumab is safe and shows promising activity as first-line treatment of HER-2-positive MBC.