Prolonged administration of weekly paclitaxel and trastuzumab in patients with advanced breast cancer

To evaluate the efficacy and safety of weekly paclitaxel and trastuzumab in patients with HER2-positive metastatic breast cancer, with trastuzumab administered beyond disease progression.

Twenty-six women with metastatic breast cancer, that was HER2-positive as determined by immunohistochemistry, were treated with weekly paclitaxel 70 or 90 mg/m2 and trastuzumab (4 mg/kg initial dose followed by 2 mg/kg weekly).

The median duration of treatment was 28 (8-72) weeks for paclitaxel and 59 (14-150) weeks for trastuzumab. Two (8%) patients experienced complete and 14 (54%) partial responses, for an overall response rate of 62%. The median time to disease progression was 11 (2.89-36) months and median survival 34+ months. Grade 3/4 adverse events were alopecia (46%), neurotoxicity (15%), leukopenia (12%) and neutropenia (12%). Infusion-related reactions were mild to moderate. No symptomatic cardiac toxicity was observed. No patient discontinued trastuzumab due to toxicity.

Prolonged administration of weekly paclitaxel and trastuzumab is effective and well-tolerated in women with HER2-positive metastatic breast cancer.