[Study of three-weekly docetaxel and weekly trastuzumab treatment in HER 2-overexpressing metastatic breast cancer patients].

Docetaxel and trastuzumab can be considered to be active drugs for HER 2-overexpressing metastatic breast cancer (MBC). This study was conducted to determine the activity of combination therapy with docetaxel and trastuzumab in MBC patients (pts) by assessing the response rate (RR), time to progression (TTP) and safety. We administered the combination of docetaxel 70 mg/m2 every 3 weeks and trastuzumab using a 4 mg/kg loading dose and thereafter 2 mg/kg weekly. One cycle was three weeks. Between March 2002 and May 2003, 40 pts with HER 2-positive (3+by immunohistochemistry 39, FISH+1) MBC were enrolled in this study, and 39 pts proved eligible. The overall RR was 72% (28/39) [95%CI 55.1%-85.0%], with 6 CR, 22 PR, 7 SD, 1 PD and 3 NE. The median follow-up time was 14.3 months, while the TTP was 6.5 months (range, 0.6-19.8), median OS has not yet been reached. The number of pts assessable for safety was 40. Hematological Grade 3-4 toxicities were leukopenia 87.5% (35/40) and neutropenia 82.5% (33/40). Non-hematological Grade 3 toxicities were weight gain in 2 pts, and anorexia, neuropathy, fever and rash in one pt each. The combination of docetaxel and trastuzumab was a well-tolerated and very active regimen for the treatment of pts with HER 2-overexpressing MBC.