Subcutaneous Trastuzumab Combined with Pertuzumab and Docetaxel as First-line Treatment of Advanced HER2-positive Breast Cancer.

Background/aim: Subcutaneous (s.c.) trastuzumab was introduced in the (neo)adjuvant setting, based on the non-inferiority results and patient preference. In the advanced setting, preliminary safety data have only been reported. We conducted an observational study of s.c. trastuzumab in combination with i.v. pertuzumab and docetaxel in the first-line setting of human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer.

Patients And Methods: In this single-institution study, patients received 600 mg s.c. trastuzumab in combination with 840 mg pertuzumab for the first cycle and 420 mg for the following cycles, and 75-100 mg/m docetaxel, followed by maintenance with s.c. trastuzumab and pertuzumab until disease progression or unacceptable toxicity. Endpoints were efficacy and safety.

Results: Forty patients were enrolled. The median number of cycles with docetaxel was six, while the median number of maintenance cycles was 21. With a median follow-up of 37 months, median progression-free survival and overall survival were 24 and 35 months.

Conclusion: Subcutaneous trastuzumab in combination with pertuzumab and docetaxel is well tolerated and effective in HER2-positive advanced breast cancer.