Trastuzumab Monotherapy Followed By the Combination of Trastuzumab and Letrozole in Post-Menopausal Women With ER-Positive, HER-2 Positive Advanced Breast Cancer Resistant to a Nonsteroidal Aromatase Inhibitor: A Multicenter Two-Step Phase II Trial
- Determine the efficacy of trastuzumab (Herceptin®) monotherapy followed by trastuzumab
and letrozole in women with progressive advanced breast cancer that is resistant to
prior treatment with a nonsteroidal aromatase inhibitor.
- Determine the safety profile of this regimen in these patients.
- Correlate HER-2-extracellular domain (ECD) levels with response to treatment in these
- Determine the efficacy of this regimen in these patients.
- Correlate response and time to tumor progression with changes in serum HER-2-ECD levels
in patients treated with this regimen.
OUTLINE: This is a multicenter study.
Patients receive trastuzumab (Herceptin®) IV over 30-90 minutes once in weeks 1-3 OR once in
week 1. Courses repeat every 3 weeks in the absence of disease progression or unacceptable
toxicity. Patients experiencing disease progression after 9 weeks receive trastuzumab as
before and oral letrozole once daily in the absence of further disease progression or
After completion of study treatment, patients are followed every 12 weeks until disease
progression and then at 6 months.
PROJECTED ACCRUAL: A total of 30-40 patients will be accrued for this study.
Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
Objective response rate as assessed by CT scan or MRI every 3 months
Dieter Koeberle, MD
Kantonsspital St. Gallen