Hormone Receptor Positive / HER2-negative Breast Cancer

An international, multicenter, two-stage optimal Simon's design, single-arm phase II clinical trial to evaluate zongertinib plus fulvestrant combination therapy in participants with hormone receptor-positive/HER2-negative advanced breast cancer harboring HER2 mutations.

This study aims to evaluate the efficacy and safety of adjuvant endocrine therapy combined with dalpiciclib at different doses and durations in patients with hormone receptor (HR)-positive, HER2-negative early-stage breast cancer. It is a multicenter, prospective clinical study. All enrolled patients will receive either dalpiciclib 125 mg for 2 years or dalpiciclib 100 mg for 3 years, in combination with standard endocrine therapy. The primary endpoint is 3-year invasive disease-free survival (iDFS).