Evaluating the Efficacy and Safety of Dalpiciclib Plus Anti-HER2 Therapy and Endocrine Therapy in Patients With Induction-Treated Hormone-Receptor-Positive, HER2-Positive Metastatic Breast Cancer

What this Trial Is About

Researchers are evaluating the effectiveness and safety of dalpiciclib combined with anti-HER2 targeted therapy and endocrine therapy as a first-line maintenance treatment for women with hormone receptor-positive, HER2-positive metastatic breast cancer. This phase II, open-label, single-arm trial focuses on patients who have completed initial induction therapy without disease progression. The study aims to improve outcomes by targeting dual pathways involved in this breast cancer subtype, which often progresses during current maintenance treatments. The study involves taking dalpiciclib, an oral CDK4/6 inhibitor, along with anti-HER2 therapies such as trastuzumab with or without pertuzumab or pyrotinib, plus endocrine therapy including letrozole, anastrozole, exemestane, or fulvestrant. Dosing schedules vary by drug, for example, trastuzumab is given subcutaneously or intravenously every three weeks, pertuzumab intravenously every three weeks, and pyrotinib daily with dose adjustments. Participants receive this combination as maintenance therapy following their initial systemic treatment. Participants will be monitored from enrollment until disease progression or up to two years after treatment completion. Assessments include progression-free survival, objective tumor response, overall survival, safety and tolerability, and quality of life using standardized questionnaires. Safety monitoring continues throughout the study, and outcomes are measured regularly to evaluate the treatment's impact on disease control and patient well-being.

Dalpiciclib, Anti-HER2 Therapy, and Endocrine Therapy for Hormone-Receptor-Positive, HER2-Positive Metastatic Breast Cancer