Randomized Phase III Trial Evaluating Adjuvant Abemaciclib Plus Endocrine Therapy Versus Endocrine Therapy Alone for Locoregional Recurrence of Hormone Receptor-Positive, HER2-Negative Breast Cancer

What this Trial Is About

Researchers are evaluating the effectiveness and safety of adding abemaciclib to endocrine therapy compared to endocrine therapy alone in patients with hormone receptor-positive, HER2-negative breast cancer who have had curative treatment for their first locoregional recurrence (LRR). This phase III randomized trial addresses the need for better treatments after LRR, a condition that increases the risk of distant cancer spread despite the generally favorable outlook for this breast cancer type. Participants are randomly assigned to one of two groups: one group receives standard endocrine therapy alone, while the other receives endocrine therapy combined with abemaciclib, a CDK4/6 inhibitor. Abemaciclib is taken orally at a dose of 150 mg twice daily for up to 2 years. Endocrine therapy is personalized based on menopausal status and previous treatments and may include aromatase inhibitors or tamoxifen, sometimes with ovarian function suppression. During the study, participants will be closely monitored for invasive disease-free survival over up to 9 years, including 4 years of enrollment and 5 years of follow-up. Researchers will also assess distant recurrence-free survival, breast cancer-specific survival, overall survival, and safety. Blood samples will be collected to study circulating tumor DNA as a marker for residual disease and treatment response. The total study duration allows for comprehensive evaluation of treatment effects and long-term outcomes.

Adjuvant Abemaciclib for Locoregional Recurrence of HR-positive, HER2-negative Breast Cancer (JCOG2313, AURA)