Retrospective Observational Study on Safety and Toxicity Management of Abemaciclib with Adjuvant Hormone Therapy in Patients with High-Risk RH+ HER2 Non-Amplified Breast Cancer

What this Trial Is About

Researchers are examining the safety and toxicity management of Abemaciclib combined with adjuvant hormone therapy in patients with high-risk hormone receptor-positive, HER2 non-amplified localized breast cancer. This observational study focuses on a population defined by criteria from the MONARCH-E study, including patients with four or more positive axillary lymph nodes or one to three positive nodes plus either a tumor size of 5 cm or more or histological grade 3. The study aims to better understand treatment tolerance and relapse risks in a real-world setting beyond clinical trials. This retrospective study collects data from patients who have already received adjuvant Abemaciclib along with hormone therapy. The primary goal is to assess the average dose intensity of Abemaciclib over six months. Secondary objectives include evaluating recurrence-free survival, safety and tolerance of the treatment, the impact of dose reductions, and the incidence and management of digestive, hematological, and pulmonary toxicities. Additional focus is on treatment tolerance in patients over 75 years old, causes for permanent discontinuation of Abemaciclib, and quality of life impacts. Participants' information is gathered retrospectively from multiple centers over a data collection period spanning May 2023 to June 2025. The study involves statistical analysis of demographic and treatment data to evaluate treatment safety and efficacy markers. The primary outcome measured is the average dose of Abemaciclib received during six months. The study will also monitor side effects according to standard classifications and assess recurrence-free survival in relation to dose adjustments. The anticipated sample size is approximately 30 patients, with inclusion lasting 23 months.

Retrospective Observational Study of the Safety and Toxicity Management of Abemaciclib in Combination with Adjuvant Hormone Therapy in Patients with RH+ ,HER2-nonoveramplified Breast Cancer, Real-life Data (MONARCHE29)