Abstract PO1-13-01: Safety profiles of Chinese breast cancer patients who received abemaciclib in MONARCH plus and monarchE study

Abstract

Abstract Aim: Abemaciclib demonstrated efficacy with tolerable safety profile in Chinese patients (CN pts) with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer (ABC) and high-risk early breast cancer (EBC). The overall safety profile of abemaciclib in Chinese ABC and EBC pts was consistent with overall population in the MONARCH plus and monarchE studies. To better understand the safety of abemaciclib in CN pts, beyond the previously reported most frequent adverse events (AEs), we report a comprehensive summary of other selected AEs in CN pts in the two trials. Methods: Study designs of MONARCH plus (NCT02763566) and monarchE (NCT03155997) studies were reported previously. To report detailed characteristics of a selected AE profile, including alanine aminotransferase increased, aspartate aminotransferase increased, blood creatinine increased, fatigue, nausea, and vomiting, data were pooled across all CN pts from these two phase 3 studies. The safety population was defined as all randomized patients receiving at least 1 dose of Abemaciclib or endocrine therapy. Data cutoff time is May 18, 2020 and July 1, 2022, respectively. Results: Among 6052 participants in the overall safety population, 875 CN pts (14.5%) were included (512/3100 abemaciclib, 363/2952 placebo). CN pts treated with abemaciclib indicated consistent AE profiles in combination with different endocrine therapies (aromatase inhibitors or Fulvestrant). Detailed characteristics of selected AEs are summarized in table. No deaths due to the selected AEs were reported in CN pts. Conclusion: The selected AEs of abemaciclib group were in low severity with limited grade 3-4 events. Those AEs were tolerable and generally manageable in CN pts in the MONARCH plus and monarchE trials. Citation Format: Zhimin Shao, Qingyuan Zhang, Quchang Ouyang, Qiang Liu, Jifeng Feng, Hui-Ping Li, Xiaojia Wang, Ning Liao, Liu Yang, Qinyi Zhu, Chenxi Qian, Zefei Jiang. Safety profiles of Chinese breast cancer patients who received abemaciclib in MONARCH plus and monarchE study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-13-01.