Real-world data on patients with early breast cancer who were prescribed abemaciclib adjuvant therapy in Japan
Creators: name: Shimoi, Tatsunori
name: Pathadka, Swathi
name: Sekine, Nobuyuki
name: Cai, Zhihong
name: Tanizawa, Yoshinori
name: Kawaguchi, Tsutomu
name: Saji, Shigehira
name: Yamashita, Toshinari
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Medicine
subject: Cell Biology
subject: Pharmacology
subject: Ecology
subject: FOS: Biological sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: Cancer
subject: Infectious Diseases
subject: FOS: Health sciences

description: <b>Aim:</b> To understand the real-world use of abemaciclib in Japanese patients with early breast cancer (EBC). <b>Methods:</b> This retrospective observational study was conducted using a Japanese administrative claims database in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative EBC who received abemaciclib adjuvant therapy from December 2021–March 2023. Patient characteristics and treatment patterns were summarized. <b>Results:</b> Among 374 patients, 38.2, 51.6 and 63.4% patients received neoadjuvant chemotherapy, adjuvant chemotherapy and radiotherapy, respectively; 13.1% were chemotherapy naive. Tamoxifen (37.7%), letrozole (35.6%), anastrozole (24.3%) were the commonly prescribed concomitant adjuvant endocrine therapies. Abemaciclib dose reductions were observed in 42.0% patients. <b>Conclusion:</b> Use of abemaciclib for treatment of high-risk EBC was described, which could help inform patient selection and treatment patterns. Abemaciclib (150 mg twice daily) is prescribed with hormonal therapy for the treatment of early breast cancer (EBC) with high risk of recurrence. We used a big database from Japan that has anonymized information about 44 million patients from 480 hospitals. We aim to describe the characteristics of patients with EBC who receive abemaciclib and their treatment patterns in Japan. We included 374 patients with EBC who had breast cancer surgery and were prescribed abemaciclib with hormonal therapy between December 2021 and March 2023. The median age of patients is 54 years, almost all (99.2%) are female. The most commonly prescribed hormonal therapy with abemaciclib is tamoxifen (37.7%), letrozole (35.6%) and anastrozole (24.3%). Of the 374 patients who were prescribed abemaciclib, 38.2% patients received chemotherapy before surgery, 51.6% received chemotherapy after surgery and 63.4% received radiation therapy after surgery; whereas, 13.1% received no perioperative chemotherapy before abemaciclib therapy. Around 42% of patients reduced their dose from starting dose of abemaciclib. Higher proportion of older patients and patients with low body weight, had dose reduction. Majority of the patients are prescribed either an antidiarrheal agent or probiotic within a day of starting abemaciclib. This is the first study describing patient characteristics and treatment patterns of Japanese patients who are prescribed abemaciclib in the clinical practice. The results will help understand who can benefit from abemaciclib, and to choose the most appropriate patients to receive abemaciclib for the treatment of EBC. Abemaciclib, a cyclin-dependent kinases 4/6 inhibitor, was approved as an adjuvant therapy for the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) early breast cancer (EBC) with high risk of recurrence in Japan in December 2021. This retrospective, observational study aimed to describe the characteristics of patients with HR+, HER2- EBC who received abemaciclib adjuvant therapy, and their treatment pattern in Japan using the Medical Data Vision Co., Ltd (MDV) database between December 2021 and March 2023. A total of 374 patients with EBC (median age: 54 years; female, 99.2%, use of LHRH agonist, 13.9%) who were prescribed abemaciclib as adjuvant therapy, were eligible. About 38.2, 51.6 and 63.4% of patients with EBC received neoadjuvant chemotherapy, adjuvant chemotherapy and radiotherapy, respectively. However, 13.1% of patients who received abemaciclib were chemotherapy naive. Overall, about 42% patients had dose reductions of abemaciclib, and 10.2% of patients received starting dose of less than 300 mg/day. Proportion of patients with dose reductions were higher in older age groups, lower body mass index and less than median weight subgroups. Treatment patterns from our real-world study were comparable to the monarchE trial (phase III clinical trial leading to approval of abemaciclib). This is the first real-world study conducted in Japanese patients with HR+, HER2- EBC who were prescribed abemaciclib and expands our understanding of real-world use of abemaciclib in an adjuvant setting.