Abemaciclib for treating patients with HR+/HER2- metastatic breast cancer: a real-world study in France, Italy and Spain

<b>Aim:</b> This real-world study aimed to describe patient and clinical characteristics, treatment patterns and outcomes for patients with HR+/HER2- metastatic breast cancer receiving abemaciclib in France, Italy and Spain. <b>Materials &amp; methods:</b> A multicenter chart review was conducted for adult females with HR+/HER2- advanced/metastatic breast cancer who received abemaciclib in routine care. Real-world progression-free survival (rwPFS) was estimated via Kaplan-Meier curves. <b>Results:</b> This study included 151, 173 and 175 patients from France, Italy and Spain, respectively. Abemaciclib was mostly prescribed as first-line therapy concomitantly with hormone therapy. Median rwPFS was &gt;20 months and the 1-year rwPFS rate was &gt;70%. <b>Conclusion:</b> Effectiveness was similar across the three countries and aligns with pivotal studies. <b>Abemaciclib use in the clinic in France, Italy &amp; Spain</b> This study describes patients, the treatments they have received and the results of those treatments for patients with the most common type of advanced breast cancer. These patients were taking abemaciclib plus hormonal therapy in routine breast cancer care in France, Italy and Spain. The information used to conduct this study was taken from patients' medical charts. In this real-world study, abemaciclib was mostly used as the initial treatment for advanced breast cancer. Abemaciclib effectiveness was similar across the three countries confirming findings from previous studies. Our study supports the use of abemaciclib for patients with HR+/HER2- advanced breast cancer. Patients receiving abemaciclib in routine care in France, Italy and Spain were predominantly postmenopausal with a mean age of approximately 60 years. Breast cancer histological type at first diagnosis was predominantly nonspecific invasive carcinoma. Abemaciclib was mostly prescribed in the first-line setting in combination with aromatase inhibitors or fulverstrant. Overall, most patients who initiated abemaciclib received a starting dose of 150 mg twice a day. Range of discontinuation was between 45 and 55% across the three countries. Real-world tumor response and rwPFS support the real-world use of abemaciclib for the treatment of HR+/HER2- advanced/metastatic breast cancer. Median rwPFS was ≥20 months for patients who received abemaciclib as first and second therapy lines across the three countries. Median rwPFS was highest for patients who received abemaciclib in the first-line setting. Levels of hospitalization remained low, and relatively constant, in the period immediately before treatment initiation and in the period after. Our findings corroborate the effectiveness of real-world abemaciclib treatment for patients with advanced/metastatic breast cancer.

**法国、意大利及西班牙临床中阿贝西利（abemaciclib）的应用情况**

**研究目的**：本项真实世界研究旨在描述法国、意大利及西班牙境内接受阿贝西利治疗的激素受体阳性（HR+）/人表皮生长因子受体2阴性（HER2-）转移性乳腺癌患者的人群与临床特征、治疗模式及预后结局。

**材料与方法**：针对在常规诊疗中接受阿贝西利治疗的HR+/HER2-晚期/转移性乳腺癌成年女性患者开展多中心病历回顾研究。通过卡普兰-迈耶（Kaplan-Meier）曲线估算真实世界无进展生存期（real-world progression-free survival, rwPFS）。

**研究结果**：本研究分别纳入法国、意大利及西班牙的151例、173例及175例患者。阿贝西利大多与激素治疗联合作为一线治疗方案。中位rwPFS超过20个月，1年rwPFS率高于70%。

**研究结论**：三国的治疗有效性相似，且与关键临床试验结果一致。

本研究聚焦于最常见类型的晚期乳腺癌患者，详细描述了法国、意大利及西班牙在常规乳腺癌诊疗中接受阿贝西利联合内分泌治疗的患者特征、治疗方案及预后结局。本研究数据均来源于患者的病历档案。在本真实世界研究中，阿贝西利大多作为晚期乳腺癌的初始治疗方案。三国的阿贝西利治疗有效性并无显著差异，验证了既往研究结果。本研究支持阿贝西利用于HR+/HER2-晚期乳腺癌患者的临床应用。在法、意、西三国常规诊疗中接受阿贝西利治疗的患者以绝经后人群为主，平均年龄约60岁。患者初诊时的乳腺癌病理类型以非特异性浸润性癌为主。阿贝西利大多以一线联合芳香化酶抑制剂或氟维司群（fulvestrant）的方案给药。总体而言，多数起始接受阿贝西利治疗的患者初始剂量为每日2次、每次150mg。三国的停药率区间为45%~55%。真实世界肿瘤应答情况及rwPFS结果均支持阿贝西利用于HR+/HER2-晚期/转移性乳腺癌的临床应用。在三国中，接受一线及二线阿贝西利治疗的患者中位rwPFS均≥20个月，其中一线治疗患者的中位rwPFS最高。在治疗启动前及启动后的短期内，患者住院率均处于较低且相对稳定的水平。本研究结果证实了阿贝西利用于晚期/转移性乳腺癌患者的真实世界治疗有效性。