演題抄録

ワークショップ

開催概要
開催回
第58回・2020年・京都
 

ER陽性HER2陰性進行再発乳癌に対するCDK 4/6阻害剤の再投与における効果予測因子

演題番号 : WS9-1

[筆頭演者]
関 大仁:1 
[共同演者]
櫻井 孝志:1、樋下田 香織:2、石黒 勇輝:1、管野 正紀:1、小高 桂子:3、清水 健:4

1:埼玉メディカルセンター・乳腺外科、2:埼玉メディカルセンター・薬剤科、3:埼玉メディカルセンター・麻酔科、4:埼玉メディカルセンター・病理科

 

Background: Treatment for ER-positive HER2-negative metastatic breast cancer (ER+HER2- MBC) has been greatly improved with the development of Cyclin-dependent kinases CDK4 and 6 inhibitors (CDK 4/6 i). However, the usefulness of rechallenge with CDK 4/6 i beyond previous CDK 4/6 i-resistance for ER+HER2-MBC is uncertain.Patients and methods: Seventeen patients treated with abemaciclib (ABM) beyond palbociclib (PAL) for ER+HER2- MBC from December 2018 to March 2020 were included in the study.Results: The median observation period was 9.8 months. Of the study population, 76.5% were postmenopausal women and 29.4% were in stage IV. Fulvestrant (FUL) and aromatase inhibitors (AIs) in combination with previously given PAL (pre-PAL) accounted for 88.2% and 11.8%, respectively. The response rate (RR) was 41.2% and a progression-free interval (PFI) of≧6 months was 64.7% in those pre-PAL. FUL and AIs in combination with ABM accounted for 41.2% and 58.8%, respectively. The RR in ABM was 17.6% and was significantly associated with the best response ≧ partial response (PR) in those pre-PAL (P=0.029). Univariate analysis showed that the best response ≧ PR in those pre-PAL [hazard ratio (HR) 0.072 (0.009-0.583), P=0.014] and PFI ≧ 6 months in those previously given PAL [HR 0.148 (0.031-0.711), P=0.017] was significantly associated with progression-free survival (PFS) in ABM beyond pre-PAL. Moreover, multivariate analysis revealed that the best response ≧ PR in those pre-PAL was the only predictive factor for PFS in ABM beyond PAL [HR 0.048 (0.003-0.893), P=0.042]. With respect to adverse events (AE) during grade 3 treatment with ABM, fatigue affected 35.3%, appetite loss affected 29.4%, and neutropenia and diarrhea affected 17.6%. A total of 41.2% required a dose reduction, 11.8% required dose interruption due to grade 3 AE.
Conclusions: The best response ≧ PR in previously given CDK 4/6 i was the only independent predictive factor for rechallenge with CDK 4/6 i in ER+HER2- MBC.

キーワード

臓器別:乳腺

手法別:分子標的治療

前へ戻る