Abemaciclib plus endocrine therapy in chemotherapy-treated patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer.

Authors

Kazutaka Narui, Kana Miyahara, Yukari Uemura, Akimitsu Yamada, Kazuhiro Araki, Fumie Fujisawa, Takahiro Nakayama, Takashi Ishikawa, Hirohito Seki, Kimito Yamada, Masahiro Kitada, Takayuki Iwamoto, Naruto Taira, Yuichiro Kikawa, Tomohiko Aihara, Hirofumi Mukai

Published in

Breast cancer (Tokyo, Japan). Jul 06, 2026. Epub Jul 06, 2026.

Abstract

Cyclin-dependent kinase (CDK) 4/6 inhibitors with endocrine therapy are the standard first- and second-line treatments for hormone receptor-positive (HR+) human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). In clinical practice, however, CDK4/6 inhibitors are also used in patients previously treated with chemotherapy, but their efficacy and safety in this setting remain unclear.
We conducted a multi-institutional prospective cohort study to obtain real-world evidence regarding the clinical efficacy and safety of combination therapy with abemaciclib and endocrine therapy in chemotherapy-treated patients with HR+/HER2- MBC.
Between December 2019 and November 2022, 181 patients were registered. The median progression-free survival (PFS) and overall survival periods for abemaciclib were 10.3 months and 25.2 months, respectively. The median number of endocrine therapies for MBC was one regimen. The median PFS period of the patients treated with abemaciclib as maintenance therapy after chemotherapy was 13.8 months. The median PFS period of patients with prior treatment history with CDK4/6 inhibitor (palbociclib) was 6.6 months. Patients with one or two chemotherapy regimens in the previous line had a significantly longer PFS period than those with three or more regimens. Regarding safety, severe adverse events were observed; these were consistent with known abemaciclib profile.
Abemaciclib with endocrine therapy demonstrates considerable efficacy and manageable safety in chemotherapy-treated HR+/HER2-MBC. Notably, the > 1-year PFS observed when used as maintenance therapy, in the absence of disease progression, underscores its potential clinical utility.

PMID:
42406276
Bibliographic data and abstract were imported from PubMed on 06 Jul 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.