Neoadjuvant palbociclib in women with operable, hormone receptor-positive breast cancer
Journal
Endocrine-Related Cancer
Series/Report No.
Endocrine Related Cancer
Journal Volume
32
Journal Issue
9
ISSN
1351-0088
1479-6821
Date Issued
2025-09-01
Author(s)
Ueno, Takayuki
Chow, Louis W C
Han, Wonshik
Mann, G Bruce
Morita, Satoshi
Haga, Hironori
Fakhrejahani, Elham
Kobayashi, Takayuki
Bando, Hiroko
Inoue, Kenichi
Tokiwa, Mariko
Suwa, Hirofumi
Aruga, Tomoyuki
Minamiguchi, Sachiko
Yamada, Yosuke
Tanabe, Yuko
Takada, Masahiro
Yamashita, Toshinari
Iwata, Hiroji
Chung, Chi-Feng
Takahara, Sachiko
Tokunaga, Eriko
Imoto, Shigeru
Lee, Eun Sook
Sagara, Yasuaki
Kim, Jee Hyun
DeBoer, Richard H
Kim, Hyun-Ah
Lai, Hung Wen
Hou, Ming Feng
White, Michelle
Umeyama, Yoshiko
Toi, Masakazu
Abstract
The addition of a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor to endocrine therapy augments biological response in breast cancer. This phase III randomized, double-blind study evaluated the efficacy of adding palbociclib to neoadjuvant endocrine therapy (NET) for operable, hormone receptor-positive human epidermal growth factor receptor 2 (HER2)-negative breast cancer. Patients randomly received 16 weeks of endocrine therapy (letrozole for postmenopausal and tamoxifen plus ovarian function suppression for pre-/perimenopausal patients) plus palbociclib or placebo. The co-primary endpoints included preoperative endocrine prognostic index (PEPI) score and EndoPredict (EPclin) risk score according to the gatekeeping procedure. Of 141 randomized patients, 130 completed the treatment with surgical samples evaluable for endpoints in 126 patients. The proportion of patients with a low, moderate, and high PEPI score was 15.2, 50.0, and 34.8% in the palbociclib arm and 13.3, 55.0, and 31.7% in the placebo arm, respectively, with no statistical difference (one-sided P = 0.563). Statistical analysis was not performed on EPclin risk score. No new safety signals were reported. Permanent treatment discontinuation by adverse events was reported for seven (9.7%) and zero patients in the palbociclib and placebo arms, respectively. In conclusion, the addition of palbociclib to NET did not improve the efficacy. ClinicalTrials.gov NCT03969121.
Subjects
CDK4/6
breast cancer
neoadjuvant endocrine therapy
palbociclib
pre-operative endocrine prognostic index (PEPI)
SDGs
Publisher
Bioscientifica
Type
journal article