Neoadjuvant palbociclib in women with operable, hormone receptor-positive breast cancer

Ueno, T; Chow, LWC; Han, W; Huang, CS; Mann, GB; Morita, S; Haga, H; Fakhrejahani, E; Kobayashi, T; Bando, H; Inoue, K; Tokiwa, M; Suwa, H; Aruga, T; Minamiguchi, S; Yamada, Y; Tanabe, Y; Takada, M; Yamashita, T; Iwata, H; Chung, CF; Takahara, S; Tokunaga, E; Imoto, S; Lee, ES; Sagara, Y; Kim, JH; DeBoer, RH; Kim, HA; Lai, HW; Hou, MF; White, M; Umeyama, Y; Toi, M

Author(s): Ueno, T; Chow, LWC; Han, W; Huang, CS; Mann, GB; Morita, S; Haga, H; Fakhrejahani, E; Kobayashi, T; Bando, H; Inoue, K; Tokiwa, M; Suwa, H; Aruga, T; Minamiguchi, S; Yamada, Y; Tanabe, Y; Takada, M; Yamashita, T; Iwata, H; Chung, CF; Takahara, S; Tokunaga, E; Imoto, S; Lee, ES; Sagara, Y; Kim, JH; DeBoer, RH; Kim, HA; Lai, HW; Hou, MF; White, M; Umeyama, Y; Toi, M;
Details: Publication Year 2025-09-01,Volume 32,Issue #9,Page e240353
Journal Title: Endocrine-Related Cancer
Publication Type: Research article
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.
Publisher: Bioscientifica
Keywords: Humans; Female; *Breast Neoplasms/drug therapy/metabolism/pathology/surgery; *Pyridines/therapeutic use/administration & dosage; *Piperazines/therapeutic use; Middle Aged; Double-Blind Method; Neoadjuvant Therapy; Aged; Adult; Receptors, Estrogen/metabolism; Receptor, ErbB-2/metabolism; Receptors, Progesterone/metabolism; *Antineoplastic Combined Chemotherapy Protocols/therapeutic use; Cdk4/6; breast cancer; neoadjuvant endocrine therapy; palbociclib; pre-operative endocrine prognostic index (PEPI)
Department(s): Medical Oncology
Publisher's Version: https://doi.org/10.1530/erc-24-0353
Open Access at Publisher's Site: https://doi.org/10.1530/erc-24-0353
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2025-10-28 02:33:57

Last Modified: 2025-10-28 02:36:22