This randomized, double-blind, placebo-controlled study involved postmenopausal patients with HR-positive, HER2-negative ABC that had failed with tamoxifen and/or nonsteroidal aromatase inhibitor...This is the first oral HDAC inhibitor combined with exemestane in a pivotal clinical study to demonstrate PFS benefit and manageable adverse effect in HR–positive ABC patients progressed after prior endocrine therapy.

...1.Adult female aged 18 years or older; 2.Eastern Cooperative Oncology Group (ECOG) performance status of 0–1; 3.Postmenopausal women, including natural menopausal and premenopausal reached the intervention level of menopause through ovarian function suppression or castrating therapy; 4.The primary breast tumor was pathologically confirmed as invasive carcinoma through puncture biopsy, clinical T2 - T4c, any N, M0(including unilateral ipsilateral supraclavicular lymph node involvement) which all performed by AJCC version 7 clinical staging, The primary tumor is required to be palpable on physical examination and to have a maximum tumor diameter of at least 2.0 cm based on physical examination or imaging evaluation; According to the criteria of the central laboratory, invasive carcinoma should be demonstrated by immunohistochemistry with estrogen receptor (ER) ratio >= 10% and/or progesterone receptor (PR) ratio >= 1%, HER2 negative (HER2 negative is defined as: IHC1+/IHC0;IHC2 + and FISH -; investigator-determined HER2 negative) 5.For tumor diseases, one preoperative neoadjuvant chemotherapy regimen is allowed, which requires early evaluation (2-4 courses) for poor efficacy, including stable disease (SD) after 2~4 courses of neoadjuvant therapy for newly diagnosed operable patients, and stable disease (SD) or progressive disease (PD) after 2~4 courses of neoadjuvant therapy for newly diagnosed inoperable patients 6.If receiving neoadjuvant chemotherapy, the primary breast tumor should be biopsied again when the efficacy was evaluated poor, ?the expression status of hormone receptor, HER2 and Ki67 should be determined, and only HR positive and HER2 negative can be considered for inclusion; 7.Absolute neutrophil count of at least 1500 cells per μL, platelet count of at least 100000 per μL, haemoglobin concentrations of 9.0 g/dL or higher, total bilirubin concentrations less than 1.5 times the upper limit of normal (ULN), alanine aminotransferase concentrations less than to 2.5 times the ULN , and serum creatinine concentrations less than 1.5 times the ULN; 8.To conduct holistic and comprehensive biomarker and related studies, patients should be volunteer to participate in this clinical trial by signing a written informed consent and?agree to provide the required biopsies at baseline and surgery (or termination of treatment)....

...- histologically or cytologically confirmed hormone receptor positive (ER positive, PR positive or negative), human epidermal growth factor receptor 2 negative # breast cancer patients;...

...women aged ≥ 18 years, histologically or cytologically confirmed HR positive (ER expression ≥ 10%, PR positive or negative), HER2 negative breast cancer patients; 2....

...Histologically or cytologically confirmed hormone receptor positive [estrogen receptor (positive, progesterone receptor (negative or positive) breast cancer patients; 3. ...

...Histological or cytologically confirmed breast cancer patients with ER or PR positive and HER-2 negative (hormone receptor positive), ER or PR negative and HER-2 negative (triple negative), and HER-2 positive. ...

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...Histologically confirmed HR positive and HER2 negative postmenopausal metastatic breast cancer patients [HER2 negative is defined as immunohistochemistry(IHC) 0 or IHC 1+, and if the score of IHC is 2+, fluorescence in situ hybridization technology (FISH) test must be negative, HR positve is defined as ER or PR ≥1%]; 3....

...- Breast cancer patients with HR positive (ER expression ≥ 10%, PR positive or negative) and HER2 negative (Immunohistochemical(IHC)0,1+; 2+, Fluorescence in situ hybridization(FISH)...

...Both postmenopausal and premenopausal for hormone receptor positive patients, but premenopausal patients need to be given concomitant ovarian function suppression (OFS) therapy (criteria for menopause: "Judgment Criteria for Menopause after Adjuvant Therapy and Consensus on Clinical Application of Aromatase Inhibitors for Premenopausal Female Breast Cancer Patients in China")....

...Histologically confirmed HR positive and HER2 negative postmenopausal metastatic breast cancer patients [HER2 negative is defined as immunohistochemistry(IHC) 0 or IHC 1+, and if the score of IHC is 2+, fluorescence in situ hybridization technology (FISH) test must be negative, HR positve is defined as ER or PR ≥1%;]; 3....

This MUKDEN 05 study aimed to assess the efficacy and toxicity of the combination of tucidinostat and EC-T as a neoadjuvant strategy in patients with HR+/HER2-, stage II-III breast cancer....ORR was 86% (95% CI, 70.6-93.7%). Four (15%; 95% CI, 5.91-32.5%) patients achieved bpCR, and one (4%; 95% CI, 0.67-18.3%) patients achieved tpCR.

The median PFS was 7.2 (95% CI, 5.83-8.49) months. In the 17 efficacy evaluable pts, the ORR was 17.6% (95% CI, 3.8%-43.4%), DCR was 88.2% (95% CI, 63.6%-98.5%)...Chidamide combined with fulvestrant showed encouraging antitumor activity and tolerable toxicity in pts with HR-positive and HER2-negative advanced breast cancer that had progressed after previous endocrine therapy.

Between July 2020 and July 2022, 26 patients were enrolled, of whom 24 were evaluable for response per RECIST 1.1 criteria. Partial response (PR) was observed in 18 patients, with an ORR of 75% (18/24). The DCR was 100%...Tucidinostat combined with exemestane was well tolerated and demonstrated meaningful responses in neoadjuvant setting for women with early HR+/HER2- breast cancer.

The pathological and clinical data of 44 HR-positive and HER2-negative breast cancer patients treated with tucidinostat...The CBR was 6.8% (3/44), the median PFS was 2.0 months (95% CI 1.9-2.1), and the median OS was 14 months (95% CI 6.3-21.7). The mPFS was 4.1 months (95%CI: 0-8.2) in patients with 1 metastatic site, and the mPFS was 4.5 months (95%CI: 4.2-4.8) in patients who received sequential tucidinostat after CDK4/6i failure...This study preliminarily shows that tucidinostat combined with endocrine therapy may be an optional sequential strategy for patients with HR+/HER2-advanced breast cancer that has progressed on CDK4/6 inhibitor...

Patients with HR-positive, HER2-negative, and node-positive, stage II–III breast cancer were enrolled at Tianjin Medical University Cancer Institute and Hospital. Eligible patients received 30 mg oral tucidinostat twice weekly in combination with 25 mg oral exemestane….The ORR was 40% with CR 5% (n=1) and PR 35% (n=7). The DCR was 100%....The combination of Tucidinostat and exemestane was well tolerated with encouraging clinical responses in early hormone receptor positive, HER2 negative breast cancer.