Dalpiciclib Combined With Letrozole in Neoadjuvant Treatment of Stage Ⅱ-Ⅲ HR-positive/HER2-negative Breast Cancer

Study Overview
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Brief Summary
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This is a single-arm, open-label, exploratory clinical study

Detailed Description
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This is a single-arm, open-label, exploratory clinical study initiated by the investigator to evaluate the objective response rate (ORR), efficacy, and safety of Dalpiciclib combined with letrozole in the neoadjuvant treatment of stage Ⅱ-Ⅲ HR+/HER2- breast cancer.

Official Title
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An Exploratory Clinical Study of CDK4/6 Inhibitor Dalpiciclib Combined With Letrozole in Neoadjuvant Treatment of Stage Ⅱ-Ⅲ HR-positive/HER2-negative Breast Cancer

Conditions
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Solid Tumor

Intervention / Treatment
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* Drug: Dalpiciclib


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 1. Postmenopausal women aged ≥18 years, the definition of postmenopausal: the patients with the history of bilateral oophorectomy, or age ≥ 60 years; or Age <60, natural postmenopausal state (defined as the spontaneous cessation of regular menstruation for at least 12 consecutive months, without other pathological or physiological causes), E2 and FSH at the postmenopausal levels 2. All patients were estrogen receptor (ER) positive (>10%), HER2 -negative invasive breast cancer regardless of PR expression level. Immunohistochemistry (IHC) score of 0+, or 2+ confirmed by pathology laboratory and negative in situ hybridization (ISH) test (HER-2/CEP17 ratio <2.0); 3. Treatment-naive patients with stage Ⅱ-Ⅲ tumors whose tumor staging meets the criteria of the 8th edition of the American Joint Committee on Cancer (AJCC) Staging; Exclusion Criteria: 1. Received any form of anti-tumor therapy (chemotherapy, radiotherapy, molecular targeted therapy, endocrine therapy, etc.) 2. Concurrently receiving any other anti-tumor therapy that those specified in the protocol; 3. Bilateral breast cancer, inflammatory breast cancer, or occult breast cancer; 4. Stage Ⅳ breast cancer;

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dalpiciclib+ letrozole<br>Dalpiciclib combined with Letrozole,28 days as one cycle. Dalpiciclib: 150 mg (p.o.) was given once daily for 3 weeks, followed by 1 week off in each 4-week cycle. Letrozole: 2.5mg, p.o., once a day, continuous administration. | Drug: Dalpiciclib<br>* An exploratory study of a single-arm, open design All subjects enrolled will receive the following treatment: Dalpiciclib combined with Letrozole, 28 days as one cycle.<br>* Other names: Letrozole;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ORR | Objective response rate | 24 month |