Study of Dalpiciclib Combined With Letrozole in the Maintenance Treatment of HR Positive and HER2 Negative Metastatic Breast Cancer After First-line Chemotherapy

Study Overview
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Brief Summary
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This study aimed to evaluate the efficacy and safety of Dalpiciclib combined with Letrozole in the maintenance treatment of HR positive and HER2 negative metastatic breast cancer after first-line chemotherapy.

Official Title
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A Multicenter, Single Arm, Prospective Phase II Clinical Study of Dalpiciclib Combined With Letrozole in the Maintenance Treatment of HR Positive and HER2 Negative Metastatic Breast Cancer After First-line Chemotherapy

Conditions
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Breast Cancer

Intervention / Treatment
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* Drug: Dalpiciclib combined with Letrozole


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Has the pathologically-confirmed diagnosis of locally recurrent or metastatic, hormone-receptor positive, HER2 negative Breast Cancer. Age: 18 - 75 years old Eastern Cooperative Oncology Group performance status (ECOG PS)=0 1 Functions of liver and kidney is normal Agreed to take contraceptive measures during treatment Exclusion Criteria: Confirmed diagnosis of HER2 positive disease. Central nervous system metastasis Patients who received prior treatment with any CDK4/6 inhibitor. Clinically significant cardiovascular and cerebrovascular diseases,including but not limited to severe acute myocardial infarction within 6 months before enrollment, unstable or severe angina, Congestive heart failure (New York heart association (NYHA) class > 2), or ventricular arrhythmia which need medical intervention； Researchers believe that is not suitable for the study

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 combined with 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 combined with Letrozole<br>* A multicenter, single arm, prospective Phase II clinical study<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Progression Free Survival (PFS) | The time from the enrollment of the subject until the first recording of tumor progression (evaluated according to RECIST 1.1 criteria) or death from any cause. | Estimated up to 23 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Progression Free Survival 2(PFS2) | The time from the first chemotherapy for the metastatic stage by the subject to the first recording of tumor progression (evaluated according to RECIST 1.1 standards) or death from any cause. | Estimated up to 27-31 months |