Observation Only Study Involving Participants Enrolled in the CHAT Trial

Study Overview
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Brief Summary
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The aim of the CHAT study (An open-label, randomized Phase II study of Herceptin (trastuzumab), Taxotere® (docetaxel) and Xeloda (capecitabine) in combination, versus Herceptin (trastuzumab) plus Taxotere® (docetaxel), in patients with advanced and/or metastatic breast cancers that overexpress HER2) was to test the combination of Trastuzumab and Docetaxel with or without capecitabine as first-line therapy for HER2 positive locally advanced or metastatic breast cancer. Overall Response Rate was the primary endpoint of the CHAT study. This study failed to meet its primary objective of showing a difference between the treatment groups, with equivalent high response rates for the Trastuzumab plus Docetaxel and Trastuzumab, Docetaxel plus capecitabine arms. Secondary endpoints in the CHAT study were Progression-Free-Survival, Time-to-Progression, Overall Survival, duration of response and safety profile. Whilst analysis of the existing data is consistent with improvement with the triplet therapy, interpretation is compromised by the relatively short median follow-up of 24 months. In hindsight the statistical design was flawed by selection of a sub optimal primary endpoint and consequently data was collected and analysed early in relation to time-dependent endpoints. Beyond CHAT will permit capture of mature data for time-related endpoints. Time-to-Progression and Overall Survival are the co-primary endpoints for the Beyond CHAT protocol. The impact of treatment following the first progression, on survival, will be explored. Time-to-Progression will be defined from the time interval between the date of randomisation and the occurrence of progressive disease under therapy according to RECIST criteria. Overall Survival will be defined as the time from date of randomisation to date of death

Detailed Description
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The objective of this study is to gain mature data on the long-term efficacy of the combination of Trastuzumab and Docetaxel with or without capecitabine as first-line therapy for HER2 positive locally advanced or metastatic breast cancer. The study also aims to gain information on the additional treatments and sequencing used in patients that have progressed following the combination of Trastuzumab and Docetaxel with or without capecitabine as first-line therapy for HER2 positive locally advanced or metastatic breast cancer. Overall Survival data on patients who have progressed following the combination of Trastuzumab and Docetaxel with or without capecitabine as first-line therapy for HER2 positive locally advanced or metastatic breast cancer will also be analysed and reported.

Official Title
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Follow-Up Observational Study In CHAT Trial Participants With Advanced And/Or Metastatic Breast Cancers That Overexpress HER2, Who Were Randomised To Receive Trastuzumab And Docetaxel With Or Without Capecitabine

Conditions
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Breast Cancer

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: CHAT trial participants whose data was used in the final data analysis for the CHAT study Exclusion Criteria: Any patients who have withdrawn consent to the CHAT study
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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| CHAT trial participants<br>CHAT trial participants whose data was used in the final data analysis for the CHAT study | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The primary endpoints are Time-to-Progression and Overall Survival in the two treatment arms of the CHAT study. |  | survival | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Progression-Free-Survival |  | 7 years | 
| Overall Survival |  | 7 years | 
| Anatomical sites of progression |  | 7 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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CHAT, breast cancer, non interventional observational study