Real-World Observational Study to Describe Treatment Patterns in Patients With HER2-Positive Locally Advanced or Metastatic Gastric or Gastroesophageal Junction Cancer in East Asia

Study Overview
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Brief Summary
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This study will be conducted to understand real-world treatment patterns, participant characteristics (demographic and clinico-pathological characteristics), clinical outcomes and safety of different treatment regimens, and healthcare resource utilization in East Asia for HER2-positive locally advanced or metastatic gastric or gastroesophageal adenocarcinoma (de novo advanced disease, relapsed/progressed) in a real-world setting.

Official Title
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A Multinational, Multicenter, Non-Interventional, Retrospective, Observational, Real-World Study: Treatment Patterns in Patients With HER2-Positive Locally Advanced or Metastatic Gastric or Gastroesophageal Junction Adenocarcinoma in East Asia (HER2+ GASTA Study)

Conditions
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Gastric Cancer

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult participants at the time of 1st LOT (Index Date 1e) initiation - Adult patients ≥18 years old. (Please follow local regulatory requirements if the legal age of consent for study participation is >18 years old.) Participants or next of kin/legal representatives who are willing to provide written informed consent as per the local regulations (if IRB/IEC/EC grants a permission to waive informed consent, it is not necessary). Participants who were pathologically and/or clinically diagnosed with locally advanced or metastatic gastric or gastroesophageal adenocarcinoma (de novo advanced disease, relapsed/progressed) since January 1, 2016, and its record is available at the study participating site. Participants whose HER2 status were pathologically confirmed HER2-positive (IHC3+ or IHC2+/ISH-positive) before/at the Index Date 2f based on the most recent archived tumor tissue sample to the Date of Diagnosisg, and its record is available at the study participating site. Participants who received at least 1 LOT for HER2-positive locally advanced or mGC/GEJC in an advanced setting, and its record is available at study participating site. Trastuzumab or its biosimilar use is not required. °Progression on or within 6 months post neoadjuvant or adjuvant therapy is counted as rapid progressor in a neo-adjuvant/adjuvant setting, and thus equivalent to advanced/metastatic disease failing 1 LOT. Participants who have at least 6 months of follow-up data from the date of 2nd LOT initiation (Index Date 2f) unless participant died within the first 6 months from the Index Date 2, and its record is available at the study participating site. For rapid progressor participants in a neo-adjuvant/adjuvant setting, Index Date 1 will be the date of neo-adjuvant treatment initiation or adjuvant treatment initiation. Exclusion Criteria: Participants with a change in HER2 status from positive to negative at progression from early-stage to advanced-stage disease (change from HER2-positive to HER2-negative on repeat biopsy during treatment for advanced stage can be participated). However, if HER2-positive was confirmed before the Date of Diagnosis (or if HER2-positive was confirmed using an archived tumor tissue sample collected during early stage) and the result was followed to make the decision for the 1st LOT, this is not the case. Participants who had multiple cancer within 3 years of 1st LOT initiation (Index Date 1), except adequately resected melanoma skin cancer, curatively treated in-situ disease, other solid tumors curatively treated. Participants who are participating or have participated in an interventional study that remains blinded at time of informed consent (IC) or at the time of data collection for participants whose IC is waived by the local IRB/EC/IEC.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants Receiving Each Regimen in Each Line of Treatment (LOT) | Percentage of participants receiving each regimen in each line of treatment (LOT) since 1st LOT initiation will be assessed. LOT is defined as one regimen, possibly a combination of several drugs, given from the date of initiation of each LOT until the treatment failed to control the disease, is not tolerated by the participant, at the time of disease relapse/progression or death. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Duration of Therapy for Each Regimen | Duration of Therapy (DoT) is defined as the length of time from initiation of each LOT to permanent discontinuation of the treatment. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Reasons for Stopping Treatments in Each Line of Treatment (LOT) | Reasons for stopping treatments will be ascertained by patient charts and assessed by frequency and percentage. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Treatment Sequencing Pathways | Treatment sequencing from 1st LOT to 2nd LOT and to the subsequent LOT will be assessed. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Percentage of Participants Receiving Locoregional Treatment for Localized Disease and Metastasis (Radiotherapy and/or Surgery) | Percentage of participants receiving locoregional treatment for localized disease and locoregional treatment for metastasis (radiotherapy and/or surgery) since 1st LOT initiation will be assessed. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Real World Progression Free Survival | Length of time from the date of initiation of LOT to the date of real-world disease progression or death due to any cause, whichever comes first. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Real Word Overall Survival | Length of time from the date of initiation of LOT to death due to any cause. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Real World Time to Treatment Failure | Length of time from the initiation of LOT to the date of real-world disease progression, treatment discontinuation, or death due to any cause, whichever occurs first. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Real World Time to Discontinuation | Length of time from the date the participant initiates the LOT to the date the participant discontinues that LOT or death due to any cause, whichever occurs first. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Real-world Time to Next Treatment | Length of time from the date the participant initiates the LOT to the date the participant initiates next LOT or death from any cause, whichever occurs first. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Real Word Objective Response Rate | Proportion of participants who achieved real-world complete response or real-world partial response to treatment for each LOT. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Real World Disease Control Rate | Proportion of participants with real-world complete response, real-world partial response and real-world stable disease during treatment for each LOT. | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Number of Deaths in Each Line of Treatment |  | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Cause of Death in Each Line of Treatment |  | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 
| Number of Participants with Adverse Events of Special Interest (AESI) In Each Line of Treatment |  | From the date of 1st line of treatment initiation to the end of follow-up, approximately 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Gastroesophageal Junction Adenocarcinoma, Gastric Cancer, Adenocarcinoma