Epidermal Growth Factor Receptor (EGFR) T790M Mutation Testing Practices in Hong Kong

Study Overview
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Brief Summary
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To describe the T790M mutation status of patients with locally advanced/metastatic NSCLC who progressed on previous EGFR TKI treatment in a real-world setting.

Detailed Description
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This is a multi-center, observational study of patients with locally advanced/metastatic NSCLC who progressed on previous EGFR TKI treatment. Eligible patients will be recruited from participating sites in Hong Kong over a 12 months enrolment period. Plasma and urine samples will be collected from enrolled patients. Plasma circulating tumor DNA (ctDNA) and urine ctDNA will be analyzed by droplet digital PCR (ddPCR) for detection of T790M mutation and EGFR sensitizing mutations. Patients who are T790M plasma-negative, regardless of the urine testing results, will be recommended to undergo re-biopsy (defined as tissue sampling or cytology sampling), tissue/cytology T790M testing, and to provide a second plasma sample for a second plasma T790M test (tested by ddPCR). Enrolled patients who subsequently receive osimertinib treatment will be followed up as per routine practice at the investigational site. Patient data will be collected for 12 months or until death or loss to follow-up, whichever occurs earlier, from the first prescription of osimertinib. All clinical decisions will be at the discretion of the treating physician.

Official Title
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An Observational, Multi-centre Study on EGFR T790M Mutation Testing Practices and Outcomes Conducted Among Locally Advanced/Metastatic NSCLC Patients Who Progressed on Previous EGFR Tyrosine-kinase Inhibitor (TKI) Therapy in Hong Kong

Conditions
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Non-small Cell Lung Cancer

Intervention / Treatment
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* Diagnostic Test: Plasma-tissue testing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria Provision of written informed consent Locally advanced (stage IIIB) or metastatic (stage IV) NSCLC, not amenable to curative surgery or radiotherapy Confirmed EGFR sensitizing mutation (exon 19 deletion or exon 21 L858R ) in medical record Progressed on previous EGFR TKI treatment, based on physician judgement, with or without additional lines of treatment Suggested to undergo T790M mutation testing by treating physician, based on physician judgement Exclusion Criteria Had been treated with osimertinib or any other 3rd generation T790M inhibitors Enrollment in studies that prohibit participation in this observational study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 100 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| EGFR NSCLC Progressed on EGFR TKI<br>Patients with EGFR NSCLC who have progressed following EGFR TKI therapy will undergo plasma-tissue testing | Diagnostic Test: Plasma-tissue testing<br>* EGFR T790M mutation plasma-tissue testing in NSCLC patients who progressed on previous EGFR TKI<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| EGFR T790M mutation prevalance | Based on the plasma-tissue testing algorithm in NSCLC patients who progressed on previous EGFR TKI therapy | 3 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of Valid Tissue T790M Testing Result | Proportion of study subjects who have a valid tissue/cytology T790M testing result after receiving a negative plasma test result for the T790M mutation | 3 years | 
| T790M Plasma Outcome | Proportions of study subjects who are T790M plasma-negative | 3 years | 
| False Negative Proportation | Proportion of study subjects who are T790M plasma-negative but T790M tissue/cytology-positive | 3 years | 
| Reasons for not performing re-biopsy | reasons given for not performing re-biopsy and tissue/cytology testing after obtaining a negative plasma test result | 3 years | 
| Demographics | Demographics of T790M-positive subjects and T790M-negative subjects | Baseline | 
| Disease Characteristics | Disease characteristics of T790M-positive subjects and T790M-negative subjects | 3 years | 
| Number of particapants with complications assoicated with re-biopsy | Number of particapants with complications assoicated with tissue/cytology re-biopsy | 3 years | 
| Clinical Outcomes in T790M plasma-positive subejects | Clinical outcomes after osimertinib treatment between study subjects who are T790M plasma-positive | 3 years | 
| Clinical Outcomes in urine-positive | Clinical outcomes after osimertinib treatment between study subjects who are urine-positive | 3 years | 
| Clinical Outcomes in tissue/cytology-positive | Clinical outcomes after osimertinib treatment between study subjects who are tissue/cytology-positive | 3 years |