DS-8201a in Patients With Cancer That Tests Positive for Human Epidermal Growth Factor Receptor 2 (HER2) Protein

Study Overview
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Brief Summary
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HER2-positive cancer is a cancer that tests positive for a protein called human epidermal growth factor receptor 2 (HER2). HER2 promotes the growth of certain cancer cells. This study will test DS-8201a (trastuzumab deruxtecan), a HER2-targeted antibody and topoisomerase I inhibitor conjugate. The safety and tolerability profile of DS-8201a will be assessed in Chinese patients with certain types of stomach and breast cancer that test positive for HER2. It also will test how DS-8201a moves within the body (pharmacokinetics).

Detailed Description
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The expected time from the first subject's enrollment until the last subject's enrollment is approximately 8 months. The screening period is 28 days and each cycle of treatment is 21 days. The number of treatment cycles is not fixed in this study. Subjects who continue to derive clinical benefit from the study drug in the absence of withdrawal of consent, progressive disease (PD), or unacceptable toxicity may continue the study drug.

Official Title
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Phase 1, Multicenter, Open-label Study of DS-8201a to Assess Safety and Pharmacokinetics in Subjects With HER2-Positive Advanced and/or Refractory Gastric, Gastroesophageal Junction Adenocarcinoma, or Breast Cancer

Conditions
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Adenocarcinoma, Gastric, Neoplasm, Breast

Intervention / Treatment
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* Drug: DS-8201a


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Has a pathologically documented unresectable or metastatic gastric or GEJ adenocarcinoma, or breast cancer, with HER2 expression [immunohistochemistry (IHC) 3+, 2+, or 1+ and/or in situ hybridization (ISH) +] that is refractory to or intolerable with standard treatment, or for which no standard treatment is available Has a left ventricular ejection fraction (LVEF) ≥ 50% Has an Eastern Cooperative Oncology Group performance status (ECOG PS) score of 0 or 1 Exclusion Criteria: Has a medical history of myocardial infarction within 6 months before enrollment Has a medical history of ventricular arrhythmias, other than rare occasional premature ventricular contractions Has uncontrolled or significant cardiovascular disease Has any other history or condition that might compromise: Safety of the participant or offspring Safety of study staff Analysis of Results

Ages Eligible for Study
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Minimum Age: 20 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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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: DS-8201a<br>DS-8201a administered by intravenous infusion on Day 1 of each cycle, once every 3 weeks (Q3W) | Drug: DS-8201a<br>* An antibody drug conjugate<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Treatment-emergent Adverse Events Following Treatment With DS-8201a (Trastuzumab Deruxtecan) | Adverse events (AEs) were to be coded using MedDRA Version 20.1 and assigned severity grades based on Common Terminology Criteria for Adverse Events (CTCAE) Version 4.03. A treatment-emergent adverse event (TEAE) was defined as an AE that occurred, having been absent before the first dose of study drug, or had worsened in severity or seriousness after initiating the study drug until 47 days after last dose of study drug. | Baseline up to withdrawal of consent, progressive disease, or unacceptable toxicity (whichever came first), up to approximately 5 months post-dose | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pharmacokinetic Parameter of Maximum (Peak) Observed Serum Concentration (Cmax) Following Cycle 1 and Cycle 3 Treatment With DS-8201a (Trastuzumab Deruxtecan) | Maximum concentration (Cmax) of DS-8201a and total anti-HER2 antibody was assessed. | Cycles 1 and 3, Day 1: before infusion (BI), end of infusion (EOI), 2 hours, 4 hours, 7 hours; Days 2 and 4, 24 hours, 72 hours; Days 8, and 15; Cycles 2, 4, 6 and 8, Day 1: BI and EOI | 
| Pharmacokinetic Parameter of Maximum (Peak) Observed Serum Concentration (Cmax) of MAAA-1181a Following Cycle 1 and Cycle 3 Treatment With DS-8201a (Trastuzumab Deruxtecan) | Maximum concentration (Cmax) of MAAA-1181a was assessed. | Cycles 1 and 3, Day 1: before infusion (BI), end of infusion (EOI), 2 hours, 4 hours, 7 hours; Days 2 and 4, 24 hours, 72 hours; Days 8, and 15; Cycles 2, 4, 6 and 8, Day 1: BI and EOI | 
| Pharmacokinetic Parameter of Area Under the Serum Concentration-time Curve During Dosing Interval (AUCtau) Following Cycle 1 and Cycle 3 Treatment With DS-8201a (Trastuzumab Deruxtecan) | Area under the serum concentration-time curve during dosing interval (AUCtau) of DS-8201a and total anti-HER2 antibody was assessed. | Cycles 1 and 3, Day 1: before infusion (BI), end of infusion (EOI), 2 hours, 4 hours, 7 hours; Days 2 and 4, 24 hours, 72 hours; Days 8, and 15; Cycles 2, 4, 6 and 8, Day 1: BI and EOI | 
| Pharmacokinetic Parameter of Area Under the Serum Concentration-time Curve During Dosing Interval (AUCtau) of MAAA-1181a Following Cycle 1 and Cycle 3 Treatment With DS-8201a (Trastuzumab Deruxtecan) | Area under the serum concentration-time curve during dosing interval (AUCtau) of MAAA-1181a was assessed. | Cycles 1 and 3, Day 1: before infusion (BI), end of infusion (EOI), 2 hours, 4 hours, 7 hours; Days 2 and 4, 24 hours, 72 hours; Days 8, and 15; Cycles 2, 4, 6 and 8, Day 1: BI and EOI | 
| Best Overall Response By The Investigator's Assessment (Unconfirmed) in Participants With HER2-Positive Advanced and/or Refractory Gastric, Gastroesophageal Junction Adenocarcinoma, or Breast Cancer | Best overall response (BOR) was assessed by the investigator based on Response Evaluation Criteria In Solid Tumors (RECIST) version 1.1. Complete response (CR) was defined as a disappearance of all target lesions, PR was defined as at least a 30% decrease in the sum of diameters of target lesions, and stable disease (SD) was defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease (PD; at least a 20% increase in the sum of diameters of target lesions. | Baseline up to withdrawal of consent, progressive disease, or unacceptable toxicity (whichever came first), up to approximately 5 months post-dose | 
| Objective Response Rate (Unconfirmed) As Assessed in Participants With HER2-Positive Advanced and/or Refractory Gastric, Gastroesophageal Junction Adenocarcinoma, or Breast Cancer | Objective response rate (ORR; defined as participants who achieved CR and PR) was assessed by the investigator based on Response Evaluation Criteria In Solid Tumors (RECIST) version 1.1. CR was defined as a disappearance of all target lesions and PR was defined as at least a 30% decrease in the sum of diameters of target lesions. | Baseline up to withdrawal of consent, progressive disease, or unacceptable toxicity (whichever came first), up to approximately 5 months post-dose | 
| Disease Control Rate (Unconfirmed) As Assessed in Participants With HER2-Positive Advanced and/or Refractory Gastric, Gastroesophageal Junction Adenocarcinoma, or Breast Cancer | Disease control rate (DCR; defined as participants who achieved CR, PR, and SD) was assessed by the investigator based on Response Evaluation Criteria In Solid Tumors (RECIST) version 1.1. CR was defined as a disappearance of all target lesions, PR was defined as at least a 30% decrease in the sum of diameters of target lesions, and SD was defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD defined as at least a 20% increase in the sum of diameters of target lesions. | Baseline up to withdrawal of consent, progressive disease, or unacceptable toxicity (whichever came first), up to approximately 5 months post-dose | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Stomach cancer, Cancer where the esophagus meets the stomach, Human epidermal growth factor 2, HER2, Breast Cancer, Adenocarcinoma, Gastroesophageal Junction (GEJ), Gastric Cancer, Antibody drug conjugate (ADC), Oncology