Brief Summary
This study is being done to find out if zanidatamab, when given with chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells plus or minus tislelizumab, is safe and works better than trastuzumab given with chemotherapy.
The patients in this study will have advancedat a late stage, far along human epidermal growth factor 2 (HER2)-positive stomach and esophageal cancers that are no longer treatable with surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence (unresectable) or chemoradiation, and/or have grown or spread to other parts of the body (metastatic).
Intervention / Treatment
- Drug: Zanidatamab
- Drug: Tislelizumab
- Drug: Trastuzumab
- Drug: Capecitabine
- Drug: Oxaliplatin
- Drug: Cisplatin
- Drug: 5-Fluorouracil
Inclusion Criteria
- Histologically confirmed unresectable locally advanced, recurrent or metastatic HER2-positive gastroesophageal adenocarcinomacancer arising from mucus-producing glands in organs (adenocarcinomas of the stomach or esophagus, including the gastroesophageal junction), defined as 3+ HER2 expression by IHC or 2+ HER2 expression by IHC with ISH positivity per central assessment. Subjects with esophageal adenocarcinoma must not be eligible for combined chemoradiotherapy at the time of enrollment
- Assessable (measurable or non-measurable) disease as defined by RECIST 1.1
- Eastern Cooperative Oncologythe study, diagnosis and treatment of cancer Group (ECOG) performance status score of 0 or 1, assessed within 3 days prior to randomization
- Adequate organ function
- Left ventricular ejection fraction (LVEF) ≥ 50% as determined by either echocardiograma type of ultrasound that uses sound waves to create detailed images of the heart to assess heart structure, function and blood flow or multiple gated acquisition scan (MUGA)