(ii) Histologically-confirmed gastric, esophageal, or gastroesophageal adenocarcinoma that is metastatic or locally recurrent (7th Edition of the AJCC TNM System) and measurable or non-measurable by RECIST 1.1 criteria with HER2/neu overexpression by immunohistochemistry (2+,3+) or FISH+ and progressive disease despite having received at least 1 prior HER2 targeted therapy for a minimum of 9 weeks duration) (determined by their physician). or with previously documented HER2 over-expressing disease not being currently treated on a HER2 targeted therapy.