Tucatinib Plus Trastuzumab and Oxaliplatin-based Chemotherapy or Pembrolizumab-containing Combinations for HER2+ Gastrointestinal Cancers

Inclusion Criteria

• •Participants must have an unresectable or metastatic solid malignancy that is histologically or cytologically confirmed to be one of the tumor types listed below:
• •* Cohorts 1A, 1B, 1C, and 1D
• •* CRC
• •* Gastric adenocarcinoma
• •* GEJ adenocarcinoma
• •* Esophageal adenocarcinoma
• •* Cholangiocarcinoma
• •* Gallbladder carcinoma
• •* Cohorts 1E, 1F, 1G, and 2A
• •* Gastric adenocarcinoma
• •* GEJ adenocarcinoma
• •* Esophageal adenocarcinoma
• •* Cohort 2B
• •* CRC
• •Participants must be candidates to receive an oxaliplatin-based regimen as part of their standard-of-care treatment for all cohorts, except Cohort 1G.
• •HER2+ disease, as determined by historic or local laboratory testing
• •Phase 1b cohorts: measurable or non-measurable disease according to RECIST v1.1 as determined by the investigator
• •Phase 2 cohorts: measurable disease according to RECIST v1.1 as determined by the investigator
• •Eastern Cooperative Oncology Group Performance Status score of 0 or 1.