Cinrebafusp Alfa in Combination With Ramucirumab and Paclitaxel in HER2-High Gastric or GEJ Adenocarcinoma and in Combination With Tucatinib in HER2-Low Gastric or GEJ Andenocarinoma

This is a multi-center, open-label study of cinrebafusp alfa in combination with clinically established doses of ramucirumab and paclitaxel in patients with HER2-positive (IHC 3+ or IHC 2+ with HER2/neu gene amplification) gastric or GEJ adenocarcinoma (Arm 1) and in combination with tucatinib in patients with low levels of HER2 (IHC 1+ or IHC 2+ without HER2/neu amplification) (Arm 2).