Futibatinib With Paclitaxel and Ramucirumab for the Treatment of Locally Advanced or Unresectable Gastric, Gastroesophageal Junction, or Esophageal Adenocarcinoma

Inclusion Criteria: * Patients must have histologically or cytologically confirmed locally advanced/unresectable gastric, gastroesophageal junction, or esophageal adenocarcinoma that is microsatellite stable and HER2 negative. (American Joint Committee on Cancer \[AJCC\] staging criteria; https://pmc.ncbi.nlm.nih.gov/articles/PMC5387145/) * Note: Histological or cytological test reports from external laboratories outside of Northwestern University (NU) will also be accepted * Patients must have measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 * Note: Patients must have documented unresectable and/or metastatic disease on CT or MRI imaging completed prior to registration. Imaging must have been completed within 90 days prior to registration for participants with measurable disease * Patients must not have received more than 1 prior line of therapy in the metastatic setting. * Note: Patients who have received neoadjuvant or adjuvant therapy must have completed therapy a year prior to registration in this study. Exception: patients with neoadjuvant or adjuvant therapy who have progressed within 6 months * Patients must be age ≥ 18 years * Patients must exhibit an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Leukocytes (white blood cells \[WBC\]) ≥ 2,000/mcL * Absolute neutrophil count (ANC) ≥ 1500/mcL * Hemoglobin (Hgb) ≥ 9 g/dL (transfusions within 1 week of registration are not allowed to meet cutoff) * Plat…