Background: Patients with advanced gastric cancer experience a 5 year survival rate <10% even with multimodality therapy representing a clear unmet need for improved treatment. In advanced gastric and gastroesophageal junction (GEJ) adenocarcinoma, ramucirumab (a monoclonal antibody against VEGFR2) has demonstrated clinical activity and has been approved as second line therapy in combination with paclitaxel with a response rate of 28% and absolute overall survival benefit of 8 weeks when compared to placebo. However, there are many patients that cannot tolerate paclitaxel due to prior exposure to oxaliplatin causing neuropathy. Therefore, novel combinations with ramucirumab, is highly desirable. TAS-102 is an oral cytotoxic agent with two active components; trifluridine (TFD) which inhibits tumor cell growth by being incorporated into DNA during DNA synthesis and tipiracil (TPI) which inhibits the metabolism of TFD, thereby prolonging its ability to exert effect. TPI also inhibits platelet derived endothelial cell growth factor which plays a key role with VEGF in tumor angiogenesis. The combination of a cytotoxic agent with an antiangiogenic agent has demonstrated a significant anticancer activity in multiple cancers. In a recent Phase III study, TAS-102 significantly prolonged overall survival as compared to best supportive care in patients with GEJ and gastric cancers that had received at least 2 prior lines of treatment. We hypothesize that a combination of TAS-102 and ramucirumab might increase efficacy without causing unmanageable toxicity. Methods: This is a single institutional phase II single arm two-stage design trial using the combination of TAS-102 and ramucirumab in advanced, refractory gastric or GEJ adenocarcinoma. Eligible patients include those with histologically confirmed gastric or GEJ adenocarcinoma that have received at least 1 prior line of treatment with performance status 0 or 1 and preserved organ function. Ramucirumab will be administered 8mg/kg every 2 weeks and TAS-102 at doses of 35 mg/m² twice daily. Each cycle length will be 28 days. The primary endpoint is 6 month OS and secondary endpoints are safety, objective response rate and PFS. Fifteen patients will be enrolled in the first stage. If ≥ 7 of the 15 are alive at 6 months, an additional 10 patients will be enrolled in the second phase. Enrollment is currently ongoing. Clinical trial information: NCT03686488