Globally, gastric cancer is a major cause of cancer mortality, with a 5-year survival rate of 32% for locally advanced and metastatic gastric cancer. This systematic literature review summarized the clinical, safety, and humanistic outcomes associated with systemic regimens given as first line therapy for locally advanced and metastatic gastric cancer. The search included articles published in English in PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and the American Society of Clinical Oncology meeting library, from inception to April 2022. Phase II and III randomized controlled trials conducted among western populations diagnosed with stage III and IV locally advanced and metastatic gastric cancer were included. Two investigators independently reviewed the studies, conducted data extraction, and assessed risk of bias in accordance with PRISMA guidelines. Twenty-four randomized controlled trials totaling 8,705 patients were included. Median overall survival ranged from 5.0-13.1 months, median progression-free survival ranged from 2.0-7.7 months, and objective response ranged from 13.0-64.1%. Two studies reported higher quality of life outcomes. Grade 3 and 4 adverse events were reported in most studies. Improvement in clinical outcomes can be seen in recently published randomized controlled trials for locally advanced and metastatic gastric cancer.