Abstract Background Platinum/fluoropyrimidine regimens are the backbone of first-line chemotherapy for advanced gastric cancer (AGC). However response rates to first line chemotherapy range from 30 to 50% and disease progression occurs after 4–6 cycles. The optimal duration of first-line therapy is still unknown and its continuation until disease progression represents the standard. However this strategy is often associated with cumulative toxicity and rapid development of drug resistance. Moreover, only about 40% of AGC pts. are eligible for second-line treatment. Methods This is a randomized, open-label, multicenter phase III trial. It aims at assessing whether switch maintenance to ramucirumab plus paclitaxel will extend the progression-free survival (PFS) of subjects with HER-2 negative AGC who have not progressed after 3 months of a first-line with a platinum/fluoropyrimidine regimen (either FOLFOX4, mFOLFOX6 or XELOX). The primary endpoint is to compare Progression-Free Survival (PFS) of patients in ARM A (switch maintenance to ramucirumab and placlitaxel) versus ARM B (continuation of the same first-line therapy with oxaliplatin/fluoropyrimidine). Secondary endpoints are: overall survival, time-to-treatment failure, overall response rate, duration of response, percentage of patients that will receive a second line therapy according to arm treatment, safety, quality of life. Exploratory studies including Next-Generation Sequencing (NGS) in archival tumor tissues are planned in order to identify potential biomarkers of primary resistance and prognosis. Discussion The ARMANI study estimates if patients treated with early swich with ramucirumab plus paclitaxel received benefit when compared to those treated with continuation of first line therapy. The hypothesis is that the early administration of an active, non-cross resistant second-line regimen such as ramucirumab plus paclitaxel may prolong the time in which patients are progression-free, and consequently have a better quality of life. Moreover, this strategy may rescue all those subjects that become ineligible for second-line therapy due to the rapid deterioration of health status after the first disease progression. Trial registration ARMANI is registered at ClinicalTrials.gov (NCT02934464, October 17, 2016) and EudraCT(2016–001783-12, April 202,016).