Sequential pembrolizumab cooperates with platinum/5FU to remodel the tumor immune microenvironment in advanced gastric cancer: A phase II chemoimmunotherapy trial
Adding anti-PD1 antibodies to 5-FU/platinum chemotherapy improves survival in a subset of advanced gastroesophageal adenocarcinoma (GEA) patients.  Beyond PD-L1 expression and mismatch repair status we have limited insight into molecular predictors of response, or the relative contribution of PD-1 blockade. We conducted an investigator sponsored phase II trial (n = 47) sequentially adding pembrolizumab to standard 5-FU/platinum in previously untreated advanced GEA (ClinicalTrials.gov: NCT04249739). With an overall response rate of 67% the activity paralleled phase III chemoimmunotherapy trials.