Advanced gastric cancer remains to be associated with high rates of mortality and morbidity, as effective therapies for the disease are not yet developed. This study aims to evaluate the antitumor activity of pembrolizumab, pembrolizumab plus chemotherapy, and pembrolizumab alone in patients with untreated, advanced gastric cancer.
This controlled, randomized, partially blinded trial included a total of 763 patients with untreated, locally advanced/unresectable or metastatic gastric cancer. The patients were randomly assigned in a 1:1 ratio to receive pembrolizumab, pembrolizumab plus cisplatin chemotherapy, or chemotherapy plus placebo. The primary outcomes of the study were overall survival (OS) and progression-free survival.
After a median follow-up of 29.4 months, pembrolizumab was found to be non-inferior to chemotherapy for overall survival in patients with PD-L1 combined positive score (CPS) of 1 or greater. Pembrolizumab was not superior to chemotherapy in patients with CPS of 1 or greater for prolonged survival. However, in patients with CPS of 10 or greater, pembrolizumab prolonged overall survival when compared with chemotherapy. However, pembrolizumab-chemotherapy was not superior to chemotherapy alone.
The research concluded that pembrolizumab was non-inferior to chemotherapy, and pembrolizumab plus chemotherapy was not superior to chemotherapy in patients with untreated, advanced gastric cancer.