Research in context
Evidence before this study
We searched PubMed on April 22, 2016, to identify studies of PD-1 or PD-L1 inhibitors in stomach and gastro-oesophageal junction cancer. The search was limited to English-language articles published in the past 5 years. Search terms were (MK-3475 OR lambrolizumab OR pembrolizumab OR nivolumab OR BMS-936558 OR MPDL3280A OR atezolizumab OR BMS-936559 OR MEDI4736 OR durvalumab OR CT-011 OR pidilizumab) AND (gastric cancer OR stomach cancer OR gastroesophageal junction cancer). The search identified one case report of a patient with microsatellite-stable gastric cancer who had an objective response to pembrolizumab treatment. We did not identify any published studies of PD-1 or PD-L1 inhibitors in a larger cohort of patients with gastric cancer.
Added value of this study
To our knowledge, KEYNOTE-012 is the first study to report results from a cohort of patients with previously treated advanced gastric cancer who received an anti-PD-1 or anti-PD-L1 monoclonal antibody. Our results suggest that pembrolizumab can be safely given to patients with advanced gastric cancer and that it has clinically meaningful antitumour activity in a mostly pretreated population. Importantly, we saw no differences in the safety or antitumour activity profiles between patients enrolled in Asia and those enrolled in the rest of the world.
Implications of all the available evidence
Overall, these data support the importance of the PD-1 pathway in gastric cancer, show the safety and antitumour activity of pembrolizumab in patients with previously treated advanced gastric cancer, and support further investigation of pembrolizumab as an anticancer therapy for advanced gastric cancer.