Predictive markers in gastric cancer immunotherapy treatment—are we there yet?

Immune checkpoint inhibitors (CPI) have become the standard of care in multiple lines of treatment in different settings in variety of cancers such as lung cancer, melanoma, renal cell carcinoma and some gastrointestinal cancers. In May 2017, Food and Drug Administration (FDA) provided the first tissue agnostic approval for pembrolizumab in mismatch repair deficient (dMMR) or microsatellite instability high (MSI-H) advanced solid tumors who have progressed on prior treatments or for which no other standard treatment exists (1).