A phase III clinical trial showed that pembrolizumab combined with trastuzumab and chemotherapy as a first-line treatment for HER-2 positive GC achieved an ORR of 74.4 %, a 22.7 % increase compared to the placebo group, with a complete response rate of 11 % (compared to 3 % in the control group) [39]. Here, ERBB2 is linked to gastric cancer.