ERBB2 and gastric cancer: The PANTHERA trial demonstrated the efficacy of pembrolizumab combined with trastuzumab and chemotherapy as a first-line treatment for HER-2 positive advanced GC, with an ORR of 76.7 %, DCR of 97.7 %, median OS of 19.3 months, and 1-year OS rate of 80.1 %.