We previously reported findings from a phase Ib/II, open-label, dose-escalation study of margetuximab in combination with pembrolizumab in patients with relapsed/refractory advanced HER2-positive gastroesophageal junction or gastric cancer (CP-MGAH22-05, NCT02689284) that a chemotherapy-free regimen consisting of margetuximab plus pembrolizumab (anti-programmed cell death protein 1 [PD-1] mAb) was well tolerated and induced favorable antitumor activity in patients with previously treated HER2-positive GEA.14 Here, ERBB2 is linked to gastric cancer.