How do you decide between HERIZON-GEA01 and KEYNOTE-811 trials when determining treatment approach for metastatic gastric/GE adenocarcinoma?

As of August 25, 2026, trastuzumab has been replaced in the first-line setting by zanidatamab, a bispecific/biparatopic antibody against 2 epitopes of HER2. This approval is based on the results of the HERIZON-GEA-01 study, which randomized patients to the control arm of trastuzumab/chemotherapy (Arm A) versus zanidatamab/chemotherapy (Arm B) and zanidatamab with tislelizumab, an anti-PD-1 antibody, and chemotherapy (Arm C). The study revealed a very significant improvement in both progression-f...