Pembrolizumab plus chemotherapy as first-line therapy for advanced HER2-negative gastric or gastroesophageal junction adenocarcinoma: 4.5-year follow-up from the randomized phase III KEYNOTE-859 study
Background KEYNOTE-859 showed a favorable benefit–risk profile for pembrolizumab plus chemotherapy compared with placebo plus chemotherapy, regardless of programmed death-ligand 1 (PD-L1) status, in participants with untreated locally advanced or metastatic human epidermal growth factor receptor 2 (HER2)-negative gastr...