Key clinical point: High tumor mutational burden (TMB) is associated with clinical outcomes with pembrolizumab with or without chemotherapy in patients with gastric/gastroesophageal junction adenocarcinoma.
Major finding: In patients with high TMB, pembrolizumab vs. chemotherapy significantly improved the objective response rate (ORR; 55.6% vs. 41.2%), progression-free survival (PFS; hazard ratio [HR] 0.52), and overall survival (OS; HR 0.34). Similarly, pembrolizumab plus chemotherapy vs. chemotherapy improved ORR (73.3% vs. 41.2%), PFS (HR 0.62), and OS (HR 0.54) in patients with high TMB.
Study details: This prespecified exploratory analysis of phase 3 KEYNOTE-062 study included patients with gastric cancer who were randomly assigned (1:1:1) to receive pembrolizumab, pembrolizumab plus chemotherapy, or placebo plus chemotherapy.
Disclosures: This study was funded by Merck Sharp and Dohme LLC. The authors declared receiving grants, personal or advisory fees, or nonfinancial support. Some authors declared owing stocks or being cofounders or employees in various companies.
Source: Lee K-W et al. Association of tumor mutational burden with efficacy of pembrolizumab ± chemotherapy as first-line therapy for gastric cancer in the phase III KEYNOTE-062 study. Clin Cancer Res. 2022 (Jun 3). Doi: 10.1158/1078-0432.CCR-22-0121