Efficacy of Pembrolizumab Monotherapy for Advanced Gastric/Gastroesophageal Junction Cancer with Programmed Death Ligand 1 Combined Positive Score ≥10
Zev A. Wainberg, Charles S. Fuchs, Josep Tabernero, Kohei Shitara, Kei Muro, Eric Van Cutsem, Yung‐Jue Bang, Hyun Cheol Chung, Kensei Yamaguchi, Eniko Varga, Jen‐Shi Chen, Daniel Hochhauser, Peter Thuss‐Patience, Salah‐Eddin Al‐Batran, Marcelo Garrido, Uma Kher, Chie‐Schin Shih, Sukrut Shah, Pooja Bhagia, Joseph Chao
Abstract
PURPOSE: Pembrolizumab demonstrated efficacy in PD-L1-positive [combined positive score (CPS) ≥1] advanced gastric/gastroesophageal junction (G/GEJ) cancer in the first-, second-, and third-line setting in KEYNOTE-062, KEYNOTE-061, and KEYNOTE-059, respectively. To better delineate the specificity of CPS as a predictor of clinical outcomes, we analyzed pembrolizumab efficacy in patients with CPS ≥ 10 in these trials. PATIENTS AND METHODS: = 90; primary). Efficacy outcomes were overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and duration of response (DOR). RESULTS: In KEYNOTE-059, median follow-up was 6 months, median OS was 8 months [95% confidence interval (CI), 5.8-11.1], ORR was 17%, and median (range) DOR was 21 months (3+ to 35+). In KEYNOTE-061, median follow-up was 9 months, median OS (pembrolizumab vs. chemotherapy) was 10 versus 8 months (HR, 0.64; 95% CI, 0.41-1.02), median PFS was 3 months versus 3 months (HR, 0.86; 95% CI, 0.56-1.33), ORR was 25% versus 9%, and median (range) DOR was not reached (4 to 26+ months) versus 7 months (3-7). In KEYNOTE-062, median follow-up was 11 months, median OS (pembrolizumab vs. chemotherapy) was 17 months versus 11 months (HR, 0.69; 95% CI, 0.49-0.97), median PFS was 3 months versus 6 months (HR, 1.09, 95% CI; 0.79-1.49), ORR was 25% versus 38%, and median (range) DOR was 19 months (1+ to 34+) versus 7 months (2+ to 30+). CONCLUSIONS: This comprehensive analysis showed consistent improvements toward more favorable clinical outcomes with pembrolizumab across lines of therapy in patients with CPS ≥ 10 G/GEJ cancer.