Background: The use of checkpoint inhibitors has changed the treatment landscape for gastroesophageal cancer in the third-line setting. However, success rates in earlier treatment lines are highly variable across trials. Herein, we compare the efficacy and safety of the different anti-PD-1/PD-L1 regimens with or without chemotherapy; Methods: We performed a network meta-analysis (NMA) of anti-PD-1/PD-L1 monotherapy or combined with chemotherapy (chemoimmunotherapy) for gastroesophageal cancers without ERBB2 overexpression; Results: The first-line NMA included four trials (N = 3817), showing that chemoimmunotherapy improved OS and PFS without significant safety difference: Nivolumab-chemotherapy, OS (HR: 0.83 [95% CI, 0.75-0.92]), PFS (HR 0.68 [95% CI, 0.57-0.81]), Pembrolizumab-chemotherapy: OS (HR 0.77 [95% CI, 0.67-0.88]), PFS (HR: 0.72 [95% CI, 0.60-0.85]. Pembrolizumab monotherapy was the safest first-line treatment, SAE (OR 0.02 [95% CI, 0.00-0.2]) but showed no survival benefit. The second-line NMA encompassed four trials (N = 2087), showing that anti-PD-1 significantly improved safety but not survival: camrelizumab, SAE (OR 0.37; [95% CI, 0.24-0.56]); nivolumab, SAE (OR 0.13, [95% CI, 0.08-0.2]) pembrolizumab, SAE (OR 0.4; [95% CI, 0.30-0.53]); Conclusions: chemoimmunotherapy improves OS and PFS in previously untreated gastroesophageal cancers. Anti-PD-1 monotherapies improve safety in refractory disease, with no significant survival benefit.
Keywords: clinical trials; esophageal cancer; gastric cancer; immunotherapy; meta-analysis; multimodality treatments.