Randomized Versus Real-World Evidence on the Efficacy and Toxicity of Checkpoint Inhibitors in Cancer in Patients with Advanced Non-small Cell Lung Cancer or Melanoma : A Meta-analysis

Background Both randomized controlled trials (RCTs) and real-world evidence (RWE) studies provide results regarding the efficacy and toxicity of checkpoint inhibitors in cancer patients. The results from these two sources are considered complementary but whether they are comparable remains unknown. Objective The aim of this study was to compare the efficacy and toxicity of checkpoint inhibitors between RCTs and RWE studies in patients with advanced non-small cell lung cancer (NSCLC) or melanoma. Patients and Methods Two electronic databases were searched to identify eligible studies, either RCTs or RWE studies, investigating the efficacy or toxicity of checkpoint inhibitors given for indications that were approved by the European Medicines Agency (EMA) at the date of the last search. A meta-analysis was performed and the pooled estimates of objective response rates (ORR), progression-free survival (PFS), overall survival (OS), and toxicity and treatment discontinuation between RCTs and RWE studies were compared. Results In total, 43 RWE studies and 15 RCTs were eligible, with adequate data for pooled estimates for immunotherapy indications regarding NSCLC and melanoma. No statistically significant or clinically meaningful differences in terms of pooled PFS, OS, or rates of treatment discontinuation due to toxicity between RCTs and RWE studies were observed. In some indications, a higher rate of response rates and lower rate of toxicity in favor of RWE was observed. Conclusion In patients with melanoma or NSCLC, the clinical value of checkpoint inhibitors is evident in both RCTs and real-world settings. Some differences in response or toxicity rates in favor of RWE mainly reflects the inherent difficulties in evaluating these outcomes in RWE studies