Fig. 1.

Direct Comparisons between Pembrolizumab plus Chemotherapy or Pembrolizumab Alone with Chemotherapy and Indirect Comparison between Pembrolizumab plus Chemotherapy versus Pembrolizumab Alone. a, b and c showed the Forest plot of risk ratios (RRs) and hazard ratios (HRs) directly comparing objective response rate (a), progression-free survival (b), and overall survival (c) between pembrolizumab plus chemotherapy or pembrolizumab alone with chemotherapy. The size of the data markers (squares) corresponds to the weight of the study in the meta-analysis. The horizontal line crossing the square represents the 95% CI. The diamonds represent the estimated overall effect, based on the meta-analysis. In d, solid lines represented the existence of direct comparisons between treatment regimens, and dashed line represented the indirect comparison between pem + chemo versus pem. The size of the circle corresponds to the enrolled patient number. All statistical tests were 2-sided. Abbreviations: Pem Pembrolizumab, Chemo Chemotherapy