Pembrolizumab in advanced renal cell carcinoma: a meta-analysis providing level 1a evidence

The recent introduction of immunotherapy in the first line setting of advanced renal cell carcinoma (aRCC) has dramatically improved patients' prognosis. The aim of the current meta-analysis was to provide level 1a evidence supporting the use of pembrolizumab plus tyrosine kinase inhibitors (TKI) as first-line treatment for advanced RCC. All published randomized prospective trials including patients with advanced RCC treated with pembrolizumab in combination with TKIs vs Sunitinib were included in this meta-analysis. An algorithm was used to reconstruct survival data from the published Kaplan-Meier curves of overall survival (OS), progression free survival (PFS) and duration of response (DoR) from the included trials. Restricted mean survival time (RMST) with 95% confidence interval (CI) for comparison among the different regimens was calculated. Main outcomes were differences in RMST for OS, PFS and DoR for pembrolizumab plus TKIs vs sunitinib arm. Reconstructed survival data from 1,573 patients were retrieved from 2 trials (KEYNOTE-581 and KEYNOTE-426) comparing pembrolizumab plus TKI (lenvatinib or axitinib, respectively) to sunitinib. Patients who received pembrolizumab-lenvatinib or pembrolizumab-axinitinib had better OS (24-month ΔRMST of 1.79 months [95% CI: 0.12-2.50; P < 0.001]), PFS (24-month ΔRMST of 3.83 months [95% CI: 2.93-4.74; P < 0.001]) and DoR (24-month ΔRMST of 2.32 months [95% CI: 0.97-3.67; P < 0.001]) relative to sunitinib. Pembrolizumab-lenvatinib combination gave a marginal benefit in terms of OS, PFS and DoR relative to pembrolizumab-axitinib group. By relying on individual survival data, we provided a level-1a evidence supporting the use of pembrolizumab plus TKI for first-line aRCC treatment.