Statistical analysis
REGRESSION
This subset analysis in Japanese patients was conducted using data from the primary analysis of the CLEAR study (data cutoff date: August 28, 2020). Efficacy (PFS, OS, ORR, and DOR) was assessed in all Japanese patients who were randomized to receive lenvatinib plus pembrolizumab or sunitinib. PFS and OS were estimated using Kaplan–Meier estimates and two‐sided 95% CIs. Stratification was not performed in this subset analysis because of the limited sample size, and because the geographic region stratification factor could not be incorporated. Differences in PFS and OS between lenvatinib plus pembrolizumab and sunitinib treatment arms were evaluated with log‐rank tests, and Cox regression models with the Efron method for handling ties were used to estimate the HRs and 95% CIs. Two HRs were calculated for OS: an unadjusted HR (which included treatment group as a covariate) and an adjusted HR (which included treatment group and MSKCC risk group as covariates). The adjusted OS HR was calculated to account for the imbalance in MSKCC risk group between the lenvatinib plus pembrolizumab versus sunitinib treatment arms. Difference in ORR between lenvatinib plus pembrolizumab and sunitinib treatment arms was evaluated by odds ratio and 95% CIs. DOR (calculated for all patients with a confirmed response) was evaluated using the Kaplan–Meier method. Safety was assessed in all Japanese patients who received ≥1 dose of any study drug.