Statistical analyses
A Simon two-stage optimal design was adopted for this study. The null hypothesis of CBR was 45% [Efficacy and safety analyses were performed in all patients receiving at least one study medication. The statistical analyses were primarily descriptive. Categorical variables were reported as numbers and percentage, and continuous variables were summarized as median (range). The 95% confidence interval (CI) of CBR and ORR was calculated using the Clopper-Pearson method. PFS was estimated using the Kaplan–Meier method. Statistical analyses were conducted using SAS 9.4.