Statistical analysis
A single-stage phase II design with a type I error of 5% and power of 80% was used to calculate the sample size. We considered the anlotinib treatment to be ineffective if DCR was ≤ 20% based on the result from the phase II study of gefitinib treatment for RM-NPC [All patients who received at least one dose of anlotinib were included in the efficacy and safety analysis set (full analysis set). No missing data was imputed. The 95% CIs of ORR and DCR were calculated using the Clopper-Pearson method. PFS and OS were calculated using the Kaplan–Meier method. Safety analysis mainly used descriptive statistics. All statistical analyses were performed using the SPSS 22.0 or GraphPad Prism software.