Statistical analysis
PD
All subjects who received placebo were included in the placebo group. Safety was assessed in all subjects who received at least one dose of SHR-1222 or a placebo. PK concentration and parameter analyses were performed in subjects who received at least one dose of SHR-1222, with at least one qualified PK concentration/parameter result. PD indicators were analyzed in those who received at least one dose of SHR-1222 or a placebo, with no missing baseline and at least one qualified post-baseline PD assessment data. Immunogenicity was assessed in patients who received at least one dose of SHR-1222 or a placebo, with baseline and at least one post-baseline qualified sample.The sample size was estimated based on the percentage changes from baseline to the 6Serum SHR-1222 concentration-time data were analyzed using non-compartmental methods. Baseline demographics, safety results, and PK parameters by treatment and dose were tabulated and summarized using descriptive statistics. At every scheduled visit, the percentage changes from the baseline for selected PD parameters and BMD were calculated. All statistical analyses were performed using SAS, version 9.4 (SAS Institute, Inc.).