Extended Data Fig. 1: BICR-Assessed PFS Per RECIST v1.1; PFS treatment effects in subgroups (ITT population).

Kaplan–Meier-estimated PFS curves as assessed by the investigator according to RECIST v1.1 are shown to compare the toripalimab plus chemotherapy arm with the placebo plus chemotherapy arm as first-line treatment for patients with initially diagnosed metastatic or recurrent TNBC (Panel A). Censored patients are marked with “|” in the graph. Numbers of patients at risk at indicated time points shown below x-axis. Number of events, median PFS, 1-year and 2-year PFS rates and stratified hazard ratio for PFS are shown to the right of Kaplan–Meier curves. Progression-free survival in key subgroups is shown in Panel B. All hazard ratios were computed using the Cox proportional hazards model. All P values were two-sided with no adjustment of multiplicity. The P values of comparing the Kaplan–Meier curves were computed using the log-rank test stratified by the baseline PD-L1 expression status, history of paclitaxel treatment, and line of therapy at enrollment. The P values of testing the interaction of the subgroup variables with the treatment (Panel B) were computed using the Cox proportional hazards regression model with the treatment arm, the subgroup variable and their interaction as the covariates.