Higher proportions of Tregs and expression of PD-1, CD25, and CD38 in T-cell subsets were associated with inferior PFS at baseline. (A-B) Kaplan-Meier curves of PFS for patients from the RP2D cohort according to proportion of baseline peripheral PD-1⁺ CD8 T cells (A) and Tregs (B) in the periphery. (C) Kaplan-Meier curves of PFS according to proportion of BM CD25-expressing CD4 T cells at baseline. (D) Kaplan-Meier curves of PFS according to proportion of BM CD38-expressing CD4 T cells at baseline. Dark green lines represent patients with proportions below the median, and light green lines represent patients with proportions equal to or higher than the median PFS in MajesTEC-1. Statistical significance was calculated using the Cox proportional hazards model.