Peripheral immune characteristics. Peripheral blood mononuclear cells were evaluated by flow cytometry for immune phenotype distributions. (A): CD4+ T cells and (B) CD8+ T cells were evaluated for distribution of naive (CD45RA+ CCR7+), CM (CD45RA− CCR7+), EM (CD45RA− CCR7−), and EMRA (CD45RA+ CCR7−) subsets in pretreatment samples (n = 15). Within (C) non‐naive CD4+ T cells and (D) non‐naive CD8+ T cells, expression of molecules PD‐1, TIGIT, TIM‐3, KLRG1, and CD137 were evaluated in addition to fractions of Tregs (CD25+ CD127−) and Tfh (PD‐1+, CXCR5+) at pretreatment (n = 15). Fold change in expression of depicted molecules and cell subsets relative to pretreatment is shown for (E) CD4+ T cells, cycle 2; (F) CD8+ T cells, cycle 2; (G) CD4+ T cells, cycle 4; (H) CD8+ T cells cycle 4 (cycle 2, n = 15; cycle 4, n = 11). For all graphs, the median is represented by a line. Nonresponders (progressive disease + stable disease) in red, responders (complete response + partial response) in blue.