Effects of itacitinib on T cells. Peripheral blood samples from serial time points from baseline through day 180 were analyzed (total samples: before treatment (Tx), n = 23; CR, n = 48; PR+MR, n = 47; NR+PD, n = 13). Patients who had both baseline and day 28 samples were evaluable for analysis of absolute change from baseline to day 28 (n = 18). Total CD4 count was not available for 1 patient at day 28, although data for activated CD4 cells were available for this patient. Only 2 nonresponders had evaluable samples at day 28. (A) Absolute peripheral blood CD4 and CD8 T-cell numbers following itacitinib treatment through day 180 by response and change over time at day 28. (B) CD4 and CD8 T-cell activation levels following itacitinib treatment through day 180 by response and change over time at day 28. (C) Overall and activated peripheral blood Treg levels following itacitinib treatment through day 180 by response and change over time at day 28. CR includes CR and VGPR. Pairwise comparison was assessed by Wilcoxon rank test. *P < .05 and **P < .01 vs before Tx, analysis of variance with Dunnett post hoc. HLADR, human leukocyte antigen D related; MR, mixed response; NR, no response; PD, progressive disease.