Voruciclib-induced pharmacodynamic changes in pRNAP2^Ser2 and Mcl-1 in samples from patients with AML. Voruciclib dose of 100 to 150 mg (blue) or 200 mg (red). (A) Levels of pRNAP2^Ser2 protein in circulating malignant cells were analyzed by flow cytometry. Data are shown as pRNAP2^Ser2 mean fluorescent intensity fold change (FC; P = .042; n = 6). (B) mRNA expression of MCL1 gene in PBMCs was quantified by quantitative real-time polymerase chain reaction. Data are shown as mRNA FC (n = 10). (C) Analysis of Mcl-1 protein by flow cytometry in circulating blasts from patients with AML expressed as FC of mean fluorescent intensity (n = 6). For panels A-C, data shown are FC for samples taken at C1D1 at 6 hours after voruciclib dose and C2D1 before dose vs C1D1 before dose. ∗P ≤ .05.