Cobimetinib inhibits activation of B cells and TNF-α production by monocytes more strongly than trametinib. (A-B) PBMCs were stimulated with allogeneic DCs and CFSE dilution evaluated in CD4⁺ and CD8⁺ T cells: representative data (A) and aggregate data (B). The line graph plots the mean value; error range, standard error of the mean (SEM). (C-D) PBMCs were exposed to trametinib and cobimetinib, and the MFI values of CD69⁺ cells among CD20⁺CD23⁺ cells after stimulation with anti-CD40 antibody and IL-4 were evaluated: representative data (C) and aggregate data (D). The bar graph plots the mean value; error range, SEM. (E-F) PBMCs were stimulated with lipopolysaccharide, and frequencies of TNF-α⁺ cells among monocytes were evaluated: representative data (E) and aggregate data (F). The bar graph plots the median value; error range, SEM. All experiments were performed 4 times, independently. A two-tailed unpaired t test was used for comparisons between 2 groups of continuous variables. ∗P < .05, ∗∗P < .01. Cobi, cobimetinib; Tra, trametinib.