Fig. 13.
SD0006 inhibition of p38α correlates to that of TNFα release ex vivo (a) and in vivo (b). Primary human monocytes were preincubated ex vivo with SD0006 for 60 min, challenged with LPS, then either medium was collected after 4 h to determine TNFα release as a mechanism biomarker, or cells were collected after 30 min, lysed and assayed for phosphorylation of MK-2 and Hsp27 as p38α target modulation biomarkers as described in Materials and Methods. p38α activities as determined by either MK-2 activity or P-Hsp27 assays, both have strong positive correlations with TNFα release, with their sample linear correlation coefficient ≥ 98% for both assays with TNFα . Each data point represents the average of 3 determinations, each from a different donor. For in vivo study, phase 1 clinical trial subjects were dosed 1 h prior to a 2 ng/kg LPS challenge as described in Materials and Methods. Blood collections near Cmax were assayed for MK-2 activity as above. Curve fit, IC50 determinations, and standard errors (SE) were made using Grafit 5(2) software, with HWB values corrected for the FF in plasma. Each data point represents the average of 6 subjects.