TABLE 5 

In vitro JAK1/2 and ACVR1 inhibition by MMB and M21 and the corresponding pharmacologic activity index values

Cellular AssayCompoundEC50anbAUCm/AUCpcEC50 m:p Ratiod,ePAIe
nM%
Inhibition of IL6-stimulated, JAK1/2 mediated, phosphorylation of STAT3 in primary human PBMCs in 10% FCSMMB259 ± 1754NANANA
M21689 ± 22741.312.7947
ACVR1 inhibition by hepcidin gene expression analysis on HepG2 cells in 1% FCS in EMEMMMB652 ± 2033NANANA
M211420 ± 39531.312.3057
  • EMEM, eagle’s minimum essential medium; FCS, fetal calf serum; NA, not applicable.

  • a Mean ± S.D.

  • b Number of replicates.

  • c AUCm, metabolite AUC; AUCp, parent AUC; unbound AUC ratio of metabolite to parent calculated with AUC unit converted to nanomolar•hour from Table 3. MMB AUC = 9759.1 ± 3325.1 nM•h; M21 AUC = 16,854.3 ± 2615.0 nM•h. For calculation of unbound exposures, mean fraction unbound in human plasma was 19.2% for MMB and 14.6% for M21 from Table 6.

  • d Metabolite-to-parent ratio for EC50. Free fractions of MMB and M21 were 80.1% and 84.6% in 1% FCS in EMEM, respectively, and were 63.4% and 66.5% in 10% FCS, respectively, from Table 6.

  • e PAI expressed as a percentage.