Background:

Direct and indirect inhibition of the JAKs has demonstrated rapid and sustained improvement in clinical measures of disease. Baricitinib phosphate (INCB 028050) is a selective JAK1 and JAK2 inhibitor.

In vitro: Baricitinib phosphate is a selective orally bioavailable JAK1/JAK2 inhibitor with nanomolar potency against JAK1 (5.9 nM) and JAK2 (5.7 nM) and