Peficitinib

Peficitinib, also known as ASP015K and JNJ-54781532, is a novel potent JAK inhibitor, which demonstrated potent efficacy in adjuvant-induced arthritis model in rats. ASP015K inhibited JAK1, JAK2, JAK3 and TYK2 enzyme activities with IC50 values of 3.9, 5.0, 0.71 and 4.8 nM, respectively. ASP015K inhibited the IL-2-induced proliferation of human T cells with an IC50value of 18 nM. Moreover, ASP015K was 14-fold more potent against JAK1/3 than JAK2/2 on the basis of EPO-induced proliferation of human leukemia cells. ASP015K has the potential to demonstrate JAK1/3-mediated immunomodulatory effects without the occurrence of JAK2-mediated hematopoietic effects. ASP015K may have potential use in prevention of rejection in solid organ transplantation; treatment of psoriasis; treatment of rheumatoid arthritis.