pamapimod

Pamapimod (RO4402257) is a potent and selective small molecule inhibitor of p38 mitogen-activated protein kinase (MAPK), specifically targeting the p38α and p38β isoforms. It was developed as an anti-inflammatory agent for the treatment of autoimmune diseases such as rheumatoid arthritis. Pamapimod inhibits the enzymatic activity of p38α (IC50 ≈ 14 nM) and p38β (IC50 ≈ 480 nM), with little to no activity against other isoforms like p38δ or p38γ. The drug acts by blocking the MAPK pathway involved in inflammatory cytokine production, including TNFα and IL-1β. Clinical trials in rheumatoid arthritis showed initial reductions in C-reactive protein but did not demonstrate sustained efficacy; typical adverse effects included elevated liver enzymes and skin rash[1][4][5][6]. Development for rheumatoid arthritis has been discontinued[7].

Other names

pamapimodR 1503R1503R-1503