Talmapimod hydrochloride is a selective and ATP-competitive p38α inhibitor (IC50: 9 nM). It also shows about 10-fold selectivity over p38β, and at least 2000-fold selectivity over a panel of 20 other kinases, including other MAPKs.

p38β:90 nM, p38α:9 nM

Talmapimod hydrochloride inhibits LPS-induced TNF-a production in human whole blood. Talmapimod hydrochloride decreases constitutive p38alpha MAPK phosphorylation of both 5T2MM and 5T33MM cells. Talmapimod hydrochloride (100-200 nM; 1 hour) inhibits phosphorylation of p38 MAPK in MM cells [1][2][3].

Talmapimod hydrochloride (10-90 mg/kg; P.o.; twice daily orally for 14 days) dose-dependently reduced tumor growth. Talmapimod hydrochloride (10-90 mg/kg; P.o.; twice daily orally for 14 days) also dose-dependently reduced weight of the palpable tumors at termination [4].