Timapiprant (sodium)

Timapiprant sodium (OC000459 sodium) is a potent, selective, and orally active D prostanoid receptor 2 (DP₂, also known as CRTH2) antagonist. Timapiprant sodium (OC000459 sodium) potently displaces [³H] PGD2 from human recombinant DP₂ (K_i=13 nM), rat recombinant DP₂ (K_i=3 nM), and human native DP₂ (K_i=4 nM). Timapiprant sodium (OC000459 sodium) inhibits mast cell activation of Th2 lymphocytes and eosinophils^[1]. IC50 & Target: Ki: 0.013 μM (human recombinant DP2); 0.003 μM (rat recombinant DP2) and 0.004 μM (human native DP2)^[1] In Vitro: Timapiprant sodium (OC000459 sodium) (0.0001 μM-10 μM; 5 hours) inhibits chemotaxis (IC₅₀=0.028 μM) of human Th2 lymphocytes and cytokine production (IC₅₀=0.019 μM) by human Th2 lymphocytes^[1].
Timapiprant sodium (OC000459 sodium) (1 μM) inhibits the activation of Th2 cells and eosinophils in response to supernatants from IgE/anti-IgE-activated human mast cells^[1].
Timapiprant sodium (OC000459 sodium) (1 nM-1000 nM; 16 hours) inhibits the anti-apoptotic effect of PGD2 on Th2 cells with an IC₅₀ of 0.035 uM^[1].
In Vivo: Timapiprant sodium (OC000459 sodium) (gavage; 2 mg/kg, 10 mg/kg) inhibits blood eosinophilia induced by 13,14-dihydro-15-keto-PGD2 (DK-PGD2) in Rat (ED₅₀=0.04 mg/kg)^[1].
Timapiprant sodium (OC000459 sodium) (gavage; 0.01 mg/kg, 0.1 mg/kg, 1.0 mg/kg) inhibits airway eosinophilia in response to an aerosol of DK-PGD2 in guinea pigs (ED₅₀=0.01 mg/kg)^[1].