| Description: |
GSK256066 is a selective PDE4B(equal affinity to isoforms A-D) inhibitor with IC50 of 3.2 pM, >380,000-fold selectivity versus PDE1/2/3/5/6 and >2500-fold selectivity against PDE4B versus PDE7. |
| Target: |
IC50 value: 3.2 pM [1]
Target: PDE4B |
| In Vivo: |
GSK256066 inhibits the LPS-induced pulmonary neutrophilia with an ED50 of 1.1 μg/kg, achieving maximal inhibition of 72% at 30 μg/kg when given in the aqueous suspension. GSK256066 inhibits the LPS-induced pulmonary neutrophilia with ED50 of 2.9 μg/kg, achieving maximal inhibition of 62% when given in the dry powder formulation. GSK256066 shows a moderate plasma clearance of 39 ml/min/kg, a moderate volume of distribution of 0.8 L/kg, and a relatively short half-life of 1.1 hour in the male CD rat [1]. GSK256066 sustains at a high lung concentration of 2.6 μg/g after intra-tracheal administration as an aqueous suspension at a dose of 30 μg/kg in rats [2]. GSK256066 (10 μg/kg) is administered intratracheally at different times (2, 6, 12, 18, 24, and 36 hours) before LPS administration, inhibiting LPS-Induced Pulmonary Neutrophilia in rat lipopolysaccharide (LPS)-induced models of acute pulmonary inflammation. GSK256066 (0.3–100 μg/kg) inhibits LPS-induced increases in exhaled nitric oxide with ED50 of 35 μg/kg in rat. GSK256066 (10 μg/kg) is administered half a hour before OVA administration in rat, inhibiting OVA-induced pulmonary eosinophilia with ED50 of 0.4 μg/kg. GSK256066 administered intratracheally as a dry powder blended in respiratory-grade lactose at doses of 3 to 100 μg/kg 2 hours before inhaled LPS challenge in ferrets, inhibiting LPS-induced pulmonary neutrophilia with ED50 of 18 μg/kg without inducing emetic episodes [3]. |
| In Vitro: |
GSK256066 is a slow and tight binding inhibitor of PDE4B with apparent IC50 of 3.2 pM. GSK256066 is an extremely potent inhibitor of LPS-stimulated TNFα production in PBMCs with pIC50 of 11.0 and IC50 of 10 pM and human whole-blood cultures with pIC50 of 9.90 and IC50 of 126 pM. GSK256066 is highly selective for PDE4 (>3.8 × 105-fold versus PDE1, PDE2, PDE3, PDE5, and PDE6 and >2.5 × 103-fold against PDE7). GSK256066 inhibits PDE4 isoforms A-D with equal affinity [1]. |
| References: |
[1]. Tralau-Stewart CJ, et al. GSK256066, an exceptionally high-affinity and selective inhibitor of phosphodiesterase 4 suitable for administration by inhalation: in vitro, kinetic, and in vivo characterization. J Pharmacol Exp Ther, 2011, 337(1), 145-154.
[2]. Woodrow MD, et al. Quinolines as a novel structural class of potent and selective PDE4 inhibitors. Optimisation for inhaled administration. Bioorg Med Chem Lett, 2009, 19(17), 5261-5265.
[3]. Nials AT, et al. In vivo characterization of GSK256066, a high-affinity inhaled phosphodiesterase 4 inhibitor. J Pharmacol Exp Ther, 2011, 337(1), 137-144. |
