GSK 256066 Trifluoroacetate is a selective and high-affinity phosphodiesterase 4 (PDE) inhibitor, with an IC50 of 3.2 pM for PDE4B; developed for the treatment of chronic obstructive pulmonary disease[1]. IC50: 3.2 pM (PDE4B)[1]

GSK 256066 Trifluoroacetate is an exceptionally high-affinity inhibitor of PDE4 designed for inhaled administration[1]. GSK 256066 Trifluoroacetate is highly selective for PDE4, with >380,000-fold versus PDE1/2/3/5/6 and >2500-fold against PDE7, and inhibits PDE4 isoforms A-D with equal affinity[1].GSK 256066 Trifluoroacetate inhibits tumor necrosis factor α production by lipopolysaccharide (LPS)-stimulated human peripheral blood monocytes with IC50 of 0.01 nM[1].

GSK 256066 Trifluoroacetate (0.3-100 μg/kg; intratracheally) inhibits the eosinophil number increased in the bronchoalveolar lavage (BAL) in a dose-dependent fashion, in lipopolysaccharide (LPS)- and ovalbumin (OVA)-induced acute pulmonary inflammation rat models.[2].GSK 256066 Trifluoroacetate inhibits LPS-induced pulmonary neutrophilia, and no emetic episodes are observed in ferrets[2]. Animal Model: Male Brown Norway rats(180-200 g)[2]

[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]. 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.