Fiboflapon sodium (GSK2190915; AM-803) is a potent and orally bioavailable 5-lipoxygenase-activating protein ( FLAP ) inhibitor with a potency of 2.9 nM in FLAP binding, an IC 50 of 76 nM for inhibition of LTB4 in human blood
In Vitro
Fiboflapon (AM803) exhibits excellent preclinical toxicology and pharmacokinetics in rat and dog. Fiboflapon (AM803) also demonstrated an extended pharmacodynamic effect in a rodent bronchoalveolar lavage (BAL) model. Oral administration of Fiboflapon (AM803) (1 mg/kg) resulted in sustained inhibition of ex vivo ionophore-challenged whole blood LTB4 biosynthesis with >90% inhibition for up to 12 h and an EC 50 of approximately 7 nM. When rat lungs were challenged in vivo with calcium-ionophore, Fiboflapon (AM803) inhibited LTB4 and cysteinyl leukotriene (CysLT) production with ED 50 s of 0.12 mg/kg and 0.37 mg/kg, respectively. The inhibition measured 16 h following a single oral dose of 3 mg/kg was 86% and 41% for LTB4 and CysLTs, respectively. In an acute inflammation setting, Fiboflapon (AM803) dose-dependently reduced LTB4, CysLTs, plasma protein extravasation and neutrophil influx induced by peritoneal zymosan injection. Finally, AM803 increased survival time in mice exposed to a lethal intravenous injection of platelet activating factor (PAF). MCE has not independently confirmed the accuracy of these methods. They are for reference only.