A-987306 is a potent and oral bioavailable histamine H 4 antagonist, with Kis of 3.4 nM and 5.8 nM for rat H4, and human H4. A-987306 exhibits anti-inflammatory activity in mice peritonitis model [1].

A-987306 is a potent and functional antagonist in vitro of human, rat, and mouse H4 receptors in cell-based FLIPR assays [1]. A-987306 is 620-fold, >1600-fold, and 162-fold selective for the human H 4 R over the human H 1, H 2, and H 3 receptors in cell-based Ca 2+ -flux functional assay (FLIPR) [1]. A-987306 shows lower selectivity for H 4 R in the rat (only 4-fold selective for the rat H 4 R over the rat H 3 R) in FLIPR [1].

A-987306 (98.23 μg/kg-9.82 mg/kg; i.p.) has been shown to reduce scratching induced by the histamine H 4 agonist clobenpropit [1]. A-987306 (10 mg/kg; p.o.) has a moderate fractional oral bioavailability (F po/iv =26%) with a half-life of 3.7 h and a C max of 0.30 μM at a T max of 1.5 h after dosing [1]. Animal Model: Mice [1] Dosage: 98.23 μg/kg, 327.42 μg/kg, 982.26 μg/kg, 9.82 mg/kg (Pharmacokinetic Analysis) Administration: Intraperitoneal injection Result: F po/iv =26%, T 1/2 =3.7 hours, C max =0.30 μM, T max =1.5 hours