JNJ10191584 (VUF6002) is an orally active and selective histamine H 4 receptor antagonist with a K i value of 26 nM. JNJ10191584 shows 540-fold selectivity to H 4 receptor over H 3 receptor with a K i value of 14.1 μM. JNJ10191584 inhibits chemotaxis of eosinophils and mast cells with IC 50 values of 530 nM and 138 nM, respectively .