PT  - JOURNAL ARTICLE
AU  - Brodbeck, Robbin M.
AU  - Cortright, Daniel N.
AU  - Kieltyka, Andrzej P.
AU  - Yu, Jianying
AU  - Baltazar, Carolyn O.
AU  - Buck, Marianne E.
AU  - Meade, Robin
AU  - Maynard, George D.
AU  - Thurkauf, Andrew
AU  - Chien, Du-Shieng
AU  - Hutchison, Alan J.
AU  - Krause, James E.
TI  - Identification and Characterization of NDT 9513727 [<em>N</em>,<em>N</em>-bis(1,3-Benzodioxol-5-ylmethyl)-1-butyl-2,4-diphenyl-1<em>H</em>-imidazole-5-methanamine], a Novel, Orally Bioavailable C5a Receptor Inverse Agonist
AID  - 10.1124/jpet.108.141572
DP  - 2008 Dec 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 898--909
VI  - 327
IP  - 3
4099  - http://jpet.aspetjournals.org/content/327/3/898.short
4100  - http://jpet.aspetjournals.org/content/327/3/898.full
SO  - J Pharmacol Exp Ther2008 Dec 01; 327
AB  - The complement system represents an innate immune mechanism of host defense that has three effector arms, the C3a receptor, the C5a receptor (C5aR), and the membrane attack complex. Because of its inflammatory and immune-enhancing properties, the biological activity of C5a and its classical receptor have been widely studied. Because specific antagonism of the C5aR could have therapeutic benefit without affecting the protective immune response, the C5aR continues to be a promising target for pharmaceutical research. The lack of specific, potent and orally bioavailable small-molecule antagonists has limited the clinical investigation of the C5aR. We report the discovery of NDT 9513727 [N,N-bis(1,3-benzodioxol-5-ylmethyl)-1-butyl-2,4-diphenyl-1H-imidazole-5-methanamine], a small-molecule, orally bioavailable, selective, and potent inverse agonist of the human C5aR. NDT 9513727 was discovered based on the integrated use of in vitro affinity and functional assays in conjunction with medicinal chemistry. NDT 9513727 inhibited C5a-stimulated responses, including guanosine 5′-3-O-(thio)triphosphate binding, Ca2+ mobilization, oxidative burst, degranulation, cell surface CD11b expression and chemotaxis in various cell types with IC50s from 1.1 to 9.2 nM, respectively. In C5a competition radioligand binding experiments, NDT 9513727 exhibited an IC50 of 11.6 nM. NDT 9513727 effectively inhibited C5a-induced neutropenia in gerbil and cynomolgus macaque in vivo. The findings suggest that NDT 9513727 may be a promising new entity for the treatment of human inflammatory diseases. The American Society for Pharmacology and Experimental Therapeutics