PF-03654764 is an orally active, selective histamine H3 receptor antagonist with Ki values of 1.2 nM and 7.9 nM for human H3 and rat H3 in whole cell assay, respectively. The combination of PF-03654764 and Fexofenadine has the potential for allergic rhinitis research[1][2].
PF-03654764 has pKi values of 8.98 and 8.10 for human H3 and rat H3 in whole cell assay, respectively. PF-03654764 has pKi values of 8.84, 7.73 and Ki values of 1.4 nM and 19 nM for human H3 and rat H3 in HEK-293 cells, respectively. PF-03654764 has >1000-fold selectivity for the H3 receptor over the other histamine receptor subtypes[1]. PF-03654764 has a human liver microsomes (HLM) T1/2 of 120 min and a HLM CLh <5 mL/min•kg[1].
PF-03654764 (10 mL/kg; oral; 14 days) has a Cmax of 8057 ng/mL and an AUC0-24 of 67400 ng•h/mL in Sprague-Dawley rats[1]. PF-03654764 (1 mL/kg; oral; 7 days) has a Cmax of 6302 ng/mL and an AUC0-24 of 18175 ng•h/mL in beagle dogs[1].
[1]. Travis T Wager, et al. Discovery of two clinical histamine H(3) receptor antagonists: trans-N-ethyl-3-fluoro-3-[3-fluoro-4-(pyrrolidinylmethyl)phenyl]cyclobutanecarboxamide (PF-03654746) and trans-3-fluoro-3-[3-fluoro-4-(pyrrolidin-1-ylmethyl)phenyl]-N-(2-methylpropyl)cyclobutanecarboxamide (PF-03654764). J Med Chem. 2011 Nov 10;54(21):7602-20. [2]. Michelle L North, et al. Add-on histamine receptor-3 antagonist for allergic rhinitis: a double blind randomized crossover trial using the environmental exposure unit. Allergy Asthma Clin Immunol. 2014 Jul 3;10(1):33.