Abstract
The endogenous cannabinoid (endocannabinoid) anandamide is principally degraded by the integral membrane enzyme fatty acid amide hydrolase (FAAH). Pharmacological blockade of FAAH has emerged as a potentially attractive strategy for augmenting endocannabinoid signaling and retaining the beneficial effects of cannabinoid receptor activation, while avoiding the undesirable side effects, such as weight gain and impairments in cognition and motor control, observed with direct cannabinoid receptor 1 agonists. Here, we report the detailed mechanistic and pharmacological characterization of N-pyridazin-3-yl-4-(3-{[5-(trifluoromethyl)pyridin-2-yl]oxy}benzylidene)piperidine-1-carboxamide (PF-04457845), a highly efficacious and selective FAAH inhibitor. Mechanistic studies confirm that PF-04457845 is a time-dependent, covalent FAAH inhibitor that carbamylates FAAH's catalytic serine nucleophile. PF-04457845 inhibits human FAAH with high potency (kinact/Ki = 40,300 M−1s−1; IC50 = 7.2 nM) and is exquisitely selective in vivo as determined by activity-based protein profiling. Oral administration of PF-04457845 produced potent antinociceptive effects in both inflammatory [complete Freund's adjuvant (CFA)] and noninflammatory (monosodium iodoacetate) pain models in rats, with a minimum effective dose of 0.1 mg/kg (CFA model). PF-04457845 displayed a long duration of action as a single oral administration at 1 mg/kg showed in vivo efficacy for 24 h with a concomitant near-complete inhibition of FAAH activity and maximal sustained elevation of anandamide in brain. Significantly, PF-04457845-treated mice at 10 mg/kg elicited no effect in motility, catalepsy, and body temperature. Based on its exceptional selectivity and in vivo efficacy, combined with long duration of action and optimal pharmacokinetic properties, PF-04457845 is a clinical candidate for the treatment of pain and other nervous system disorders.
Footnotes
This work was supported by Pfizer Worldwide Research and Development; the National Institutes of Health National Institute on Drug Abuse [Grants DA017259, F31-DA026261, K99-DA030908] (to B.F.C., J.L.B., and D.K.N., respectively); and a Pfizer Postdoctoral Fellowship (to E.W.).
Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
doi:10.1124/jpet.111.180257.
↵ The online version of this article (available at http://jpet.aspetjournals.org) contains supplemental material.
-
ABBREVIATIONS:
- FAAH
- fatty acid amide hydrolase
- hFAAH
- human FAAH
- rFAAH
- rat FAAH
- ABPP
- activity-based protein profiling
- AEA
- anandamide
- CB1
- CB1 cannabinoid receptor
- CB2
- CB2 cannabinoid receptor
- CC
- click chemistry
- CFA
- complete Freund's adjuvant
- FP
- fluorophosphonate
- FP-rhodamine
- FP-carboxytetramethylrhodamine
- MIA
- monosodium iodoacetate
- NAE
- N-acyl ethanolamine
- OEA
- N-oleoyl ethanolamine
- PEA
- N-palmitoyl ethanolamine
- PWT
- paw withdrawal threshold
- PAGE
- polyacrylamide gel electrophoresis
- PBS
- phosphate-buffered saline
- DMSO
- dimethyl sulfoxide
- COX2
- cyclooxygenase 2
- OL-135
- 1-oxo-1-[5-(2-pyridyl)oxazol-2-yl]-7-phenylheptane
- URB597
- (3′-carbamolybiphenyl-3-yl cyclohexylcarbamate
- PF-750
- N-phenyl-4-(quinolin-3-ylmethyl)piperidine-1-carboxamide
- PF-3845
- N-(pyridin-3-yl)-4-(3-(5-(trifluoromethyl)pyridin-2-yloxy)benzyl)piperidine-1-carboxamide
- PF-04457845
- N-pyridazin-3-yl-4-(3-{[5-(trifluoromethyl)pyridin-2-yl]oxy}benzylidene)piperidine-1-carboxamide
- PF-04457845yne
- 4-(3-((5-(pent-4-yn-1-yloxy)pyridin-2-yl)oxy)benzylidene)-N-(pyridazin-3-yl)piperidine-1-carboxamide
- JP104
- 3′-carbamoylbiphenyl-3-yl undec-10-ynylcarbamate
- SR141716
- 5-(4-chlorophenyl)-1-(2,4-dichloro-phenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide
- SR144528
- 5-(4-chloro-3-methylphenyl)-1-[(4-methylphenyl)methyl]-N-[(1S,2S,4R)-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl]-1H-pyrazole-3-carboxamide
- WIN 55,212-2
- (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-napthalenylmethanone.
- Received February 2, 2011.
- Accepted April 14, 2011.
- Copyright © 2011 by The American Society for Pharmacology and Experimental Therapeutics
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|