title: Peripheral Administration of a Long-Acting Peptide Oxytocin Receptor Agonist Inhibits Fear-Induced Freezing.
abstract: Oxytocin (OT) modulates the expression of social and emotional behaviors and consequently has been proposed as a pharmacologic treatment of psychiatric diseases, including autism spectrum disorders and schizophrenia; however, endogenous OT has a short half-life in plasma and poor permeability across the blood-brain barrier. Recent efforts have focused on the development of novel drug delivery methods to enhance brain penetration, but few efforts have aimed at improving its half-life. To explore the behavioral efficacy of an OT analog with enhanced plasma stability, we developed PF-06655075 (PF1), a novel non-brain-penetrant OT receptor agonist with increased selectivity for the OT receptor and significantly increased pharmacokinetic stability. PF-06478939 was generated with only increased stability to disambiguate changes to selectivity versus stability. The efficacy of these compounds in evoking behavioral effects was tested in a conditioned fear paradigm. Both central and peripheral administration of PF1 inhibited freezing in response to a conditioned fear stimulus. Peripheral administration of PF1 resulted in a sustained level of plasma concentrations for greater than 20 hours but no detectable accumulation in brain tissue, suggesting that plasma or cerebrospinal fluid exposure was sufficient to evoke behavioral effects. Behavioral efficacy of peripherally administered OT receptor agonists on conditioned fear response opens the door to potential peripheral mechanisms in other behavioral paradigms, whether they are mediated by direct peripheral activation or feed-forward responses. Compound PF1 is freely available as a tool compound to further explore the role of peripheral OT in behavioral response.
authors.affiliation: Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.).
authors.forename: Meera E
authors.initials: ME
authors.lastname: Modi
authors.affiliation: Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.).
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Majchrzak
authors.affiliation: Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.).
authors.forename: Kari R
authors.initials: KR
authors.lastname: Fonseca
authors.affiliation: Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.).
authors.forename: Angela
authors.initials: A
authors.lastname: Doran
authors.affiliation: Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.).
authors.forename: Sarah
authors.initials: S
authors.lastname: Osgood
authors.affiliation: Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.).
authors.forename: Michelle
authors.initials: M
authors.lastname: Vanase-Frawley
authors.affiliation: Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.).
authors.forename: Eric
authors.initials: E
authors.lastname: Feyfant
authors.affiliation: Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.).
authors.forename: Heather
authors.initials: H
authors.lastname: McInnes
authors.affiliation: Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.).
authors.forename: Ramin
authors.initials: R
authors.lastname: Darvari
authors.affiliation: Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.).
authors.forename: Derek L
authors.initials: DL
authors.lastname: Buhl
authors.affiliation: Neuroscience and Pain Research Unit (M.E.M., M.J.M., D.L.B.), Department of Pharmacokinetics, Dynamics and Metabolism (K.R.F.), Global Biotherapeutics Technologies (E.F.), and Worldwide Medicinal Chemistry (N.M.K.), Worldwide Research and Development, Pfizer Inc., Cambridge, Massachusetts; Department of Pharmacokinetics, Dynamics and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut (A.D., S.O., M.V.-F.); and Biotherapuetics Pharmaceutical Research and Development, Worldwide Research and Development, Pfizer Inc., Andover, Massachusetts (H.M., R.D.) Natasha.M.Kablaoui@pfizer.com.
authors.forename: Natasha M
authors.initials: NM
authors.lastname: Kablaoui
mesh_terms: D000818:Animals; D016466:CHO Cells; D003213:Conditioning, Psychological / Q000187:drug effects*; D006224:Cricetinae; D003412:Cricetulus; D004333:Drug Administration Routes; D055808:Drug Discovery; D005239:Fear / Q000523:psychology*; D046353:Immobility Response, Tonic / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051379:Mice; D010121:Oxytocin / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D011092:Polyethylene Glycols / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D051381:Rats; D018045:Receptors, Oxytocin / Q000819:agonists*
chemical_list: C000619420:PF-06655075; D010456:Peptides, Cyclic; D018045:Receptors, Oxytocin; D011092:Polyethylene Glycols; D010121:Oxytocin