title: Pharmacology of AMG 181, a human anti-α4 β7 antibody that specifically alters trafficking of gut-homing T cells.
abstract: OBJECTIVE
  AMG 181 is a human anti-α4 β7 antibody currently in phase 1 and 2 trials in subjects with inflammatory bowel diseases. AMG 181 specifically targets the α4 β7 integrin heterodimer, blocking its interaction with mucosal addressin cell adhesion molecule-1 (MAdCAM-1), the principal ligand that mediates α4 β7 T cell gut-homing.
  
  
  METHODS
  We studied the in vitro pharmacology of AMG 181, and the pharmacokinetics and pharmacodynamics of AMG 181 after single or weekly i.v. or s.c. administration in cynomolgus monkeys for up to 13 weeks.
  
  
  RESULTS
  AMG 181 bound to α4 β7 , but not α4 β1 or αE β7 , and potently inhibited α4 β7 binding to MAdCAM-1 (but not vascular cell adhesion molecule-1) and thus inhibited T cell adhesion. Following single i.v. administration, AMG 181 Cmax was dose proportional from 0.01 to 80 mg·kg(-1) , while AUC increased more than dose proportionally. Following s.c. administration, dose-proportional exposure was observed with single dose ranging from 5 to 80 mg·kg(-1) and after 13 weekly doses at levels between 20 and 80 mg·kg(-1) . AMG 181 accumulated two- to threefold after 13 weekly 80 mg·kg(-1) i.v. or s.c. doses. AMG 181 had an s.c. bioavailability of 80%. The linear elimination half-life was 12 days, with a volume of distribution close to the intravascular plasma space. The mean trend for the magnitude and duration of AMG 181 exposure, immunogenicity, α4 β7 receptor occupancy and elevation in gut-homing CD4+ central memory T cell count displayed apparent correlations.
  
  
  CONCLUSIONS
  AMG 181 has in vitro pharmacology, and pharmacokinetic/pharmacodynamic and safety characteristics in cynomolgus monkeys that are suitable for further investigation in humans.
authors: Department of Pharmacokinetics and Drug Metabolism, Amgen Inc., Seattle, WA 98119-3105, USA. wpan@amgen.com
authors: W J
authors: WJ
authors: Pan
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authors: Hsu
authors: W A
authors: WA
authors: Rees
authors: S P
authors: SP
authors: Lear
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authors: Lee
authors: I N
authors: IN
authors: Foltz
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authors: Rathanaswami
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authors: Manchulenko
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authors: Chan
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authors: Zhang
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authors: Xia
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authors: Patel
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authors: Prince
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authors: Sheckler
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authors: Reynhardt
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authors: Krill
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authors: Harder
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authors: Wisler
authors: J L
authors: JL
authors: Brandvig
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authors: Lynch
authors: A A
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authors: Wienkers
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authors: Borie
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D061067:Antibodies, Monoclonal, Humanized; D001682:Biological Availability; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D005260:Female; D006207:Half-Life; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism*; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D016023:Integrins / Q000378:metabolism*; D008252:Macaca fascicularis; D008297:Male; D009088:Mucoproteins / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; D016023:Integrins; C504265:MADCAM1 protein, human; D009088:Mucoproteins; C071777:integrin alpha4beta7; C000591337:abrilumab