title: Physiologically relevant binding affinity quantification of monoclonal antibody PF-00547659 to mucosal addressin cell adhesion molecule for in vitro in vivo correlation.
abstract: A monoclonal antibody (PF-00547659) against mucosal addressin cell adhesion molecule (MAdCAM), expressed as both soluble (sMAdCAM) and trans-membrane (mMAdCAM) target forms, showed over 30-fold difference in antibody-target KDbetween in vitro (Biacore) and clinically derived (KD,in-vivo) values. Back-scattering interferometry (BSI) was applied to acquire physiologically relevant KDvalues which were used to establish in vitro and in vivo correlation (IVIVC).
  
  
  
  BSI was applied to obtain KDvalues between PF-00547659 and recombinant human MAdCAM in buffer or CHO cells and endogenous MAdCAM in human serum or colon tissue. CHO cells and tissue were minimally processed to yield homogenate containing membrane vesicles and soluble proteins. A series of binding affinities in serum with various dilution factors was used to estimate both KD,in-vivoand target concentrations; MAdCAM concentrations were also measured using LC-MS/MS.
  
  
  
  BSI measurements revealed low KDvalues (higher affinity) for sMAdCAM in buffer and serum, yet a 20-fold higher KDvalue (lower affinity) for mMAdCAM in CHO, mMAdCAM and sMAdCAM in tissue. BSI predicted KD,in-vivoin serum was similar to clinically derived KD,in-vivo, and the BSI-estimated serum sMAdCAM concentration also matched the measured concentration by LC-MS/MS.
  
  
  
  Our results successfully demonstrated that BSI measurements of physiologically relevant KDvalues can be used to establish IVIVC, for PF-00547659 to MAdCAM despite the lack of correlation when using Biacore measured KDand accurately estimates endogenous target concentrations. The application of BSI would greatly enhance successful basic pharmacological research and drug development.
authors.affiliation: Pharmacokinetics, Dynamics and Metabolism, Pfizer Inc, Andover, MA, USA.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Vanderbilt Institute for Chemical Biology, Vanderbilt University, Nashville, TN, USA.
authors.forename: Amanda K
authors.initials: AK
authors.lastname: Kussrow
authors.affiliation: Pharmacokinetics, Dynamics and Metabolism, Pfizer Inc, Andover, MA, USA.
authors.forename: Mireia Fernandez
authors.initials: MF
authors.lastname: Ocana
authors.affiliation: Pharmacokinetics, Dynamics and Metabolism, Pfizer Inc, Andover, MA, USA.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Chabot
authors.affiliation: Pharmacokinetics, Dynamics and Metabolism, Pfizer Inc, Andover, MA, USA.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Lepsy
authors.affiliation: Department of Chemistry, Vanderbilt Institute for Chemical Biology, Vanderbilt University, Nashville, TN, USA.
authors.forename: Darryl J
authors.initials: DJ
authors.lastname: Bornhop
authors.affiliation: Pharmacokinetics, Dynamics and Metabolism, Pfizer Inc, Andover, MA, USA.
authors.forename: Denise M
authors.initials: DM
authors.lastname: O'Hara
mesh_terms: D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000494:pharmacology*; D001665:Binding Sites / Q000187:drug effects; D016466:CHO Cells; D015815:Cell Adhesion Molecules / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D003106:Colon / Q000187:drug effects*; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D006801:Humans; D013329:Structure-Activity Relationship
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D015815:Cell Adhesion Molecules; C000597368:ontamalimab