title: Indirect assessment of neutralizing anti-drug antibodies utilizing pharmacokinetic assay data.
abstract: Neutralizing anti-drug antibodies (NAbs) can adversely impact efficacy and safety of biologic therapeutics. However, current assay formats to detect NAbs are limited in their use during the dosing phase due to interference by circulating drug, resulting in low drug tolerance. To improve the drug tolerance for NAb detection, an alternative approach for indirect NAb (iNAb) assessment was developed and qualified that uses a combination of pharmacokinetic (PK) assays to measure the serum concentrations of free and total drug. It is demonstrated that the ratio of free to total drug concentrations, referred to as F/T ratio, is a novel PK parameter that can indicate neutralizing activity in test samples. The iNAb assessment correctly identified NAb-positive samples with high drug concentrations that led to false negative results in a conventional NAb assay. Moreover, iNAb reliably distinguished between NAbs and non-neutralizing anti-drug antibodies over a wide range of concentrations. A proposal on how to deploy iNAb assessment within a broader immunogenicity testing strategy is presented.
authors.affiliation: Bioanalytical Sciences, Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States.
authors.forename: Christian
authors.initials: C
authors.lastname: Vettermann
authors.affiliation: Bioanalytical Sciences, Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States.
authors.forename: Jessica
authors.initials: J
authors.lastname: Ortiz
authors.affiliation: Bioanalytical Sciences, Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Lee
authors.affiliation: Bioanalytical Sciences, Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States.
authors.forename: Sergio
authors.initials: S
authors.lastname: Sanchez
authors.affiliation: Bioanalytical Sciences, Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States.
authors.forename: Hannah P
authors.initials: HP
authors.lastname: Victor
authors.affiliation: Bioanalytical Sciences, Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States.
authors.forename: Mark
authors.initials: M
authors.lastname: Ma
authors.affiliation: Bioanalytical Sciences, Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States.
authors.forename: Timothy
authors.initials: T
authors.lastname: Heath
authors.affiliation: Bioanalytical Sciences, Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, United States. Electronic address: shalinig@amgen.com.
authors.forename: Shalini
authors.initials: S
authors.lastname: Gupta
mesh_terms: D057134:Antibodies, Neutralizing / Q000097:blood* / Q000276:immunology*; D004336:Drug Antagonism; D006801:Humans; D004364:Pharmaceutical Preparations / Q000097:blood*; D010599:Pharmacokinetics
chemical_list: D057134:Antibodies, Neutralizing; D004364:Pharmaceutical Preparations
keywords: Drug interference; Free/total drug; Neutralizing antibodies; PK assay; iNAb