title: Storage Conditions of Conjugated Reagents Can Impact Results of Immunogenicity Assays.
abstract: Consistent performance of anti-drug antibody (ADA) assays through all stages of clinical development is critical for the assessment of immunogenicity and interpretation of PK, PD, safety, and efficacy. The electrochemiluminescent assays commonly employed for ADA measurement use drug conjugated with ruthenium and biotin to bind ADA in samples. Here we report an association between high nonspecific ADA responses in certain drug-naïve individuals and the storage buffer of the conjugated reagents used in a monoclonal antibody ADA assay. Ruthenylated reagents stored in phosphate-buffered saline (PBS) buffer had increased levels of aggregate and produced variable and high baseline responses in some subjects. Reagents stored in a histidine-sucrose buffer (HSB) had lower aggregate levels and produced low sample responses. In contrast to PBS, conjugated reagents formulated in HSB remained low in aggregate content and in sample response variability after 5 freeze/thaw cycles. A reagent monitoring control (RMC) serum was prepared for the real-time evaluation of conjugated reagent quality. Using appropriate buffers for storage of conjugated reagents together with RMCs capable of monitoring of reagent aggregation status can help ensure consistent, long-term performance of ADA methods.
authors.affiliation: Drug Metabolism, Pharmacokinetics and Biological Safety Assessment, MedImmune LLC, One MedImmune Way, Gaithersburg, MD 20878, USA.
authors.forename: Robert J
authors.identifier: 0000-0003-2953-1131
authors.initials: RJ
authors.lastname: Kubiak
authors.affiliation: Drug Metabolism, Pharmacokinetics and Biological Safety Assessment, MedImmune LLC, One MedImmune Way, Gaithersburg, MD 20878, USA.
authors.forename: Nancy
authors.initials: N
authors.lastname: Lee
authors.affiliation: Drug Metabolism, Pharmacokinetics and Biological Safety Assessment, MedImmune LLC, One MedImmune Way, Gaithersburg, MD 20878, USA.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Analytical Biotechnology Sciences and Strategy, MedImmune LLC, One MedImmune Way, Gaithersburg, MD 20878, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Franch
authors.affiliation: Analytical Biotechnology Sciences and Strategy, MedImmune LLC, One MedImmune Way, Gaithersburg, MD 20878, USA.
authors.forename: Sophia V
authors.initials: SV
authors.lastname: Levitskaya
authors.affiliation: Drug Metabolism, Pharmacokinetics and Biological Safety Assessment, MedImmune LLC, One MedImmune Way, Gaithersburg, MD 20878, USA.
authors.forename: Surekha R
authors.initials: SR
authors.lastname: Krishnan
authors.affiliation: Drug Metabolism, Pharmacokinetics and Biological Safety Assessment, MedImmune LLC, One MedImmune Way, Gaithersburg, MD 20878, USA.
authors.forename: Varghese
authors.initials: V
authors.lastname: Abraham
authors.affiliation: Drug Metabolism, Pharmacokinetics and Biological Safety Assessment, MedImmune LLC, One MedImmune Way, Gaithersburg, MD 20878, USA.
authors.forename: Peter F
authors.initials: PF
authors.lastname: Akufongwe
authors.affiliation: Analytical Biotechnology Sciences and Strategy, MedImmune LLC, One MedImmune Way, Gaithersburg, MD 20878, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Larkin
authors.affiliation: Drug Metabolism, Pharmacokinetics and Biological Safety Assessment, MedImmune LLC, One MedImmune Way, Gaithersburg, MD 20878, USA.
authors.forename: Wendy I
authors.initials: WI
authors.lastname: White
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D006801:Humans; D007118:Immunoassay / Q000379:methods / Q000592:standards*; D007202:Indicators and Reagents; D011309:Preservation, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000911:Antibodies, Monoclonal; D007202:Indicators and Reagents