title: Online 2D-LC-MS/MS assay to quantify therapeutic protein in human serum in the presence of pre-existing antidrug antibodies.
abstract: The formation of antidrug antibodies (ADA) can interfere with the accurate quantitation of therapeutic proteins, leading to significantly underestimated drug concentrations and confounded pharmacokinetic (PK) data interpretation. Although highly desirable, development of ADA-tolerant bioanalytical methods enabling unbiased measurement of both free and ADA-bound drug presents a considerable challenge. We report herein the development and validation of a robust LC-MS assay capable of quantifying therapeutic protein immunoglobulin A1 protease (IgAP) in human serum in the presence of pre-existing anti-IgAP antibodies. The procedure included sodium dodecyl sulfate (SDS) denaturation and chemical reduction of serum proteins to dissociate ADA-drug bindings, followed by tryptic digestion of protein pellets and subsequent LC-MS analysis of the surrogate IgAP peptide using stable isotope labeled peptide internal standard. Substantial enhancements in the sensitivity and selectivity were achieved by the combination of online two-dimensional reversed-phase LC (2D-LC) operated in high and low pH buffers, respectively, for efficient enrichment and quantitation of the surrogate peptide by multiple-reaction monitoring (MRM) mass spectrometry. Unlike ligand-binding assay, our method is not prone to interferences from ADA, allowing accurate and precise measurement of the IgAP in the range of 0.05 to 10 μg/mL in 25 μL of human serum with a wide range of anti-IgAP antibody levels. The intra- and inter-run precision (coefficient of variation (CV%)) was within 11.5% and 10.5%, respectively, and the bias was within ±7.1% for all quality control (QC) concentrations. With little modification, the described method can readily be applicable to the quantitation of other biotherapeutic proteins in the ADA-positive clinical matrices.
authors.affiliation: Bioanalytical and Biomarker Development, Research and Nonclinical Development, Shire, Lexington, Massachusetts 02421, United States.
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Bioanalytical and Biomarker Development, Research and Nonclinical Development, Shire, Lexington, Massachusetts 02421, United States.
authors.forename: Guodong
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Bioanalytical and Biomarker Development, Research and Nonclinical Development, Shire, Lexington, Massachusetts 02421, United States.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Yang
authors.affiliation: Bioanalytical and Biomarker Development, Research and Nonclinical Development, Shire, Lexington, Massachusetts 02421, United States.
authors.forename: Yongchang
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: Bioanalytical and Biomarker Development, Research and Nonclinical Development, Shire, Lexington, Massachusetts 02421, United States.
authors.forename: Thomas
authors.initials: T
authors.lastname: McCauley
authors.affiliation: Bioanalytical and Biomarker Development, Research and Nonclinical Development, Shire, Lexington, Massachusetts 02421, United States.
authors.forename: Luying
authors.initials: L
authors.lastname: Pan
authors.affiliation: Bioanalytical and Biomarker Development, Research and Nonclinical Development, Shire, Lexington, Massachusetts 02421, United States.
authors.forename: Jiang
authors.initials: J
authors.lastname: Wu
mesh_terms: D000906:Antibodies / Q000097:blood* / Q000276:immunology; D002247:Carbon Isotopes / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007553:Isotope Labeling; D010455:Peptides / Q000737:chemistry; D012015:Reference Standards; D012697:Serine Endopeptidases / Q000097:blood* / Q000276:immunology / Q000592:standards; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000592:standards
chemical_list: D000906:Antibodies; D002247:Carbon Isotopes; D010455:Peptides; D012967:Sodium Dodecyl Sulfate; D012697:Serine Endopeptidases; C021433:IgA-specific serine endopeptidase