title: Overcoming soluble target interference in an anti-therapeutic antibody screening assay for an antibody-drug conjugate therapeutic.
abstract: BACKGROUND
  The standard safety evaluation of biotherapeutics includes assessment of immunogenicity. Anti-therapeutic antibodies (ATA) can be detected in serum using immunoassays with a bridging format. However, these assays can be subject to interference.
  
  
  RESULTS
  In the bridging ATA assay for 3A5 TDC, an antibody-drug conjugate that binds to the multimeric extracellular domain of MUC16 (CA125), soluble CA125 in the serum caused false-positive results by binding to the ATA assay reagents. This interaction was blocked by wheat germ agglutinin lectin as it binds to the glycans in CA125; thus, the specificity of the assay improved.
  
  
  CONCLUSIONS
  The assay development and validation results showed that the addition of wheat germ agglutinin eliminates the interference from circulating CA125 without impacting the ability to detect ATA.
authors.affiliation: Bioanalytical Sciences Department, Genentech, Inc, 1 DNA Way, South San Francisco, CA 94080, USA. montserc@gene.com
authors.forename: Montserrat
authors.initials: M
authors.lastname: Carrasco-Triguero
authors.forename: Connie
authors.initials: C
authors.lastname: Mahood
authors.forename: Marija
authors.initials: M
authors.lastname: Milojic-Blair
authors.forename: Caroline
authors.initials: C
authors.lastname: Amaya
authors.forename: Jane
authors.initials: J
authors.lastname: Ruppel
authors.forename: Kyu
authors.initials: K
authors.lastname: Hong
authors.forename: Joo-Hee
authors.initials: JH
authors.lastname: Yi
authors.forename: Surinder
authors.initials: S
authors.lastname: Kaur
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000097:blood* / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000276:immunology; D001688:Biological Products / Q000276:immunology* / Q000627:therapeutic use; D018394:CA-125 Antigen / Q000276:immunology* / Q000378:metabolism; D004337:Drug Carriers / Q000009:adverse effects; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005189:False Positive Reactions; D006801:Humans; D007118:Immunoassay / Q000379:methods; D018796:Immunoconjugates / Q000276:immunology* / Q000627:therapeutic use; D008252:Macaca fascicularis; D008565:Membrane Proteins / Q000276:immunology* / Q000378:metabolism; D009369:Neoplasms / Q000276:immunology / Q000628:therapy; D012680:Sensitivity and Specificity; D012995:Solubility; D014909:Wheat Germ Agglutinins / Q000276:immunology / Q000378:metabolism*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D001688:Biological Products; D018394:CA-125 Antigen; D004337:Drug Carriers; D018796:Immunoconjugates; C451759:MUC16 protein, human; D008565:Membrane Proteins; D014909:Wheat Germ Agglutinins