Quantification of a bifunctional drug in the presence of an immune response: a ligand-binding assay specific for 'active' drug.
OBJECTIVE
During development of biologics, safety and efficacy assessments are often hampered by immune responses to the treatment. The raised antidrug antibodies (ADA) might interfere with the bioanalytical method and complicate result interpretation if non-fully characterized bioanalytical methods were applied.


METHODS
Here, we report an approach to characterize a ligand-binding assay (LBA) for the quantification of active drug exposure of a bifunctional therapeutic protein in the presence of antidrug antibodies, by correlating LBA results with those of a cell-based PK assay.


RESULTS
A clear correlation between both assays could be observed when monoclonal and polyclonal antibodies against the toxin moiety of the drug were used as ADA surrogates, and results were confirmed with human ADA-positive sera.


CONCLUSIONS
The observed correlation between the LBA-based and cell-based PK assay indicated the suitability of the developed LBA for the determination of active drug exposure in the presence of an immune response.
Roche Pharma Research & Early Development (pRED), Pharmaceutical Sciences, Global DMPK & Bioanalytical R&D, Roche Innovation Center Penzberg, Germany.
Roland F
RF
Staack
Roche Pharma Research & Early Development (pRED), Pharmaceutical Sciences, Global DMPK & Bioanalytical R&D, Roche Innovation Center Penzberg, Germany.
Gregor
G
Jordan
Roche Pharma Research & Early Development (pRED), Pharmaceutical Sciences, Global DMPK & Bioanalytical R&D, Roche Innovation Center Penzberg, Germany.
Maria
M
Viert
Roche Pharma Research & Early Development (pRED), Pharmaceutical Sciences, Global DMPK & Bioanalytical R&D, Roche Innovation Center Penzberg, Germany.
Martin
M
Schäfer
Roche Pharma Research & Early Development (pRED), Pharmaceutical Sciences, Global DMPK & Bioanalytical R&D, Roche Innovation Center Penzberg, Germany.
Apollon
A
Papadimitriou
Roche Pharma Research & Early Development (pRED), Pharmaceutical Sciences, Global DMPK & Bioanalytical R&D, Roche Innovation Center Penzberg, Germany.
Julia
J
Heinrich
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000936:Antigen-Antibody Complex / Q000276:immunology*; D001681:Biological Assay / Q000379:methods*; D001685:Biological Factors / Q000276:immunology / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D006801:Humans; D008024:Ligands; D004364:Pharmaceutical Preparations / Q000097:blood*; D053719:Tandem Mass Spectrometry
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D001685:Biological Factors; D008024:Ligands; D004364:Pharmaceutical Preparations
active drug; antidrug antibody; cell-based assay; drug exposure; free drug; immunogenicity; ligand-binding assay; quantification