Anti-Peg Antibody Bioanalysis: A Clinical Case Study with Peg-Ifn-λ-1A and Peg-Ifn-α2A in Naive Patients

BACKGROUND: Extensive use of polyethylene glycol (PEG) in consumer products necessitates the assessment of anti-PEG antibodies (APAb). METHODS: In clinical trials comparing PEG-IFN-λ to PEG-IFN-α, conventional bridge and direct assays were assessed. RESULTS & CONCLUSION: The bridge assay detected IgM and IgG APAb reactive with common PEG sizes and derivatives at sufficient sensitivity, 15-500 ng/ml. Of subjects evaluated, 6% of PEG-IFN-λ and 9% of PEG-IFN-α subjects had persistent APAb while 60% of PEG-IFN-λ and 33% of PEG-IFN-α subjects had persistent anti-interferon antibodies (AIAb). Pre-existing APAb and AIAb prevalence was comparable (approximately 10% of subjects). APAb were earlier onset, less frequent, less persistent and lower titer than AIAb. No associated hypersensitivity events were reported.