Aim: High drug concentrations in ocular fluids after intravitreal administration preclude the use of drug-sensitive immunoassays. A drug-tolerant immunoassay is therefore desirable for immunogenicity testing in ophthalmology.
Experimental: Immune complex (IC) antidrug antibody (ADA) assays were established for two species. The assays were compared with the bridging assay in ocular and plasma samples from two preclinical studies.
Results: The IC assays showed high drug tolerance, which enabled a reliable ADA detection in ocular fluids after intravitreal administration. The IC assays were superior to the bridging assay in the analysis of ocular fluids with high drug concentrations.
Conclusion: The IC assay allows a reliable ADA detection in matrices with high drug concentrations, such as ocular fluids.
Keywords: ELISA; antidrug antibody; aqueous humor; drug tolerance; immune complex assay; immunogenicity; ophthalmology; safety assessment; vitreous humor.