An Introduction to Bioanalysis of Bispecific and Fusion Proteins

Bispecific antibodies and fusion proteins are part of the next generation of biotherapeutics that contain more than one functional domain. These biotherapeutic modalities are structurally complex and require unique approaches to bioanalysis. For their pharmacokinetic analysis, multiple assays may be required to characterize the disposition of the whole drug molecule as well as the individual functional domains. The immunogenicity analysis of these biotherapeutics also requires additional tiers of domain-specific characterization. The bioanalytical approaches for these modalities thus require additional considerations due to the complexity of their structure, additional domain-specific critical reagent generation, and increased assay complexities due to interferences observed by individual functional domains.