Across chronic inflammatory disease states, anti-drug antibodies (ADAbs) were detected in as many as 50% of patients in studies of adalimumab, infliximab, and the infliximab biosimilar CT-P13, but in lower proportions of patients (<20%) in studies of secukinumab, ustekinumab, etanercept, and golimumab. (Immunogenicity data are not directly comparable among studies because of heterogeneity in immunoassays and other methodological features.)

ADAb formation was associated with reduced clinical efficacy of several biologics/biosimilars, including adalimumab, golimumab, infliximab, rituximab, ustekinumab, and CT-P13, and higher risk of infusion reactions with infliximab and CT-P13.

Because of these potential clinical consequences, the immunogenicity of biologics/biosimilars is an essential (albeit not the only) consideration when clinicians select a therapeutic approach in patients with chronic immune-mediated inflammatory disease.