Medication Review: Anti-Drug Antibody Development With Guselkumab in Psoriasis, PsA & IBD

February 2026

In this comprehensive medication review, Lisa Asfahani, PA-C, a rheumatology physician assistant with over 14 years of clinical experience, explores the rates of anti-drug antibody development to guselkumab in patients with psoriatic arthritis. Guselkumab, an IL-23 p19 monoclonal antibody inhibitor, is approved for the treatment of plaque psoriasis, psoriatic arthritis, ulcerative colitis, and Crohn’s disease. This video breaks down the mechanisms of immunogenicity, how anti-drug antibodies can reduce treatment efficacy, and their potential role in secondary loss of response and adverse drug reactions. Lisa reviews key data from peer-reviewed studies, including findings on neutralizing antibody rates, ELISA assay detection methods, and long-term safety and efficacy outcomes in biologic-naïve patients. Learn how therapeutic drug monitoring, specialized antibody assays, consistent dosing strategies, and potential concomitant immunosuppressive therapy may help mitigate immunogenicity risks. Whether you manage psoriatic arthritis, psoriasis, or inflammatory bowel disease, this evidence-based overview provides practical insights to support confident biologic prescribing and long-term disease control in rheumatology practice. Visit the RhAPP Content Rheum or RhAPP ACE app for more educational resources.