Biologic Therapies in AD and CSU: Progress and the Push for Precision Medicine

A recent narrative review examined the evolving role of biologic therapies in atopic dermatitis (AD) and chronic spontaneous urticaria (CSU), highlighting how advances in disease biology are reshaping treatment options while emphasizing the need for precision medicine.¹

The review evaluated published evidence from phase clinical trials, randomized controlled trials, observational studies, meta-analyses, and real-world evidence available in PubMed through the end of 2023. Investigators focused on biologic agents studied in AD and CSU and assessed outcomes using commonly reported disease severity, symptom, and quality-of-life measures.

Pathophysiology and Immune Dysregulation

The author notes that both AD and CSU are driven by immune dysregulation, but the underlying biology differs substantially. In AD, multiple inflammatory pathways—including T-helper 2 (Th2), Th1, Th17, and Th22 responses—contribute to disease development. Because of this complex cytokine network, biologic therapies must target specific inflammatory pathways rather than broadly applying approaches used in other inflammatory skin diseases.

CSU has a different pathophysiology. The disease is characterized by mast cell and basophil degranulation, resulting in histamine release, wheals, and angioedema lasting longer than 6 weeks. Autoimmunity and cytokine dysregulation also appear to contribute to disease activity. The review suggests that a better understanding of disease endotypes will help clinicians select therapies more precisely in the future.

Biologic and Targeted Therapies for AD

Among currently available biologic therapies, dupilumab has the strongest evidence base for moderate to severe AD. The review identifies dupilumab as an FDA- and European Medicines Agency (EMA)-approved monoclonal antibody that targets the shared IL-4 and IL-13 signaling pathway. Across clinical studies, approximately 40% to 60% of patients with severe AD achieved meaningful clinical improvement with treatment.

Clinical trials consistently demonstrated improvements in disease severity, pruritus, and quality of life using validated outcome measures such as the Eczema Area and Severity Index (EASI), Investigator's Global Assessment (IGA), SCORAD, Peak Pruritus Numeric Rating Scale, and Dermatology Life Quality Index.

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The review also summarizes evidence for several newer targeted therapies that address different inflammatory pathways involved in AD. Tralokinumab and lebrikizumab selectively target IL-13, while nemolizumab inhibits IL-31, a cytokine closely associated with itch. The author describes these agents as expanding the therapeutic landscape by targeting distinct components of AD pathogenesis.

In addition to biologics, the review discusses targeted oral therapies, including the Janus kinase (JAK) inhibitors baricitinib and upadacitinib. Both have received FDA and EMA approval for AD and represent alternative options for appropriate patients. Although several therapies demonstrated promising efficacy across studies, the review notes that differences in study design and patient populations make direct comparisons challenging.

Biologic Therapies for CSU

For CSU, the review focuses primarily on omalizumab, an anti-IgE monoclonal antibody that has become an important treatment option for patients whose disease remains uncontrolled despite antihistamine therapy.

The author acknowledges that published studies have reported variable efficacy, leading to ongoing debate regarding treatment response. Nevertheless, current European Academy of Allergy and Clinical Immunology (EAACI) guidelines continue to recommend omalizumab as add-on therapy for recalcitrant CSU. Clinical trials and real-world studies evaluated multiple patient-reported and physician-assessed outcomes, including the Urticaria Activity Score, Dermatology Life Quality Index, visual analog scales, and disease-specific quality-of-life questionnaires.

Conclusion and Future Outlook

The review concludes that biologic therapies have substantially expanded treatment options for patients with difficult-to-treat AD and CSU, particularly those who have not responded adequately to conventional therapies.

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For AD, dupilumab remains the most established biologic, while tralokinumab, lebrikizumab, baricitinib, and upadacitinib provide additional targeted options. In CSU, omalizumab continues to serve as the primary biologic therapy for refractory disease despite variability in reported response rates.

The author emphasizes that future advances will likely depend on improving understanding of disease endotypes and inflammatory pathways. As biomarkers and disease classification continue to evolve, clinicians may be better able to match individual patients with the biologic therapy most likely to provide durable disease control while minimizing unnecessary treatment exposure.

Reference

1. Salavoura A. Review on the Application of Biologic Factors in Atopic Dermatitis and Chronic Spontaneous Urticaria. Dermatol Res Pract. 2026;2026:5283760. Published 2026 Jun 21. doi:10.1155/drp/5283760