Dupilumab Reduces Urticaria Activity, Itch, and Hives in Patients with Chronic Spontaneous Urticaria Regardless of Baseline Serum Immunoglobulin E Levels

In chronic spontaneous urticaria (CSU), interleukin (IL)-4 and IL-13 may promote mast cell activation directly via IL-4 receptor expression, or indirectly via upregulated immunoglobulin E (IgE) production. Dupilumab significantly improved CSU signs and symptoms in the phase 3, randomized, placebo-controlled LIBERTY-CSU CUPID Study A. This analysis explores the impact of dupilumab on CSU signs and symptoms and serum IgE levels in patients from LIBERTY-CSU CUPID Study A with serum total IgE above and below 100 IU/mL at baseline. Patients with H1-antihistamine-refractory CSU received dupilumab (n = 70) or placebo (n = 68) for 24 weeks. Efficacy endpoints were change from baseline to weeks 12 and 24 in serum total IgE levels, Itch Severity Score over 7 days (ISS7), Urticaria Activity Score over 7 days (UAS7), and Hives Severity Score over 7 days (HSS7) in dupilumab- or placebo-treated patients with serum total IgE above and below 100 IU/mL at baseline. Dupilumab treatment significantly reduced median (interquartile range) IgE levels at week 12 [dupilumab: −31.9% (−41.9; −22.6); placebo: −6.3% (−21.3; 14.9)] and week 24 [dupilumab: −48.2% (−56.8; − 39.5); placebo: − 6.3% (−34.5; 14.8)]. Similar IgE reductions relative to baseline were observed in dupilumab-treated patients regardless of baseline IgE level. Dupilumab treatment improved ISS7, UAS7, and HSS7 over 12 and 24 weeks, regardless of baseline serum IgE level (interaction p ≥ 0.59 for all treatment by subgroup comparisons), with weak correlations (r < 0.2) observed between IgE level changes and ISS7, UAS7, and HSS7 outcomes. Dupilumab significantly improved CSU signs and symptoms and reduced serum IgE, regardless of baseline IgE levels. In the current analysis, baseline total IgE had no predictive value as a dupilumab treatment response biomarker in CSU. Downregulation of IgE, a key mediator of mast cell activation and histamine release, may at least partially explain the effectiveness of dupilumab in reducing CSU signs and symptoms. ClinicalTrials.gov Identifier: NCT04180488.