Dual blockade of IL‐4 and IL‐13 with dupilumab, an IL‐4Rα antibody, is required to broadly inhibit type 2 inflammation

BACKGROUND: Dupilumab, a fully human monoclonal antibody that binds IL‐4Rα and inhibits signaling of both IL‐4 and IL‐13, has shown efficacy across multiple diseases with underlying type 2 signatures and is approved for treatment of asthma, atopic dermatitis, and chronic sinusitis with nasal polyposis. We sought to provide a comprehensive analysis of the redundant and distinct roles of IL‐4 and IL‐13 in type 2 inflammation and report dupilumab mechanisms of action. METHODS: Using primary cell assays and a mouse model of house dust mite–induced asthma, we compared IL‐4 vs IL‐13 vs IL‐4Rα blockers. RESULTS: Intranasal administration of either IL‐4 or IL‐13 confers an asthma‐like phenotype in mice by inducing immune cell lung infiltration, including eosinophils, increasing cytokine/chemokine expression and mucus production, thus demonstrating redundant functions of these cytokines. We further teased out their respective contributions using human in vitro culture systems. Then, in a mouse asthma model by comparing in head‐to‐head studies, either IL‐4 or IL‐13 inhibition to dual IL‐4/IL‐13 inhibition, we demonstrate that blockade of both IL‐4 and IL‐13 is required to broadly block type 2 inflammation, which translates to protection from allergen‐induced lung function impairment. Notably, only dual IL‐4/IL‐13 blockade prevented eosinophil infiltration into lung tissue without affecting circulating eosinophils, demonstrating that tissue, but not circulating eosinophils, contributes to disease pathology. CONCLUSIONS: Overall, these data support IL‐4 and IL‐13 as key drivers of type 2 inflammation and help provide insight into the therapeutic mechanism of dupilumab, a dual IL‐4/IL‐13 blocker, in multiple type 2 diseases.