Role of Biologics Targeting Isolated IL-13 in Bronchial Asthma: A Narrative Review

Abstract

Bronchial Asthma (BA), a chronic inflammatory airway disorder, results in recurrent respiratory symptoms characterised by Immunoglobulin E (IgE)- mediated and T2-mediated inflammation. Type-2 inflammation constitutes a large portion of the total inflammatory process and occurs through the secretion of several pro-inflammatory cytokines, such as Interleukin-4 (IL-4), IL-5, and IL-13. IL-13 is one of the predominant cytokines involved in airway inflammation, excessive mucous production, eosinophilic infiltration, and airway remodelling. Targeting IL-13 as a therapeutic agent is a promising approach for the treatment of severe BA that is uncontrolled with conventional agents. Monoclonal antibodies such as lebrikizumab and tralokinumab have been evaluated in clinical trials and have demonstrated variable efficacy across different patient populations and study outcomes, with benefits observed in selected patients rather than consistently across all trials. Several biomarker tests, including fractional exhaled nitric oxide, blood eosinophil count, and serum periostin, are utilised to identify patients who would benefit from IL-13-directed therapies. Due to the complicated, heterogeneous pathophysiology of BA, the indications for IL-13-directed therapy use in routine clinical practice are still evolving. This review aimed to evaluate the role of IL-13 in BA, the rationale behind targeting select cytokines, the therapeutic use of biologics that target IL-13, and future options for biomarker-based precision medicine to improve the management of BA.