Biologic therapies targeting type 2 cytokines are effective at improving asthma symptoms and control—a systematic review and meta-analysis

Allergic asthma is a highly prevalent chronic inflammatory disease driven by aeroallergen exposure. In severe asthma, the current standard of care does not fully control disease symptoms, indicating an unmet clinical need. Biologic therapies targeting cytokines IL-4, IL-5, and IL-13 have been shown to provide benefits to asthmatic patients over currently existing asthma treatments. We sought to review the effects of recently developed biologic therapies for asthma treatment. In this meta-analysis, the impact of IL-5 and IL-4/IL-13 biologic inhibitors was critically appraised considering overall lung function, symptom control, and oral corticosteroid use in asthmatic patients. Trials were identified using PubMed, Web of Science, Scopus, and clinicaltrials.gov. Clinical trials assessing severe asthmatic participants older than 12 years were included. The meta-analysis included 6600 participants from 14 trials published in 2013 to 2020. For IL-5 inhibitors, improvements in FEV1 (mean difference [MD], 0.11; 95% CI, 0.11 to 0.12), Asthma Control Questionnaire scores (MD, −0.4; 95% CI, −0.41 to −0.38), annual exacerbation rates (MD, −0.46; 95% CI, −0.48 to −0.45), and oral corticosteroid use (MD, −50; 95% CI, −52.58 to −47.42) favored biologic treatment. Significant improvements in FEV1 (MD, 0.11; 95% CI, 0.10 to 0.11), Asthma Control Questionnaire scores (MD, −0.20; 95% CI, −0.22 to −0.18), and annual exacerbation rates (MD, −0.15; 95% CI, −0.16 to −0.14) were also seen with anti–IL-4/IL-13 biologic therapies. However, anti–IL-4/IL-13 inhibitors were associated with more adverse events than placebo (MD, 1.13; 95% CI, 0.97 to 1.3). Biologic inhibitors targeting TH2 cytokines are beneficial for improving overall asthma control.