Anti-IL-5 therapies for asthma

Area of Science:

• Immunology
• Pulmonology
• Pharmacology

Background:

• Interleukin-5 (IL-5) is a key cytokine driving eosinophilic airway inflammation in asthma.
• Monoclonal antibodies targeting IL-5 or its receptor (IL-5R) are investigated for severe asthma.
• Previous reviews (2015, 2017) have assessed these therapies.

Purpose of the Study:

• To compare anti-IL-5/IL-5R therapies with placebo in chronic asthma.
• To evaluate effects on exacerbations, quality of life (HRQoL), and lung function.
• To specifically assess outcomes in eosinophilic asthma refractory to existing treatments.

Main Methods:

• Systematic review and meta-analysis of randomized controlled trials (RCTs).
• Included mepolizumab, reslizumab, and benralizumab versus placebo.
• Searched multiple databases up to February 7, 2022.

Main Results:

• Seventeen RCTs involving ~7600 participants were included, predominantly severe eosinophilic asthma.
• Anti-IL-5 treatments approximately halved exacerbation rates in severe eosinophilic asthma.
• Improvements in HRQoL and lung function (FEV1) were observed but often below clinical significance thresholds.
• No excess serious adverse events were noted, though benralizumab had more discontinuations due to adverse events.

Conclusions:

• Anti-IL-5 therapies are supported as an adjunct for severe eosinophilic asthma with poor control.
• Limited evidence for clinically meaningful HRQoL and lung function improvements.
• Further research is needed on biomarkers, long-term effects, and comparisons with other biologics.