Impact of biologics on lung hyperinflation in patients with severe asthma

In asthma, inflammation affects both the proximal and distal airways and can cause significant hyperinflation, which is thought to be a major cause of dyspnea.

This is a retrospective observational study evaluating the effect of three months of treatment with different biologic drugs (benralizumab, dupilumab and omalizumab) on pulmonary hyperinflation in a cohort of patients with severe asthma already receiving regular triple inhaled therapy. Changes in RV, RV/TLC ratio, FRC and FRC/TLC ratio were the primary efficacy measures. Secondary outcomes included FEV₁, FVC, FEV₁/FVC ratio, IC, IC/TLC ratio, asthma control test, the percentage of eosinophils in the blood and fractional F_ENO.

Benralizumab led to significant changes (p < 0.001) in RV, RV/TLC, FRC, and FRC/TLC. Dupilumab demonstrated a notable reduction in RV (p = 0.017) and RV/TLC (p = 0.002), but the decreases in FRC and FRC/TLC were merely numerical and not as pronounced as those induced by benralizumab. Omalizumab's positive impact on RV (p = 0.057) and RV/TLC (p = 0.085), as well as FRC (p = 0.202) and FRC/TLC (p = 0.096), was also predominantly numerical, with a tendency towards efficacy, albeit excluding the effect on FRC. Treatment with biologics resulted in improvements in all other lung function parameters assessed and a decrease in F_ENO levels.

This study, although limited by small sample size, lack of a placebo control, and unbalanced group sizes, suggests that biological agents are effective in reducing lung hyperinflation even after a relatively short treatment.