D2.132 - Characteristics of Patients with Uncontrolled Severe Asthma Undergoing Biological Therapy Based on Spirometric Response: Our Experience

Severe uncontrolled asthma is a condition characterized by persistent respiratory symptoms and frequent exacerbations despite standard treatment. According to medical literature, biological treatments significantly improve lung function, as indicated by increases in FEV1, fewer exacerbations, reduced oral corticosteroid use, and better asthma control.

We conducted a single-center retrospective observational study analyzing electronic medical records of adult patients who initiated biologic treatment between January 2023 and October 2024. These patients were seen at the severe uncontrolled asthma unit of our hospital. The objective was to analyze the differences between patients with spirometric improvement of >400mL FEV1 and <400mL FEV1 across multiple clinical parameters. We selected a 400mL increase in FEV1 as it represents a substantial improvement in lung function, exceeding expected variability.

In a cohort of patients receiving biologic therapy for severe asthma, 16 individuals achieved >400mL FEV1 improvement compared to 102 with <400mL FEV1. The >400mL group was predominantly female (75%) with a mean age of 52.8 years (±9.2), significantly younger than the <400mL group (64.4±10.7,p<0.05). Conditions such as FRCV, rhinoconjunctivitis, and atopic dermatitis were more prevalent in the latter group. The >400mL FEV1 improvement group was biologic-naïve in 81% vs. 51%.Benralizumab was the most frequent biologic in both groups (50% vs. 32.3%). FEV1 increased significantly in the >400mL group from 2116.3±254.2mL to 2709.4±306.8mL (p<0.001), whereas the <400mL group showed only a modest improvement (1784.4±200.5mL to 1796.9±210.7mL, p>0.05). FVC improvements were also greater in the >400mL group (3544.4±289.7mL vs. 2580.9±267.3mL,p<0.01). No significant differences were observed in FEV1/FVC ratios or ACT scores between groups at baseline or after one year of treatment. Exacerbations decreased similarly in both groups (0.3vs0.6;p=0.597). Corticosteroid use declined more in the >400mL group but was not statistically significant (0.2vs0.6;p=0.688).

In our study, patients with spirometric improvement >400mL FEV1 demonstrated significantly better lung function outcomes after treatment compared to those with <400mL FEV1 improvement. Patients who achieved a considerable improvement in lung function were predominantly middle-aged females with significant comorbidities, an atopic history, and prior biologic-naïve status. However, no significant differences were found in ACT scores, exacerbation rates, or corticosteroid use.