Clinical Remission Predictors in Non-Colonized Bronchiectasis and Severe Asthma with Type 2-Targeted Biologic Therapy: A Retrospective Real-Life Pilot Study

Background/Objective: Patients with severe asthma (SA) and non-cystic fibrosis bronchiectasis (BE) without microbiological colonization represent a unique and understudied population. Type 2-targeted biologic therapies have emerged as a promising treatment for these patients. However, predictive factors for achieving clinical remission remain unclear. This study aims to identify the predictive factors for achieving clinical remission in patients with severe asthma and non-colonized bronchiectasis undergoing type 2-targeted biologic therapies. Methods: A retrospective longitudinal analysis was conducted on 14 patients with severe asthma and non-cystic fibrosis bronchiectasis without microbiological colonization. Clinical remission was assessed at baseline (T0) and after 12 months (T1) of biologic therapy. Clinical remission was defined according to the Severe Asthma Network Italy (SANI) criteria, including the absence of oral corticosteroid use, no asthma-related symptoms, stable lung function, and no exacerbations. Logistic regression was performed to identify predictors of remission. ROC curves were constructed to evaluate the predictive accuracy of lung function parameters, specifically FEV1 and FVC. Results: After 12 months of biologic therapy, 28.6% of patients (n = 4) achieved clinical remission. The mean FEV1 percentage at baseline was significantly higher in the remission group (92.25 +/- 15.64%) compared to the non-remission group (65.10 +/- 23.36%, p = 0.034). Logistic regression analysis identified baseline FEV1 as a significant predictor of remission (OR = 1.008, p = 0.050). ROC curve analysis revealed that an FEV1 cutoff of 72.5% had a sensitivity of 100% and a specificity of 70% (AUC = 0.900, p = 0.024) for predicting clinical remission. Conclusions: FEV1 is a crucial predictor of clinical remission in patients with severe asthma and non-colonized bronchiectasis treated with type 2-targeted biologic therapies. An FEV1 threshold of 72.5% can guide clinicians in identifying patients most likely to achieve remission. These findings underline the importance of preserving lung function to optimize therapeutic outcomes in this complex population.