A prospective study to assess the efficacy of extra fine particle inhaled corticosteroid and LABA in small airway diseases associated with interstitial lung diseases

Following Clinical Trials Registry-India (CTRI) approval, we will commence a prospective, single-arm interventional trial, recruiting patients over 8 months from our specialized Interstitial Lung Disease (ILD) clinic at out institute, AIIMS, Jodhpur. Eligible participants will be adults with a confirmed diagnosis of ILD and evidence of small airway disease (SAD), defined as a pre-bronchodilator FEF25-75% < 65% predicted. Key exclusion criteria will include active smoking, co-existing obstructive lung diseases (e.g., asthma, COPD), an acute ILD exacerbation or respiratory infection within one month of enrollment, inability to correctly use the inhaler device, or known contraindications to the study medication. After baseline assessments, including full pulmonary function tests and the King’s Brief Interstitial Lung Disease (K-BILD) questionnaire, all enrolled patients will be prescribed an extra-fine particle combination inhaler (formoterol and beclomethasone) for a duration of 8 weeks, in addition to their standard ILD therapy. The primary outcome will be the change in FEF25-75% from baseline to the 8-week follow-up, with secondary outcomes including changes in the K-BILD score and RV/TLC. We anticipate that this targeted treatment will yield a statistically and clinically significant improvement in small airway function and patient-reported symptoms. If successful, the findings from this study will provide crucial evidence to support a more comprehensive management strategy for ILD that addresses the airway component of the disease, potentially establishing a new standard of care to improve functional capacity and quality of life for this patient population and justifying larger, randomized controlled trials in the future.