Related Experiment Video
Updated: Jun 13, 2025

Monitoring Neutrophil Elastase and Cathepsin G Activity in Human Sputum Samples
Published on: May 21, 2021
Cathepsin C (dipeptidyl peptidase 1) inhibition in adults with bronchiectasis: AIRLEAF, a phase II randomised,
James D Chalmers1, Michal Shteinberg2,3, Marcus A Mall4,5,6
1Division of Respiratory Medicine and Gastroenterology, University of Dundee, Dundee, UK j.chalmers@dundee.ac.uk.
Background:
Bronchiectasis is characterised by uncontrolled neutrophil serine protease (NSP) activity. Cathepsin C (CatC; dipeptidyl peptidase 1) activates NSPs during neutrophil maturation. CatC inhibitors can potentially reduce neutrophil-mediated lung damage. This phase II, randomised, double-blind, placebo-controlled trial (AIRLEAF®; clinicaltrials.gov identifier NCT05238675) evaluated efficacy, safety and optimal dosing of BI 1291583, a novel, reversible CatC inhibitor, in adults with bronchiectasis.
Methods:
In total, 322 participants were randomised (2:1:1:2) to receive one of three oral doses of BI 1291583 (1 mg/2.5 mg/5 mg) or placebo for 24-48 weeks. A multiple comparison procedure and modelling approach was used to demonstrate a nonflat dose-response curve based on the time to first pulmonary exacerbation up to week 48. In addition, efficacy of individual BI 1291583 doses was evaluated based on the frequency of exacerbations, severe exacerbations (fatal or leading to hospitalisation and/or intravenous antibiotic administration), lung function and quality of life.
Results:
A significant dose-dependent benefit of BI 1291583 over placebo was established based on time to first exacerbation (shape: maximum effect curve 1; adjusted p=0.0448). Treatment with BI 1291583 5 mg and 2.5 mg numerically reduced the risk of an exacerbation compared with placebo (hazard ratio (95% CI) 0.71 (0.48 to 1.05) and 0.66 (0.40 to 1.08), respectively; both p>0.05). BI 1291583 2.5 mg showed numerically better efficacy compared with 5 mg across several end-points; 1 mg was similar to placebo. The safety profile of BI 1291583 was similar to placebo.
Conclusion:
Treatment with BI 1291583 resulted in a reduction in the risk of experiencing an exacerbation in adults with bronchiectasis.
More Related Videos
09:26Antibiotic Efficacy Testing in an Ex vivo Model of Pseudomonas aeruginosa and Staphylococcus aureus Biofilms in the Cystic Fibrosis Lung
Published on: January 22, 2021
10:18Real-Time, Semi-Automated Fluorescent Measurement of the Airway Surface Liquid pH of Primary Human Airway Epithelial Cells
Published on: June 13, 2019
Related Concept Videos
Cystic Fibrosis: Management
Sinus disease and chronic...
COPD: Management Using Bronchodilators and Corticosteroids
Cystic Fibrosis: Pathogenesis
CF is primarily caused by a genetic mutation in a chromosome 7 gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most common gene mutation leading to CF is the ΔF508 mutation,...
Chronic Obstructive Pulmonary Disease-II: Pathophysiology
Chronic Inflammation
Antiasthma Drugs: Inhaled Corticosteroids and Glucocorticoids
ICS work through a multifaceted mechanism of action. They suppress the inflammatory response caused by the proliferation of TH cells. They also reduce the transcription of the IL-2 gene, which is involved in the...
Antiasthma Drugs: Leukotriene Modifiers
Leukotriene modifiers work through two distinct mechanisms: