Airway Disorders Network
Bronchiectasis Section
and persistent inflammation. In bronchiectasis, excessive neutrophil accumulation in the airways leads to release of neutrophil serine proteases (NSPs), which contributes to tissue damage and perpetuates the inflammatory process in the lungs. The three main NSPs include neutrophil elastase (NE), proteinase3, and cathepsin G. Elevations in NE activity in sputum in NCFBE are associated with increased exacerbations and declines in lung function. Dipeptidyl peptidase 1 (DPP1), an enzyme primarily found in neutrophils, is responsible for activating NSPs during neutrophil maturation. In bronchiectasis, increased DPP1 activity results in an augmented production of active NSPs, exacerbating lung damage and inflammation.
Dr. Shyamsunder Subramanian
Brensocatib, an oral, reversible inhibitor of DPP1 is currently being developed as a novel approach to managing bronchiectasis. Brensocatib was evaluated in a phase 2 clinical trial (WILLOW), a randomized, double-blind, placebo-controlled trial involving adults with non–cystic fibrosis bronchiectasis (NCFBE). Treatment with brensocatib for 24 weeks significantly prolonged the time to the first exacerbation at both the 10 mg and 25 mg doses and lowered the risk of exacerbation by 40% relative to placebo. The treatment was well tolerated, with no significant safety concerns. Results of a recent post hoc analysis from the WILLOW study show that brensocatib effectively reduces exacerbations and slows lung function decline across different severities of bronchiectasis. These findings suggest that brensocatib holds potential as the 1st new therapeutic option for patients with NCFBE, with currently no FDA-approved drugs. Results of a larger-scale phase 3 trial are awaited later this year, which will hopefully confirm these results and ascertain the long-term safety.
Shyamsunder Subramanian, MD, MBBS, FCCP
Section Chair