Ensifentrine

Ensifentrine is a newly approved inhaled dual phosphodiesterase 3 and 4 inhibitor for the maintenance treatment of chronic obstructive pulmonary disease. Because post-marketing safety experience is still limited, this study evaluated adverse event reporting patterns for ensifentrine. Quarterly US Food and Drug Administration (FDA) Adverse Event Reporting System/Adverse Event Monitoring System files from 2024Q3 to 2026Q1 were analyzed. Duplicate reports were removed using Case Identification Number (CASEID), FDA receipt date (FDA_DT), and Primary Identification Number (PRIMARYID), and the primary analysis was restricted to reports in which ensifentrine was recorded as the primary suspect drug. Preferred Terms (PTs) were mapped to Medical Dictionary for Regulatory Activities primary System Organ Class categories, and report-level disproportionality was assessed using reporting odds ratio, proportional reporting ratio, an information component approximation, and an observed-to-expected approximation. After deduplication, 2,831,030 records were reduced to 2,500,712 unique reports. Ensifentrine was identified in 1137 reports across all drug roles and in 823 primary-suspect reports, which included 1817 PT records. At the System Organ Class level, Respiratory, thoracic and mediastinal disorders was the only category meeting all predefined robust signal criteria. At the PT level, respiratory, cardiovascular, psychiatric/neuropsychiatric, and product quality- or medication-use-related terms were notable. Time-to-onset could be calculated for 139 reports, with a median of 12 days. Respiratory reporting patterns predominated in early post-marketing reports for ensifentrine. These findings should be interpreted as hypothesis-generating pharmacovigilance signals rather than estimates of incidence or causality.

The ENHANCE trials demonstrated that ensifentrine (CAS Number 1884461-72-6), an inhaled dual phosphodiesterase (PDE) 3/4 inhibitor, offers additional benefits in chronic obstructive pulmonary disease (COPD). Its bifunctional activity warrants pharmacological investigation to elucidate mechanisms behind lung function improvements and exacerbation reduction. Human bronchial tissues from COPD donors were examined after lipopolysaccharide challenge. The effects of ensifentrine on bronchial relaxation were evaluated in response to carbachol and electrical field stimulation (EFS), also in combination with long-acting muscarinic antagonist (LAMA), long-acting β₂-adrenoceptor agonists (LABA), and inhaled corticosteroids (ICS). Anti-inflammatory effects were assessed by profiling cytokines, alarmins, and growth factors. Drug interactions were analyzed using the Bliss-Loewe Uncertainty Range (BLUR) model. Ensifentrine induced concentration-dependent relaxation to carbachol in both epithelium-intact and epithelium-denuded tissues (E_max 81.97 ± 6.17%, pEC₅₀ 4.86 ± 0.17) and inhibited EFS-induced contractility from 0.1 μM, with maximum reduction of 29.01% ± 2.50%. When combined with a LAMA, dual LABA/LAMA, or triple ICS/LABA/LAMA combinations, ensifentrine showed synergistic bronchorelaxant effect (overall increase in relaxation 20.47% ± 0.39%), leading to near-complete relaxation (>90%) at higher concentrations. At lower concentrations, ensifentrine reduced inflammation by 84.34% ± 8.69% in medium bronchi and 64.75% ± 8.96% in small airways; at the higher concentrations, inflammation was almost abolished (>90%), comparable to roflumilast. Drug combinations showed synergistic anti-inflammatory interactions in 31.43% of cases, mainly affecting interleukin 10, interleukin 25, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor-α. This study supports ensifentrine as an adjunct in COPD therapy, because of its dual bronchodilator and anti-inflammatory actions. Further research is warranted to optimize combination strategies to maximize clinical benefits and to identify additional activities in the target tissue. SIGNIFICANCE STATEMENT: The inhaled dual PDE 3/4 inhibitor ensifentrine emerges as a potent therapeutic option for COPD, showing remarkable bronchodilator and anti-inflammatory effects within human airways, the primary target tissue. It exhibits synergistic interactions with existing inhaler therapies, enhancing their efficacy. By demonstrating anti-inflammatory efficacy comparable to the established PDE4 inhibitor, roflumilast, our findings emphasize ensifentrine's capacity to significantly improve treatment outcomes and guide the development of optimized future combination strategies for COPD management.