Multicenter randomized trial assessing efficacy and safety of aerosolized dornase Alfa in COVID-19 ARDS.

Acute respiratory distress syndrome (ARDS) caused by SARS-CoV-2 infection is associated with high mortality rates and respiratory compromise in which excessive neutrophil extracellular trap (NET) production may amplify alveolar inflammation and injury. Dornase alfa, a recombinant DNAse 1, has been proposed to attenuate these effects by degrading extracellular DNA and enhancing alveolar clearance of NETs. In this multicenter, open-label, randomized in two parallel arms (1:1) controlled trial, intubated COVID-19 ARDS patients received either standard-of-care (SOC) alone or SOC plus aerosolized dornase alfa (2500 IU twice daily for 7 days). The primary endpoint was the proportion of patients with ARDS severity improvement at Day 7, defined by at least one-grade improvement on the Berlin criteria scale. Secondary outcomes included 28-day mortality, ventilator-free days, ICU-free days, and changes in key ventilatory parameters. Biological samples were analyzed to assess NET related markers, DNAse drug activity and indicate possible bioavailability issues associated with aerosolization of dornase alfa. Seventy-seven patients were enrolled (dornase alfa group, n = 39; SOC group, n = 38). At Day 7, ARDS severity improved in 18% of patients receiving dornase alfa compared with 29% in the SOC group (adjusted OR: 0.33; 95% CI 0.09-1.14; p = 0.11). Secondary endpoints, including 28-day mortality, ventilator-free days, and ICU-free days, showed no significant differences between groups. Adverse events occurred in 38.5% of patients in the dornase alfa arm versus 31.6% in the SOC arm, indicating comparable safety profiles. Despite early increases in NET plasmatic levels observed in both groups and successful ex vivo NET degradation, aerosolized dornase alfa failed to significantly enhance DNAse activity or reduce NET-related markers in patients' plasma and mucus, suggesting potential bioavailability limitations with this delivery method. In patients with COVID-19-related ARDS, dornase alfa did neither significantly reduce ARDS severity nor improve clinical outcomes over SOC. Although well tolerated, analysis of biological samples suggests that aerosol administration may have compromised drug bioavailability. Further trials are needed to determine whether specific patient subgroups could benefit more from dornase alfa or if alternative drug delivery methods might enhance treatment efficacy. ClinicalTrials.gov, NCT04355364. Registered on 21/04/2020.