Background: Dornase alfa (DNase) is one of the commonest cystic fibrosis (CF) treatments and is often used for many years. However, studies have not evaluated the effectiveness of its long-term use. We aimed to use UK CF Registry data to investigate the effects of one-, two-, three-, four- and five-years of DNase use on lung function to see if the benefits of short-term treatment use are sustained long term. Methods: We analysed data from 4,198 people in the UK CF Registry from 2007 to 2015 using g-estimation. By controlling for time-dependent confounding we estimated the effects of long-term DNase use on percent predicted FEV 1 (ppFEV 1 ) and investigated whether the effect differed by ppFEV 1 at treatment initiation or by age. Results: Considering the population as a whole, there was no significant effect of one-year's use of DNase; change in ppFEV 1 over one year was −0.1% in the treated compared to the untreated (p = 0.51) and this did not change with long-term use. However, treatment was estimated to be more beneficial in people with lower lung function (p < 0.001); those with ppFEV 1 < 70% at treatment initiation, showed an increase in lung function over one year that was sustained out to five years. The estimated effect of DNase did not depend on age (p = 0.35). Conclusions: DNase improved lung function in individuals with reduced lung function, bringing a step-change in lung function, but no change in the slope of decline. There was no evidence for a benefit in lung function in those initiating treatment with ppFEV 1 > 70%.
Newsome, S. J., Daniel, R. M., Carr, S. B., Bilton, D., & Keogh, R. H. (2019). Investigating the effects of long-term dornase alfa use on lung function using registry data. Journal of Cystic Fibrosis, 18(1), 110–117. https://doi.org/10.1016/j.jcf.2018.08.004