Van Devanter DR, et al. - The goal of this paper was to examine the clinical features related to the dornase alfa treatment regimen change, in the case of cystic fibrosis. This study culminated in the following observation, the most common clinical attribute linked with the switch from QD to BID dornase alfa was a significant deterioration in stability characterized by increased incidence and frequency of pulmonary exacerbation. The deterioration in lung function did not serve as a driver for this switch. The patients receiving BID dornase alfa who were ultimately switched to QD, nevertheless, were found to be clinically stable, on average. This data indicated that treatment burden and cost could present as drivers of the decision to switch regimens.