General Information

Pulmozyme (dornase alfa) is a recombinant DNase enzyme.

Pulmozyme is specifically indicated for the management of mild to moderate cystic fibrosis in conjunction with standard therapies to reduce the incidence of respiratory tract infections requiring parenteral antibiotics and to improve pulmonary function.

Pulmozyme is supplied as an inhalation solution for oral inhalation. The recommended dosage for use in most cystic fibrosis patients is one 2.5 mg single-use ampule inhaled once daily using a recommended jet nebulizer/compressor system or eRapid Nebulizer System. Some patients may benefit from twice daily administration.

Mechanism of Action

Pulmozyme (dornase alfa) is recombinant human deoxyribonuclease I (rhDNase), an enzyme which selectively cleaves DNA. In preclinical in vitro studies, Pulmozyme hydrolyzes the DNA in sputum of CF patients and reduces sputum viscoelasticity. In CF patients, retention of viscous purulent secretions in the airways contributes both to reduced pulmonary function and to exacerbations of infection. Purulent pulmonary secretions contain very high concentrations of extracellular DNA released by degenerating leukocytes that accumulate in response to infection.

Clinical Trial Results

The benefit of treatment with Pulmozyme in advanced Cystic Fibrosis was demonstrated in a placebo-controlled study of 320 subjects that examined safety and efficacy of Pulmozyme during a 12-week period. Advanced disease is defined by a standard measure of forced vital capacity of less than 40% of predicted (FVC less than 40%). In this study of subjects with advanced disease, measures of pulmonary function--the forced expiratory volume in one second and FVC--were significantly improved as compared to placebo. In contrast to the mild to moderate cystic fibrosis patient population, no benefit reducing the incidence of respiratory tract infections was seen.