The U.S. FDA has granted Orphan Drug Designation for AB569 from Arch Biopartners, Toronto-based biotechnology company, as a treatment for Pseudomonas aeruginosa (P. aeruginosa) pulmonary infections in patients with cystic fibrosis.  Cystic fibrosis (CF) is a genetic disease that affects various organs and is characterized by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. CF patients are susceptible to lung infections due to abnormal mucus production in the lungs and airways, which results in regular infective pulmonary exacerbations with opportunistic pathogens, such as Pseudomonas aeruginosa (P. aeruginosa). In cystic fibrosis patients, the mucoid form of P. aeruginosa is highly resistant to antibiotics and phagocyte-mediated killing by innate immune cells, inducing epithelial inflammation that ultimately causes tissue damage, which leads to poor prognosis. AB569 is a combination of two compounds, sodium nitrite and ethylenediaminetetraacetic acid, and is an novel potential nebulized (inhaled) treatment to deal with mucoid and non-mucoid P. aeruginosa pulmonary infections that are resistant to conventional antibiotics.