Study With Phage for CF Subjects With Pseudomonas Lung Infection

Key Inclusion Criteria: * Cystic fibrosis patients with chronic Pseudomonas aeruginosa pulmonary infection receiving standard of care inhaled antibiotics (cycling or continuous regimen) or no inhaled antibiotics * Age ≥ 18 years * FEV1 40%-80% predicted * Clinically stable lung disease * Willing and able to provide adequate sputum samples, using any method (spontaneously expectorated, induced, from home or clinic) at designated study visits. Key Exclusion Criteria: * Known hypersensitivity to bacteriophages or excipients in the formulation. * Receipt of prior bacteriophage therapy within the 6 months prior to Screening or Day 1 * Detection of Burkholderia cenocepacia from respiratory tract within 1 year prior to Screening or from Screening culture * Currently receiving systemic treatment for allergic bronchopulmonary aspergillosis * Currently receiving treatment for active infection with non-tuberculous mycobacteria or prior detection of Mycobacterium abscessus in 12 months prior to Screening * History of severe neutropenia * History of lung transplant * History of solid organ transplant * Acquired or primary immunodeficiency syndrome * Initiation or change in type of CFTR modulator less than 3 months prior to Screening * Pregnant or breastfeeding female