Study With Phage for CF Subjects With Pseudomonas Lung Infection

Key Who May Qualify: - 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 Who Should NOT Join This Trial: - 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 weakened immune system syndrome - Initiation or change in type of CFTR modulator less than 3 months prior to Screening - Pregnant or breastfeeding female Always talk to your doctor about whether this trial is right for you.