Bacteriophages for Adults With Cystic Fibrosis and Chronic Achromobacter Lung Infection

Inclusion Criteria: * In order to be eligible to participate in this study, an individual must meet all of the following criteria: 1. Adults of any gender, age 18 years or greater at the time of enrollment. 2. Weight of 40 kg or greater. 3. Diagnosed with cystic fibrosis (CF), including transplant recipients 4. Stable respiratory symptoms within 30 days prior to screening, with no change in CF maintenance medications (including cystic fibrosis transmembrane conductance regulator (CFTR) modulators) within 30 days prior to screening. 5. Chronic Achromobacter respiratory infection, defined as isolation by culture of Achromobacter species from two or more respiratory, oral, and/or nasopharyngeal samples provided by the participant within 24 months before the date of pre-screening. Polymicrobial infection (co-isolation of other organisms) does not exclude participation. 6. At least one Achromobacter isolate cultured from a respiratory, oral, and/or nasopharyngeal sample within 12 months of the date of planned enrollment must be susceptible to at least 1 phage in AchromoPhage cocktail using study assays. 7. FEV1 ≥ (greater than or equal to) 40% of predicted at time of screening 8. Ability and willingness to provide informed consent or, if applicable, the ability and willingness of legal guardian/representative to provide informed consent. 9. Willingness to comply with study procedures. 10. Ability to travel to the University of Pittsburgh or the University of California San Diego if activated for in-person phage administration visits. 11. Agreement not to enroll in other bacteriophage studies or receive bacteriophages for clinical care during the study, except in life-saving situations. 12. For females of reproductive potential, a negative urine pregnancy test at the time of consent (before randomization and dosing). 13. Willingness to use highly effective contraception or other preventive measures to avoid conception during the study and for 6 months after the last phage dose. Note, criteria 5 and 6 are the microbiologic criteria. Exclusion Criteria: * An individual who meets any of the following criteria will be excluded from participation in this study: 1. Serious medical illness requiring systemic treatment or hospitalization within 30 days prior to screening (unless medically stable and approved by the investigator). 2. Acute pulmonary exacerbation requiring systemic antibiotics within 30 days prior to screening. 3. Acute respiratory illness, including viral infection, within 30 days prior to screening. 4. Grade 3 or higher alanine aminotransferase (ALT) or aspartate aminotransferase (AST) at or within 30 days prior to screening, defined as ALT or AST values \>5.0 x upper limit of normal (ULN). 5. Currently breastfeeding, pregnant, or planning to become pregnant within 6 months. 6. Hemoglobin \< 8 g/dL 7. Absolute neutrophil count \< 1000 cells/uL 8. Intolerance to inhaled therapies. 9. Known allergy or sensitivity to components of the AchromoPhage cocktail. 10. Any other condition that, in the investigator's opinion, would interfere with the conduct of the study or would not be in the participant's best interest.