• Pregnant, intending to continue pregnancy, enrolled in the Cystic Fibrosis Foundation Patient Registry (CFFPR)
• None

1. Subject gives voluntary informed consent to participate in the study. 2. Subject is ≥40 years of age, inclusive, at the time of signing informed consent. 3. The subject has a diagnosis of IPF based on the 2018 ATS/ERS/JRS/ALAT Clinical Practice Guideline (Raghu 2018) and confirmed by central review of high-resolution computed tomography (HRCT) (performed within the previous 12 months), and if available, surgical lung biopsy. 4. FVC ≥45% predicted at Screening. 5. Subjects on pirfenidone or nintedanib must be on a stable and optimized dose for ≥30 days prior to Baseline. Concomitant use of both pirfenidone and nintedanib is not permitted. 6. Women of childbearing potential must be non-pregnant (as confirmed by a urine pregnancy test at Screening and Baseline) and non-lactating, and will abstain from intercourse (when it is in line with their preferred and usual lifestyle) or use 2 medically acceptable, highly effective forms of contraception for the duration of the study, and at least 30 days after discontinuing study drug. 7. Males with a partner of childbearing potential must use a condom for the duration of treatment and for at least 48 hours after discontinuing study drug. 8. In the opinion of the Investigator, the subject is able to communicate effectively with study personnel, and is considered reliable, willing, and likely to be cooperative with protocol requirements, including attending all study visits. 1. Subject is pregnant or lactating. 2. Subject has primary obstructive airway physiology: FEV1/FVC <0.70 at Screening. 3. The subject has shown intolerance or significant lack of efficacy to a prostacyclin or prostacyclin analogue that resulted in discontinuation or inability to effectively titrate that therapy. 4. The subject has received any PAH-approved therapy, including prostacyclin therapy (epoprostenol, treprostinil, iloprost, or beraprost; except for acute vasoreactivity testing), IP receptor agonists (selexipag), endothelin receptor antagonists, phosphodiesterase type 5 inhibitors (PDE5-Is), or soluble guanylate cyclase stimulators within 60 days prior to Baseline. As needed use of a PDE5-I for erectile dysfunction is permitted, provided no doses are taken within 48 hours of any study-related efficacy assessments. 5. Use of any of the following medications: azathioprine (AZA), cyclosporine, mycophenolate mofetil, tacrolimus, oral corticosteroids (OCS) >20 mg/day or the combination of OCS+AZA+N-acetylcysteine within 30 days prior to Baseline; cyclophosphamide within 60 days prior to Baseline; or rituximab within 6 months prior to Baseline. 6. The subject is receiving >10 L/min of oxygen supplementation by any mode of delivery at rest at Baseline. 7. Exacerbation of IPF or active pulmonary or upper respiratory infection within 30 days prior to Baseline. Subjects must have completed any antibiotic or steroid regimens for treatment of the infection or acute exacerbation more than 30 days prior to Baseline to be eligible. If hospitalized for an acute exacerbation of IPF or a pulmonary or upper respiratory infection, subjects must have been discharged more than 90 days prior to Baseline to be eligible. 8. Uncontrolled cardiac disease, defined as myocardial infarction within 6 months prior to Baseline or unstable angina within 30 days prior to Baseline. 9. In the opinion of the Investigator, the subject has any condition that would interfere with the interpretation of study assessments or would impair study participation or cooperation. 10. Use of any other investigational drug/device or participation in any investigational study in which the subject received a medical intervention (ie, procedure, device, medication/supplement) within 30 days prior to Screening. Subjects participating in non-interventional, observational, or registry studies are eligible. 11. Life expectancy <6 months due to IPF or a concomitant illness. 12. Acute pulmonary embolism within 90 days prior to Baseline.

Key
• Completed study drug treatment in a parent study VX20-121-102 (NCT05033080) and VX20-121-103 (NCT05076149); or had study drug interruption(s) in a parent study but did not permanently discontinue study drug, and completed study visits up to the last scheduled visit of the Treatment Period in the parent study Key
• History of drug intolerance in a parent study
• Pregnant or breast-feeding females Other protocol defined Inclusion/Exclusion criteria may apply.

• All genders ≥ 6 years of age at Visit 1
• Documentation of a CF diagnosis
• Clinician intent to treat index CF PEx with a planned 14-day course of IV antimicrobials
• At least one documented Pa positive culture within two years prior to Visit 1
• Participant is not pregnant
• No known renal impairment or history of solid organ transplantation
• No IV antimicrobial treatment, ICU admission, pneumothorax, or hemoptysis within 6 weeks prior to Visit 1
• No use of investigational therapies, new CF transmembrane conductance regulator (CFTR) modulators, or treatment for Nontuberculous mycobacteria (NTM) within 4 weeks prior to Visit 1
• No history of hypersensitivity, vestibular, or auditory toxicity with aminoglycosides
• No more than one day of IV aminoglycosides administered for the current PEx treatment prior to Visit 1

Key
• Body mass index is less than (<) 30.0 kilograms per meter square (kg/m^2)
• A total body weight greater than (>) 50 kg
• Stable CF disease
• CFTR gene mutations on both alleles that are not responsive to CFTR modulator therapy o Example mutations include but are not limited to, mutations that do not produce CFTR protein (i.e., Class I): nonsense mutations (e.g., G542X, W1282X) and canonical splice mutations (e.g., 621+1G->T)
• Forced expiratory volume in 1 second (FEV1) value for SAD: greater than or equal to (≥)40 percent (%), MAD: ≥ 40% to less than or equal to (≤) 90% Key
• History of uncontrolled asthma within a year prior to screening
• History of solid organ or hematological transplantation
• Hepatic cirrhosis with portal hypertension, moderate hepatic impairment (Child Pugh Score 7 to 9), or severe hepatic impairment (Child Pugh Score 10 to 15)
• Arterial oxygen saturation on room air less than (<) 94% at screening Other protocol defined Inclusion/Exclusion criteria may apply.

Key
• Participants who have completed study drug treatment in the parent study (VX21-121-105; NCT Number: NCT05422222) Key
• Hepatic cirrhosis with portal hypertension, moderate hepatic impairment, or severe hepatic impairment that might pose an additional risk in administering study drug
• History of solid organ, hematological transplantation, or cancer
• History of drug intolerance in the parent study Other protocol defined Inclusion/Exclusion criteria may apply.