A Study to Assess the Safety, Tolerability, and Pharmacokinetics of Brensocatib Tablets in Adults With Cystic Fibrosis

- Participants must be ≥18 years of age at the time of signing the informed consent.

- Male or female participants with a confirmed diagnosis of CF related lung disease:

- Has a body mass index ≥18 kg/m^2.

- Male and female participants must use contraceptives that are consistent with local regulations regarding the methods of contraception for those participating in clinical studies.

- Female participants of childbearing potential must have a negative serum pregnancy test at Screening.

- Male participants with pregnant or nonpregnant women of childbearing potential partners must use a condom.

- Severe or unstable CF, per Investigator's judgement.

- Currently being treated for allergic bronchopulmonary aspergillosis or nontuberculous mycobacteria or tuberculosis.

- Active and current infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

- History of malignancy in the past 5 years, except completely treated in situ carcinoma of the cervix and completely treated non-metastatic squamous or basal cell carcinoma of the skin.

- Established diagnosis of hepatitis B viral infection or positive for hepatitis B surface antigen (HBsAg) at Screening.

- Established diagnosis of hepatitis C virus (HCV) infection at Screening. Participants positive for hepatitis C antibody are eligible only if HCV RNA is negative.

- History of human immunodeficiency virus (HIV) infection.

- Acute upper or lower respiratory tract infection, pulmonary exacerbation, or changes in therapy (including intravenous and oral antibiotics) for pulmonary disease within 4 weeks prior to Day 1 (administration of the first dose of study drug). Participants meeting this criterion could be rescreened 4 weeks after resolution of symptoms.

- History of prolonged QT/QTc interval with QTcF >480 millisecond (msec) at Screening.

- History of solid organ or hematological transplantation.

- Have diagnosed periodontal disease and are either:

- Received any live attenuated vaccine within 4 weeks prior Screening.

- Ongoing participation in another therapeutic clinical study or prior participation in an investigational drug study within 90 days prior to Screening.

- Known history of hypersensitivity to brensocatib or any of its excipients.

- Use of any immunomodulatory agents within 4 weeks before the Screening Visit is prohibited during the study through end of study (including, but not limited to: bortezomib, ixazomib, thalidomide, cyclophosphamide, mycophenolate, Janus kinase inhibitors, interferon gamma (IFN-γ], and azathioprine).

- Continuous use of high-dose non-steroidal anti-inflammatory drugs (NSAIDs) is prohibited during the study through end of study.

- History of alcohol, medication, or illicit drug abuse.

- Current smoker, as defined by Centers for Disease Control and Prevention: An adult who has smoked 100 cigarettes in his or her lifetime and who currently smokes cigarettes.