Inclusion Criteria:

* Forced vital capacity (FVC) ≥ 45% of predicted.
* Diffusion capacity of the lung for carbon monoxide (DLco) corrected for hemoglobin ≥ 30% of predicted value
* Ratio of forced expiratory volume in 1 second (FEV1) to FVC ≥ 0.70.

Exclusion Criteria:

* Best, acceptable FVC from separate screening spirometry that differ by ≥ 200 mL.
* Respiratory exacerbation(s) or hospitalization for IPF exacerbation within 3 months before screening.
* Anticipated to receive a lung transplant during the subject's participation in the study.
* Active smoker or smoking cessation within 12 weeks before screening.
* Malignancy within the last 5 years, with the exception of curable cancer that has received adequate treatment.
* Evidence of any unstable or untreated, clinically significant disease or condition that, in the opinion of the Investigator, might confound the interpretation of the study or place the subject at increased risk.
* Treatment with high dose corticosteroids, cytotoxic agents, unapproved IPF targeted therapy, and cytokine modulating agents within 8 weeks or 5 half-lives (whichever is longer) before screening
* Participation in an investigational study with the last dose of investigational product occurring within 8 weeks or 5 half-lives (whichever is longer) before screening.
* Pregnant or breastfeeding.
* Medical history of infection with HIV, hepatitis B, or hepatitis C.
* History of alcohol abuse and/or dependence within the last 2 years.
* History within the last 2 years of significant mental illness, or physical dependence on any opioid or illicit drugs.

Other protocol defined inclusion/exclusion criteria could apply.