• ≥ 40 years of age

• Diagnosis of IPF supported by centrally read chest high-resolution computed tomography

• Definite or probable usual interstitial pneumonia (UIP) pattern on chest high-resolution computed tomography (HRCT) performed within 12 months of screening, confirmed by central review (if an evaluable HRCT \< 12 months is not available, the baseline HRCT will be used to determine eligibility).

• FVC ≥ 45% of predicted (at Screening).

• Diffusing capacity of the lung for carbon monoxide (DLCO) ≥ 25% predicted.

• Forced expiratory volume in 1 second (FEV1)/FVC ≥ 0.70 at Screening or FEV1/FVC ≥ predicted value minus 0.10 (if predicted value according to the spirometry report at Screening is \<0.80).

• Either stable dose with an approved antifibrotic for at least 8 weeks prior to screening or not treated with antifibrotics for at least 8 weeks prior to screening.