A Study of Oral Vismodegib in Combination With Pirfenidone in Participants With Idiopathic Pulmonary Fibrosis

Inclusion Criteria:

- Have a diagnosis of IPF 5 years from time of screening, confirmed at baseline

- Tolerated dose of pirfenidone 1602-2403 mg once daily (QD) for a minimum of 24 weeks
required prior to and during screening

- Greater than or equal to (>=) 50 percent (%) and less than or equal to (<=) 100% of
predicted forced vital capacity (FVC) at screening

- Stable baseline lung function as evidenced by a difference of less than (<) 10% in
absolute FVC measurements (in liters) between screening and Day 1/Visit 2 prior to
enrollment

- >=30% and <=90% of predicted diffusion capacity of the lung for carbon monoxide at
screening

- Agree to use protocol defined methods of contraception

- Male participants must agree not to donate semen during the study and for at least 2
months (or as per local requirements) after the last dose of vismodegib

- Agree not to donate blood or blood products during the study and for at least 9 months
(or as per local requirements) after the last dose of study treatment

Exclusion Criteria:

- Prior treatment with vismodegib or any Hh-pathway inhibitor

- Evidence of other known causes of interstitial lung disease

- Hospitalization due to an exacerbation of IPF within 4 weeks prior to or during
screening

- Lung transplant expected within 6 months of screening

- Evidence of clinically significant lung disease other than IPF

- Post-bronchodilator forced expiratory volume in 1 second/FVC ratio <0.7 at screening

- Any clinically significant medical disease (other than IPF) that is associated with an
expected survival of <6 months, likely to require a change in therapy during the study

- Class IV New York Heart Association chronic heart failure or historical evidence of
left ventricular ejection fraction <35%

- Known current malignancy or current evaluation for a potential malignancy

- Known immunodeficiency, including, but not limited to, human immunodeficiency virus
infection

- Evidence of acute or chronic hepatitis or known liver cirrhosis

- Creatinine clearance <=30 milliliter per minute, calculated using the Cockcroft-Gault
formula