- Participants receiving pirfenidone for at least 12 weeks, at a dose in the range of 1602 to 2403 mg/day for at least 4 weeks prior to Screening and must not have experienced either a new or ongoing adverse event of National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) (version 4.03) Grade 2 or higher and considered by the investigator to be related to pirfenidone, or an interruption of pirfenidone treatment of greater than (>)7 days for any reason