Inclusion Criteria:

   1. Diagnosis of systemic sclerosis-related (SSc) confirmed by the American College of
   Rheumatology classification criteria of systemic sclerosis (Masi 1980); duration of
   diagnosis less than (<) 7 years

   2. Diagnosis of SSc-ILD based on an high-resolution computed tomography (HRCT) scan

   3. Screening forced vital capacity (FVC) greater than equal to (>=) 50 percent (%) of the
   predicted value, and screening carbon monoxide diffusing capacity (DLCO) >=40% of the
   predicted value

   4. At study entry, the participant either was not taking SSc-ILD medication or was taking
   cyclophosphamide or mycophenolate

Exclusion Criteria:

   1. Clinically significant pulmonary hypertension

   2. Known underlying liver disease

   3. Clinical evidence of significant aspiration or uncontrolled gastroesophageal reflux

   4. History of clinically significant asthma or chronic obstructive pulmonary disease

   5. Active infection

   6. Diagnosis of another connective tissue disorder

   7. Evidence of a malignancy that is likely to result in significant disability or require
   significant medical or surgical intervention

   8. History of unstable or deteriorating cardiac or pulmonary disease (other than SSc-ILD)

   9. Pregnancy or lactation

10. Creatinine clearance <40 milliliters per minute (mL/min)

11. Prior use of pirfenidone

12. Unsuitable for enrollment or unlikely to comply with study requirements