Phase ll Study of Pirfenidone in Patients With RAILD This is a phase 2, multi-center clinical trial of pirfenidone for the treatment of Rheumatoid Arthritis associated interstitial lung disease. Approximately 270 subjects will be randomized to receive Pirfenidone 2403 mg/ day or placebo in 1:1 ratio. The primary outcome will be progression free survival over 52 week study period. Brigham and Women Hospital, Boston, is the study sponsor and Genentech is funding the study.