Pirfenidone to Treat Kidney Disease (Focal Segmental Glomerulosclerosis)

During the study drug period of 12 months, patients will receive oral pirfenidone daily. For patients whose initial renal function is 50-80 ml/min as assessed by the MDRD equation, the initial pirfenidone dosage will be calculated at 40 mg/kg/d, with a maximum dose of 800 mg TID. For patients whose initial renal function is 30-50 ml/min, the initial dose will be 30 mg/kg/d. For patients whose initial renal function is between 15 and 30 ml/min, the initial dose will be 20 mg/kg/d.