The purpose of this study is to determine whether a new investigational drug, pirfenidone, will be an effective therapy for diabetic patients with kidney dysfunction. Our hypothesis is that administration of pirfenidone to type 1 and type 2 diabetic patients with advanced kidney disease will lead to preservation of kidney function.

Diabetic kidney disease is the leading cause of new cases of kidney failure in the United States. In the kidneys of diabetic patients, there is accumulation of protein that leads to the formation of scar tissue and poor kidney function. Because of this many patients eventually require dialysis or kidney transplantation. A new investigational drug, pirfenidone, has been shown to be beneficial in a number of diseases in which scar formation leads to disease progression. It is our goal to examine whether pirfenidone is effective at stabilizing or reducing progressive diabetic kidney dysfunction.

Inclusion

• Type 1 or type 2 diabetes
• Males and females greater than or equal to 18 years.
• Abnormal kidney function determined by glomerular filtration rate
• History of proteinuria
• Blood pressure controlled to <140/90 on anti-hypertensive medication

Exclusion

• Cancer, liver disease, hepatitis, HIV+
• History of heart attack, unstable angina, stroke or peptic ulcer in the past 6 months
• Pregnant or planning to become pregnant during the study period
• Other known kidney disease besides diabetic nephropathy
• Expect to begin dialysis or receive a kidney transplant within 1 year of study enrollment