Promising results from drug in treating kidney disease in diabetic patients

Researchers at the University of California, San Diego School of Medicine, the National Institutes of Health (NIH) and the Mayo Clinic have published promising results of a clinical study using an experimental anti-fibrotic and anti-inflammatory drug called pirfenidone to treat patients with diabetic nephropathy.  Their study will be published in the April 21 issue of the Journal of the American Society of Nephrology (JASN).

Diabetic nephropathy remains the leading cause of end-stage kidney disease (ESKD) in the United States. It is a common complication of diabetes, in which kidney cells are damaged as a result of high blood sugar levels.

''The dramatic finding of this exploratory study is that an appropriate dose of pirfenidone not only halted decline but actually improved kidney function in these patients,'' said Kumar Sharma, MD, FAHA, professor of medicine in the UCSD division of nephrology and director of the Center for Renal Translational Medicine, who headed the study.

The principal process underlying the progression of chronic kidney disease to ESKD – where dialysis is required to keep a patient alive – is called renal (kidney) fibrosis. The fibrosis, or scarring, damages tiny blood vessels in the glomerulus, structures that filter and remove waste from the blood, and in between tubular cells.

Transforming growth factor beta (TGF-ß) is a protein that controls many cellular functions, including extracellular matrix accumulation. TGF-ß is stimulated in the diabetic kidney due to uncontrolled blood sugar and elevated blood pressure and can promote renal fibrosis. 

''To date, therapies for diabetic nephropathy have been limited to drugs that improve blood pressure or control blood sugar levels,'' said Sharma.  Instead, pirfenidone seems to work by blocking TGF-ß; in effect, shutting down the growth factors that cause renal fibrosis.