Diabetic nerve damage breakthrough seen

CHICAGO (CNNMoney.com) -- Cholesterol-lowering statins - which include the world's top-selling drug, Lipitor - and other drugs called fibrates can lower the risk of developing a common form of nerve damage in diabetics that often results in amputations, according to study results unveiled Friday.

Statins, prescribed to lower a type of cholesterol called lipids, also decreased the risk of nerve damage by 35 percent, said Dr. Timothy Davis, lead researcher in the study and professor of medicine at the University of Western Australia in Fremantle, Australia.

In the five-year study of about 400 patients, another class of drugs called fibrates reduced the risk of nerve damage by 48 percent, said Dr. Davis, who made the announcement at the annual meeting of the American Diabetes Association.

The statin class includes Pfizer (Charts, Fortune 500)'s Lipitor, the top-selling drug of all time with nearly $13 billion in 2006 sales. Dr. Davis said his study included Lipitor, as well as the statins Pravachol from Bristol-Myers Squibb (Charts, Fortune 500) and Merck (Charts, Fortune 500)'s Zocor.

Lipitor's patent lasts until 2011, but the patents on the other drugs expired in 2006, resulting in plunging sales as the drugs opened up to generic competition. Zocor was once worth $4.4 billion in annual sales, and Pravachol was worth $2.2 billion.

The statin class also includes Crestor from AstraZeneca, which totaled $2 billion in 2006 sales. Crestor was not included in the study, though its maker stands to gain from positive information about the class.

As for fibrates, Dr. Davis' study used Abbott (Charts, Fortune 500)'s TricCor, which lowered risk of diabetic nerve pain by an even greater amount than the statins: 48 percent. TriCor sales were more than $300 million in 2006. The study also used Pfizer's Lopid, a fibrate. (Pfizer does not break out Lopid sales in its balance sheet.)

But whether the finding will help sales of cholesterol drugs isn't clear.

Jon LeCroy, analyst for Natexis Bleichroeder, said the study results are unlikely to benefit sales for statin-makers, because many diabetics already take them.

Diabetics tend to have problems with high cholesterol and obesity, thus the industry slang "diabesity." Therefore, they usually get prescribed with statins.

Also, LeCroy said that fibrates are less popular than statins because of gastro-intestinal side effects such as indigestion, and are unlikely to get a sales lift from the study.

Dr. Davis said the study was funded by a trust established through the University of Western Australia, with no funding from drug companies.

Diabetes-related nerve disease is a common and serious condition, said Dr. Aaron Vinik of the Strelitz Diabetes Research Institute at the Eastern Virginia Medical Center in Norfolk, Va. Dr. Vinik, who accompanied Dr. Davis on the ADA panel, said at least half of all diabetics are diagnosed with a condition that often results in amputation of the feet.

Nonetheless, diabetic neuropathy is a neglected area of medical science, said Dr. Vinik, who referred to it as "the Cinderella of diabetes, which is unfortunate."

More than 20 million Americans have diabetes, according to the ADA, and the problem is growing in step with the aging population.