Drug for diabetes nerve damage 'on the horizon'

An experimental drug has been shown to combat the underlying cause of nerve damage that occurs in people with diabetes.

"An effective disease-modifying treatment is on the horizon," Dr. Vera Bril of the University of Toronto told AMN Health.

A compound called sorbitol builds up in diabetes, and increased levels of sorbitol in nerves has been associated with nerve damage in animals, Bril and her colleagues explain in the medical journal Diabetes Care.

High sorbitol results from increased activity of an enzyme called aldose reductase, suggesting that treatments to block the enzyme might prevent or reverse nerve damage.

Bril's team gave patients with diabetic neuropathy a potent inhibitor of aldose reductase called AS-3201, and measured sorbitol in a nerve in their calf before and after 12 weeks of treatment.

Compared with the placebo treatment, AS-3201 reduced average nerve sorbitol concentrations by 65 percent to 84 percent depending on the dosage given, the researchers report.

"For the first time, we may see disease regression with a disease modifying treatment," Bril said.

Patients treated with the higher dose of AS-3201 showed improvement in the velocity of nerve signal conduction, the investigators report, but vibratory perception threshold and clinical scores did not change during this brief study.

A long-term study of the drug has started, Bril added. Nerve function will be measured, and symptoms and signs will also be summarized in a clinical score to determine efficacy over a longer interval.

"There is great hope for the treatment of diabetic sensorimotor polyneuropathy," she concluded.

SOURCE: Diabetes Care, October 2004.