Novo Nordisk Inc.'s (NVO) proposed diabetes treatment reduced weight and controlled blood-sugar levels in patients over a two-year period better than a competitor's, according to a study released on Sunday.

The Novo Nordisk study, released at the annual American Diabetes Association conference, followed diabetes patients for two years and tracked their blood glucose control and weight loss while on Novo's proposed medicine liraglutide and glimepiride, marketed by Sanofi-Aventis SA (SNY) as Amaryl.

Representatives from Sanofi weren't immediately available to comment.

About 58% of patients on liraglutide reached appropriate average blood sugar levels, while 37% achieved such levels on Amaryl. Patients on liraglutide had a mean weight loss of six pounds, while those taking Amaryl gained about two pounds.

The study is important because it shows patients sustain weight loss and blood glucose levels for two years, said Alan Moses, chief medical officer for Novo. Weight control is important for diabetes patients, as obesity is a major factor in the disease, which affects more than 24 million Americans. Many diabetes drugs increase patients' weight.

Liraglutide has yet to be approved in either the U.S. or Europe, though a European medicines commission has recommended the treatment be approved. The U.S. Food and Drug Administration has yet to make a decision on the drug.

In April, a panel of medical experts said they were split on whether to recommend approval amid concerns the drug may cause a rare, but potentially serious type of thyroid cancer. Data Novo submitted to the FDA showed rodents tested with liraglutide grew tumors, which isn't uncommon in rats. The panel and the FDA, however, said it wasn't clear that the data from the rodents are relevant to humans.

Moses said the company has been closely tracking patients to determine whether liraglutide is linked to thyroid cancer but hasn't seen any such signals. Cancer risks are tracked by measuring a patient's calcitonin levels. Moses said studies show "that there is absolutely no change in calcitonin" levels in patients taking liraglutide.

-By Jared A. Favole, Dow Jones Newswires; 202-862-9207; jared.favole@dowjones.com