A Food and Drug Administration panel split on whether it thought the agency should approve liraglutide, a proposed diabetes drug from Novo Nordisk Inc. (NVO).

The panel voted 6 to 6 with one abstention on whether data on a certain type of thyroid tumors seen in rodent studies permitted marketing of the product. The panel still has one other question on another type of tumor and the outcome of that vote could sway the panel in another direction.

Earlier, most panel members said the product wasn't linked to an excess in heart attacks and strokes, a key concern the FDA has with diabetes drugs.

Specifically, the panel voted 8 to 5 on a question that asked whether the liraglutide data was enough to rule out an "unacceptable excess cardiovascular risk relative to competitors."

Liraglutide is Novo Nordisk's most important drug in development. It belongs to the same class of drugs as Byetta, which is sold by Eli Lilly & Co. (LLY) and Amylin Pharmaceuticals Inc. (AMLN).

The FDA said it saw a low cardiovascular event rate in clinical studies of liraglutide but raised concerns about a small number of patients who developed a type of thyroid cancer during clinical studies as well as tumors that were seen in animal studies. The agency said it didn't have data to "dismiss" the relevance of the rodent studies relative to humans.

-By Jennifer Corbett Dooren, Dow Jones Newswires; 202-862-9294; jennifer.corbett@dowjones.com