2nd UPDATE:FDA Panel Splits On Diabetes Drug Liraglutide NVO

A Food and Drug Administration panel split Thursday 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 concern is that the type of tumor seen in rats and mice could cause a rare, but potentially more serious type of thyroid cancer in humans. Both the panel and the FDA said although it isn't clear whether the data is relevant to humans, there isn't enough data to rule it out.

Liraglutide is Novo Nordisk's most important drug in development and now faces the possibility of approval delays if the FDA seeks additional clinical data. It belongs to the same class of drugs as Byetta, which is sold by Eli Lilly & Co. (LLY) and Amylin Pharmaceuticals Inc. (AMLN).

However, the panel said a small number of a common type of thyroid tumor found in humans in clinical studies were likely found because study investigators were looking for thyroid problems, and 12 panel members said that alone shouldn't stop marketing of the drug. One person abstained from voting.

Mary Parks, the director of FDA's division of metabolism and endocrinology products, said the agency faced a "difficult task" in deciding whether to approve the product given the panel's divergent votes.

Novo Nordisk officials weren't immediately available for a comment. The company said during the meeting it thought the "substantial" benefits of lowering blood-glucose levels in people with type 2 diabetes far outweighed potential cancer risks.

Earlier Thursday, 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 that was sparked by a 2007 paper linking GlaxoSmithKline PLC's diabetes (GSK) drug Avandia.

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."

During the panel meeting, 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.

Some panel members questioned whether the concerns about thyroid cancer might apply to Byetta. Parks told reporters after the meeting that the agency looked back at Byetta's clinical data and didn't see any thyroid-cancer risk. She also said the agency so far hasn't detected an increased risk when looking at post-marketing data but also said there's limited data to definitively rule out a possible increased risk.

Shares of Novo Nordisk fell 4.3% to $47.92 during the regular NYSE session Thursday and were at $47.20 in recent late trading.

-By Jennifer Corbett Dooren, Dow Jones Newswires; 202-862-9294; [e-mail]