The company said Sunday that the Food and Drug Administration requested information from a study that looks at cardiovascular health before it can finish reviewing Tresiba and Ryzodeg.

Novo Nordisk said it was surprised and disappointed by the decision. The company plans to provide the requested data, but it probably will not be able to do that this year.

The F.D.A. also told the drugmaker it could not approve the drugs until the company resolved some manufacturing violations the agency outlined in a recent warning letter. The Dec. 12 letter said an inspection of the company’s drug-making factory in Denmark found significant violations of good manufacturing practices.

The letter accused the company of not establishing or following appropriate written procedures for preventing contamination of sterile drug products.

Diabetes is a chronic condition in which the body either does not make enough insulin to break down the sugar in foods or uses insulin inefficiently. It can cause early death or serious complications like blindness, a stroke, kidney disease or heart disease when blood sugar climbs too high and damages organs and blood vessels.

Demand for drugs that treat diabetes is climbing as rising instances of obesity are causing an explosion of diabetes cases globally.

Tresiba and Ryzodeg have already received approval in Europe, Japan and Mexico. Both drugs use the insulin degludec, which can last more than 42 hours and helps diabetics control their blood sugar levels beyond the 24-hour period offered by current products on the market.

In November, an F.D.A. panel had voted 8-4 in favor of approval for degludec. The panelists also voted unanimously that the drugmaker should be required to conduct a definitive cardiovascular study of the drug due to concern about possible heart safety side effects.

But the panelists recommended that the trial should be conducted after the drug is approved, Novo Nordisk said in a statement.

Shares of Novo Nordisk fell 13 percent Monday in Copenhagen, to 930 kroner, or $167.

Article source: http://www.nytimes.com/2013/02/12/business/global/novo-nordisk-shares-fall-after-delay-in-approval.html?partner=rss&emc=rss