The Food and Drug Administration will need more time to evaluate Takeda Pharmaceuticals North America Inc.’s experimental diabetes drug alogliptin, delaying a potential blockbuster billion-dollar seller from reaching the market.

New safety guidelines of the FDA issued in December 2008 (Guidance for Industry: Diabetes Mellitus -- Evaluating Cardiovascular Risk in New Antidiabetic Therapies to Treat Type 2 Diabetes )suggest that alogliptin should be tested in additional clinical data in order to satisfy the agency’s review of the product before it can be sold as a treatment for diabetes.

The new guidelines follow reports that currently-available drugs may raise cardiovascular risks. In November 2007, Avandia, once a popular diabetes drug, received a black box warning because increased risk of heart attacks in diabetes patients. The drug increases the risk of heart attack by 40 percent, doubles the risk of heart failure and bone fractures and increases the risk of anemia and vision loss from macular edema.

Referring to the new diabetes drug alogliptin, the FDA doesn’t consider there is currently enough data to meet “certain statistical requirements in the new guidance. Takeda will continue to work closely with the FDA to discuss a protocol” for the necessary cardiovascular study of alogliptin, Takeda spokesman Matt Kuhn said.

Alogliptin is part of a new class of diabetes drugs known as dipeptidyl peptidase IV inhibitors, which are being reviewed as an adjunct to diet and exercise for the treatment of type 2 diabetes. A drug belonging to this class is Januvia, which is already on the market, generating $1.4 billion in worldwide sales last year for New Jersey drug giant Merck & Co.