Diabetes drug Byetta (exenatide), an injected drug used by type 2 diabetics who were not able to achieve adequate blood sugar control on the commonly prescribed metformin or sulfonylurea, has now been approved as an add-on therapy for those taking a thiazolidinedione (TZD).

The FDA decision to approve Byetta's use along with newer TZD drugs Avandia and Actos follows a clinical trial in which 62 percent of patients who added Byetta to a TZD achieved an A1C blood glucose level of 7 or less compared to 16 percent of those on a TZD alone.

Those taking Byetta with a TZD in the tiral also lost an average of 3.3 pounds over 16 weeks, compared to an average weight loss of 0.4 pounds for those on Avandia or Actos alone.

"Due to the progressive nature of type 2 diabetes, previous approaches to management frequently failed to achieve target levels of A1C, or resulted in subsequent failure over one to three years," said Dr. Robert Ratner, Vice President for Scientific Affairs at the MedStar Research Institute in Washington, DC.

"The combination of exenatide with metformin, sulfonylureas, or TZDs not only expands our options to achieve optimal glycemic control, but does so with accompanying weight loss," Ratner added.

Byetta controls blood sugar through several physiologic actions, including the stimulation of insulin secretion only when blood sugar is high. Byetta restores the first-phase insulin response (an activity of the cells in the pancreas that is lost in patients who have type 2 diabetes), decreases glucose output from the liver, regulates gastric emptying, and decreases food intake.

"Almost half a million people with type 2 diabetes have used Byetta to help reduce their blood sugar," said Ginger L. Graham, Chief Executive Officer, Amylin Pharmaceuticals. "Now, even more people -- those who use another common category of oral medicines, TZDs -- have a new treatment option and have the opportunity to benefit from the unique clinical benefits of Byetta."