Amylin, Lilly, and Alkermes Await FDA Decision on Byetta for Diabetes

On February 25th, 2010, Amylin, Lilly, and Alkermes announced in a press release that the FDA had set March 12th 2010 as the Prescription Drug User Fee Act (PDUFA) action date for Byetta’s long acting formulation –  exenatide once weekly.   Our readers will recall that Byetta is used by type 2 diabetics for glycemic (blood glucose) control and is administered subcutaneously twice daily.   With an FDA decision imminent we thought it would be useful to review some of the salient points concerning this innovative therapy.

Similar to a class of compounds known as incretins (which includes glucagon-like peptide-1 (GLP-1)) Byetta is thought to exert its action by enhancing pancreatic beta-cell insulin secretion, suppression of elevated glucagon secretion, and the slowing of gastric emptying.  In all three pivotal clinical trials supporting Byetta’s original approval body weight decreased at Week 30 in the 10 mcg treatment groups.   We reviewed a 2008 Lancet article by Drucker et al involving 295 patients with type 2 diabetes which demonstrated that exenatide once weekly performed better in terms of glycemic control than exenatide twice daily over a 30 wk period with no increased risk of hypoglycemia.

Byetta, a first in class therapy,  was approved in 2005 and was originally used as an adjunctive therapy to improve glycemic control in patients with type 2 diabetes who are taking metformin, a sufonylurea, or some combination of the two and have not achieved adequate blood sugar control.  In 2009 Byetta’ s indication was expanded to include its use as a stand alone or monotherapy in addition to diet and exercise to improve blood sugar control in Type 2 diabetes.  Since the drug’s approval, safety concerns have arisen around the risk of  acute pancreatitis with complications, including death and altered kidney function associated with Byetta use. 

CDC data suggest that more than 1 000 000 Americans are diagnosed with diabetes annually and that there are in excess of 14 000 000 Americans currently afflicted with the disease. It is estimated that about 5 000 000 diabetics require daily insulin injections to control their blood sugars. Complications commonly associated with uncontrolled or poorly controlled diabetes include heart disease, stroke, kidney failure and blindness. Diabetes and its complications may account for more than $100 billion annually in healthcare costs in the United States.

At the risk of stating the obvious – we believe that if exenatide once weekly recieves FDA approval, simplification of the exenatide dosing regimen from twice daily to once weekly would be seen as very favourable by patients and physicians alike. 

Thanks for reading.