NEW YORK (Reuters Health) – Once-a-week treatment with long-acting exenatide (Byetta) produces sustained glycemic control and weight loss in diabetics, a multicenter trial has shown.
“This study confirms the superiority of exenatide once weekly over the current twice daily formulation to reduce A1C and fasting plasma glucose in patients with type 2 diabetes,” lead author Dr. John B. Buse, from the University of North Carolina School of Medicine, Chapel Hill, told Reuters Health by email.
He added, “The future availability of this once weekly therapy for diabetes addresses several of the barriers to achieving excellent control of type 2 diabetes.”
Last week, however, the U.S. Food and Drug Administration denied approval of long-acting exenatide, saying it wanted more information about the drug’s product label, risk-management plan and manufacturing process. (The FDA did not request additional clinical data or analysis of already submitted data, however.)
In their March 9th online paper in Diabetes Care, Dr. Buse and his colleagues presented the results of a 22-week extension of their earlier open-label 30-week DURATION-1 trial. In the initial phase, 295 type 2 diabetics took either 2 mg of exenatide weekly or 10 mcg twice daily. Both regimens improved glycemic control, but the improvement in hemoglobin A1C was significantly greater with the weekly formulation. Both regimens improved weight, blood pressure, and lipids to a similar extent.
For the extension phase, 128 patients continued the weekly protocol and 130 switched to it from the twice-a-day regimen.
Those who continued on weekly treatment maintained their A1C reductions, and those who switched to weekly doses had improvements. At 52 weeks, both groups had similar improvements and a mean A1C of 6.6%.
Overall, 71% of patients achieved A1C levels of less than 7.0%, and 54% achieved 6.5% or less. The mean fasting plasma glucose level fell by more than 40 mg/dL and both groups had mean weight reductions of more than 4 kg.
The researchers point out that patients who switched from the twice-daily to the weekly therapy had transient plasma glucose elevations that generally resolved in two weeks. They attribute this phenomenon to “the time required for plasma exenatide levels to reach the therapeutic range” after the switch. At any rate, the magnitude of the increase – roughly 15 mg/dL – was “unlikely to be associated with symptoms or harm over a short period,” they say.
The study was supported by Amylin Pharmaceuticals and Eli Lilly & Company, the manufacturers of exenatide (Byetta).
Diabetes Care 2010.