Amylin shares fall as Bydureon disappoints in diabetes study

USA-based Amylin Pharmaceuticals saw its shares fall nearly 4% to $17.10 yesterday morning, after it revealed new clinical data showing that, while its new type 2 diabetes drug candidate Bydureon, an extended-release injectable version of already marketed Byetta (exenatide) beat one comparator drug, it was little better than two others, one of which was the now generic metformin.

The new formulation is being developed with US drug major Eli Lilly (which co-markets Byetta), using technology from Alkermes. The results were from DURATION-4, the fourth in a series of studies designed to test the superiority of Bydureon compared to other type 2 diabetes medications. The new drug candidate is currently under review by the US Food and Drug Administration, which is expected to give its decision by October 22.

This 26-week clinical study compared Bydureon monotherapy to Merck & Co's Januvia (sitagliptin), Takeda's Actos (pioglitazone) or metformin, three oral type 2 diabetes medications commonly prescribed early in the treatment of the disease. Study participants were not achieving adequate A1C control using diet and exercise, and were not on any diabetes therapy when they entered the study. A1C is a measure of average blood sugar over three months. After 26 weeks of treatment, patients randomized to Bydureon experienced a reduction in A1C of 1.5 percentage points from baseline, which was significantly greater than the reduction of 1.2 percentage points for Januvia. Study subjects randomized to metformin experienced a reduction in A1C of 1.5 percentage points, and those receiving Actos experienced a reduction of 1.6 percentage points. Patients receiving Bydureon, Actos and metformin treatment achieved an average A1C of less than 7% by study end.