Exenatide, a new drug for diabetes developed by Amylin Pharmaceuticals and Eli Lilly, can control blood glucose in patients who are not meeting treatment goals on thiazolidinedione drugs, with or without metformin, according to data reported yesterday at the American Diabetes Association annual conference.

Exenatide, from a new drug class known as incretin mimetics, is already approved in the USA as an add-on therapy for patients who cannot meet their blood glucose targets using a sulphonylurea and/or metformin, and has been filed in Europe for the same indication.

If added into the product’s labelling, the new data would expand the number of patients eligible to receive exenatide to include those on thiazolidinediones, such as GlaxoSmithKline’s Avandia (rosiglitazone) and Lilly/Takeda’s Actos (pioglitazone).

In the study, patients taking exenatide showed improvements in key measures of blood glucose control, including haemoglobin A1C which gives an idea of glucose control over time.

62% of trial participants using exenatide who completed the full study reached the target HbA1C of 7% or less, compared to 16% of those who received placebo on top of their existing treatment. An HbA1c level of 7% or less is the therapeutic target laid down by ADA therapy guidelines.

Exenatide treatment also resulted in a reduction in average body weight. Patients on exenatide lost an average of 1.5 kg of body weight, while those treated with placebo lost on average 0.2 kg (0.4 pounds).

The drug is an analogue of GLP-1, an incretin hormone that acts throughout the body to help maintain healthy blood sugar levels and to control appetite. In healthy individuals, GLP-1 levels rise during a meal and along with glucose stimulate the production of insulin. This response is blunted in type 2 diabetics. GLP-1 also contributes to the health and survival of the insulin-producing cells in the body.

Exenatide was launched onto the US market a year ago under the Byetta tradename, and achieved sales of $67 million in the second half of the year. The drug is given twice daily, although Amylin and Lilly are working on a once-weekly formulation.

Meanwhile, Danish drugmaker Novo Nordisk recently kicked off a Phase III programme for its own incretin mimetic, liraglutide (formerly known as NN2211).