The investigational diabetes drug liraglutide, which like Byetta (exenatide) is part of a new class of drugs called incretin mimetics, provided promising glucose control for type 2 diabetics in the second and third of five phase III studies, according to developer Novo Nordisk.

Liraglutide and Byetta, like diet pill Januvia (sitagliptin), are drugs that operate on the incretin hormone system. But Byetta and liragllutide inject a synthetic version of GLP-1 into your body, while Januvia tablets allow GLP-1 secreted by your body naturally to rise to higher levels by inhibiting the action of DPP-4.

The two 26-week liraglutide studies reported on by Novo Nordisk involved a total of 2,132 diabetics, and explored the effect of different doses of liraglutide in combination with a single oral antidiabetic drug. Patients inadequately controlled by one or two oral antidiabetic drugs could enter the studies.

In the first study, liraglutide provided statistically significantly better glucose control than rosiglitazone, resulting in around 40 percent of patients reaching the American Diabetes Association goal of an HbA1c glucose level of 7% at study completion.

However, among the patients that had previously been treated with only a single oral antidiabetic drug, liraglutide treatment led to more than 50 percent of patients reaching this goal.

In the second study, liraglutide treatment led to an HbA1c improvement that was similar to that observed in the glimepiride-treated group and at the highest dose of liraglutide, more than 40 percent of patients achieved the HbA1c target of 7 percent.

Among patients previously treated with a single oral antidiabetic drug, close to 65 percent of the patients on this dose reached the target.

Mads Krogsgaard Thomsen, executive vice president and chief science officer of Novo Nordisk, said: "The encouraging clinical results from the two new trials confirm the positive effect of liraglutide on blood glucose control, body weight and hypoglycaemia risk seen in previous studies and leave us confident that we are on track to submit for regulatory approval mid-2008.