Merck & Co., Inc. announced that the US Food and Drug Administration (FDA) approved Januvia (sitagliptin phosphate), the first and only DPP-4 inhibitor available in the United States for the treatment of type 2 diabetes.

Januvia has been approved as monotherapy and as add on therapy to either of two other types of oral diabetes medications, metformin or thiazolidinediones (TZDs), to improve blood sugar (glucose) control in patients with type 2 diabetes when diet and exercise is not enough. The recommended dose of Januvia is 100 mg once daily. Januvia should not be used in patients with type 1 diabetes or for the treatment of diabetic ketoacidosis, as it would not be effective in these settings.

Januvia enhances a natural body system to significantly lower elevated blood sugar. Januvia belongs to a new breakthrough class of prescription medications called dipeptidyl peptidase-4 (DPP-4) inhibitors that improves blood sugar control in patients with type 2 diabetes. Januvia enhances a natural body system called the incretin system, which helps to regulate glucose by affecting the beta cells and alpha cells in the pancreas. Through DPP-4 inhibition, Januvia works only when blood sugar is elevated to address diminished insulin due to beta cell dysfunction and uncontrolled production of glucose by the liver due to alpha-cell and beta-cell dysfunction.

"Those patients who are unable to adequately manage their type 2 diabetes with lifestyle changes, like healthy eating and increased physical exercise, and who require medications now have a new product to help regulate their blood sugar levels," said Edward S. Horton, M.D., director of clinical research, Joslin Diabetes Center and professor of medicine, Harvard Medical School, Boston.

"Januvia underscores Merck's commitment to the field of diabetes, and the benefits we strive to bring to patients and physicians who struggle in the treatment of type 2 diabetes," said Richard T. Clark, president and chief executive officer, Merck. "The approval of Januvia is a clear example of Merck's focus on developing innovative therapies to improve human health around the world, " he added.

In clinical trials, Januvia demonstrated an overall incidence of side effects comparable to placebo. The most common side effects reported with Januvia (> 5 per cent and higher than placebo) were stuffy or runny nose and sore throat, upper respiratory infection, and headache.

Januvia addresses two of the three key defects that cause poor glucose control: diminished insulin release due to beta-cell dysfunction and uncontrolled production of glucose by the liver due to alpha-cell and beta-cell dysfunction. By adding Januvia to the insulin sensitizers metformin or pioglitazone (a TZD), the three key defects of type 2 diabetes can be addressed: insulin resistance, beta-cell dysfunction (decreased insulin release), and alpha-cell dysfunction (unsuppressed hepatic glucose production).

In separate 24-week studies of patients with type 2 diabetes who were inadequately controlled on either metformin or pioglitazone alone, Januvia 100 mg once daily provided a complementary effect. Januvia showed significant mean differences in A1C from placebo of -0.7 per cent in the metformin add-on study (p<0.001) and -0.7per cent in the pioglitazone add-on study (p<0.001). In those same studies, the mean A1C reduction from baseline with Januvia was 0.7 per cent from a mean baseline A1C of 8.0 per cent and 0.9 per cent from a mean baseline of 8.1 per vent, respectively.