Sitagliptin, a diabetes drug awaiting U.S. regulatory approval, lowered blood sugar to levels that were comparable to those obtained with conventional treatment - and also helped patients lose weight, the drug’s developer, Merck & Co., said on Tuesday.

After 1 year of treatment with sitagliptin (Januvia), one of a new class of diabetes drugs called DPP-4 inhibitors, reductions in A1C levels, a common measure of blood sugar control, were the same as reductions seen with glipizide in patients with type 2 diabetes.

Merck also said patients taking Januvia had weight loss, compared with weight gain on glipizide, and had a significantly lower incidence of hypoglycemia (low blood sugar). The study results were presented at the American Diabetes Association scientific meeting in Washington.

Patients in the group treated with Januvia lost an average of 1.5 kg (3.3 pounds) after 52 weeks, according to Merck. By comparison, patients treated with glipizide gained 1.1 kg (2.4 pounds).

Obesity is the leading cause of type 2 diabetes, and weight loss associated with Januvia is considered a major advantage over some older diabetes drugs that can cause weight gain.

Nearly 21 million people in the United States, or 7 percent of the population, have diabetes, with type 2 diabetes accounting for 90 percent to 95 percent of the cases, according to the American Diabetes Association.

Merck has said it expects the U.S. Food and Drug Administration to decide whether to approve Januvia by mid-October.