SEATTLE — Sitagliptin can be safely added to other oral diabetes medications, producing a drop in hemoglobin A1c levels that averages about 0.7%, according to a report at the annual meeting of the American Association of Clinical Endocrinologists.
In one trial, when 100 mg/day sitagliptin (Januvia) was added to metformin treatment (1,500 mg or greater per day) for 24 weeks, patients with type 2 diabetes had a mean reduction in HbA1c of 0.65% from a baseline mean of 8.0%.
In another trial, when sitagliptin was added to pioglitazone treatment, at a dose of 30 mg or greater per day, patients had a mean reduction in HbA1c of 0.7%, from a baseline HbA1c of 8.1%, Dr. Peter Stein said in a poster presentation.
Placebo controls in the studies had no decline in mean HbA1c in the group also on metformin, and a decline of about 0.1% in the group also on pioglitazone.
Of all the patients in the study who were also on metformin, 18% of the patients who took sitagliptin achieved an HbA1c level below 6.5%, as did 25% of those also on pioglitazone. In the controls, only about 5% achieved an HbA1c that low.
Almost 50% in both groups achieved an HbA1c level below 7.0% when sitagliptin was added, versus less than 30% of those that had placebo added to their treatment.
The presumed advantage of sitagliptin, a dipeptidyl peptidase 4 inhibitor which was approved in 2006, is that it is less likely to cause hypoglycemia and weight gain. In these trials, sitagliptin had a neutral effect on body weight and the incidence of hypoglycemia was not significantly different in the sitagliptin-treated and placebo-controlled patients (1.2% versus 0.9%), Dr. Stein, senior director in clinical research at Merck Research Laboratories, Rahway, N.J., said in the poster.
There also were no differences in adverse events or discontinuations in the trials, although the sitagliptin-treated patients did have a slight increase in white blood cell count due to an increase in neutrophils.
The studies were funded by Merck & Co.?