SAN DIEGO – Type 2 diabetes patients achieved greater blood sugar control with once-daily liraglutide injections than with other standard type 2 diabetes medications, according to the findings from a meta-analysis of seven phase III studies. The findings were presented April 14 at the annual meeting of the American Association of Clinical Endocrinologists.
"The progressive nature of type 2 diabetes makes it difficult for any single therapy to be effective long-term," said Dr. Robert Henry of the University of California, San Diego.
Liraglutide (Victoza) was approved by the Food and Drug Administration in January 2010 to treat type 2 diabetes in adults as an adjunct therapy to a healthy diet and exercise.
To further evaluate the impact of liraglutide on blood sugar control, Dr. Henry and his colleagues consolidated data from seven phase III clinical trials and divided the patients into five categories based on their baseline hemoglobin A1c level: 7.5% or less (651 patients), 7.6%-8.0% (601 patients), 8.1%-8.5% (538 patients), 8.6%-9.0% (432 patients), and greater than 9.0% (607 patients).
The researchers reviewed the mean changes in HbA1c from baseline to 26 weeks of treatment. Overall, mean hemoglobin A1c reductions with a once-daily, 1.8-mg dose of liraglutide were greater than the reductions achieved with standard regimens involving exenatide, insulin glargine, glimepiride, rosiglitazone, or sitagliptin.
In particular, HbA1c levels were significantly reduced in patients with a baseline HbA1c of 7.5% or less in the liraglutide group compared with all other groups. The mean reductions in HbA1c for patients on liraglutide ranged from 0.7% in the 7.5% or less category to 1.8% in the greater than 9.0% category. The next best mean reduction in HbA1c was seen among patients taking two other injectable therapies: insulin glargine and exenatide. Reductions in HbA1c in patients taking insulin glargine ranged from 0.3% to 1.5%, and HbA1c reductions in those taking exenatide ranged from 0.4% to 1.3%.
Patients taking sulfonylureas, sitagliptin, or thiazolidinediones showed less improvement from baseline than did patients taking the injectables. The average reduction in patients taking sitagliptin ranged from 0.0% to 1.1%. The average reduction with sulfonylureas ranged from 0.4% to 1.4%, and the average reduction with thiazolidinediones ranged from 0.4% to 0.8%.
Among 348 patients in the liraglutide group with baseline HbA1c levels of 7.5% or less, 216 (63%) reached the AACE-recommended HbA1c target of 6.5% or less, compared with less than half (20%-49%) of patients with a baseline HbA1c of 7.5% or less in the other groups, Dr. Henry noted.
Among 333 patients in the liraglutide group with HbA1c levels greater than 9.0%, 33 (10%) reached the 6.5% or less target, compared with 4 (12%) of 34 patients in the insulin glargine group and 0%-5% of patients in the other groups.
The study was limited by the use of mean data, which does not account for individual variability, but the results suggest that liraglutide was effective at reducing HbA1c throughout the baseline HbA1c spectrum, Dr. Henry said.
The study was sponsored by Novo Nordisk, which manufactures liraglutide. Dr. Henry has received research support from multiple pharmaceutical companies, including Amylin Pharmaceuticals, AstraZeneca, and Novartis. He has served as an adviser or consultant for, and has received consulting fees from, several companies, including Amylin, Eli Lilly, and Novo Nordisk.