In a study in Japanese patients, Merck's investigational once-weekly type 2 diabetes drug omarigliptin provided comparable efficacy and tolerability to it its once-daily Januvia (sitagliptin), according to data presented at the 50th European Association for the Study of Diabetes Annual Meeting. Both omarigliptin and Januvia are DPP-4 inhibitor.

"One of the challenges in the treatment of chronic diseases is medication adherence," Ira Gantz, MD, a clinical researcher for metabolism at Merck Research Laboratories, said during his presentation at the meeting in Vienna, Austria. "Pill burden and dosing complexity are factors that can contribute to poor medication adherence. The convenience of an effective, well-tolerated, weekly, oral antihyperglycemic agent has the potential to improve patient adherence, which might translate to better glycemic control and disease outcomes.”

Merck is supporting omarigliptin with a global clinical development program that includes 10 Phase 3 clinical trials involving approximately 8,000 patients with type 2 diabetes. These are the first Phase 3 data presented for omarigliptin and are the pivotal data for filing in Japan. Merck plans to file for approval in Japan by the end of 2014.

About the study
The Phase 3 double-blind, non-inferiority trial assessed the efficacy, safety and tolerability of omarigliptin 25 mg once-weekly compared to sitagliptin 50 mg once-daily (standard starting dose in Japan), and to placebo. The primary efficacy endpoint was the change in HbA1c1 levels from baseline at week 24.

At baseline, randomized patients (n=414) had a mean HbA1c concentration of 7.9, 8.0 and 8.1 percent in the omarigliptin, sitagliptin and placebo groups, respectively. Mean fasting plasma glucose levels were also similar between treatment groups.

The primary objectives of the study were met, demonstrating at 24 weeks a significant change from baseline in lowering HbA1c levels versus placebo, while demonstrating similar efficacy to sitagliptin.

At week 24, omarigliptin significantly reduced HbA1c levels by -0.80% from baseline relative to placebo. The change relative to sitagliptin was -0.02% and met the prespecified non-inferiority criterion. There were no meaningful differences in the incidences of adverse events with omarigliptin compared to placebo and sitagliptin.