written by Michael O’Leary

In a head-to-head comparison of the daily type 2 diabetes drug Victoza and weekly injections of Bydureon, those taking the daily drug did significantly better in lowering their HbA1c than those taking the weekly injections.

The down side was that those taking the higher than normal dose of Victoza had more side effects.

The results were published in the Nov. 7 Lancet and reported by MedPage Today. The study named DURATION-6 was designed to be what researchers call a non-inferiority trial. A way of lowering the bar to show that drug A is not less effective than drug B.

In this case they wanted to see if the once-weekly GPL-1 drug, Bydureon, was at least not any less effective than daily Victoza in lowering blood sugar. The trial involved 911 patients with type 2 diabetes at 105 study sites in 19 countries. While 450 were randomly assigned to the Victoza group and 461 were assigned to Bydureon, patients knew which drug they were taking.

After 26 weeks the average reduction in HbA1c  for the Victoza group was 1.48 percent and the reduction in the Bydureon group was 1.28 percent. This difference was greater than the study design’s defined criteria for determining that once-weekly Bydureon is at least as effective as daily Victoza.

The most common side effects were nausea, experienced by 21 percent of those in the Victoza group, diarrhea 13 percent, and vomiting 11 percent. By contrast, 6 percent of the Bydureon group experienced diarrhea, 4 percent vomiting. The side effects declined over the course of the study for both groups.

Drs. Tina Thethi and Vivian Fonseca of Tulane University pointed out several flaws in the study in an editorial that appeared with the study. The 1.8 mg dose of Victoza was higher than the usual dose of 1.2 mg, which might account for the higher rate of side effects, and increased lowering of blood sugar levels in the Victoza group than might normally be seen at the usual dose.

“A true comparison could have been made between the maximum tolerated doses of each drug,” they wrote.

They also noted that there might have been differences in the characteristics of the patients in each study group that were not evaluated in the study. One such characteristic they mentioned was the formation of antibodies, which they suggested may have resulted in the Bydureon group not responding as well as expected.

The study was funded by Eli Lilly and Amylin, which previously co-marketed Bydureon. Lilly is currently developing its own version of the drug. Novo Nordisk makes Victoza and recently received backing by an FDA panel for approval of its once-weekly drug Tresiba.