Comparing GLP-1 Agonists: Dulaglutide vs. Liraglutide

All currently available GLP-1 agonists (albiglutide, dulaglutide, exenatide, liraglutide) have four attributes in common: glucose-dependent stimulation of insulin secretion, glucose-dependent blunting of glucagon secretion, improved satiety, and delay in gastric emptying. These physiologic effects are associated with improved glucose control, less risk for hypoglycemia, and weight loss. Head-to-head trials can inform us about potential differences among the agents, but within this class there is much more in similarity than difference.

To date, head-to-head comparisons of GLP1 agonists have suggested a modest A1c reduction advantage for liraglutide (Victoza). The most recently FDA-approved GLP1 agonist, dulaglutide (Trulicity), is the subject of this head-to-head trial vs. liraglutide. In the AWARD-6 trial, patients (n = 599) were randomized (open-label) to maximum as per-labeling dose of once-weekly dulaglutide 1.5 mg or once-daily liraglutide 1.8 mg.

The degree of A1c reduction at 26 weeks with dulaglutide (1.42%) was slightly greater than liraglutide (1.36%), which did meet the threshold for non-inferiority (the primary outcome of the study). The adverse-effect profiles were very similar, except for a substantially lesser degree of hypoglycemia (0.34 vs. 0.52 events/year) with dulaglutide.

Maximum dose once-weekly dulaglutide is non-inferior to maximum dose once-daily liraglutide.