Byetta is a popular drug, and it's helped many patients. But liraglutide -- soon to be called Victoza if approved by the FDA -- works better, says Lawrence Blonde, MD, director of the diabetes clinical research unit at Ochsner Clinic Foundation, New Orleans.
"Our direct comparison study shows patients who took liraglutide once a day had a greater reduction in [average blood sugar levels] at the end of the 26-week study than did [Byetta] twice a day," Blonde tells WebMD. "Obviously, once-a-day injections would be preferred by many patients because of the convenience -- and it is not tied to meals. Liraglutide can be taken any time as long as you take it the same time each day."
Blonde and colleagues reported the results of the study -- funded by Victoza maker Novo Nordisk -- at this week's meeting of the American Diabetes Association (ADA) in New Orleans. The study also appears in the June 8 advance online issue of The Lancet.
The study's main focus was how well liraglutide and Byetta lowered A1c, a measure of blood-sugar control over time. The ADA recommends that patients keep their A1c level below 7%. At the start of the study, which enrolled 464 patients with poor blood-sugar control despite standard treatment with metformin and/or a sulfonylurea, study participants' average A1c level was 8.2%.
Byetta helped patients lower their A1c by 0.79%; 43% of patients were able to get their A1c under 7%.
But patients on liraglutide had a 1.12% drop in A1c -- and 54% got their A1c under 7%.
Byetta makes many patients feel nauseous, although this side effect gets better over time. Nausea is also a side effect of liraglutide, but patients got over it much more quickly.
"By week six the proportion of patients with nausea in the liraglutide group was below 10%, whereas it took patients on [Byetta] 22 weeks to reach that value," Blonde says.
Patients on liraglutide had about half as many episodes of too-low blood sugar as those on Byetta. And patients on liraglutide lost a little more weight (7.1 pounds) than patients on Byetta (6.28 pounds), although the difference was not statistically significant.
The findings convince Christophe E.M. DeBlock, MD, and Luc F. Van Gaal, MD, PhD, of the University of Antwerp, Belgium, who reviewed the study for The Lancet.
"Liraglutide provides greater improvements in glycemic control and is better tolerated than [Byetta]," they write. "This novel GLP-1 analog might be a good option for the treatment of type 2 diabetes."
Victoza Works at Least 2 Years
Will the results seen by Blonde and colleagues last longer than 26 weeks? Yes, says Alan J. Garber, MD, PhD, professor of endocrinology and metabolism at Baylor College of Medicine, Houston.
In another Novo-Nordisk-funded study reported at the ADA conference, Garber and colleagues followed patients who took liraglutide for two years.
"This drug shows extremely good durability in terms of blood-sugar control without any loss of the weight loss benefit or any other features that we like to see in terms of blood-sugar reduction," Garber tells WebMD. "This is more than just a flash in the pan. It is a very reliable, durable drug."
Rodent studies have raised a concern that liraglutide might increase the risk of thyroid cancer. But Garber says there's no sign this happens in humans.
If Victoza wins FDA approval, Garber says he'd prescribe the drug as a first-line treatment for newly diagnosed patients. That's because the drug stimulates insulin production by the beta cells of the pancreas. As diabetes progresses, beta cells die off -- so Garber says patients would get the most benefit if treated early in their illness.
"It would be a good treatment choice for initial therapy, Garber says. "Besides, it is associated with weight loss, and that is a profile we want to see. And it is virtually free of low-blood-sugar reactions, something no patient likes to see. And finally it does have benefits with regard to blood pressure, particularly systolic blood pressure, which is a pesky problem with diabetic patients."
Garber and Blonde each report serving as a speaker for Novo Nordisk, among other companies. Garber reports sitting on Novo Nordisk's advisory board.