More than two-thirds of all type-2 diabetes patients do not achieve good control of their disease with the first-line medication metformin combined with second-line insulin shots. For the first time, a global research effort led by John Buse, MD, PhD, professor of medicine at the UNC School of Medicine and director of the UNC Diabetes Care Center, determined the efficacy of an alternative called IDegLira, which combines the basal insulin degludec (brand name Tresiba) and a drug called liraglutide (Victoza), a diabetes medication that activates GLP-1 receptors in the pancreas to stimulate insulin production.
Published today in the Journal of the American Medical Association (JAMA), the researchers show that IDegLira injections were more effective than basal insulin glargine (Lantus) injections at reducing the average amount of blood sugar over the course of several months. The combination therapy was also associated with weight loss and a substantially lower rate of hypoglycemia - low blood sugar - compared with insulin glargine.
"It's quite remarkable that IDegLira can achieve such excellent control of diabetes in the toughest group of patients we treat," said Buse, senior author and division chief of endocrinology at UNC. "Without a doubt, if I were a diabetes patient, I'd consult with my doctor about using IDegLira instead of basal insulin."
The UNC group collaborated with 75 diabetes treatment centers in 10 countries from September 2013 to November 2014 to enroll 557 patients with type-2 diabetes that had been uncontrolled with insulin glargine (20-50 units) and metformin (at least 1500 mg per day). The researchers randomized the patients into two groups. One group increased their use of glargine insulin. The second group used IDegLira shots, which contained less insulin. All patients remained on metformin, the first-line diabetes medication.
Patients on IDegLira saw their fasting glucose drop quicker, though both groups saw their fasting glucose numbers drop from an average of 160 mg/dl at the start of the clinical trial to an average of 110 mg/dl after 26 weeks. Currently, between 100 and 126 is considered "pre-diabetic."
The IDegLira patients saw their three-month average blood glucose (HbA1C) drop from 8.4 percent to 6.6 percent. The glargine patients saw their HbA1C drop from 8.2 percent to 7.1 percent. According to current guidelines, HbA1C levels below 7 percent are considered well controlled.
"That 7.1 percent still was very good for this patient group," Buse said. "But the patients on IDegLira did better overall, especially when factoring in weight loss and significantly decreased hypoglycemia risk."
Hypoglycemia occurred in fewer IDegLira patients (28.4 percent) than in the glargine group (49.1 percent). There was one reported case of severe hypoglycemia out of the 557 patients. That patient had received glargine.
Ildiko Lingvay, MD, MPH, associate professor of internal medicine and clinical sciences at UT Southwestern Medical Center and the study's first author, said, "The advantage of the combination product is that the treatment burden is the same as taking basal insulin - one shot a day - but you are getting an additional product that works through a different mechanism and addresses different pathophysiologic defects of the disease. The liraglutide affects satiety and induces weight loss, while also stimulating insulin secretion. The combination product addresses more underlying abnormalities present in this disease."
The researchers found that IDegLira was also associated with decreased systolic blood pressure but more "non-serious" gastrointestinal side effects - mainly nausea. Few patients dropped out of the study due to side effect concerns.
"I think IDegLira is a very good therapy," Buse said. "One could argue that there's no clinical rationale for using any of the basal insulin products, including glargine. Our study raises the question of whether we should use basal insulin at all in the future."
The combination drug IDegLira is available in Europe, but not in the United States, where it is currently under review at the U. S. Food and Drug Administration.
University of North Carolina Health Care System