New GLP-1 Approved for Type 2 Diabetes

Written by J. Michael Gonzalez-Campoy, MD, PhD, FACE

There are an estimated 26 million people with diabetes in the United States, and two-thirds of them are overweight or obese. Excess weight causes a state of insulin resistance that makes diabetes management more difficult. For this reason, the standard of care has shifted from the use of medications that stimulate insulin production, or the administration of insulin itself, to medications that allow for improved glycemic control and also promote weight loss.

The glucagon-like peptide-1 (GLP-1) agonists were the first new generation medications to achieve favorable effects on both weight and glycemia. This week the Food and Drug Administration announced its approval to allow GlaxoSmithKline the right to begin marketing albiglutide (Tanzeum) in the United States. Albiglutide is the third agent in the GLP-1 class of medications to reach the market, joining exenatide (Byetta; Bydureon) and liraglutide (Victoza). Albiglutide is dosed once a week, like Bydureon (exenatide), by subcutaneous injection.  Its efficacy is similar to other drugs in this category.

In announcing the approval of albiglutide, Curtis Rosebraugh, MD, MPH, director of the Office of Drug Evaluation II in the FDA’s Center for Drug Evaluation and Research, noted that the agent “can be used alone or added to existing treatment regimens including metformin, glimepiride, pioglitazone, and insulin to control blood sugar levels in the overall management of diabetes.”

Drug Safety

The drug’s safety and effectiveness were evaluated in 8 clinical trials involving more than 2,000 patients with type 2 diabetes. Patients participating in the trials showed an improvement in their HbA1c level (hemoglobin A1c or glycosylated hemoglobin, a measure of blood sugar control). 

According to the FDA, "Tanzeum should not be used to treat people with type 1 diabetes; those who have increased ketones in their blood or urine (diabetic ketoacidosis); or as first-line therapy for patients who can’t be managed with diet and exercise."

The FDA has required the following Boxed Warning to accompany the package insert for Tanzeum: tumors of the thyroid gland (thyroid C-cell tumors) have been observed in rodent studies with some GLP-1 receptor agonists, but that it is unknown whether Tanzeum causes thyroid C-cell tumors, including a type of thyroid cancer called medullary thyroid carcinoma (MTC), in humans. Tanzeum should not be used in patients with a personal or family history of MTC or in patients with Multiple Endocrine Neoplasia syndrome type 2 (a disease where patients have tumors in more than one gland in their body and that predisposes them to MTC).

The FDA also is requiring the following post-marketing studies for Tanzeum:

  1. A clinical trial to evaluate dosing, efficacy, and safety in pediatric patients;
  2. A medullary thyroid carcinoma (MTC) case registry of at least 15 years duration to identify any increase in MTC incidence related to Tanzeum; 
  3. A cardiovascular outcomes trial (CVOT) to evaluate the cardiovascular risk of Tanzeum in patients with high baseline risk of cardiovascular disease.

In clinical trials, the most common side effects observed in patients treated with Tanzeum were diarrhea, nausea, and injection site reactions.
The FDA approved Tanzeum with a Risk Evaluation and Mitigation Strategy (REMS), which consists of a communication plan to inform health care providers about the serious risks associated with Tanzeum.