Although the new diabetes medication Onglyza is effective, it may be associated with serious side effects such as heart failure and pancreatic cancer.

Onglyza, also known by its generic name saxagliptin, is a product of AstraZeneca Pharmaceuticals. It’s a relatively new drug, having been first approved by the FDA in 2009. It is one of a class of diabetes drugs called DDP-4 inhibitors, which are used to control blood sugar in patients with type-2 diabetes. Onglyza helps the body to release more insulin, reducing excessive levels of blood sugar. Onglyza also inhibits the pancreas’ release of glucagon, the hormone that promotes glucose production in the liver.

Onglyza is particularly popular because it does not cause the weight gain that some other diabetes medications cause, and brisk sales are a reflection of that popularity. Sales reached $709 million in 2012 and $820 million in 2014, with sales projected to reach into the billions within a few years.

Onglyza Side Effects

Despite Onglyza’s popularity, reports of undesirable Onglyza side effects have been leaking out. With Onglyza’s ability to lower blood sugar comes a possibility of hypoglycemia. Onglyza’s current FDA-approved label notes that in a clinical trial, patients reported instances of hypoglycemia at a rate of 10.1 percent with Onglyza, compared to 6.3 percent with a placebo.

Some studies have also found evidence of a possible link between incretin-based drugs like Onglyza and pancreatic cancer.

Part of Onglyza’s action mechanism is to increase the size and number of beta cells, the cells that secrete insulin. One study published in the journal Diabetes in March 2013 found these increased beta cells were abnormal. The study also found pancreatic adenomas, or small and benign tumors, in some Onglyza patients. These results were found in patients taking drugs like Onglyza that work on DPP-4 or GLP-1, but not in those who had taken other diabetes medications.

Pancreatic cancer is particularly deadly: the five-year survival rate of pancreatic adenocarcinoma patients is only two percent. However, regulatory agencies in both the U.S. and Europe did not find evidence of a causal link between Onglyza and pancreatic cancer in the results of these studies.

There have also been reports of acute pancreatitis, or inflammation of the pancreas, associated with Onglyza. Pancreatitis can be mild or life-threatening, and it usually requires hospitalization with monitored fasting to rest the pancreas.

In April 2015, an FDA advisory committee reported that in clinical trials, Onglyza patients showed a “significant or near-significant” increase in death from all causes. However, the results did not identify specific causes of the deaths. Other clinical trials showed Onglyza patients had a 27 percent greater risk of heart failure than patients who took a placebo. The advisory panel recommended the FDA add information from those clinical trials to Onglyza labeling.