Researchers from the British Medical Journal have dug into the data previously withheld on Byetta and Januvia, drugs, known as incretin mimetics, and found the diabetes drugs could be riskier than previously thought.

Exenatide is a synthetic hormone that was first found in the saliva of a Gila monster.

Exenatide is a synthetic hormone that was first found in the saliva of the Gila monster.

Both drugs are used to treat type 2 diabetes. Byetta (exenatide) is made by Bristol-Myers Squibb and Januvia (sitagliptin) is made by Merck. They are known as “the darlings of diabetes treatment,” according to BMJ, since they are a fairly new breakthrough therapy. They work to switch on insulin while suppressing glucagon to help control elevated blood sugar levels.

The researchers obtained previously unpublished data. Under a freedom of information (FOIA) filing, they looked at thousands of pages of documents and uncovered information no company would want published – a proliferation of adverse events involving the pancreas.

Deborah Cohen, who is the Investigative Editor for BMJ, says the companies have not completed safety studies and had denied access to raw data. Without access to data, doctors and their patients cannot be truly informed.

Just this year, three studies have linked incretin therapies with pancreatic risk. One study looked at insurance records to find the use of Byetta and Onglyza could double the risk of developing acute pancreatitis. In 2008, the FDA reported it received 6 reports of hemorrhagic or necrotizing pancreatitis among patients taking Byetta. Two of those patients died.

In March, the FDA announced it would study the connections to pancreas inflammation and pre-cancerous changes to pancreatic cells. The agency said it was evaluating unpublished new findings based on tissue samples taken from patients who died after taking incretin mimetic drugs including Byetta, Victoza, Januvia, Onglyza, Nesina and Tradjenta, among others.

Stay tuned – bad news aside, companies are interested in using incretin therapies as a new treatment for obesity. Novo Nordisk among them said that it’s obvious that changes to one’s behavior are not enough to slow obesity. The company is testing the drug liraglutide to fill the gap.