Januvia and Byetta Increase Pancreatic and Neuroendocrine Cancer Risk

Washington, DCResults from a small study of organs from diabetic patients who were treated with Merck’s Januvia (sitagliptin) and Bristol-Myers Squibb’s Byetta and Bydureon (exenatide) show increases in pancreatic mass and beta cell mass, potentially increasing their risk for pancreatic cancer.

The study, which involved organs donated from 34 diabetic patients, was reported online in the journal Diabetes, and conducted by Dr. Alexandra Butler, University of California Los Angeles, and colleagues. Butler and his fellow researchers examined the pancreas of three groups of patients: those with type 2 diabetes who received incretin therapy (eight), those on other therapies (12), and non-diabetic controls (14). They found that seven of the eight organs from the incretin treatment group had received sitagliptin (Januvia) while one had received exenatide (Byetta, Bydureon). Those in the incretin therapy group had a 40% increase in pancreatic mass, which was significant. Further, there was a six-fold increase in beta cell mass compared with diabetes patients not on incretin therapy.

In their paper, the investigators wrote "These findings lend additional weight to concerns regarding the effects of long-term GLP-1 related therapy with respect to both unintended proliferative actions on the exocrine pancreas and now also a possible increased risk of neuroendocrine tumors." And, they concluded by warning: "In addition to the surveillance previously recommended for the potential association of GLP-1-based therapy and pancreatic cancer risk, the current data imply that surveillance for a possible increased risk of pancreatic neuroendocrine tumors is warranted."

This study follows on the heels of a report published in JAMA Internal Medicine, (2/25/13), which showed people taking Byetta, Bydureon or Januvia had double the rate of acute pancreatitis. Most recently, the FDA announced it would review the safety data on incretin mimetics, including Januvia and Byetta and Bydureon.