Researchers have found that a drug widely used to treat type 2 diabetes may have unintended effects on the pancreas that could lead to a form of low-grade pancreatitis in some patients and a greater risk of pancreatic cancer in long-term users.
Pancreatic cancer is the fourth leading cause of cancer death in the United States, with approximately 32,000 deaths a year. Only five percent of individuals with pancreatic cancer live for at least one year after diagnosis.
The researchers found that sitagliptin, sold in pill form as Januvia, caused abnormalities in the pancreas that are recognized as risk factors for pancreatitis and, with time, pancreatic cancer in humans.
The researchers used human IAPP transgenic (HIP) rats to test sitagliptin and found the rats had abnormally high rates of cell production in their pancreatic ducts; a few developed an abnormality known as ductal metaplasia, and one developed pancreatitis.
“Type 2 diabetes is a lifelong disease, people often take the same drugs for many years, so any adverse effect that could over time increase the risk for pancreatic cancer would be a concern,” said Dr. Peter Butler, the study’s lead investigator. “A concern here is that the unwanted effects of this drug on the pancreas would likely not be detected in humans unless the pancreas was removed and examined.”
An observed connection between Byetta, a drug used to treat type 2 diabetes that is related to Januvia in its intended actions, and pancreatitis has already been reported, prompting a Food and Drug Administration warning. This study suggests that there may indeed be a link between drugs that enhance the actions of GLP-1 and pancreatitis, by increasing the rate of formation of cells that line the pancreatic ducts.