Diabetes drugs Januvia (Merck) and Byetta (Bristol-Myers Squibb) were linked to double the risk of pancreatitis in a recent study, Bloomberg reported. The news may affect the way doctors choose to treat the 25 million Americans with type 2 diabetes.
According to the study published on Feb. 25, 2013, in the JAMA Internal Medicine journal, patients taking Januvia or Byetta were twice as likely as those who took other drugs to end up in the hospital with pancreatitis – inflammation of the pancreas that can be fatal. Research found that the inflammation results from pancreatic lesions caused by the drugs.
This concerns doctors because pancreatitis can lead to additional serious problems like pancreatic cancer and kidney failure.
Januvia (sitagliptin), an oral medication, and Byetta (exenatide), an injectable medication, both increase amounts of GLP-1, a hormone in the body that stimulates the pancreas to produce insulin. In addition to insulin, the pancreas also produces digestive enzymes, and if these enzymes are activated before leaving the pancreas they can actually digest the tissue of the organ, causing inflammation, abdominal pain, fever and nausea.
The findings of the study have doctors calling for more research into how GLP-1 drugs work in the body. In a statement, the study's author, Dr. Sonal Singh, said: "This is the first real study to give an estimate of what the risk is; until now we just had a few case reports. We really need to know more about these drugs, as pancreatitis is on the pathway to pancreatic cancer."
Other doctors like Aaron Cypress of Joslin Diabetes Center in Boston said that the results of the study will not change how he treats his patients. Cypress told Reuters, "For me personally it's not going to change my practice pattern in terms of stopping the drugs, but we may revisit whether you're showing any of the risk factors."
Pancreatitis currently affects about 3 in 1,000 diabetes patients. The new study indicates that the number jumps to 6 in 1,000 for patients taking Januvia or Byetta.
Merck and Bristol-Meyers: Drugs Are Safe
In response to the study, Merck maintains Januvia and Janumet – sitagliptin mixed with metformin – are safe and effective.
According to the company, it has reviewed preclinical, post-marketing safety data and told Bloomberg that it found "no compelling evidence of a causal relationship" between sitagliptin and pancreatitis or pancreatic cancer. A spokeswoman added that the company takes the safety of its medicines and the patients who take them very seriously.
Meanwhile, Bristol-Myers Squibb is taking a similar approach. Ken Dominski, a company spokesman, told Bloomberg the company was confident in the safety profile of Byetta and Bydureon (a once-a-week formula of Byetta). He also said the company "will continue to monitor any post-marketing reports of acute pancreatitis."
Despite the companies' insistence on the drugs' safety, however, a number of lawsuits have been filed against both Merck and Bristol-Myers, which bought Amylin, Byetta's original manufacturer, in 2012.
Januvia and Byetta Lawsuits Mount
According to Food and Drug Administration (FDA) data compiled by the Institute of Safe Medication Practices, there were hundreds of reports of acute and chronic pancreatitis attributed to Januvia and Byetta in 2011. People who took these drugs and were diagnosed with pancreatitis and pancreatic cancer filed lawsuits against the drugmakers.
Kathleen Riley was diagnosed with pancreatic cancer after taking Januvia and Byetta to treat her type 2 diabetes and died as a result of the disease. Her heir, Guy Riley filed a lawsuit against Merck and Amylin, now Bristol-Meyers.
The lawsuit claims Merck and Amylin failed to warn patients of the risks and marketed the drug even when they knew the risks, endangering patients. More lawsuits are expected to be filed as reports of complications rise.