Has Pancreatic Damage From Glucagon-Suppressing Diabetes Drugs Been Underplayed?
U.K. investigators cite growing safety concerns (June 10)
A new report published online in the British Medical Journal has looked into the potential harm from drugs in industry studies.
In the course of this investigation, the journal reviewed thousands of pages of regulatory documents and found unpublished data pointing to “unwanted proliferative or inflammatory pancreatic effects” of glucagon-like peptide-1 (GP-1)–based drugs, which are used to regulate blood sugar in patients with type 2 diabetes. Some of these drugs also suppress appetite and are currently being tested as a possible treatment for obesity.
The BMJ also found that, despite published reports that indicated safety concerns, companies have not done certain critical safety studies; nor have regulators requested them. Moreover, access to raw data that might help resolve doubts about the safety of these drugs has been denied.
Dr. Deborah Cohen, the BMJ's Investigation Editor, says: “On their own, the individual pieces of unpublished evidence may seem inconclusive, but when considered alongside other emerging and long-standing evidence, a worrying picture emerges, posing serious questions about the safety of this class of drug.”
According to the BMJ report, three publications this year have raised concerns about the potential side effects of GLP-1–based drugs, prompting both the FDA and the European Medicines Agency (EMA) to launch a review into whether these agents may cause or contribute to the development of pancreatic cancer.
Some scientists argue, however, that the published evidence against GP-1–based drugs is weak, while others are calling for all of the study data to be made public for independent analysis.
Researchers at the University of California–Los Angeles, for example, found worrying changes in the pancreases of animals that received a GLP-1–based agent. They also found abnormal changes, including precancerous lesions, in the pancreases of eight organ donors taking GLP-1–based drugs compared with patients taking other antidiabetic agents.
In addition, studies of side effects reported to regulators have turned up cases of pancreatic cancer among patients on GLP-1–based drugs, according to the report. Both the FDA and the EMA have confirmed to BMJ that they have a “signal” for pancreatic cancer — but this does not mean there is a causal link.
Together, these findings raise questions about a possible connection between GLP-1–based diabetes drugs and pancreatic cancer, the BMJ says, but no safety alert has been issued by regulators.
More information is expected later this month, when the National Institutes of Health (NIH) holds a 2-day meeting on possible links among diabetes, diabetes drugs, and pancreatic cancer.
Dr. Fiona Godlee, Editor in Chief of BMJ, remarked: “All drug licensing is about balancing benefits and risks. But instead of engaging in open debate about legitimate and important scientific questions, the manufacturers have been unwilling to share their data. Meanwhile, patients and doctors have not been kept properly informed about the uncertainties surrounding these drugs.”
Source: BMJ; June 10, 2013.