Unsubstantiated claims against incretin drugs draw fiery response

The conclusions reached by the authors of a recent autopsy study stating that incretin-based drugs to treat diabetes can increase the risk of pancreatic cancer are overstated and unnecessarily alarmist, according to a Critique published in Diabetes Technology & Therapeutics (DTT), a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. The Critique is available free on the DTT website at www.liebertpub.com/dia.

Important differences between the two groups of patients studied were overlooked, leading to irresponsible claims made against two effective classes of glucose-lowering drugs used by millions of people with diabetes, say Evis Harja, MD, Jonathan Lord, MD, and Jay Skyler, MD, University of Miami Miller School of Medicine (Florida). They identify specific flaws in the design and analysis of the autopsy study by Butler et al. (Diabetes 2013;62:2595–2604).

In the Critique, "An Analysis of Characteristics of Subjects Examined for Incretin Effects on Pancreatic Pathology," the authors point out the "clear and unambiguous difference between the [diabetes mellitus] DM-incretin and DM-other groups." Furthermore, "the beneficial clinical effects of the incretin drugs were ignored" and claims of potential harm were made with the intent to create controversy rather than to represent the facts.

"Incretin drugs can yield significant improvement in glucose control without causing hypoglycemia, and are associated with an improved lipid profile and either no weight gain or even weight loss, which are important outcomes for patients with diabetes," says Satish Garg, MD, Editor-in-Chief of Diabetes Technology & Therapeutics and Professor of Medicine and Pediatrics at the University of Colorado Denver. "These therapeutic agents are widely used in clinical practice. The database available to judge their effects on the pancreas is small, and claims that they are harmful are unsubstantiated. Large, ongoing studies will lead to more definitive conclusions."

These studies were made possible through tissues obtained from the Network for Pancreatic donors with Diabetes (nPOD). nPOD is a multi-national collaborative investigation funded by JDRF and is designed to further scientific understanding of the causes of type 1 diabetes. "nPOD has been organized to help investigators have access to tissue samples that are normally difficult to obtain, but may prove beneficial to studies of diabetes," said Mark Atkinson, PhD, nPOD Director and Professor of Pathology at the University of Florida. "We are proud to support, free of charge, well over 100 projects with that goal and look forward to seeing additional research that will bring clarity to this question."