Diabetes Drugs May Cause Damage to Pancreas, Study Finds

People taking diabetes drugs such as Merck & Co.’s Januvia were affected by pancreatic cell growth and damage that may turn cancerous, a small study found.

The study, led by Alexandra Butler and Peter Butler of the University of California, Los Angeles, provides evidence of increased pre-cancerous changes in diabetic patients using so-called incretin mimetics, Public Citizen, a Washington-based public advocacy group, said in a statement today after the research was published.

The U.S. Food and Drug Administration said this month it was reviewing unpublished findings by a group of academic researchers suggesting pre-cancerous cellular changes may be associated with Type 2 diabetes treatments known as incretin mimetics, which also include Bristol-Myers Squibb Co.’s Byetta and Novo Nordisk A/S’s Victoza.

“These findings are in accord with the rapidly increasing number of reports to the U.S Food and Drug Administration of pancreatic cancer in patients using these drugs compared with diabetics using other drugs,” Public Citizen said.

Doctors have been concerned that this category of diabetes treatments may damage the pancreas since the FDA said in 2007 it received a high number of reports of pancreatitis in patients taking Byetta. The agency issued a similar alert for Januvia in 2009. An analysis of insurance records published last month in the journal JAMA Internal Medicine showed such drugs may double a user’s risk of pancreatitis. That hasn’t stopped these medicines from becoming multibillion-dollar drugs.

Merck shares rose less than 1 percent to $43.90 at 4 p.m. New York time. Bristol-Myers rose 1.7 percent to $40.39. Novo Nordisk fell 1 percent to 927.50 Danish kroner.

20 Diabetics

An examination of pancreases from 20 diabetics showed a 40 percent increase in pancreatic cells as well as cell damage in the people treated with incretin therapy, today’s study found. Of the 20 pancreases, eight were from people taking incretin therapy, while 12 were on other treatment, according to a study in Diabetes, a journal of the American Diabetes Association. Seven of the eight patients taking incretin therapies for a year or more were using Merck’s Januvia while the other was using Byetta, according to the study.

The research showed that in humans, incretin therapy resulted in “marked” cell proliferation and damage, with a potential for evolution into cancer, the authors wrote.

Merck disagrees with the study’s hypothesis, is confident in the safety of its drug and hasn’t seen any causal link between it and pancreatitis or pancreatic cancer, Kelley Dougherty, a spokeswoman for the Whitehouse Station, New Jersey-based drugmaker, said in a statement.

No Conclusions

“We would remind you that the FDA said last week that the FDA has not reached any new conclusions about safety risks with these medicines, and at this time patients should continue to take their medicine as directed until they talk to their health care provider, and health care providers should continue to follow the prescribing information in the drug labels,” Dougherty said.

Januvia generated about $4.1 billion in 2012 worldwide sales, Merck has reported.

Ken Dominski, a spokesman for New York-based Bristol-Myers, declined to comment on the study’s findings.

As for Byetta, known as exenatide, “an extensive nonclinical safety program was conducted to support the marketing applications of exenatide twice daily and exenatide once weekly,” Dominski said in an e-mail. “In those studies, exenatide administration was not associated with any drug-related pancreatic tissue damage or toxicity in any species tested.”

Byetta and its longer-acting version, Bydureon, had $227 million in 2012 sales, Bristol-Myers reported.

Victoza, also known as liraglutide, is the fastest-growing product for Bagsvaerd, Denmark-based Novo, with sales jumping 58 percent in 2012 to 9.5 billion kroner ($1.7 billion). The medicine mimics a hormone called GLP-1 to stimulate natural insulin production.

A Novo spokeswoman declined to comment on the study published today.

(Updates with closing share prices in sixth paragraph.)
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