New Warnings On Diabetes Drug Byetta

The U.S. The Food and Drug Administration (FDA) issued new warnings Monday of more cases of pancreas inflammation in patients taking Byetta, the diabetes drug made by Amylin Pharmaceuticals Inc.

The agency said it received six reports of hemorrhagic or necrotizing pancreatitis requiring hospitalization.  Two of the patients died, while the other four were still recovering at the time of the reports.

Pancreatitis is an inflammation of the pancreas, which aids digestion by releasing vital hormones.  The condition usually subsides within a week, according to the National Institutes of Health.

However, the condition was found to worsen in some patients taking Byetta.

"There are no signs or symptoms that distinguish acute hemorrhagic or necrotizing pancreatitis associated with Byetta from the less severe form of pancreatitis," the FDA said, adding that doctors should discontinue use of the Byetta and carefully monitor patients.

The FDA said it was working with Amylin "to add stronger, more prominent warnings in the product label".  

Byetta was broadly seen as one of the most promising new diabetes medicines in recent years. Launched in mid-2005, it was believed to have widespread potential uses, in part because of its ability to assist type II diabetes patients lose weight.  The drug is co-marketed by Eli Lilly and Co. and Amylin, whose shares were down over 17 percent in the two days since the warnings were released. 

It is not yet clear if the FDA will require a so- called "black box" warnings, the strongest type available, for Byetta, but Amylin and Eli Lilly said they would work with the agency to update the drug’s label.

The new reports follow an previous warning last October, when the agency cited 30 reports of pancreatitis in patients taking Byetta.  The drug was suspected in some of the cases, and Amylin added information about the risk to Byetta’s label notified doctors about the problem.

The additional cases could pressure doctors to discontinue use of the drug, analysts said Monday.  Indeed, Byetta prescriptions have seen declining growth in recent months, partially due to the necessity of twice daily injections.

"This is very negative and damaging news for Amylin," wrote Jason Zhang, a BMO Capital Markets analyst, in a research note.

"Growth in demand for Byetta has been lackluster in the last couple of years … and this development obviously can’t help," wrote Deutsche Bank analyst Barbara Ryan.

The agency’s ongoing worries may also indicate a potentially difficult approval path for the experimental, once-a-week version of Byetta.  But Amylin and Eli Lilly still plan to file for U.S. approval by the middle of next year.

Although the pancreatitis complication appears rare, fewer than 300 patients have been studied in advanced trials, according to Sanford C. Bernstein & Co. analyst Timothy Anderson.

The "FDA may worry about LAR’s effects once it is approved and used in a broader, less closely-monitored, patient population. To us, this creates regulatory risk with Byetta LAR," he wrote in a research note.

Kindra Strupp , a spokeswoman for Eli Lilly, said no link had been established between Byetta and pancreatitis.

"We do remain very confident in the development program of our once-weekly" formulation of Byetta, she said during an interview with Reuters.

To date, there have been no pancreatitis cases in Byetta LAR trials, Strupp said.

Byetta, also know by its chemical name, exenatide, lowers blood sugar levels by regulating insulin production.  It is the first in a new class of drugs called incretin memetics, which generated $636 million in 2007 net product sales, according to Amylin. 

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On the Net:

• FDA
• Amylin Pharmaceuticals Inc.
• National Institutes of Health