Byetta Pancreatitis Problems Cause Sales and Amylin Stock to Fall

Amylin Pharmaceuticals has reported a larger fourth quarter loss, which they indicate was caused in part by Byetta pancreatitis problems that have caused sales to decline sharply for their diabetes drug.

Byetta (exenatide), which is marketed jointly by Amylin and Eli Lilly & Co., was approved in 2005 for treatment of type 2 diabetes. It has been prescribed to about 1 million people in the United States, and Amylin has been attempting to gain expanded approval to market a new long-acting version of the drug.

Concerns about a possible association between Byetta and pancreatitis caused a number of patients and doctors to move away from the drug in the second half of last year, following a health alert issued by the FDA.

In August 2008, the FDA posted a notice for healthcare providers about 6 reports of severe necrotizing pancreatitis and hemorrhagic pancreatitis among Byetta users, including two deaths.

Although Eli Lilly and Amylin have maintained that no causal relationship between Byetta and pancreatitis has been established to date, they confirmed during the days after the FDA announcement that they were aware of at least four other pancreatitis deaths among Byetta users.

The pancreatitis reports caused an immediate impact on Amylin, which is much more dependant on sales of Byetta than Eli Lilly. Over the eight weeks after the Byetta pancreatitis cases were reported, Amylin’s stock price fell nearly 20%.

Pancreatitis involves inflammation of the pancreas, which can cause symptoms like nausea, vomiting, severe pain in the upper abdomen and back, a rise or fall in blood pressure, increased heart and respiratory rates.

Information about potential pancreatitis side effects of Byetta was added to the drug’s warning label in 2007, after the FDA warned that at least 30 cases of acute pancreatitis had been associated with use of the diabetes drug.

The six cases highlighted by the FDA in August 2008, involved severe forms of pancreatitis, such as hemorrhagic pancreatitis where severe bleeding can be caused by massive errosion of blood vessels, and necrotizing pancreatitis where tissue damage can lead to the release of toxins and enzymes into the bloodstream, potentially causing multi-organ failure or death.

Byetta lawsuits have been filed against Amylin and Eli Lilly on behalf of individuals who developed pancreatitis, alleging that the drug makers have not adequately tested and monitored the side effects of their drug, and failed to adequately warn about the risk of Byetta pancreatitis problems.

During the fourth quarter earnings report, Amylin did not provide projections for 2009, as they are still not sure what kind of label changes the FDA will require about the pancreatitis risk with Byetta.

Prior reports have speculated that the FDA is considering a “black box” warning, which would be the strongest type of warning that can be placed on a prescription drug. Such a warning would likely have a further negative effect on sales.