Will Byetta Side Effects Haunt the Approval of Bydureon?

Washington, DCThe long-anticipated approval of a once-weekly injectable version of Byetta was sealed late last month when the US Food and Drug Administration (FDA) gave the Type 2 diabetes drug its blessing. However, the news is not without controversy, given the various delays and setbacks inherent with the approval of Bydureon. The FDA snubbed its nose at Bydureon twice in 2010.

Bydureon won approval on January 27, but that approval comes with a caveat. The FDA made approval contingent on Amylin Pharmaceuticals, which recently gained full control of Byetta and Bydureon, conducting a clinical trial in tandem with its market availability to assess Byetta side effects—namely, the potential for heart attacks and other cardiovascular problems. Additionally, according to The New York Times (1/28/12), the trial will also assess potential risks for thyroid cancer, pancreatitis and other health problems. Byetta has been linked to Byetta acute pancreatitis. Given that both Byetta and Bydureon have exanatide as the active ingredient, it is understandable to suspect that Bydureon may carry a similar risk.

Critics of this Byetta news (Bydureon is essentially Byetta that contains unique technology allowing once-weekly injections) note that the clinical trial required to assess Bydureon's risks is concurrent with the availability of the injectable medication to a wider market, which gives it access to a growing diabetic population.

It should be noted that the FDA, in rejecting Bydureon in the past, expressed concern that the Type 2 diabetes drug may contribute to heart rhythm abnormalities. However, Bydureon's manufacturer Amylin conducted its own study and, based on the study's findings, suggested otherwise.

Bydureon is expected to gain favor amongst Type 2 diabetes patients currently using Byetta, but who dislike needles. At the moment, Byetta requires injections twice daily to control blood sugar. In spite of a more rigorous pre-injection regimen in order to prepare the Bydureon injection—and a larger needle notwithstanding—it is anticipated that Type 2 diabetes patients will eventually drive annual sales of Bydureon to the $1 billion mark.

That said, concerns with Bydureon mirror those of Byetta: namely Byetta acute pancreatitis and other Byetta side effects that include the fear of heart rhythm abnormalities. While more Bydureon is delivered in the single, once-weekly injection than the twice-daily injections inherent with Byetta, advanced technology allows for the slow release of Bydureon, in measured amounts, throughout the course of a week.

Critics wonder if we will be seeing Bydureon litigation down the road, inherent with Bydureon adverse reactions, akin to the kind of Byetta lawsuit that has stemmed from use of exanatide in the past. What happens if the Bydureon clinical trials prove to reveal troubling side effects? Will Bydureon be pulled from the market just as quickly? Time will tell…