Better than Byetta?

Washington, DCDo pharmaceutical companies make drugs to make us well, or simply to make money? Eli Lilly and Co. is currently waiting for a Food and Drug Administration (FDA) decision on a longer-acting version of its diabetes drug Byetta, which it partners on with Amylin Pharmaceuticals Inc.

The patent for Byetta expires in 2013, according to a Citigroup Investment Research report. The drug brought in $450 million in 2006, making up 85 percent of the firm's revenues, according to the report.

Along with Byetta, Lilly will also lose protection for its top seller next year, anti-psychotic Zyprexa, and its second-best seller, Cymbalta, in 2013. To make things worse for the pharmaceutical giant, a US District Court judge has ruled invalid a patent protecting the attention deficit hyperactivity drug Strattera. No doubt Lilly expects generic competition to enter the market soon.

So the race is on for Lilly to launch new drugs in the next few years. "We think we're plenty big enough to continue to innovate and to bring new medicines forward that will help Lilly resume a growth trajectory following the expiration of these various patents," said John Lechleiter, Lilly Chairman and CEO. Lilly is betting on Amylin's GLP-1 diabetes drug Bydureon to replace Byetta, but it didn't perform well in recent trials. A spokesperson for the company says that the trial results will not be submitted to the FDA as part of its application for approval. (Shares of Amylin Pharmaceuticals fell after data from the trial was posted.)

According to Reuters, Bydureon proved better at reducing blood sugar levels than one currently marketed medicine, but was only comparable to two others. A study published last June is the fourth one to compare Bydureon to other diabetes drugs.

Byetta, Victoza, Bydureon, and Byetta are all part of a new class of drugs called GLP-1 diabetes drugs. Byetta was the first to hit the market, but the drug hasn't "performed to expectations"—meaning it hasn't made enough profits for investors—because of its association with pancreatitis and other life-threatening adverse events.

Meanwhile, Victoza is the new drug on the block, and (so far) it has not been linked to kidney problems and other serious side effects like those with Byetta. But it took three years before Byetta kidney problems surfaced.

The FDA approved Victoza this January based on five clinical trials involving more than 3,900 people, but pancreatitis occurred more often in patients who took Victoza than in patients taking other diabetes medicines in those trials.

Perhaps every GLP-1 diabetes drug will eventually be linked to pancreatitis and other serious kidney problems. Still, the drug companies are bent on churning out another "bigger and better" drug. Will Bydureon really be that much safer than Byetta?

Meanwhile, the FDA has said that it will announce an approval decision for Bydureon by October 22.