Another Snowstorm, Another Complete Response Letter?

The snow is falling and that can mean only one thing – a Complete Response Letter for Amylin Pharmaceuticals’ Byetta LAR (long-acting exenatide). At least that’s what Jon LeCroy, an analyst at Hapoalim Securities, suggests after trying to decipher how the FDA reacts to inclement weather.

For those who weren’t aware, the agency yesterday extended the PDUFA date for the once-weekly diabetes drug from March 5 to March 12. Normally, a delay of a few days isn’t expected to amount to much, if anything. Besides, the agency had signaled PDUFA user fee dates could slip by up to five business days due to the blizzards that shut down the federal government earlier this month.

But LeCroy worries something ominous is under way. Given that PDUFA delays have become the norm, the March 5 date was always uncertain. Until now, in fact, LeCroy assumed the date would just slide by. But the fact that the agency assigned a new and specific date suggests to him that, not only will a decision actually come down on March 12, but the likelihood is it won’t a be positive for Amylin and its two partners, Eli Lilly and Alkermes.

As a result, he’s ballparking approval this way – the odds of a full approval on March 12 are just 20 percent; a Complete Response Letter is a 60 percent bet and there’s a 20 percent chance the FDA will simply miss the PDUFA date. In an investor note, he points out that Xenoport, after all, recently received a PDUFA extension, ostensibly due to bad weather, and wound up with a rejection letter.

In his note, LeCroy writes that he thinks “approval will likely be delayed” until the FDA reviews several studies – including data from ongoing animal trials for twice-daily Byettta – that were requested at the time the Byetta monotherapy indication was approved last October. The last required study on Byetta LAR is expected to be done mid-year and a final report submitted to the FDA next January. “This implies,” he wrote, “that the FDA will not approve (Byetta LAR) until mid-2011."

Unless it keeps snowing, in which case the drug may never get approved.

--Emily Hayes

photo thanks to LD Flickr creative commons