The Food and Drug Administration sure gave Amylin Pharmaceuticals (NASDAQ:AMLN) and Alkermes (NASDAQ:ALKS) a good punch yesterday, although they're far from knocked out.

The companies announced bad news yesterday. The FDA wouldn't let Amylin use its in vitro-in vivo correlation studies to prove that the extended-release Byetta manufactured on a commercial scale at its new plant using Alkermes' technology is the same as the drug manufactured on a smaller scale that was used in clinical trials.

The companies, along with marketing partner Eli Lilly (NYSE:LLY), have two more means of proving to the agency that the drugs manufactured at different sites are equivalent. Patients in the maintenance phase of the pivotal phase 3 trial have already been given the commercial-scale drug, so the FDA may accept data from that trial.

The other possibility, a new bridge trial, could result in the company not being able to file a new drug application by its goal of the middle of next year. A delay would be a huge benefit to Novo Nordisk (NYSE:NVO), which has a pending application with the FDA to approve liraglutide, a drug fairly similar to Byetta, but which only needs to be taken once a day. Half as many injections as needed now would be great selling point, but only until the once-weekly Byetta makes it onto the market. Clearly, an extended delay for the extended-release Byetta is a benefit to Novo Nordisk.

The companies and investors knew a delay was possible -- the FDA is giving Genzyme (NASDAQ:GENZ) grief over a larger-scale production of one of its drugs -- so I'm not sure that the giant drops in market caps Amylin and Alkermes experienced yesterday were entirely justified. Even in this time of FDA slowdown, extended-release Byetta will make it onto the market eventually.

Amylin may be knocked down, but this is only round one of a three round fight. Don't give up on "the kid" yet.

Are Amylin and Alkermes bad-news buys? Let us know what you think in Motley Fool CAPS. Make an out- or underperform call on these companies; post a pitch about when you think extended-release Byetta will make it to market. It's free. It's fun. And, it's Foolish.

Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. Novo Nordisk is a Motley Fool Global Gains recommendation. Eli Lilly is an Income Investor selection. The Fool has a disclosure policy.