A Byetta Beating

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.