Advisory-panel meetings are always great windows into the mind of the FDA. Influenza vaccine FluMist, from MedImmune (NASDAQ:MEDI), was the subject of an advisory panel meeting yesterday as MedImmune seeks to expand its use into a broader patient population.  

The advisory panel debated several issues related to FluMist. It voted that the safety and efficacy data supported the drug's use in children as young as 2 years old, but not younger. This is important because FluMist's biggest advantage is its dosing via nasal spray rather than injection, but the largest population that would prefer a spray flu vaccine -- children younger than age f5 -- are not all yet approved to use the drug.

With the unanimously positive advisory panel vote in favor of the drug's efficacy and safety for most of this patient group, FluMist should gain regulatory approval, and thus an expanded label, in this patient population later this month. Keep in mind, though, that advisory panel votes are non-binding.

FluMist has been something of a flop for MedImmune since its marketing approval in 2003, with sales of only $36 million last year, up 71% versus 2005. The drug is relatively expensive compared to other options from companies like GlaxoSmithKline (NYSE:GSK) and Sanofi-Aventis (NYSE:SNY), and insurers are not willing to reimburse a drug's use for non-approved patient groups. These issues are likely holding back sales. MedImmune also didn't have much success when it used Wyeth (NYSE:WYE) to help promote FluMist several years ago.

Getting this improved label for FluMist doesn't nearly justify the $15 billion purchase price that AstraZeneca (NYSE:AZN) paid for MedImmune. But the combination of the potential expanded label, the recently approved, easier to store formulation of the drug, and AstraZeneca's expanded marketing abilities should promote much higher sales of the drug in future flu seasons. Even a few hundred million dollars in extra sales would be nothing to sneeze at.

Looking for more Foolish drug stock coverage? Check out the Fool's market-beating Rule Breakers newsletter. You can check out all our recommendations as well as get access to our message boards and exclusive content with a 30-day free trial.

GlaxoSmithKline is an Income Investor recommendation.

Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool has a disclosure policy.