Reviewing Proveng's chances of FDA approval from the point of view of investors, Matthew Herper gives an overview useful for patients as well. Herper writes:

The FDA has a legal deadline of May 15 to make a decision--although it is possible to break or extend it. But buying the stock in front of this deadline is probably highly risky. There is a reasonable chance the FDA will decide to go against the panel vote and ask for more data. And the downside to the stock if the FDA does delay approval by asking Dendreon for more data is probably much bigger than any potential gain.
...continue reading Forbes View of Provenge