Just wondering- If there was unanimous decision to recommend the drug, it is just about certain that they will approve, no? Why would the stock price increase because of a decision that everyone expects?
This only applies to small companies who have few, if any, products besides the new drug.
My observation has been that there's a surge of excitement and stock buying when the committee recommends that a drug be approved. Then there's a cooling and the price drops a bit. Then, when it's actually approved it goes back up again.
Then it often drops as the reality sets in: production costs, breadth of patients, cost/ insurance approval, etc.
I understand your question and can't really answer, but the price usually/ often rises after approval.
The questions: how much? for how long?
Often the highest price is right after the market opens, and then is softens over the day. But NOT always.