I've been in this since the days of HTFBS, maybe 9 years.
I'm in it for the long haul, obviously, can't really answer your question about timing a quick exit or entry.
To me, the open interest looks really positive for this week and through next month, at least. That being said, this is options expiration week (on Friday), so who knows what wacky stuff might ensue.
Another thing I look at is the ratio of buyers vs sellers over the past 30 days, per CNBC. It's a wash so definitely not indicating that institutions are heading for the exit.
If you average is the lower 3s, you should be up about 33%, or about 10% per year. Not bad, of course you haven't gotten wealthy, but still.
In your position I would hold, although I've been wrong before. It would be depressing to get out then have to chase share price if FDA approval comes unexpectedly soon.