Every company (or its precursers) on my list of large cap drug stocks was once in a similar position.  There is always a first phase 3.  There is almost always a good sized investment in early trials with high degrees of doubt.  There is rarely a big time partner until there are strong trial results...although one could argue Hepalink is no slouch.  There is often failure and restart.  ETC!

I have been lucky enough to be an investor in 5 companies that were successful and then acquired.  Resverlogix (or one of my other current holdings) has IMO a good chance of being number 6.

I have also seen several others go down the tubes.....along with my investment.

It can be dicey, and it is not for the faint of heart.