I would submit that a primary endpoint failure for a company like Pfizer, or Sanofi, or Merk, or GSK....or any BP, it would not be devestating.  Biogen's recent failure with abducanumab (sp?) for alzheimer's/cognition is a case it point...it may haved knocked something like $16 billion off their Market Cap, but that company is still worth $45-$50 billion USD and is earnings + having made over $23 per share for the trailing twleve months.

Resverlogix is in an entirely different boat entirely....the mostly likely outcome in the case of a primary endpoint failure imo would be more dilution at greatly reduced prices.  Right now we're a couple/three months away from what might be groundbreaking results in the nascent field of Epigenetics and our Mcap is about $450 million USD.  Push the goal post out another 3 years and I would guess that we'd leave smallcap land, pass right through microcap and end up somewhere in Nanocap space with a valuation of less than $50 million USD.  

Its not something i like to consider, but I have to (at least in my own mind) acknowledge that it is possible.