In the light of your conversation with Don, it seems that RVX will be sold fairly soon; I am guessing by March 2020. As you noted, a buyout makes most sense for all involved: scientists in RVX, shareholders and society at large.
IMHO, it comes down to the FDA letter in mid December. If the FDA says RVX can apply for an NDA without too much extra work, then we get closer to $8 billion valuation. If the FDA wants bolt on work, then we get $4 billion. Let's hope Don meant US$ or not C$, when he was talking about enterprise value! If you assume 250 million shares fully diluted, then we are looking at a buyout at $16 to $32 per share.