Further to Narmac's post I have attached a link below to an article from Genetic Engineering News that is quite excellent at summarizing the last few years of biotech M&A/deals. I previously posted it on the RVX side when Don was whining wrt the market and RVX.  

Personally I think the problem is likely two fold with respect to RVX/Zen 1) the high level business (ie proper financing/financal management) has not been properly attended to for many years, far before any challenges the biotech market as a whole has faced. Therefore there is likely little faith that any new funding to RVX/Zen will be well managed go forward.  2) on an all out sale of both companies I would guess the asking price is probably way too high.  

Like others here I would love to see a successful biotech exec replace Don at the top of both companies.  I actually think that with just hiring a CEO who the market knows has the track record and connections to access adequate funding would be enough to take RVX to at least the $1 level.  Hiring that person now with 20-25 million options across both companies with exercise at current levels could probably attract someone very good. That level of dilution would likely be far cheaper to shareholders than continuing to be stuck in the muck of the status quo.  Sadly, I doubt it will happen.

https://www.genengnews.com/a-lists/top-10-biopharma-takeover-targets-of-2024/