I would welcome anyone's analysis or speculation of what other reasons might explain this strange divergence in getting BP support. 

Efficacy has to be demonstrated in the trials.  In how many trials has RVX failed the primary endpoint over 10+ years?  I've lost count.  Four?  Each time they pivot to a new subgroup. And now, pulling the plug on the recent COVID trial?  None of that is going to inspire confidence in the pharmas.

And Zenith?  They are advancing multiple clinical programs in combination with multiple oncology drugs that would be of signficant value to multiple pharmas.  And the trials? Smooth sailing so far ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~