The ESPR drugs were notoriously difficult to manufacture. Very complex and very large, requiring multiple steps. This was a popular reason for the short interest -- that and the Durus nonsense.
One of the reasons we were surprised at the PFE bid was that big pharma traditionally doesn't pay up for hard-to-manufacture drugs. There was also more than a little dispute that there was a big market for an IV drug for dyslipidemia.
We always assumed the "wonder pill" that was about to enter clinical development at the time of purchase was the key. Manufacturing was more complex than say Lipitor or Vytorin (to use a current example of a combo pill), but management indicated they had the essential issues nailed down and even at the Phase I process the margins would be acceptable.
I'm actually more interested to learn whether Matt's comment that PFE kept all the ESPR proteins is accurate. I don't think it is, based upon the fact there would have been no reason for PFE to get any ownership of the spinout if they didn't contribute any of the tech (Roger wouldn't have given up stock just for the name and all the team is outside their non-competes).
Unless otherwise indicated, this is the personal viewpoint of David Miller and not necessarily that of Biotech Stock Research, LLC