Luly did make the potency comparison with the ICPT's OCA and target by mid-2015 to select his lead compound that DD mentioned from the JPM presentation.
Other than that, his reply to you struck me a accurate, rather than evasive, description of the difficulty that every drug company goes through in developing a reliable small molecule drug with good shelf life that goes to the right part of the body that doesn't kill people.
"The curious task of economics is to demonstrate to men how little they really know about what they imagine they can design." -F.A. von Hayek