David Rodman
Analyst · Wells Fargo. Please state your question.
Well, first of all, MRAs generally are pretty similar. It doesn't matter if it's spironolactone from 1959 or a very new one. The only difference are the steroidal side effects, things like breast development in men and impotence and vaginal bleeding and that kind of stuff. As far as everything else, mechanistically, they're the same. What we observe with the MRAs is almost always you are unable to achieve the maximum therapeutic benefit on something like blood pressure because you're limited by the on target increases in potassium and also sodium going down, those kinds of things. For instance, with spironolactone, the maximum efficacious dose is probably 200 milligrams. The conventional dose that's used is 25 mg, 50 mg by nephrology specialists sometimes. That's different. So we found in our drug, we can go above the maximum efficacious dose. 100 mg is the same as 50 mg. So we can safely give 50 mg, which is the maximum efficacious dose. So, overall, what I would say is the biggest difference that's apparent in the trials we're running is that the benefit risk, the ability to dose people all the way up to their applications, dose from getting rid of aldo is probably more achievable with an ASI like ours than an MRA. Now, long-term, there are a lot of aldo effects that aren't blood pressure and kidney, their effects on adipocytes, on insulin sensitivity, on inflammation, on heart and blood vessel fibrosis. And not all of them are mediated through the MR that's blocked by those MRAs. And, in fact, if you give an MRA, you increase aldosterone by 200% or 300%, and you drive it into these other pathways. So, if you did a longer trial and looked at things like vascular stiffness, maybe even [indiscernible], I think eventually they would differentiate, but that's for us, something to define. Once we're in the market for hypertension, we will certainly be looking at that. Those are really the two aspects we would say, that look pretty likely to differentiate and show the advantage of ASI over MRA.