Mitchell Steiner
Analyst · B. Riley Securities.
Yes. Great question. So, first of all, functional endpoints, we have to understand that if you're trying to build muscle or preserve muscle, then the functional endpoint is going to be a strength endpoint, okay? Not a duration endpoint. So, 6 minute walk test and anything related to endurance probably is not going to be very sensitive. What's going to be sensitive are things related to strength, burst strength. So if you're trying to measure quadriceps and arm strength, interestingly, it's not just strength from a regulatory standpoint. The agency is taking it one step further and we've seen in writing from the FDA. And that is they do not like grip strength or chest press or leg press. So in the regulatory world, that's not seen as a functional test, as a strength test. So the reason I bring this up, I think it's very important that people focus on what is, from a regulatory standpoint, an acceptable physical function endpoint. Stair climb test is one of those tests. And we've been very fortunate. We have Dr. Shale Bhasin, who's one of our members of the Scientific Advisory Board. He's done over 2,000 patients with stair climb tests. And we've been working with him for many years, first with GTx and now through Veru. But interestingly, in 1,000 patients, in those 5 clinical studies, about 920 of those patients, we did stair climb tests. FDA recognized stair climb tests as a functional endpoint where you can measure speed going up the steps, and you can also measure power. From a regulatory standpoint, Taro Pharma had a drug approved for muscular dystrophy, I think, in the last 3 months, and that was based on a stair climb test. So measuring functional endpoints, we're going to focus on the functional endpoint that correlates well with, for example, leg strength. There's a lot of literature over the last 10 years, 12 years, showing that stair climb power, if you have good stair climb power and decrease in time to go up the steps, that, that correlates very nicely with leg strength and other strength endpoints, which is how you want to measure a medicine that goes after muscle. So, we're going to focus on stair climb power. It's not a primary endpoint. I'm being very clear. It's not really a secondary endpoint. It's an endpoint to allow us to power what we want to see in a Phase III setting. I'm going to ask Dr. Gary Barnette, who's our Chief Scientific Officer, who's one of the pioneers of the stair climb test to comment.