Emil Kakkis
Analyst · Adam Walsh from Stifel. Your line is now open
Very good. So, on the assay for ureagenesis question, the assay was developed by a consortium for urea cycle disorder, it's an NIH funded consortium, they've been doing that work for a number of years, and feel it's the best method to assay ureagenesis. Usually patients, when repeatedly measure, are within 10% of where they were around in that range. And if you look even in our study, we have some patients that are pretty stable within a range.We've had on occasion people who have not been, but we are doing -- collecting more data now to help define that variation, but it appears over repeated period of time, reasonably consistent.So, we feel as long as is it has done in the prescribed way and that is one of the sources for variation, the patient is happy, fasted and cannot sneak food in while they're doing that test, for example.So, as long as they do it in the prescribed way, it can't be consistent and we feel the variation should be less than 10%. Therefore, the amount of change we're seeing in the patients that we're calling responders as well past what you would observe just through variation, to answer that part.The second question you asked was an 007 level's confidence. Well, we've had great and detailed discussion with FDA both the pre-NDA previously an ongoing dialog on assuring that we're providing the information, so we have a high confidence that the filing will be accepted and reviewed.We feel that between the time they accepted, the filing for review, let's get to review; we added additional 20 patients worth of data. Another third quarter of naive patients treated that had an 80% reduction in the median number of days in the hospital from 10 days to two, consistent with the prior data that we had in our Phase 2 study, as well as in the retrospective study.So, we feel actually they are getting more data now than they actually had when we made the decision. In addition to that we've added expanded access information we've been collecting, which we think is strongly support of. So, our confidence is high that it is packages and sufficient size of the 150 patients exposed, some of them for more than 10 years of continuous exposure, combined with the magnitude and the seriousness of the type of data we're talking about.These aren't small changes in hospitalization rates; these are very large changes and very substantive clinically meaningful types of changes. Combined that with the safety profile of a drug that is simply a GI oral drug, there's some GI upset issues, but no observed toxicities at downside. I think the benefit of risk is pretty strong and we feel -- we feel confident, we can get through this review and get approved.As said the FDA had questions they raised, and we'll have to work through those questions in the process with them and they're good questions and we want to make sure we're getting the right answers.