Ultragenyx Pharmaceutical Inc ASGCT DTX301 and DTX401 Data Updates Call Transcript

The following is excerpted from the question-and-answer section of the transcript.

Question: Arlinda Anna Lee - Canaccord Genuity Corp., Research Division - Analyst : Congrats on the progress. I maybe wanted to follow-up a little bit more on the cadence of response in 301 and the -- I guess, the effect of the steroid on that? And I'm kind of curious if you can maybe talk further about the steroid prophylactic and the level that you're going to, are they -- is it like a short course and then a tapering? Or -- and how do you decide if you need to give more?

Question: Arlinda Anna Lee - Canaccord Genuity Corp., Research Division - Analyst : Great. And then maybe on the cadence of response in 301. Can you maybe talk about -- you said that it was within the range of what you were expecting. But I was wondering if you can maybe speculate a little bit further on if there's a way to tell ahead of time and if it makes this difference in the longer run if you're getting into the -- the range that you're expecting?

Question: Arlinda Anna Lee - Canaccord Genuity Corp., Research Division - Analyst : On the 301, the cadence of response. Wondering, there was a patient that looked like they had a more delayed response? And I'm wondering if you could speculate on why that might be and if they're within the range of your estimated time frame in any way if that makes a difference? And how you're thinking about this?