-Please describe your specialty and details about your clinical practice

How many patients with mod/severe Hemophilia B do you treat?

How are patients with Hemophilia B currently managed, and what is the unmet need as you see it? 

How do you view the potential of a gene therapy in this space? What would be the ideal product characteristics of a gene therapy in a perfect world?

Turning to the efficacy of AMT 061 or ETRANACOGENE DEZAPARVOVEC:

64% reduction in bleeds77% reduction in treated bleeds71% reduction in A spontaneous bleeding rate78% reduction in annual joint bleed rate

FIX level 36.9% at 18 months

What is the most important of these 4 metrics or the most important aspect of efficacy for a gene therapy product in your mind, and how do these numbers stack up to what you expect?

- FIX expression looks pretty stable when I look at month 6 to 18 which is the new primary endpoint the FDA required, following stabilization of FIX by 6 months. But even looking from week 7/8 or so, out to 6 months it looks pretty stable to me.  What is your view on the 37% number, is this good, and do you anticipate further stability as it goes to 2 years and beyond, or are you concerned that it may decrease over time even though so far it looks relatively stable?

96% reduction in FIX prophylaxis (52/54 came off), with similar ~upper 90s percent reduction in FIX consumption in the 7-12 and 12-18 month periods compared to baseline. How important are these numbers?

There were 2 non-responders, one of which involved an infusion reaction that prevented receipt of a full dose. The patient received only 10% of the intended dose.  
Although only 1 out of 54 patients, is this something that may become a problem when this therapy is commercialized?

For this trial, FDA required counting all bleeds reported by the patient, not only the investigator adjudicated as true and new bleeding events. Would this make a difference in underestimating the benefit shown?   How often is this something that happens where the patient would report a bleed but it's not really adjudicated as such or isn't a meaningful event?   Does this understate the benefit of this treatment?

They did something interesting here by not excluding any patients based on nAbs,
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One patient had a sky high nAb level over 3000, and they were a non responder in terms of FIX production. But on the other hand beyond that outlier it seemed there was no relationship or a very small impact from nAbs to expression with this vector.

In clinical practice, would you intend to test for Nabs anyway, and therefore it's a moot point? And if so what will be your cutoff? The second highest level was around 450 and this patient responded, so it seems like there is a gray zone between 450 and 3000 where you wouldn't really know what is the true threshold level where the therapy won't work the same.  How will you determine the cutoff or who to give the therapy and who would not be expected to benefit?

In their exclusion criteria they listed advanced liver fibrosis.  and active hep B or C ----- How common are these in HemB patients?

Will patients want this treatment?  Are they aware of the data and the product that is potentially on its way?  

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Do you expect FDA approval based on this dataset?

In terms of the costs of managing a HemB patient, do you see this as reducing those costs in a compelling way that you'd want patients to do this and where insurance companies would recognize the benefit to the system reducing overall costs and be willing to pay a high price for this?

Please rate your level of excitement about AMT-061 on a scale of 1-10 and provide the rationale.