Good afternoon, everyone. Thank you for joining the 25th Annual Needham Healthcare Conference. My name is Joey Stringer, and I'm one of the biotech analysts at Needham & Company. It's my pleasure to introduce our next company, Stoke Therapeutics. Joining us today from Stoke is CEO Ian Smith and Chief Patient Officer Jason Hoitt. We also have Doug Snow from Investor Relations on as well. For those of you joining on the webcast, if you would like to ask a question, you can do so at any time. You can submit a question using the chat box at the bottom of your screen. With that, we'll get started. Ian, Jason, and Doug, thank you so much for joining us today.
Thank you, Joey. Happy to be here. Looking forward to taking questions, whether it's from yourself or online, and I appreciate everybody giving us their time this afternoon. Over to you, Joey.
Great. Well, the next year or so is shaping up to be a transformational period for Stoke. Can you talk about the opportunity for the lead asset, zorevunersen in Dravet syndrome, and what topics are coming up most in your recent discussions with investors?
Good intro question, Joey, because it gives me the opportunity to talk about maybe the last 12 months. I've been acting as the CEO of Stoke Therapeutics since March of last year, so nearly just over 12 months now. It's been interesting to see the evolution of the company, where it's taken data from the trials that it has been running and continues to run, and really educate the investor around what Dravet syndrome actually is and the severity of the disease, the fact that there are no medicines to treat Dravet syndrome, although there are medicines to treat seizures within Dravet, and then also to kind of educate on the long-term benefits of our medicine, of how it treats Dravet patients.
Not just the efficacy data, which reflects reductions in seizures and improvements and gain of function within cognition and behavioral aspects of life, but also the safety, because we've been running a study now, well, it's an open-label extension study, OLE, and that study has been going on now for four years currently. We've been using three-year data over the last year. The evolution for the investor is more the evolution of Stoke as an understanding that its lead medicine is here to potentially treat Dravet syndrome. As that has been more understood and the devastation of Dravet, the investor intrigue, I would say, has now become more towards the success within the phase III.
I'm sure we'll talk about what success looks like within the phase III, which translates to a label, which translates to how you may promote your medicine and have access to patients, and how you may price your medicine. The latter two or three topics are where most investors now are spending the time, and it's around the commercial opportunity, the regulatory environment, and also the potential to get a label that allows you to have a strong launch within Dravet syndrome. It's been an evolution, and which is also an evolution of the company. It's been a fun 12 months, and it's been a fun last few months as well.
For zorevunersen in Dravet syndrome, what are the key efficacy takeaways from the clinical data to date? What type of seizure reductions are you seeing?
Just to remind folks that we've run a phase I/II dose-escalating study, and all the way through to doses of 70 mg, and then these patients, through the phase I/II study, then rolled over into an OLE study. That OLE study, as I mentioned, is now four years old, but we've provided data through three years. What we're seeing with the dose commensurate to what we're using in our phase III is we're seeing seizure reductions of around ±75%. Those seizure reductions are not just initial seizure reductions, but they've actually been maintained roughly two years post the phase I/II and into the OLE study. We're looking forward to understanding the four-year OLE data later this year, which will be coming.
Doug just flipped up the slide that shows the seizure reductions in the OLE study that have been showed this durability of seizure reduction that has been maintained around 75%. I want to be clear that this is compared to the patient's baseline, and the patient is already on anti-seizure medications. Ours is a further reduction on top of these anti-seizure medicines, standard of care medicines right now, that also continue to provide an incremental 75% reduction in seizures. Yeah, the data's very powerful in terms of seizure reduction, and seizure reduction is our primary endpoint in our phase III study.
I think one of the most important and differentiating aspects of the drug is its disease-modifying aspects, in addition to the seizure reduction you're showing here. What have you shown in terms of the improvements in cognition and behavior, and how does that data compare to, say, the natural history data?
Yeah. I want to first of all talk about the pathophysiology of Dravet syndrome, which at its root cause is a lack of expression of NaV1.1. What we do with zorevunersen is we upregulate through SCN1A, the allele that is functional, but we upregulate NaV1.1. We do that, and therefore there's good biodistribution around the brain. Not only are we seeing seizure reductions, but we're also seeing, in layperson speak, we're actually seeing the brain switched back on. We've studied the drug in ages two through 18 years old. We haven't seen a differential response in that age category. It appears as though patients gain function, and those functions are measured in the Vineland-3 study. Doug's going to flip up the slide in a moment.
What we've seen is gain of function in year one, we've seen it in year two, and we've seen it in year three. As you can see, there are incremental improvements in key domains of cognition and behavior of these patients. Joey, you're absolutely right. This is fundamental to treating the syndrome as opposed to just reducing seizures.
Yeah.
The practical aspects of these kind of scores in Vineland have been also captured in videos that have been provided at medical conferences. I'm sure at some point on this call I'll explain what those practical repercussions or, let's say, the practical benefits of what does it mean to improve expressive and receptive communication, which, just as an aside, are the two most important measures for these Dravet patients. We'll talk about that later. Yes, this medicine treats the syndrome. It reduces seizures and increases gain of function in terms of cognition and behavior while the patient continues on the medicine.
Obviously safety, tolerability are very important. What are you seeing there? What are some of the key takeaways from the clinical data to date?
Yeah, we're seeing that the medicine is well-tolerated, and Doug's going to flip up the slide. Thank you, Doug. The benefit of the OLE study, which again, is three years on from the phase I/II, but we're seeing that the medicine is well-tolerated. Just as a reference, we had approximately 81 patients in the phase I/II. 90% of those patients did actually cross over, or just over 90% of the patients crossed over into the OLE study. As of last year, when we looked into the data of the OLE, we still had 90% of those patients that continued on medicine. Those features or those data points are really important to help you understand that obviously patients are feeling a benefit, but also it's well-tolerated.
This long-term data, not just from efficacy but also from safety, gives us confidence in terms of being well-tolerated. We do get questions on CSF protein elevations.
Right.
We measure those in our studies. We haven't seen anything to note that relates in clinical manifestations of those protein elevations. When we do see protein elevation, it's not that there's a correlation to a certain patient, it's not that it stays in a patient, it becomes more asymptomatic or periodic and transient. The drug has been well-tolerated to date.
And-
Joey, actually it makes me think of something.
Sure.
Just want to mention that we are in an unusual position where we have an ongoing phase III study, which we'll talk about in a moment, with a genetic medicine that potentially treats the root cause of a really devastating disease. Yet we have the equivalent of three- to four- year data in terms of efficacy and safety. That's an unusual position because you don't normally have that kind of longitudinal data when you have a genetic medicine that treats the root cause of a disease. You may have been in development in a more accelerated manner, but we haven't been. What that has resulted in is this data from the OLE that we continue to collect and help us understand how the medicine has benefited these patients.
You had a publication in NEJM last month, the phase II clinical data for zorevunersen. Anything to highlight there, and what impact do you think that publication is having with key stakeholders?
Well, I'll first talk about maybe the investment community and maybe the audience at large, and ask Jason to comment. Jason runs medical affairs here at Stoke as well and has been out in the field. Overall, it brings credibility to the phase I/II results, but also the three-year OLE results. With the endorsement of an editorial that was very strong from a key opinion leader that was not involved in the study, but a key opinion leader within Dravet, the endorsement of the editorial on the article has just provided credibility. Obviously, we've shared the publication with our treating physicians, advocacy community, and I'll ask Jason to maybe comment on what he's seen and heard in those communities.
Yeah, Joey, I think to Ian's point, that credibility that comes along with the New England Journal.
It translates across audiences, right? Whether you're speaking to a healthcare provider, a payer, an investor, I think everyone's pretty well aware of just how influential the New England Journal is and how rigorous their standards are. I think what we see here is a healthcare provider audience that appreciates both the impact that New England Journal has, but I think also the longitudinal nature of these data are proving to be incredibly compelling with this audience. I think now having a New England Journal citation to go with that further enhances their belief, their understanding, and their enthusiasm for a medicine like zorevunersen.
I think that's reflected when you look at some of the media coverage around the New England Journal publication, and what you hear from those healthcare providers associated with the study, and the anecdotes from their patients. Some of that coverage is just remarkable, and I think an appropriate reflection of the potential of this medicine and what you see reflected in the recruitment timeline so far in EMPEROR.
Joey, I got asked the exact same question just yesterday afternoon about New England Journal. For the listeners today, I assume you have interest in Stoke and otherwise you wouldn't be attending the call. I would ask you to go to the New England Journal article. There are click-throughs or videos that are referenced in there. Sometimes videos and data can be viewed as anecdotal data or evidence. No, these were presented at a medical conference. The New England Journal has included them in the article, and they help you understand what a patient with Dravet may be like pre-treatment, at baseline, and what that patient is like after treatment of potentially, I think it was nine months to a year.
It helps you see some of those benefits, and it puts Vineland in a perspective when you can see a child that struggles to walk that might be now walking and kicking a soccer ball, or a child that unfortunately can't communicate or receive communication, but then nine months, 12 months later, is actually communicating with the physician, receiving communication and then expressing their own communication. It's quite impressive, but it's very practical to help you understand what these scores that are up on the screen right now actually mean for these patients when achieved.
Yeah, it's a great point. I guess in terms of the ongoing clinical program here, Stoke provided an update on timelines in January of this year. As it relates to the possibility of an expedited development or approval pathway, can you walk us through your current thinking here and maybe give us an update as to where things currently stand from a regulatory standpoint with FDA?
Yeah. Just to remind investors, we did go to the FDA in December as part of our multidisciplinary meeting through Breakthrough Therapy Designation, and we did ask the question to the FDA of whether they would support an NDA filing on the basis of phase I, II, and OLE data, both safety and efficacy data. We thought it was very compelling. The FDA pushed back in December, but while pushing back, did ask for more information and did give us a pathway forward in terms of trying for them to understand our data. We've continued to work with them, but I would say as time has passed by, and then the other end of this timeline is what is the timeline for the phase III.
Right.
We're now in a position where the timeline saving on potentially an expedited filing of an NDA may be six months or three months, three to six months, maybe closer to three months now. Frankly, we're at that point where there's little opportunity, and there may be even some downside risk in filing an NDA on the phase I, II, and the OLE data, and potentially not getting the label that you expect compared to running a successful phase III. We're defaulting to the accelerated timeline to the phase III right now. However, in saying all of that, we have ongoing and continuous discussion with the FDA and also Europe, frankly, but that's mainly in Biogen's territory.
Just to help people understand, that ongoing discussion with the FDA is generally around understanding Vineland and the impact of what a Vineland score means, such as a score of two is clinically beneficial.
Right.
Helping them understand the key domains, we've run various analyses, one at the request of the FDA. They requested it. They've also requested our codes and individual patient data. They requested that back in December and January, and we've provided that. We continue this discussion to help them understand how our medicine is more than seizures, and our phase III study is designed in a way to show that it's a disease-modifying therapy.
Got it. I guess, in terms of a potential update on, say, the regulatory discussions in terms of accelerated-
...an expedited pathway here, is there any timing in terms of when we should anticipate an update? You're kind of saying it's still ongoing discussions, TBD?
Yeah. I feel as though it is ongoing discussions. However, I do feel as though the clarity of our timeline that people should understand is running a phase III.
Yeah.
The benefit of an expedited timeline is very small now. We're focused on the phase III, and so maybe if I outline with clarity our phase III program, which we've communicated that we anticipate to complete enrollment in Q2. We're here in Q2 of 2026, and we anticipate completing enrollment in this quarter. We're still on track to do that. What that does with a 52-week study marks the end of the study, which would be at a similar time, Q2 of next year, which helps people also understand that the top-line readout from the phase III study would be in mid-2027. In addition to that, and one of the reasons why the timeline does accelerate, is that we anticipate starting a rolling submission in early 2027.
Because of that early start of a rolling submission for an NDA, we anticipate that this could provide us the opportunity to have an approval as early as Q4 of 2027. That's the timeline that we're working towards. Just to put some kind of background on that, if our last clinical submission, which is clinical, is usually your last piece of submission, along with safety in a rolling submission, if that was around the middle of the year, most drugs with rolling submission, and certainly those one with a Breakthrough Designation, are approved within six months of their last clinical submission, and that's why we're saying Q4 of 2027. Continuous work with the FDA will help with the speed of the review of that rolling submission.
Great. We could dive into some of the details of the EMPEROR trial, the phase III trial that's ongoing. Just for those who may not be as familiar, can you give us an overview of trial design, key endpoints, and the timing of both the primary and secondary endpoints?
Yeah, sure. The EMPEROR study is a phase III registrational study. It is 150-160 patients. The primary endpoint, oh, I'm sorry. It's a double-blind, randomized, sham-controlled study. The primary endpoint is at week 28, and that is measuring seizures against sham control. The secondary endpoint is five key domains of Vineland-3, and that would be at week 52. We do have other secondary endpoints, such as quality of life and also durability of seizure reduction. The important ones are the Vineland scores. In terms of the process and ongoing, we anticipate closing enrollment or finalizing enrollment in this quarter. Currently, we're closing in on recruitment into screening. There is an eight-week screening period before you actually move into dosing, because we want to ensure we have the right kind of patients.
We're approaching closure of screening, which therefore translate to eight weeks later, through to the closure of randomization and dosing in EMPEROR. It is moving very quickly. Part of the result is this accelerated timeline through to filing in the middle of next year.
In terms of the primary endpoint, the seizure reduction, can you provide any details on the powering for that in the phase III, and what placebo response are you assuming, and how is it powered on this?
Yeah. The study is actually powered to the secondary endpoints, not the primary. Obviously, we've got very conservative powering for the primary endpoint, but we're seeing seizure reductions of 75%-85% compared to baseline. Running a study of 150-160 patients gives you significant powering for that primary endpoint. Just as a point of reference, that primary endpoint, we did assume a 20% reduction in terms of achieving those seizure reductions. It took, in effect, a conservative reduction of those seizure reductions. We also expected a placebo or a sham control effect of seizure reductions as well. We're very conservative regarding the primary endpoint. The study is actually powered for the two key secondary endpoints of receptive and expressive communication.
Powering of the study with 150-160 patients is to achieve a p-value of 0.01 with a confidence level of 90%. Just so you understand, that was all based on anticipating a two- to three-point improvement in Vineland of expressive and receptive communication. Doug just flashed up on the screen probably the closest data that we have at this point in time to help investors understand the opportunity to reach those secondary endpoints. This slide with the data on the left, the orange, was presented at a medical conference last year, I believe in the middle of last year. This shows Vineland improvements in the key domains are varying between roughly nine and 11 points, which obviously is significantly higher than the two or three that we've powered 0.01, 90% confidence level, too. On the right is a natural history study we ran.
It was a 24-week natural history study. You can see that there's basically these patients don't improve. They're actually stable, unfortunately, from 18 months to 24 months of age, whereas we're seeing improvement. We're seeing gain of function as I mentioned earlier. There is one other piece of data that I would like to refer to because, Joey, this is one of the areas that we get questioned on a lot, which is what is your confidence level of achieving the secondary endpoints? Well,-
Yeah.
... This data shows how we've powered the secondary endpoints, and our confidence level, as I said, is 0.01 with 90% confidence level. When Doug flashes up this next slide, thank you, Doug, we showed this data at AES. We also shared this data with the FDA in December.
Yeah, yup.
They actually asked for our codes of individual patients from this data, I think, to run their own analysis. This is very compelling because what it shows, again, is where you take a dosing that's similar or consistent to the one that we're using in the phase III, you can see that when you do a propensity matching to natural history, you can actually see that we achieve p- values even with n's of eight. The gray bars, the n of 23, is the patients that come from the natural history study. We then have to propensity match those patients based on age, based on baseline seizures, obviously Dravet SCN1A, and we've run our analysis and done our calculations. Now, we don't hit p- values in all the domains. You can certainly see the trends.
Yeah.
We do hit p-values in certain areas, and that's with a dosing consistent with the phase III, even though this was over a longer period of time. It gives us great confidence as to 150-160-patient study, sham-controlled, that we're running in phase III.
Yeah, you have the Vineland-3 up here, the different components. Just wondering if you could walk us through how it's measured and maybe go into a little more detail on why the communication sub-domains are most important and what's considered a clinically meaningful change at one year?
Yeah. I'll ask Jason to talk about why expressive and receptive are the key domains for these patients and their families, but I'll start by helping you understand what Dravet is and also how it's measured. Yeah, we're on video right now, but we can still do this, Joey. If I raise my hand, you can see my hand, right? Joey, please look at my hand.
Yes.
You said "Yes," and you're looking at my hand. I'm going to put it down, and I'm going to put it up again. I'm going to go, "Hey, Joey, can you look at my hand, please?" You're looking at my hand again, are you?
Yes.
The answer's yes. You do that a few times, and your response is every time. A neurotypical person, for those that are on this call, I'm assuming, and also here in this room, we're neurotypical, so we respond to those commands and receive that communication normally, and then we can respond to it, just as you did. You would score a two when you do it frequently all the time. If you do it often, you would score a one.
Unfortunately, Dravet children don't do it, and this is why I wanted to refer to New England Journal of Medicine. You'll be able to see how a Dravet child is doing this neuropsych, the Vineland kind of question and response with a physician, where you can see how they respond at baseline before dosing, and you can see how they respond after, I believe it's nine months of being on therapy. That's what a two means. We're achieving sevens because there's multiple questions in these domains. We're having a dramatic impact on these children and changing their cognition and behavior in these five domains, and this includes motor skills, coping skills, personal skills, interpersonal relationships.
In terms of the important ones, after explaining the clinical benefit of this and what a Vineland score means of two, and that's what's defined as clinically beneficial, Jason can explain expressive and receptive, of why they're the key.
Yeah. I think the key element here, Joey, is that those are what matter most to the families, to the caregivers that are taking care of patients. It's a reflection of their ability to communicate with their child, which when that's lost as they plateau and as they get older, it's really hard for families. I think Ian mentioned the videos associated with the New England Journal publication. One thing that's not captured in there is when those were first presented at AES in 2024, the investigator who was ultimately taking care of this patient gave some additional details about her in that she wasn't able to really conceptualize what days of the week were.
After treatment, she would be at the dinner table with her family talking about what she's doing next Monday, that evolution and that ability to communicate and understand what the parents are saying, and then be able to communicate back and have a conversation and conceptualize both time, days of the week. Again, this is an example from one patient, but I think it's reflective of the potential of what this drug could do, and it helps contextualize what a point change in the Vineland means to a clinician audience, for example, that isn't routinely using Vineland in clinical practice with their patients. I think it's going to be important that we continue to do this over time, but expressive and receptive communication rank highest among caregivers.
We get this question a lot from investors. What's the importance of hitting on the Vineland-3 from, one, a regulatory perspective, and how aligned are the agencies on what is considered as success? Two, how important is it to hit from a commercial perspective?
I'll ask Jason to answer the commercial question because he's been doing a lot of work recently with labels, example labels, potential labels that we anticipate, and he's been doing work with payers. From a regulatory perspective, I want to be very clear. We achieve our primary endpoint. This is an approvable drug subject to safety as well. To be very clear, primary endpoint achieved, p-value of less than 0.05, we have an approvable drug. What you're referring to, though, Joey, is the secondaries, I assume. We have full conviction in achieving those secondaries. I would suggest that you hit expressive and receptive, and you're in very good shape.
However, in saying all of that, what is maybe more important than hitting the secondary endpoint, it's actually having the data from the OLE study and the phase I/IIs, that although this is three-year data, by the time we file, we will be at five-year data. If that three-year data moves further right, i.e., there's further improvement in these key domains after four years and then again after five years, and that data is on the label, then what you've got is an approved drug because of your primary endpoint, and you've got longitudinal data that's unique because it would be a five-year duration that shows this continuous improvement and also the durability of seizure reduction, but this continuous improvement and gain of function in cognition and behavior. That's what regulatory success will be.
For those investors and analysts that are listening to us today, I would ask you to do research around Section 14 within a label. Most companies don't talk about this because, frankly, they don't have four-year data with a genetic medicine. The Section 14, its principle is to help caregivers or physicians for the benefit of the medicine in treating the patient. With the New England Journal of Medicine providing the credibility around this data, there is high confidence that data will be on our label, which is what Jason has been doing analysis around with payers. To just quickly summarize before I pass over to Jason, primary endpoint allows approvable of drug. Secondary endpoint, nice. Focus on express and receptive, and we have full commitment.
Very importantly, Section 14 observed data of our OLE, which is longitudinal data of both seizure and cognition and behavioral benefits. Jason, over to you.
Yeah. So, what Ian was referring to toward the end of last year, late Q4, we conducted some market research with our core constituent audiences, including healthcare providers, neurologists, epileptologists, both academic and community-based, and payers. And we went through a variety of different scenarios, with respect to what's included in the label, what's published but not included in the label, directional versus statistical significance, et cetera, et cetera, to understand what the value drivers were from a perception perspective in those audiences' minds. And what I can tell you is that, by far and away, the most compelling piece of evidence that we will have in hand at the time of a potential approval is the longitudinal four- to five-year OLE data. Because I think from a clinician perspective, that then informs what this product could look like over time, right? Showing the durability of the seizure-
Yeah.
...suppression, showing the continuous improvements in cognition and behavior over time as patients stay on treatment. I think ultimately as a clinician, that's what they want to see in their patients. They want to know if they're prescribing an intrathecally administered antisense oligonucleotide, that over time they're going to see continuous benefits in these patients. Having those data at our disposal, as Ian mentioned, as observed data in Section 14 of the label, allows us to promote to those data in the field, allows us to have those conversations. The audience for whom they matter most are the community neurology practitioners that are maybe less up to date with the most recent advances in what's happening, may not be reading the New England Journal on a monthly basis.
That as we're able to speak to them about this, enhances their conviction, and that's consistent with what we've seen over time over the last couple of years as we've continued to release more and more data and enhance people's understanding of these drugs, is their level of conviction in the drug and what it could potentially mean for their patients has grown significantly over that period of time. And the same principle applies to the payers. So, even having this data published is adequate for the payer audience, and they too appreciate the longitudinal data more so than anything we could show in a 52-week study. And so I think we feel, you know, as Ian mentioned, a strong conviction in the design of this study and our ability to demonstrate an impact across both primary and secondary endpoints.
In the end, what's going to matter most to families, to doctors, and ultimately to payers that will be reimbursing the product will be the long-term data that, at the time of potential approval, should be five years.
Are there any historical company precedents that we can look at to support your strategy of getting the OLE data in Section 14 of the label?
Yeah, it's a great question, Joey. A question that we've been asked frequently, going back to the first question you asked today, which is what are investors currently asking this about, and it is about label through to promotion and access and pricing of the medicine. We put together this chart, and Doug will be happy to share it with yourself, and you can share it with others, and they can also reach out to Doug. I think the best example is right at the top there, and it's Spinraza. Spinraza ran a study that patients rolled over into an OLE study. As everybody knows, Spinraza is a genetic medicine, ASO, similar to ours, that continued to provide benefit for these children with SMA. Not only benefit in terms of their function, and it also showed that they continued to live longer.
As you're familiar with SMA, that data was on the label and therefore allowed Spinraza to be promoted and therefore accessed and pricing because of this data that was on their label, because they had that longitudinal data. It's probably the best example, but as you can see, there are a number up there as well.
Got it. No, that's very helpful, and a nice summary on that. I guess maybe zooming out a big picture on commercial opportunity in Dravet and how you plan to position the drug, give us a rundown of the commercial opportunity, the number of addressable patients you think you can target initially, and then we can go from there, I guess.
Yeah, it's a great question. I'm glad you asked, Joey. So, going back more than a year and a half now, as we were thinking about the EMPEROR study and where we wanted to conduct the EMPEROR study, obviously, we did a really robust project to understand the epidemiology across kind of the core seven geographies as we think of them. And these are the geographies where we're running EMPEROR. So it's the U.S., U.K., EU4, and Japan. And we scaled incidence to prevalence by looking at the last 85 years of live births on a country-by-country basis, scaled incidence to prevalence, applied a rate for SUDEP, so sudden unexpected death in epilepsy, which unfortunately affects this population where one in five children unfortunately die before they reach adulthood.
We looked at WHO mortality tables and applied those to get to what we anticipate to be the addressable market at the time of a potential approval across these geographies. What you'll see is in those seven geographies, you've got somewhere between 35,000 and 40,000 patients, with about 16,000 in the U.S., 16,000 in Europe, and roughly 7,000 in Japan. Now, obviously, these are only seven markets, right?
Right.
With a partner like Biogen, where you have Spinraza available in more than 70 countries, obviously we can go a lot further with the addressable market. Just to hyper-focus on the U.S. right now, of those 16,000 patients, right? You asked what the immediately addressable market size would be at the time of an approval. I can come at this in two different ways. From an epi perspective, of the 16,000, 4,000 are pediatric patients, right, 18 and younger. That's the purest way of looking at the exact population that we're studying in EMPEROR. Now if you think about the dynamics that exist in the U.S. today, a pediatric epileptologist is likely to care for a patient into their mid-20s. If you then look at patients that are, call it, 25 and younger, that's about 6,000.
What we've been saying is we've got about 6,000 immediately addressable patients at the time of a potential approval under the care of a pediatric epileptologist, pediatric neurologist. That's then, if you come at it from a different perspective and you look at claims data of confirmed patients with an ICD-10 code for Dravet syndrome, the most robust claims database in the U.S. right now has about 6,000 identified patients. We're looking at 6,000 as being about the addressable market that's immediate at the time of an approval, while we then work to identify, you know, the additional 10,000+ patients-
Yeah.
...that we believe are out there in the U.S. today, but are largely, you know, in the adult setting. We have a little bit of work to do there, because those patients ultimately were identified and diagnosed with what, call it intractable epilepsy, which a lot of them are coded with, before there was an ICD-10 code for Dravet or even before genetic testing became as commonplace as it is today. We've already started that process, but we'll be working to identify those additional patients over time.
Joey, just as a fact to support what Jason's saying, yes, 6,000 immediately addressable patients, but the average age of diagnosis of Dravet is around seven years of age. It helps you understand that there is a undiagnosed patient population of potentially of zero age or newborns all the way through to seven, which is significant. On top of that 6,000 immediately addressable, we are already starting to think about a screening campaign to identify patients.
Broaden that addressable patient population.
Great. Well, we are up on time. We're into overtime, in fact. We really appreciate the discussion. Thank you so much, Ian, Jason, and Doug, for participating. It was an excellent discussion.
Yeah. Thank you, Joey, and thanks for those people that joined us today.
Yeah. Thanks, everyone, for joining us on the webcast. Have a good day and a good rest of the conference.