Good afternoon, welcome to the Turn Therapeutics Investor Update call. At this time, all participants are in a listen-only mode. Please be advised that today's conference is being recorded at the company's request. I will now turn the call over to Sasha Damouni-Ellis, Head of Investor Relations and Communications at Turn Therapeutics. Sasha, you may begin.
Thank you, operator. Good afternoon, thank you all for joining us today. Earlier today, we issued a press release announcing the final stage two design and data-driven expansion of GX-03 phase II program in atopic dermatitis. Before we begin, I would like to remind everyone that some of the statements we are making today are forward-looking statements under the applicable securities laws. These forward-looking statements involve substantial risks and uncertainties that could cause our clinical development programs, future results, performance, or achievements to differ significantly from those expressed or implied by such forward-looking statements. These risks and uncertainties and risks associated with our business are described in the company's reports filed with the Securities and Exchange Commission, including Forms 10-K, 10-Q, and 8-K.
Today's remarks will be delivered by Brad Burnam, Chief Executive Officer, and Dr. Stephen Hahn, Executive Clinical and Lead Regulatory Advisor for Turn Therapeutics, who both will walk through the full interim analysis findings and our optimized stage two design. As a reminder, we will not be taking questions following today's remarks. I'll turn the call over to Brad.
Thank you, Sasha, I'd like to thank everybody for being here, the participants who've joined us on this afternoon, as well as our amazing team. My name is Brad Burnam, Founder and CEO of Turn Therapeutics, and it's a pleasure to be here. I will be beginning with this slide. I'm hoping everybody can see my screen okay. The question becomes is why does someone do a staged adaptive study? In a very simple sense, the purpose of a staged adaptive study is to use your own study and the patients within that study to actually design for the second stage. The first 50 patients of our clinical trial, our phase II trial for atopic dermatitis, are the stage one of this trial. The trial remains ongoing. Enrollment did not pause throughout this interim review period.
We are able to take those first 50 patients under the oversight of the Data Monitoring Committee without affecting the integrity of the trial and actually refine stage two using data that we got in real-time from those trials. It's a very smart use of resources, of course, because we are not stopping one trial to begin another. This is, again, the same trial. It is a higher probability of success, we believe, because once again, we are using the same population, the same investigators, and the same patient population, and we're moving on to stage two. So I'm going to begin with a bit of the idiosyncrasies, a bit of the nuances that are eczema measurement, eczema diagnosis. On your screen, you'll see two visuals. One is lesion severity measured through vIGA-AD. That is Validated Investigator Global Assessment scale.
The industry and the clinicians know this as the IGA scale. It is a zero to four scale that measures the worst lesion on the body. If you have a series of patches around your body, we take a look at the worst one, and it rates them from zero to four. Four being the most severe, zero essentially being not there at all. The other measurement is called the EASI measurement, the Eczema Area and Severity Index, and note the word area in that acronym. That looks not just at the severity, which is a similar measurement as it is to IGA, but also essentially the amount of the body that these lesions are taking up. It doesn't just take into account the severity or the burden of one lesion, such as the visual on the left might show on the back of the neck.
In order to qualify for higher levels of EASI, such as the moderate or severe criteria, which begin at 7.1, you actually have to have a larger surface area of your body covered by these lesions. This is a very good example that we worked up. This patient has a very severe lesion on the back of his or her neck. You can see this is an IGA of four, indicating that this is the worst on the rating scale. But the EASI is 1.1 because you can see this is not a large area of the body. On this particular patient, you have the same severity in terms of the IGA scale, but a much larger area is being burdened by the disease, which puts them at approximately an EASI of 17. We used artificial intelligence to generate approximations.
This is something that dermatologists face on a daily basis. It affects trial design, it affects patients. For the most part, the biologics of the world tend to operate in the EASI of 16 or above. The topicals tend to sort of operate in the lower sphere of those numbers. When we last spoke to you at our preliminary interim, what we were essentially looking for was which EASI do we begin with. We were looking at the moderate-to-severe population, and we still are looking at the moderate-to-severe population. A lot of trials do, you try to set that mark on the Eczema Area and Severity Index, whereby you would have enough of the surface area of the body to actually calculate a useful measurement. Majority of trials in the moderate-to-severe world usually begin at least 10. The injectables tend to begin above 16.
Some of the topicals begin around six or seven. We actually had identified that an EASI of greater than or equal to 10, corresponding to the amount of area of the body that was being burdened with the inflammation, was probably the right marker for us if we were doing just moderate to severe. As you can see, based upon these measurements, we were seeing a pretty strong separation at EASI-75, which in a simple sense means 75% of the overall EASI burden of the body is reduced, and there are incremental improvements as far as getting better, disease severity reducing 90% of the overall surface area, 100% of the overall surface area. The week four IGA AD success, just for the sake of information, is defined as reaching a zero to one on that zero to four scale that we talked about earlier.
The patient also has to have at least a two-grade improvement. Now, this was our plan, and I will simply say that the data had other plans for us as far as how much work we might have to do. When we designed this trial, we were trying to make this more like what a clinician might face in the real world. Not necessarily just a certain level of EASI, not necessarily just a certain level of IGA, but people that show up and are truly miserable. Their eczema is bothering them. They're going to the doctor to actually be seen. They might have clinically severe hand eczema, which would probably be a three or a four on the EASI scale, but it could be a four on the IGA.
We wanted to let people in either based upon the IGA of being three or four , which would be moderate to severe lesions, or an EASI of at least seven or 7.1 or more, which categorizes as moderate to severe eczema. Because of that, we ended up with a bit of a mix of everybody. People that were all clinically moderate to severe according to the IGA index, but had more or less of their body surface area essentially covered. The subgroup of the EASI 1.1 to seven, which according to the EASI scale is the mild to moderate population as far as the total amount of surface area that's being taken up, was roughly 32 patients. Which ended up being, after we did the numbers, some really compelling, I'll call it, results.
Using that IGA success score, that measurement score of getting down to zero or one with a greater than or equal to 2-point improvement, you can see on the drug arm, we had a 71.4% improvement against a 33.3% vehicle improvement. That's a treatment difference of 38.1%. We're not writing it here, but I will mention the P value of that was less than 0.05 on this population. We also had some pretty stark separations at some pretty meaningful endpoints. It seems to be the word that people use on these discussions. EASI-100 means total clearance of the body. 100% of the EASI burden has been eliminated. You can see at week four, we had a 23.1% separation. At week eight, a 24.6% separation. What was extremely meaningful about this group is that it was very balanced, meaning that we had the mean on the bottom.
You could see the EASI of the drug arm versus the vehicle arm was almost identical, 3.59 versus 3.99. The mean IGA was three. We were comparing apples to apples as far as drug versus vehicle. It was a very interesting population to evaluate. Of course, this made us take pause. This is a population of people that is quite miserable. Just because their EASI is not over 7.1, it does not mean that they are not clinically meaningful. It simply means that we were not thinking that they would be part of stage two. Like I said, the data had other plans. I got a chance to work with arguably some of the smartest people I've ever come in contact with, the overseers of this trial design work, Dr. Stouch and Dr. Hahn, we also were looking for predictive biomarkers.
I call them drivers when we're talking about a trial. It's some variable that might affect success, that you wouldn't necessarily think of in the immediate to the IGA or the EASI. In other trials, you might think it could be age or it could be something in the blood or some kind of a lab test. In our trial, there was a notable increase as we got up what's called the pruritus index, the PP-NRS. Pruritus means itch. We noticed that when we started at five, which is really the baseline that anybody who goes to a doctor for eczema should be above. I spoke to a KOL today who said the average is about seven. It's an up to 10-point scale.
We noticed that as we got from five to six to seven, and we looked across these four endpoints, we started seeing even greater separation, just sort of uniformly across the endpoints. We determined that for efficiency purposes, not because we want to necessarily look at five or six in the future in a phase III design, we would enrich for seven. We would make sure that the stage two population had a seven or more, which is in keeping with what we're seeing in other trials. I believe the most popular injectable on the market right now was roughly 7.3 on their trials. We saw pretty drastic separation, 53.2 on the week four IGA. We saw 37.9 on the week eight EASI-100. The enrichment improves the efficiency of the stage two. One of the other. Excuse me, I took a sip of water.
One of the other important things to keep in mind when you're doing a trial where you've got such a large range of patients across the scale of one to 72 on EASI, or 1.1 to 72, is you want to make sure that you're comparing apples to apples. If somebody has an EASI of, say, three and you're comparing it to an EASI of 50, it's not a fair comparison because we don't know which one is going to end up in which arm. We want to make sure that we have balance across those two populations of the drug versus vehicle in each what we call bucket, is being compared in a fair way. We did what's called stratification. We have three groups of people. There is the EASI of 1.1 to seven.
That is the roughly milder group on that Eczema Area and Severity Index. We have approximately 60 people that will be in that bucket. Inside of that bucket, they will be one-to-one randomized, meaning that they will be as close to equal as possible, that the drug and the vehicle each be treating an equal number of patients. We did the same thing by stepping up a scale, 7.1-15.9. That is the next severity scale on the EASI index, roughly equivalent to the moderate to moderate to severe group. Same thing, approximately 60 patients, one-to-one between drug and vehicle. We're also including patients that would typically only be put in systemic trials. People that are greater than or equal to 16, we're adding 15 of those patients. We're making it one-to-one randomized. It's not as large as the other buckets.
Those patients tend to be more difficult to recruit, we wanted to make sure that they were at least properly represented. As far as the endpoints that we will be evaluating, this is where I got to learn something pretty fascinating on the statistical design side. In the traditional clinical trial that we sort of are used to seeing, people pick a primary endpoint and then key secondaries or a bunch of secondaries. The way the statistical methodology works is you have this alpha, is the term for it. It's essentially the debit card that you spend every time you measure an endpoint that you get to use as saying, "Okay, this is our confidence in terms of this being significant." On a traditional clinical trial, you use up that entire debit card if your primary endpoint is not statistically significant.
You essentially don't get a chance to prove that your others are statistically significant. That, to me, is not how doctors practice medicine. They don't practice medicine based upon one endpoint, especially when you're thinking about something like eczema. You have an opportunity to actually evaluate multiple endpoints. It turns out that the FDA actually encourages people to use these multiplicity analyses, where you can take multiple endpoints. The way Hochberg works, which has been in multiple FDA guidance documents as recently as 2021, it is something that they consider for registrational trials, is you pick a family of endpoints. In our case, we picked four. These are all relatively related endpoints. Does eczema get 75% better, 90% better, 100% better? We use different time points. Week four for two of them, week eight for the others.
At the end of the trial, Hochberg says rank them from the worst to the best as far as your likelihood of hitting statistical significance. Speaking via example, if we get to the end of the trial and the top one is a 0.05 as the worst one, the bottom one is a 0.01, it will test the top one first, thereby assuming that if that one is statistically significant, the others will be also. You have a chance to achieve statistical significance on multiple endpoints at the same time, which of course is far more efficient and useful when you're actually designing your phase III trial. We're not spending all of our alpha on the single endpoint. Instead, we're using what I consider increasingly rigorous endpoints. Week four, IGA success, week four, EASI-75, week eight, EASI-90%, week eight, EASI-100%.
If you hit two or three or four of these, or one of these, you have a chance to hit statistical significance. I find this methodology to be incredible. As far as the phase II design, in summary, this is what we just talked about. We will be putting in 120 to 135 people. This includes every completer since the phase I. The other thing that people are beginning to appreciate more is that when you do a stage trial in this way, you are not breaking the blind or looking at the patients after the first 50 patients. We have no idea who's in drug, who's in vehicle. We just know that they're still being enrolled. Those patients are put into this phase II design in a retrospective way. They're swept in.
We will have 120 to 135 people among those three buckets that we talked about earlier. We will make sure that their pruritus, their itch scale, is at least a seven. Their age range will be the same. They will not be on any concomitant therapy. Nothing else will change. These selected endpoints will be using the Hochberg procedure that I just discussed. We will be looking at all four of these endpoints, every one of them increasingly rigorous over the other. This slide is the one that I'd like to spend an extra few minutes on, just sort of discussing what it is. The design that I showed you on the last slide, the summary of the trial that we are doing in the phase II, we took that design.
We essentially made an overlay of it, and we applied it to the first 50 people, the first 50 completers. Now, using that design with a PP-NRS of greater than or equal to seven, that itch index, everybody who's at least a 1.1 on the EASI scale, we ended up with 25 total patients. Now, going through those four endpoints that we will be evaluating in the phase II, you can see the treatment difference is rather encouraging, is an understatement. The week four IGA success is a 53.2% separation. We're not writing in here, but I will mention that P is below 0.05. The week four EASI-75, same, the P is below 0.05. You are seeing a 69.2% versus 25% on vehicle. We get into the higher echelons, EASI-90s, 37.1% separation. Week eight, EASI-100, 37.9% separation. Again, we have a 13 versus 12 population.
The EASI, interestingly enough, favors the vehicle. As we ran into with our preliminary analysis, even though this is a larger group that we're applying it to, this vehicle actually had a very large head start, almost 50%, when you consider that it was 7.2 versus 12.1, and we still got that much of a separation. At this point, I'm going to turn it over to Dr. Hahn, one of the smartest and most fun people I've ever worked with, and I look forward to his remarks.
Brad, really appreciate it and great to be here with you all today. Wanted to go through first kind of some background material about atopic dermatitis, which probably this audience doesn't need, but a significant and growing problem around the world. 16.5 million adults, 9.6 million children under the age of 18. It is a significant future goal of the company to help develop these agents in the pediatric population, not now, of course, but in the future, because 3.2 million children in the U.S. have moderate to severe disease, a significant problem. What really needs to be developed, what is considered, I think, significant high unmet need, is a therapeutic that is safe, most importantly, non-systemic, so needle-free is an option, and rapidly acting, particularly for those patients who suffer from itch.
Because it remains the largest and fastest growing inflammatory problem that patients face, there is a significant market for this. That's, I think, a really important backdrop for the safety and regulatory update, which I'll provide. In the next slide, as Brad mentioned, GX-03 continues to show us a very favorable safety and tolerability profile. There were no treatment-related serious adverse events demonstrated in either treatment group in this preliminary study. There are no tolerability issues that have been observed. We have seen no new safety signals that have emerged from further, obviously, clinical exploration of GX-03. Stage two of this trial is governed by an independent Data and Safety Monitoring Committee. We, I think, based upon all the data we have so far, remain highly confident in the tolerability as we advance into stage two and then plan for our phase III study.
If we go to the next slide, this sort of is an outline of the timeline for the clinical and regulatory approach that we're taking for GX-03. I want to sort of emphasize the fact that ultimately what the FDA does is it assesses the risk-benefit ratio of any sort of new therapeutic for a disease. I think where we start from a position of strength here is the fact that this is very significantly safe with what the preliminary data we've seen so far, and that will be an important component of our discussions with the agency. We will proceed with stage two enrollment, and we expect to have a data readout in the fourth quarter of 2026.
Important to recognize the fact that despite this preliminary announcement of data, we continue to enroll in the trial without recruitment, which as you know, for those who are experienced with clinical development work, really does help speed the subsequent enrollment, even with changes in enrollment criteria. Once that completed data set in his hand by the end of the fourth quarter 2026, we will work very closely with Dr. Stouch to conduct the same sort of rigorous analytical approach that we used for the initial stage, and then we'll be able to report those out. That will allow us to inform our discussions with the FDA. We will be having a Type B meeting, you can see on the timeline here, to discuss the design of our phase III trial. Our priority is to move as efficiently as possible without compromising the quality of the science.
I'm confident based upon the experience of the company so far and the interactions to date that we will be able to do that. Really believe that the benefit risk profile here is quite favorable. You saw the efficacy results as presented by Brad. The safety results are also pretty significant in terms of not having any serious adverse events. As we think about what we're going to look for in phase II of this trial and the phase III, continued safety, and obviously a significant focus on the efficacy. Subject to a successful phase II readout and alignment with the FDA, and that's really important, we need to make sure that we're aligned with the FDA on this, and capital availability, we're targeting the initiation of the phase III trial in mid-2027. Brad, I think I'm turning it over to you now. Is that right?
Sure. As far as the clinical progression of where we believe GX-03 could be used, and of course, there are investors on this call, we recognize that means market opportunity as well. I think of this when a patient shows up to the doctor's office, what is the typical thing that sort of begins the treatment protocol? Most everybody will be given something to try and feel better as quickly as possible. That is usually the doctor's immediate goal is trying to make people feel better. Usually, that means something topical. Typically, that means a powerful steroid, sometimes even an oral steroid. These have trade-offs, as we all know. Persistent use can cause fat atrophy, necrosis of the skin. With steroids, you tend to actually have a dose reduction response or a dose response reduction over time where you end up needing more.
It's as if the skin becomes addicted. As that goes along, you might want to try a stronger topical. The PDE4, the AhR, those tend to have some side effects risks. Some of them are even written on the side of the box. Doctors don't love getting phone calls from the pharmacy from parents saying, "Why are you giving me something with a black box on the side?" Of course, if those don't do the trick or even if they're being used in conjunction, there are a number of patients who end up on the immunosuppressive biologics, the injectables, the orals, and these do have incredible efficacy. We have seen the numbers on the efficacy side, but there's a couple of trade-offs for those as well. Number one is it takes a very long time for these to show the kind of numbers that we're used to seeing.
Some cases, 16 weeks Which in the interim, the patients are still miserable. They also tend to have a number of side effects. Immunosuppression, stinging at the needle site. Also, people just don't love using needles. When you're thinking about the endpoints that we're using, the week four significant reduction, the week eight continued clearance, there is a method to the madness as far as what we want the patients to be able to obtain, what we want the doctors to be able to provide. Something that makes people feel better very fast, something that is very powerful, yet very safe, that in theory could be first-line therapy for anybody who walks in the door, whether or not they end up choosing to stay on systemics for a later period, they still have the opportunity to feel better very fast.
As Dr. Hahn mentioned, we do see a huge opportunity in the pediatric population, because a number of parents do not want to inject their children or use systemic drugs on them. I think I'll close up from here. I'll simply say that it's been an incredible experience working with this group. I do want to thank again, Dr. Hahn, Dr. Stouch, Sasha Damouni, my partner in crime, Zuraiz Chaudhary. This group is truly an amazing family of people. If we leave you with a couple of points today, one of them is, I'm sure you can tell that we have done a serious amount of work planning for stage two of this trial. This was an endeavor.
The word that comes to mind, a forensic-level analysis of the stage one completers, those 50 patients, in order to make for a higher likelihood of success on stage two. The other is that we are not sitting on our hands here. We are racing to the market as fast as we can. We're working on the FDA meeting package as we speak. We hope to have it done within a matter of weeks to submit to the agency for the Type B meeting using the stage one data that we have. This is a huge priority to get this product out there. We're very grateful to everybody who's involved, very grateful to the investigators, the patients, the investors who believe in us, and once again, to my amazing team. With that, I will turn it back over to the operator.
Thank you. Ladies and gentlemen, that concludes today's Turn Therapeutics investor update call. A replay will be available on the company's investor relations website at www.turntherapeutics.com. Thank you all for joining. You may now disconnect.