Good afternoon, welcome to the Belite Bio Q2 2023 financial results conference call. At this time, all attendees are in a listen-only mode. The question and answer session will follow the formal presentations. If you'd like to submit a question, you may do so by using the Q&A text box at the bottom of the webcast player or by emailing your questions to questions@lifesciadvisors.com. As a reminder, this call is being recorded and a replay will be made available on the Belite Bio website following the conclusion of the event. Before we begin, I would like to bring your attention to the forward-looking statement slide. During this call, we may be making forward-looking statements. Please refer to the language on this slide for further reference. On today's call, we have Tom Lin, Chairman and CEO, Nathan Mata, CSO, and Hao-Yuan Chuang, CFO.
With that, I'd like to turn the call over to your host, Tom Lin, Chairman and Chief Executive Officer at Belite Bio. Please go ahead, sir.
Thank you, Sarah. Thank you, everyone, for taking the time to join this meeting. I'm Tom Lin, CEO of Belite Bio. I'll start off by giving the overview and the milestones we have achieved so far. For those that are new to the Belite story, the drug that we are developing, Tinlarebant, is a novel once-daily oral tablet designed to bind to serum retinol-binding protein as a means to specifically reduce retinol delivery to the eye. This approach is intended to slow or halt the formation of toxic retinol-derived byproducts, which are generated in the visual cycle and are implicated in progression of Stargardt disease and geographic atrophy, secondary to dry AMD.
Belite Bio believes that earlier intervention directed at emerging retinal pathology, which is not mediated by inflammation, would be the best approach to potentially slow disease progression in Stargardt disease and GA dry AMD. There's still significant unmet need for both indications. As currently, there is still no approved treatment for Stargardt disease, there are currently no approved oral treatments for GA. Which oral treatments are expected to capture a much wider market for advanced dry AMD. We have so far received Fast Track designation, Rare Pediatric Disease designation, and Orphan Drug designation, which allows us to frequently discuss with FDA of our progress and see how we can expedite the approval of this drug if we show positive results from our phase III study.
I would also like to mention that we still have a long patent life with the first composition of matter patent expiring in 2035. This is without patent extension and with new patents being filed, which will extend the patent portfolio into 2050s. Now, in terms of important milestones achieved this quarter, our phase II 18-month treatment data continues to show slowing of lesion growth. We are also expecting our phase II 24-month final data readout in Q4 this year. We've also recently completed enrollment of our global phase III Stargardt, Stargardt trial, and we are now expecting interim readouts around mid-2024. We've also started enrollment for our global phase III trial in GA dry AMD. With this, I'll pass it on to Nathan to go through the clinical trial results. Nathan?
Yeah, thanks, Tom. I'd like to first start by providing an overview of the trials we have going on in Stargardt disease. We have 2 studies, as Tom mentioned. We have an ongoing open label phase II study. The 2-year study, which is just about ready to end in October. I'll give you some more information about that as we move forward. We've got 18-month data to share with you, and I'll provide that in a moment. There's also the phase III data, which, as Tom mentioned, has recently stopped enrollment. We've met our target. In fact, we've exceeded our target by about 10 subjects. We've got 100 subjects in there. Both of these studies are 2-year studies.
They're both looking at the primary endpoint, which is the growth of atrophic lesions, that is DDAF. I'll explain what that is in a moment. There's a lot of similarities between these designs. The differences are as follows: In the open label, phase II, there's only 13 subjects. These subjects came in with only autofluorescent lesions. I'll show you some of the biology on how the autofluorescent lesions turn into this atrophic lesion that we call DDAF. That's one of the differences. The other difference, of course, it's an open label study. We're looking at the same efficacy measures, the same assessments by imaging modalities such as fundus fluorescent autofluorescence photography to look at the lesion growth. You can see here at the bottom what the key inclusion criteria were.
The Stargardt phase III study is also a 2-year study and design. Of course, it's global. There'll be a 2-1 randomization favoring Tinlarebant, and you can see there the various inclusion criteria at the bottom of this slide. Next slide, please. I want to show you first, as Tom mentioned, this agent, Tinlarebant, is a Retinol Binding Protein 4 antagonist. The first biomarker you will, if you will, that we will see is reduction in the Retinol Binding Protein 4 levels in serum. That's what's shown here from the phase II data out to 18 months. You see the very first point, which is shown there at 100%. That's before the patients got dosed. And you can see over the period of 18 months, we've achieved about 80% reduction from baseline of Retinol Binding Protein 4.
You see here this target threshold of, greater than or equal to 70% reduction. This number has been determined in a clinical study in Geographic Atrophy with a different Retinol Binding Protein 4 antagonist. I'll share that data with you as well. This has become our marker because we believe that you need to achieve at least this level of RBP4 reduction to affect a change in lesion growth. By the way, the daily oral dose these kids are getting, these 13 adolescent Stargardt kids, is 5 milligrams per day, and no one's left study, out to 18 months. I'll go over the safety data as well. Next slide. A little bit about the biology. Early in the disease course, there are only autofluorescent lesions, and that's shown on the left-hand side here, the left image.
These lesions are called questionably decreased autofluorescence by ophthalmologists. Basically, what they do is they represent cells laden with autofluorescent entities. These autofluorescent entities are bisretinoids. These are the agents that we're trying to reduce. Because these bisretinoids are formed from vitamin A, we've reasoned that by reducing the amount of retinol going into the eye, we can have effect on reducing the accumulation of these bisretinoids and slow the growth of these autofluorescent lesions. These autofluorescent lesions are amenable to rescue, but if left alone, which of course they have to be because there's no treatment, they will transition into atrophic retinal lesions, which is shown on the right-hand side. You see that black demarcated image, that basically is irreversible photoreceptor cell loss. Those cells are never coming back.
That atrophic area is what ophthalmologists refer to as Definitely Decreased Autofluorescence, and stopping the growth of that lesion type is the primary endpoint. Of course, ophthalmologists look at the combined lesion growth rate because both of these lesions are pathologic. In one study, conducted in 2020 by Georgiou and coworkers, they found in 53 adolescent Stargardt kids, the growth rate of the combined lesion was roughly about 0.7 millimeters squared per year. When we look at that same anatomical feature in our 18-month data and annualize it out to a year, we see a growth of only about 0.28 millimeters squared per year.
That represents about a 60% reduction in the combined lesion growth rate based upon comparison to this very well-conducted natural history study, which, by the way, at that time, was the largest natural history study conducted in adolescent patients. We were very concerned about comparing the atrophic lesion growth, because that is, after all, the endpoint. For that comparison, we had to go to the largest natural history study of Stargardt disease conducted today, called ProgStar. This study enrolled hundreds of patients with Stargardt disease. Many of them were adult patients, but among these patients, there was a small group of 20 subjects that had the exact same baseline characteristics as our subjects in the open label phase two. That is, they were 18 years or younger, and they had no atrophic lesions at baseline, only autofluorescence.
We were able to compare the combined lesion growth rate in that ProgStar group to ours, as well as the atrophic lesion growth. The combined lesion growth is shown on the left-hand side. This is called DAF, or decreased autofluorescence, so it represents the QDF area plus the DDF area. You can see here out to 18 months, we're getting about a 50% reduction in the combined lesion growth rate. You remember this slide previously showed you a 60% reduction. It's pretty, pretty good comparison between these 2 separate and independent natural history studies. When we look at the atrophic lesion growth as the dDAF, we see at 18 months about 50% or sorry, 60% reduction in that atrophic lesion growth rate. Noticeably, not many subjects are converting.
In fact, there seems to be a slowing of the conversion in our treatment group, transitioning from the autofluorescent lesion to the atrophic retinal lesion type. That is all very consistent with our hypothesis that we would first affect a change on the autofluorescence and then subsequently a change in the atrophic lesion growth. We believe that's what these data are showing us. I should have mentioned, but the, the investigators from both the previous study by Georgiou and this study, ProgStar, which was Hendrik Scholl, commented that we are seeing a definite bona fide treatment effect in these natural history study comparisons. That's very promising for us to see. Next slide. This is showing you the visual acuity data. We're showing you both eyes, the study eye and fellow eye.
Of course, both eyes are going to get the same treatment because this is an oral, systemically, applied drug. We're showing you this because in clinical studies, you do have to designate a fellow eye, sorry, a study eye, and then the other eye just becomes a fellow eye. We just want to show you that across 18 months, we're having a stabilization of visual acuity in these subjects. This is a very promising trend because typically, these subjects lose anywhere from 4-6 letters per year. The fact that we've stabilized over 18 months is a very promising trend. That, combined with the slow lesion growth, tells us we're affecting exactly what we want to do, stop the lesion growth and eventually have an effect on preserving or improving vision.
You can see there the letters lost is roughly within noise of the variability of the visual acuity assessment. Next slide, please. Now we want to get into the safety data. I should start by saying there have been no systemic toxicities or AEs noted to date, so no clinically significant findings in relation to vital signs, physical exams, cardiac health, or organ functions. What we are seeing are 2 expected features of this therapy, and they're expected because we are reducing the amount of vitamin A going into the eye. We expect effects on rod and cone photoreceptors, which are the 2 photoreceptor cell types in your retina. The 1st AE we're finding is a form of chromatopsia called xanthopsia.
This is mediated by cone photoreceptors, and it typically happens when patients transition suddenly from a very dark light to a very bright light, or for instance, from waking after sleeping and being exposed to very high room light or sunlight. Basically, cone photoreceptors are activated. They will demand chromophore. Under our treatment regimen, that chromophore doesn't get there quite as quickly, so there will be a delay in the timing for these cone photoreceptors to fill up with chromophore, and during that time, they will misfire and produce these artificial electrical-mediated hues of color in the visual field. In this case, xanthopsia is yellow. You can see here the majority of subjects are experiencing xanthopsia, but no one's leaving study because of it. In fact, we are seeing some recovery over time, and we're not taking subjects off drug.
They are recovering while still getting dosed. The second ocular AE is known as delayed dark adaptation. Again, when rod photoreceptors, when you transition suddenly from a very bright light to a very dim light, rod photoreceptors activate, they require chromophore. There will be a delay in the timing of that chromophore to fill up the rod photoreceptors, and during that time, these rod photoreceptors will not have maximum dim light sensitivity, so there is a delay in the accommodation to dim light. This is not night blindness. I want to make that very clear. This is simply a delay, sometimes 8-12 minutes, in cases where it's very severe, out to 20 minutes in this 1 subject, it's called night vision impairment. Overall, we're very satisfied with these findings. we basically lost 1 subject to follow-up at 12 months.
Out of 13 subjects, we are, we are now at, at 12 subjects at 18 months, but this is still very, very promising safety profile. Next slide, please. Now I want to talk about that proof of concept study I told you about, the 70, 70% marker. How did we get there? Well, this was a study I conducted approximately 12, 13 years ago when I was, with another company. I always had this idea that reducing retinol delivery to the eye might have an effect on slowing lesion growth. I didn't have a drug, to do that with, but I did find an anticancer drug called fenretinide, which had a side effect of reducing Retinol Binding Protein 4 in the blood.
As I said before, it was developed as an anticancer drug. In all the cancer studies, what investigators noted was a dose-dependent reduction of RBP4. I repurposed fenretinide into a 2-year phase II proof of concept study, enrolling 246 GA patients to see if this drug would have any effect on slowing lesion growth. There were 2 treatment arms and placebo, 100 mg, 300 mg, and of course, placebo. I want to show you the lesion growth data just from the high dose arm and placebo, because the middle dose, that's 100 mg, had absolutely no effect on lesion growth. What you're seeing here on this histogram, shown on the left-hand side in the black bars, is the lesion growth in the placebo group, expressed as a % increase from baseline.
We're getting about a 50% increase over 24 months in the placebo subjects. In the 300 milligram group, there was something very interesting. There was a group of subjects who had a very profound reduction of Retinol Binding Protein 4 of at least 70% or more. In those subjects, there was about a 25% slowing of lesion growth over 2 years. In the subjects that did not have this reduction of Retinol Binding Protein 4 of 70% or more, there was absolutely no effect on the lesion growth rate. We're pretty convinced, especially in GA, that this is the level of reduction that would be required to effect a change in lesion. Of course, this is the same sort of approach that we're applying to Stargardt disease.
An interesting thing about this lesion growth reduction, you'll notice it started right at about the 12-month time point, and it stabilized between 18 and 24 months. When we look at the visual acuity loss in these subjects, we also notice in these subjects that had a preservation of lesion growth, that is a reduction of lesion growth, there was also a stabilization of visual acuity loss right at about the same time. 12 months, there was a 6-letter loss, and there was no further loss out to 24 months. Meanwhile, the placebo group and the patients, or the subjects that did not get that profound reduction in RBP4, continued to lose vision out to about 11 or 13 letters over the 2 years.
We have a very significant visual acuity gain and a very significant lesion reduction that has never been observed before in a GA study. The problem with this phase II study was that only one in three subjects actually achieved this profound reduction of RBP4 in the 300 milligram group, and the reasons for that are twofold. One, fenretinide has terrible bioavailability, so we asked subjects to take this drug with a high-fat meal at dinner to increase exposure into the blood. Many patients complied out to about 1 year, but after 1 year, we had a lot of patients falling off of that compliance, and we knew that because the RBP levels in these patients would inflect upward, indicating, in fact, that they're no longer having a suppression of RBP4. The second problem was the low potency of fenretinide.
fenretinide is a terrible drug for RBP4 antagonists because it has the same affinity for the target as does the native ligand vitamin A. With Tinlarebant, we have designed a drug that specifically overcomes those deficits of fenretinide, it has greater bioavailability and a 100-fold greater potency than does fenretinide. We're convinced, with this better purpose-designed RBP4 antagonist, we can achieve at least this benefit, and probably even greater, because, again, we'll have better compliance, and we'll have greater potency of the drug on target. Next slide, please. Now a little bit of our a little bit of our phase III study in Geographic Atrophy. This is important to note.
We were concerned that with the higher age and higher BMI of patients that have GA versus Stargardt disease, we would have to do a dose higher than 5 milligram. We did a PK/PD study with both 5 milligram and 10 milligram, and what we found was a 5-milligram dose produces the same pharmacodynamic profile as it did in younger subjects. In these healthy adults, we're seeing about a 80% reduction of RBP4 across the dosing period with this 5-milligram dose. It's also important to note, and we see this in the adolescent subjects as well, once you withdraw the treatment, the RBP4 levels start bounding back upward, showing a nice reversibility of the pharmacodynamic effect, which of course is a nice safety feature in the event of any untoward AE, or you want to return the patient back to baseline status.
Sorry about that. Now, a little bit about the clinical design overview for our phase III study we call PHOENIX. This study design is going to be nearly identical to the phase III trial design for Stargardt's. That is, it's 2 years in duration. It has the same randomization frequency, 2- 1 favoring Tinlarebant. It has the same endpoint measures, we're still looking at the same DDAF measure as a primary measure for efficacy. Of course, we're looking at other measures such as BCVA and looking at the autofluorescence. There are 2 major differences. One, of course, is the indication, Geographic Atrophy, not Stargardt's. The second one is that we'll be enrolling up to 430 subjects instead of the 90 that we targeted for the Stargardt disease study. This, of course, reflects the higher prevalence of GA in the population.
Otherwise, these studies are essentially identical, and I think Tom mentioned that we've actually kicked off this study. We've enrolled our first patient, I believe it was last week, and we continue to get more interest and more patients rolling into this phase III study as we move forward. With that, I believe I can turn it back to Haoyuan so he can discuss the 2023 Q2 financial results. Thank you.
Thank you, Nathan. As of June 30, 2023, we have $57.4 million in cash. For the R&D expenses for the three-month ended June 30, we had research and development expenses that was about $5.5 million, compared to $1.6 million for the same period last year. The increase was mainly due to the expense on the PHOENIX trial and also the increase on the wage and salary due to our R&D team expansion. For the G&A expenses, again, in Q2, we had G&A expenses $1.4 million compared to $0.9 million for the same period last year. The increase is due to the increase in professional service fee and also the wage and salaries. The net loss...
was $6.8 million this quarter, compared to $2.4 million last year for the same quarter. About the key milestone, as Tom mentioned earlier, we initiate the study, this Q1, and we just got the first patient in this quarter. We also fully complete enrollment for the DRAGON study with 100 subjects so far, and we expect to have the 24-month data by Q4 this year. Also, we expect to have the interim result from the phase III DRAGON study in Stargardt disease by mid-next year. With that, I'll turn it back to Sarah.
Thank you. At this time, we will begin conducting our Q&A session. For those analysts that are in the Zoom with us, please raise your hand to indicate you would like to ask a question. For those on the webcast, as a reminder, if you are in full screen mode, you may need to exit it in order to see the Q&A portal. With that, I'm gonna open it up for questions from our first analyst, which is Basma Radwan from Leerink. Basma, you may go ahead and unmute your line.
Hi, good afternoon. This is Basma on for Marc Goodman. We have a few questions on the upcoming final readout of the phase II trial in Stargardt disease. The first question is, really, what should we expect in terms of the efficacy at month 24? More specifically, I'm talking about the reduction of the DDAF lesion growth rate. Should we expect a similar level of reduction in the lesion growth rate to the level demonstrated at month 18, which is a 50% reduction, when you compare it to the matched controls from the ProgStar study? The second question, it's about the conversion from the QDAF lesion to the DDAF lesions. At month 18, 5 out of 12 patients on lumigan had DDAF lesions, versus 9 out of 20 patients in the ProgStar study.
What changes to this proportion should we expect at month 24? The final question is about any updates you have about dropout in the study. Do we still expect 12 patients for the, for the time point at month 24? I do have a follow-up question for the phase III DRAGON study, if you don't mind.
Sure. Nathan, you wanna take this?
Yeah, I'd be happy to, if Hao-Yuan can go exactly, yeah, exactly go here. The first question related to what we expect to see at 24 months. If you follow these trajectories, particularly for the DDAF, basically you're gonna see the same thing. Basically, the lines will continue to sort of track the same way, so we'll get at least a 50% reduction. We already know what the 24-month data look like in ProgStar, so it's gonna go a little bit higher than where it is, where it is now. Of course, our DDAF will inflect upwards a little bit as well. But this study is going to end in October, so basically, you know, 2.5 months from now.
I don't expect that there's gonna be any significant change from these trajectories over the next 2-3 months. I think what you're seeing here is a very good snapshot of what you can expect to see at 24 months. In terms of the numbers, numbers of subjects, I don't expect we'll lose any additional subjects. Again, we lost 1 out of 13 when we first started due to l- a lost to follow-up at 12 months. No one has left because of any safety or AE concerns, so don't have any real concern about that. Your other question was relating to the conversion from autofluorescent lesion to the atrophic retinal lesion, I expect that probably by 18 months, we- sorry, by, by 24 months, we should see at least 2 more subjects convert.
That's based upon the sort of, sort of run rate that we're going. There will be a significant percentage difference, numerical difference in the percentage of subjects in ProgStar that converted versus the number of subjects in our study that's converted. Our study will show a lower number, which again, is consistent with our hypothesis and our MOA, that reducing the autofluorescence will then slow the transitioning of the autofluorescent lesion to the atrophic retinal lesion. I think I addressed all three points, Basma, but please let me know if I missed anything.
Thank you. That was very helpful. The one question we have about the Phase 3 DRAGON study, it's about the inclusion criteria. You do specify in the, in the inclusion criteria, lesion size, to be within 3 disc areas. Could you provide more color on the rationale behind this inclusion criterion, really?
Yeah. This, this goes to our approach for early intervention. I've, I've done number, a number of studies in Stargardt disease and geographic atrophy, and one thing I've consistently seen. By the way, all of the studies I've done on these diseases have been with oral therapeutics and either visual cycle modulators or RBP4 antagonists to sort of mediate the effect. What I've seen consistently in these studies is that lesions that are smaller at baseline tend to respond better to these types of therapeutic approaches. That's even been shown in natural history studies, where you look at growth rate of lesions that are small versus large. You do tend to see faster lesion growth rates in lesions that are smaller, then they tend to sort of slow down as they get large.
The term I'm using, large and small, of course, is ambiguous, but when I say small lesions, I'm talking about lesions that are less than, for instance, five millimeters square, and certainly nothing bigger than 10 millimeters square. Anything bigger than 10 millimeters square is what I consider too large. In fact, that's where inflammation starts kicking in. It's important to know sort of the chronology of the pathology. Early in the disease course, there's very little inflammation, so when these early lesions, Hao-Yuan, could you go to the lesion comparison, the QDAF and DDAF? Yes, here. These QDAF lesions that you're seeing here are really the first lesions that are actually going to convert, right? Turn into the atrophic retinal lesion.
Once the lesion, if you look at the left-hand, right-hand side right now, once that atrophic lesion gets too large, there's nothing you can do to slow it down. The reason that we're specifying less than 3 disc areas is, again, based upon all the prior clinical studies that I've done, and natural history studies in both GA and Stargardt's, that show that smaller lesions respond better to treatment. A sort of a real-world evidence for that is data from the Emixustat study. This is a study conducted by Kubota Pharmaceuticals, or maybe even called Kubota Vision, formerly Acucela Pharmaceuticals, is what it was. They were advancing a drug called Emixustat, which is an RPE65 inhibitor, intended to do the same thing that we're doing, which is reduce the bisretinoids.
In fact, it worked very well in animal models, but it's a very aggressive approach because it, it hits an enzyme of the visual cycle that's the rate-limiting enzyme. Anyway, they ran a phase III study with 194 Stargardt subjects, and they didn't reach their endpoint at two years. In a post hoc analysis, what they found was that patients who came in with smaller lesions at baseline had as much as a 40% slowing of lesion growth. That's a very, very important note for us, particularly in Stargardt disease, because that's exactly what we're doing, is we're recruiting subjects with smaller lesions at baseline. We believe all this clinical evidence and scientific evidence tells us we're doing the right thing for these, for these kids.
Again, early intervention is the best way to stop these emerging retinal lesions that will eventually affect vision.
Great. Thank you. That's very helpful.
Yes. Thank you.
Thank you for the questions, Basma. The next question comes from Jennifer Kim at Cantor.
Hi. Thanks for taking my questions. Congrats on the execution this quarter. Maybe to start off with DRAGON, I believe the original announcement for enrollment completion highlighted 90 adolescent patients, and here it says 100 subjects. I was wondering, maybe you could provide any color around that difference?
Yeah, I'd love to do that, if I could. I just-
Yeah.
I'm sure that was going to come up, it's important to note that when we, when we stopped the enrollment at sites, there were a number of subjects in the screening queue. We can't just turn those subjects away. Basically, we-- although we stopped accepting new patients, the patients that were in the queue, which amounted to roughly, I think it was about 20 patients in the queue, went through screening, and of those subjects, approximately 10 qualified for study. That's why we went from our target of 90 to approximately 100 subjects to date.
Okay, wonderful. A follow-up. For DRAGON, prior to the interim data next year, are you considering at all disclosing, like, the baseline characteristics for these patients?
Paul?
Yeah. It's right now, we, we, we do wanna present that, that data, but it's a discussion with the DSMB and, and with FDA. Right now, we're still in discussion, but I think this is a discussion when it comes closer to the date.
Okay, great. Then maybe, just as we're thinking about the October 24-month data, are you thinking of a, a venue for presentation?
Yes. In fact, we are looking forward to presenting this data at AAO this year. The 24-month data readout, which coincides with the AAO conference, by end of the year. I think that's in early November.
Okay. Maybe one just in GA, more of a broad question. With safety becoming even more of a focus, given the concerns with Syfovre, I'm just wondering, how does that play into your thinking around the opportunity for an oral once daily?
Yes, good question. We are talking about a quite elderly population in AMD, with GA. I guess, again, a oral treatment, a non-invasive treatment is always much more attractive and those that are concerned with the safety and with now given, given, the recent news of Apellis. I think in this elderly population, I think, invasive intravitreal injection is always gonna be an issue for patients that either want to take the treatment, and I would say, quite some majority of those elderly patients would, would not want a needle in the eye. Nathan, you want to add more color to this?
No, I think, you know, there's a, there's clearly a treatment burden for the patient with an injectable therapeutic. That the fact is that there's not gonna be a clinically meaningful benefit derived by the patient for at least two years, perhaps longer. The same could be said with an oral therapeutic, but there's less of a treatment burden for the patient. I think when offered the option between oral and an injectable, obviously the patient is gonna choose the oral, so there'll be a greater uptake for an oral therapeutic. With respect to AEs, such as the retinal vasculitis that have been observed, or vasculitis, as they call it, in the eye.
This is, even though a rare finding, these are the risk factors associated with injections in the eye, and there will be others. There's, there's inflammation, there's all types of things that can happen when you puncture, you know, an eyeball with a needle, and you have to do it repeatedly every other month or every third month, whatever it is. This is a very aggressive, invasive treatment therapy. Like, we believe, you know, once an oral therapeutic is, is approved, I think patients will flock to it, and that will certainly detract from the uptake of either of Apellis' drug or the Astellas/Iveric drug that just recently got approved. We're not too concerned about the injectable therapeutics.
I do want to emphasize, as I said before, those therapeutics address late-stage disease because actually what they're doing is they're quelling an inflammatory response that's driving the disease process. Early in the disease course, there's no inflammation, either in Stargardt disease or in GA. You just have these incipient biomolecules or factors that are causing sort of retinal pathology, but there's no inflammation yet. Inflammation only kicks in later. Those therapeutics, those injectables, would not be effective in our patient population. Conversely, our therapeutic would be expected to be beneficial in that later stage, sort of as a maintenance therapy for patients who are sort of getting treatment, and they need to sort of keep the Geographic Atrophy at bay.
We think there's a, there's synergy rather than competition, and we're certainly not concerned about any safety concerns that they have because we don't think they're gonna affect what we have in terms of an oral therapeutic. Which to date, has shown to be very safe and well-tolerated in these adolescent Stargardt subjects.
Got it. That's helpful. Thanks, guys.
Yep. Thanks, Jennifer.
Thank you for the questions. The next question comes from Yi Chen at H.C. Wainwright.
Thank you for taking my questions. You just talked about the, the AE as associated with Apellis drugs. Just to clarify, you believe that the retinal vasculitis is associated with injection, but not the drug itself, you know, in terms of the mechanism of action or complement inhibitors?
It could be a combination of both, Yi. I, I was just saying that in other studies. For instance, when they first started developing the first anti-VEGF drugs, they had, I believe at that time it was Macugen, they had things like this as well. It wasn't necessarily attributed to the drug. It was attributed to the procedure. Yes, it is possible that the drug in itself could cause that. But that, I think that's a rare possibility because it didn't occur, I don't think, in their phase three study. Again, you know, once you start getting real-world evidence for how this drug is gonna be applied, you'll start unearthing some of these potential risks. You know, these are, you know, not manageable risks.
These are very serious concerns where patients are losing vision, even though it's a small number of patients. Yes, it could be aided by the drug, but I believe more about the actual intervention itself. That's just my personal belief.
All right.
Yi, I believe the one of the causes of retinal vasculitis is infection and inflammation and neovascularization. All of that can be associated with intravitreal injections or invasive treatment that causes that.
It is reasonable to expect the newly approved Izervay may have those, AE as well, I mean, when it's commercialized, right?
Very possible.
Uh-
I would predict yes. Yeah.
Okay. Thank you.
Okay. Thank you for the questions. The next question comes from Bruce Jackson at Benchmark.
Hi, thank you for taking my questions. You mentioned the increase in the study size for the DRAGON trial. Originally, you put it up to 90 patients in order to improve the probability of, of getting an efficacy signal. Now that you're at 100, has that increased your confidence that we're gonna get an efficacy signal on the results?
Yeah, I can take that.
Yeah. Yeah, yeah. It's not really about- we, we always believed that we would be getting an efficacy signal since the 6-month data, right? In the Stargardt open label phase II study, we have seen positive data at every 6-month interim analysis, now out to 18 months. It's not so much about changing the, the, the, the treatment effect size, it's about increasing the power, that is, the, the, the confidence and probability that that effect will be durable through 2 years. Yes, that additional 10 subjects does give us an additional buffer for that power. It doesn't necessarily mean we're gonna get greater treatment effect or greater statistical significance at end of study, but we'll have greater power to say that that is a true, bona fide, robust result. Because, again, there's more patients showing that treatment effect.
It's more about the power than it is rather the treatment effect size.
Okay. That's helpful.
Bruce, to add on that, so, we ran the simulations and all that, so with the added sample size onto the study, and now given that we, we, we've gone up to 100, I think that gives us a better chance of getting a positive, or a statistical significance at interim. That gives us a, a better chance of reaching that.
Okay, great. One finance question I thought I'd throw 1 in. In terms of your cash balance and your burn rate, how many quarters of cash do you have right now?
Yes. Thank you, Bruce. We do expect that we have cash burn rate to end of 2025 with the current rates.
All right. perfect. Thank you very much.
Thank you.
Okay, this concludes the verbal portion of the Q&A session. Hao-Yuan, do we have any questions for the webcast, or should we hand it back to Tom for concluding remarks?
No, I don't have any questions here. You can turn it back to Tom. Thank you.
Okay. Well, thanks, everyone, for joining this call, and, we look forward to updating everyone on our end of phase II results shortly. Thank you very much.