Conference Transcript - SRZN 2026-09-16

Operator

Hello, everyone, and welcome to today's Fireside Chat with the management team of Surosin. Would you two like to briefly introduce yourselves before we get started with questions? Sure.

Dan Chow, Other

I'm Craig Parker. I'm the CEO at Surosin. And I'm Dan Chow, Vice President and Head of Clinical Development.

Operator

Great. Thank you so much for joining us here today. Anyway, to kick things off, Sorosin is pioneering a new class of Wnt-based therapeutics aimed at some of the largest, most persistent unmet needs in eye disease, with a lead candidate now approaching the clinic in diabetic macular edema. As you sit here today, how do you frame the opportunity in front of the company, and what are you most excited about?

Craig Parker, CEO

Yeah, so this is a really momentous year and great time for the company. we just filed an IND to start our first clinical trial with SCN 8141. The excitement about the molecule is about bringing together two mechanisms in one molecule to treat retinolvascular diseases. One is anti-VEGF. This is a well-established therapy. It really has been a phenomenal, I think, breakthrough for patients with retinolvascular diseases, but it doesn't provide complete control for all patients. And so we started off as a Wnt biology company, and it turns out that Wnt has been implicated in normal function of retinal vessels. And one of our competitors has shown some clinical data validating the approach of activating the Wnt pathway for retinal vascular diseases. And so I think we're really excitingly bringing together what we think are the two best mechanisms for treating these diseases into one molecule. Dan and our clinical development team have designed a study we've called DUET, which we think has the opportunity to really reveal what could be a best-in-category or best-in-disease even control of fluid accumulation in these patients, potentially visual acuity, and potentially something which could really be breakthrough of reperfusing the retina in patients who have diabetic eye disease in particular. So really, it's a pretty unique moment for the company, and I think an exciting time for particularly the clinical development team to get this molecule into patients.

Operator

Fantastic. Your platform rests on SWAP technology, bispecific antibodies that mimic natural Wnt proteins and activate the pathway selectively in diseased tissue. For investors newer to the science, how do you explain why modulating Wnt signaling is a fundamentally different way to treat retinal disease than today's mono-antivegist approach?

Craig Parker, CEO

So I'll let Dan answer that.

Dan Chow, Other

Yeah, sure. Thanks, Greg. I think when we think of the Wnt pathway, I think, first of all, the Wnt pathway is a very ancient and conservative pathway important in many organ systems for regulation and repair, and that is no different than in the eye and in particular the retinal vasculature. It's been known for a very long time that these Wnt proteins are important for both the development of the normal vasculature as well as maintenance of the blood retina barrier and in fact there is actually human genetic evidence that some of the key proteins such as the Wnt receptors frizzled for an LRP5 are actually linked to human disease where there's incomplete development of the retinal vasculature. And so this leads to a really, I think, complementary approach as we think of anti-VEGF. Now, vascular endothelial growth factor is a pathologic cytokine in the context of diabetic macular edema, which causes leakage, so kind of a pro-pathogenic cytokine, whereas Wnt we think of as more a restorative, reparative pathway, where we know that the Wnt pathway is important for upregulating tight junctions of proteins which are important for repair of the blood retina barrier. So in fact, we think we're attacking this through very complementary mechanisms compared to anti-VEGF where we're preventing leakage and with Wnt, it's really more restorative, reparative pathway. And we think that combining these two then leads to additive and even synergistic effects and control of disease.

Operator

That's great. SVN8141, your lead candidate, pairs fizzle-pore agonism with VEGF antagonism for diabetic macular edema in what AMD is expected to begin initial clinical development in the DUET study mentioned by year-end. Can you tell us more about the rationale for this combo and how you expect it to differentiate from mono-VEGF in the clinic?

Dan Chow, Other

Yeah, absolutely. So I think part of it is highlighting some of the data that Craig had mentioned. First, I think there's strong scientific rationale for targeting the Wnt pathway as a restorative pathway. And in fact, a lot of preclinical data, including our own, shows that activating the WIT-ceiling pathway can show actually strong efficacy in a number of preclinical retinovascular disease models. And in particular, I think the recent phase 1-2 data from first generation WIT agonist restorative showed very robust increases in BCVA and CST that are comparable to VEGF, and that level of efficacy has not been seen outside of a non-VEGF mechanism. And so on the surface, the idea of putting together the two strongest mechanisms within disease, VEGF and Wnt, could have the potential to lead to better therapies beyond the standard of care. I think the next piece of evidence is what is the evidence that actually Wnt and VEGF are actually additive and not overlapping. And I think that comes from our preclinical data where we've shown that when we compared our molecule, the SCN8141 dual molecule, versus a molecule where we've either inactivated the Wnt part of the molecule or the VEGF part of the pathway, or even a co-formulation of the two is that our SCN8141 combination molecule shows superior efficacy compared to all those. So it suggests not only additive efficacy but potential also synergistic efficacy. In a different preclinical model, in a wet AMD model, we've also shown that SCN8141 was superior to a fliburcept or ILEA in reducing leakage, again showing the additive benefit of these two pathways. And so then we've now designed a DUET trial then to test and confirm whether these preclinical results translate into humans.

Craig Parker, CEO

And it's probably worth mentioning, The outcome measurements in these studies will allow us to detect whether we have significant clinical benefit, not statistically significant, it's not powered for that, but whether there's meaningful clinical benefit on the kinds of endpoints that you would be looking at in a phase three trial. So these are visual acuity, these are fluid accumulation measured through something called OCT imaging, and we can even measure through some other types of imaging modalities whether that we have this effect of reperfusing these areas of non-perfusion in the retina. And, of course, safety is a critical endpoint in any early clinical trial. So the study has been designed to really try to capture these elements that could be differentiating for the molecule.

Operator

Thank you. Rather than combining two individual monotherapeutics, you've decided to combine your two targets into one. Can you tell us a little bit more about the approach for using a bispecific rather than two different molecules and the advantages you think that could convey for cirrhosis?

Craig Parker, CEO

Yeah, so maybe I'll let Dan expand a little bit on those comments about what we've seen preclinically. There is synergy in combining them into one molecule, and so I think there's a scientific rationale for doing that and a really compelling one. There's also just the, I think, some patient convenience issues associated with trying to do separate injections as well as reimbursement issues. So, you know, for example, if one were to show that, you know, a Wnt agonist alone was very effective and safe, why wouldn't you combine that with an existing anti-VEGF therapy? And I think, and Dan's a retinal specialist, I think, you know, a retinal specialist would tell you their patients would not like to get two injections. There are some volume limitations around getting two injections at the same time, and I think it would be very challenging to get reimbursed for using two therapies that would probably be roughly equally priced at the same time. So I think there are other reasons, but there are also really compelling scientific reasons that Dan can expand on a little bit.

Dan Chow, Other

Yeah, I mean, I think just to add on, again, I think what we notice is that in the preclinical models, not just additive effects, but the synergistic effects, suggesting that I think bringing these two mechanisms in close proximity could show stronger effects than, again, the co-formulation.

Operator

Okay, thank you. Now, I know you touched on this a little bit before earlier, but it'd be great to hear more about the DUET study design. It looks like you're taking SCN 8141 head-to-head against WSMO in roughly 60 treatment-naive patients. Can you tell us a little bit more about how you designed this trial and what you're hoping to see out of it?

Dan Chow, Other

Yeah, absolutely. So our DUET study is divided into two parts. The first part is a first-in-human dose-descending phase. And so participants will receive a single injection, and then they'll be observed for three months in ascending dose. We would obviously start with lower doses, and if safety permits, we would then escalate to the top dose. This would be open label. And our study is being performed in both parts in DME, and in this first part, the majority of these patients will likely have had previous VEGF or other treatments for DME. I think the main purposes of these two parts is to determine initial safety as well as the two doses that we'd like to take into the part two. We'd obviously get some initial efficacy data after single injection as well. And then that would transition to the part two portion, which is our randomized dose expansion with comparator. And so we would have three arms in this study, two dosing levels of SCN8141, randomized one-to-one compared to Babismo at the labeled dose. All three of these groups would be given three monthly injections of the drug and then observed for four months. And that dosing regimen is typical of a common clinical dosing regimen that one would see in clinical practice. The main endpoint for all of these, again, is safety and tolerability. And the second part, again, as was mentioned, is about 60 patients total, so about 20 patients per arm. And so from an efficacy standpoint, it is not statistically powered to show statistical differences. However, we do think we can get meaningful, robust, directional data on a number of endpoints, such as best corrected visual acuity, fluid and OCT metrics, as also other measures related to retinal non-perfusion. And I think in particular what we've designed this study is hopefully to show in the second part is, again, how does SEN81 compare to a contemporary standard of care? And we think there are, I think, three ways of differentiation. that we would like to see for the molecule. One, I think, is related to anatomic control or drying. And we think that this is a reasonable number of patients to see directionally to compare Babismo compared to SCN8141. The second is also an early look at the durability of the effect. As I mentioned, we will be observing these patients four months without treatment after the three-monthly doses. And the third part is also related to this idea of retinal non-perfusion, is whether SCN8141 could help to reverse retinal non-perfusion, looking at some of these exploratory endpoints.

Craig Parker, CEO

You know, I think for people who don't follow, you know, retinal vascular diseases and clinical development there, you know, it's important to highlight that the drugs that have been developed for retinal vascular diseases have a very rapid effect. And so I think one can get a pretty good idea about clinical benefit, like probably literally within days, but certainly within weeks. And at 12 weeks, I think you'll have a pretty good indicator about what the ultimate efficacy of the drug can be in a relatively small study. And so for those of us in the industry and for investors, I think it's a really attractive therapeutic area because of the opportunity to see clinical benefit really early and in a relatively small sample size have a pretty good idea about ultimately what the efficacy is going to look like.

Dan Chow, Other

And maybe one thing just to fall back on, and again, for those that are not familiar, is like, you know, what are really the key unmet needs in DME? And I think we've tried to address that actually with our three points of differentiation. I think number one is better anatomic control. With our current standard of care, not all patients respond. In fact, you know, there are numbers from studies is that about 40% are suboptimal responders to our current therapy based on anatomical measures. And so agents which can improve drying is certainly a big unmet need. The second is durability and reducing treatment burden. You know, I think current patients need to receive these injections as frequently as monthly, and so I think that's kind of a very clear value proposition. And then the third part is then, again, addressing this retinal non-perfusion, which is known as a clear driver of diabetic retinopathy, and we know our current treatments, our current anti-VEGFs, do not reverse this non-perfusion. So the potential to be able to revascularize or perhaps disease-modifying the effect is also something of high interest in the field.

Operator

Great, thank you. The next area I'd like to talk about is your second candidate, SCN8143, which layers in IL-6 antagonism on top of the two targets from 8141 to reach uveatic macular edema alongside DME and YAMD. How does a triple mechanism broaden the franchise, and how do you differentiate the two programs?

Craig Parker, CEO

You want to start on that one?

Dan Chow, Other

Sure. I think one thing, I think in the field of retinal vascular disease, I think IL-6 has also been established as a key mediator of disease, and now there are a number of programs looking both at kind of IL-6 inhibition as a monotherapy or in combination and have shown some interesting results. And so I think the strategy there is that IL-6, again, is more on an inflammatory axis. And, again, that could cover another, I think, circle of the Venn diagram of retinal vascular diseases that may or may not be addressed by the other two. And so I think we're very excited about the molecule that we've created and its potential in retinolvascular diseases?

Craig Parker, CEO

I mean, a foundation of our approach broadly, and it's very much true for 8143 and 8141, is these are diseases that we know have multiple contributors to the pathology of disease. And so while anti-VEGF therapy is very effective, I think the biology and biomarker studies and then studies with some of these other monotherapy agents have shown that there are these multiple contributors to the disease pathology. And so I think, you know, you'll hear at retinal conferences more and more people talk about multifunctional antibodies because of this growing evidence that there are these multiple contributors to the disease. So, you know, we think it just makes sense for these disease entities with multiple contributors to try to go after multiple pathways within one molecule. And as Dan said, now there's, you know, growing evidence that IL-6 is an important contributor to certain patients with macular edema. There's a related inflammatory-driven disease called uveatic macular edema where IL-6 has been shown clearly to be a contributor to that. So that's sort of a natural fit for 8143. And then how they fit together with each other, I think, is, you know, 8141 is ahead of 8143. I think we don't have to make decisions early. We have the opportunity to look at evolving data from others to see what the clinical data with 8141 looks like and to really not have to decide on the relative positioning until we have a lot more information. But ultimately, it could be that going after all three of those pathways is the best for every retinal vascular disease. And if that's the way the landscape and our own data evolves, I think that's great for us.

Operator

Okay, thank you. The markets you're targeting are all large and continue to grow. So, like you said, anti-VEGFs still leave considerable unmet need for these populations. How do you think about the areas where your therapeutics could be most helpful in the current therapeutic landscape?

Craig Parker, CEO

Yeah, so as you said, these are highly prevalent diseases. If you include wet AMD and diabetic macular edema and some of these other related diseases like uvetic macular edema, You know, the current market for the anti-VEGF agents today is about $15 billion globally. You know, don't have to tell anyone who's a health care investor that, you know, the population is aging. And for the most part, these are age-related diseases. And so that's currently going to be a growing market. You know, so our opportunity is really large. You know, Dan's alluded to differentiation. differentiation, you know, the most recently launched drug, and now also I think it's market leader for, I don't know if it's true for both wet AMD and DME, but certainly for one of those is Vibismo. And that product, I think, showed you how differentiation can translate to very rapid adoption by retinal specialists. So they showed somewhat better drying on a secondary endpoint in phase three trials, you know, and that led to very rapid adoption because I think retinal specialists are like they're treating to fluid. They can visualize it very clearly with this OCT imaging. It's all part of normal clinical practice. And I think there are certainly opportunities to be the best agent for drawing for some of these areas like retinal non-perfusion for durability. It could be that you hit all of those with this molecule with 8141. So, again, really large growing markets with very clear evidence that retinal specialists are very quick to adopt products that have some differentiation. That makes sense. Thank you.

Operator

On the IP front, we recently saw some news that the Patent Trial and Appeal Board recently declined to institute Merck's post-grant review of one of your core patents. Can you tell us a little bit more about the IP situation there and how it relates to your own product portfolio?

Craig Parker, CEO

Yes, so we have what we think is a broad issued patent for these swap-like molecules that are frizzled binders and LRP-5 or 6 binders. Merck filed an opposition to that called the Post-Grant Review. People can find those documents online at the USPTO website. Ultimately, what's called the Patent Trial and Appeals Board chose not to institute that. When they make that decision, it's based on the low likelihood that they would win that opposition. So right now, one has to institute this PGR, or at least file for it, within nine months of the patent issuing. That's long past now. So there isn't an opportunity for anyone else to challenge that patent through a post-grant review process. So we feel like we are discoverers of this technology. The company was started around this technology and went agonism, and we have a broad-issued patent for this general approach and format of antibodies or antibody-like molecules that bind frizzle and LRP molecules.

Operator

Great. And then beyond just the retinolvascular programs, I understand you also have earlier research on corneal endothelial disease. in RPE and photoreceptor protection, where you pointed to Wnt's relevance, including conditions like Fuchs endothelial coronaryl dystrophy. How should investors think about the potential opportunity in some of these other disease spaces?

Craig Parker, CEO

Yeah, so Dan can elaborate on, I think, this disease called Fuchs endothelial dystrophy and some of the other opportunities. The biology behind this is related to the Wnt pathway again. So we know that the Wnt pathway is involved in preservation of some of these cell types, in some cases differentiation of some of these cell types. Actually, Wnt has been implicated or demonstrated in other actually lower species to be involved in differentiation of different cell types into photoreceptors. So that's some potential relevance for disease like geographic atrophy. So fundamentally, the Wnt pathway is important in many of the cell types. in the eye, so there is a pretty rich opportunity set just in ophthalmology for pursuing molecules that can modulate the Wnt pathway. Some of those cell types include cells in the cornea, so I'll let Dan describe that and what the disease is and what the opportunity is there.

Dan Chow, Other

Yeah, we think this is a particularly interesting one. It's a disease called Fuchs corneal endothelial dystrophy, and what it is, the cornea, again, is the front of the eye, the clear part of the eye. You can think of it as a window, And at the back end of that is a monolayer of cells called endothelial cells, which are there essentially to dehydrate and pump out materials to keep that clear. So in the absence or dysfunction of these corneal endothelial cells, essentially the cornea gets steamy and you can't see. Just imagine you're in the shower and imagine that's every day of your life. And one of the diseases is this Fuchs corneal endothelial dystrophy, which is kind of a native disease, an age-related corneal endothelial degeneration. Now, there are other ways to have corneal endothelial dysfunction. Like, for instance, after surgery, you also lose these endothelial cells. And currently, the treatment for corneal edema is surgery to essentially transplant and replace those endothelial cells. That is quite effective, but you can imagine that's limited both by donor tissue as well as risk benefits of going into surgery. and I think what we've shown is some really interesting science showing the Wnt pathway being important for proliferation of these corneal endothelial cells and so you can imagine say what if you had a drug that you could inject in the front or in the back of the eye that could endogenously regenerate these endothelial cells and clear the cornea and I think we have some interesting preclinical data to suggest that's possible through manipulation of the Wnt pathway and I think represents a very interesting opportunity that we're looking into.

Craig Parker, CEO

So we have a candidate-ready molecule actually right now. We don't have, we're not, we're very well financed to run clinical trials for 8141 and 8143, but not so, not as much for SCN113 is the designation for this molecule for Fuchs dystrophy. So that's really just limited by capital at this point, but I think really compelling animal models of corneal injury combined with all of the kinds of biophysical characterizations that you do for the molecule itself to prepare it for further development and it's ready to go right now.

Operator

Alright, great. Looking forward to seeing more of that in the future. Speaking of the future, finally, for investors just getting to know this story, what does Therosen's success look like over the next 12 to 8 months and what are the key milestones you think people should be paying attention to?

Craig Parker, CEO

Yeah, so I'll talk a little bit about some of the, you know, development milestones and financial milestones. You know, we filed our IND, I think, eight or nine days ago. We did a pipe financing in March of 2025. The second tranche of $95 million of that is due when our IND is open. So we would hope for that to, you know, happen quite soon. That's what would adequately finance us through clinical trials for the first two molecules. Dan mentioned Restorate, which is a Merck molecule. It's not being called Restorate anymore, MK3000, or Remig-Gromig, I think is the molecule name. There's phase three data for that forthcoming. It's actually scheduled to be presented at the American Academy of Ophthalmology on October 10th. There may be a press release before that. That's a Wnt-only molecule. Remember, our molecule in A141 is Wnt agonism combined with VEGF antagonism. But that could be really important validation that the Wnt pathway alone has benefit that could be VEGF-like. Again, that would be really supportive of our thesis of combining these two best pathways. So that's relatively near-term. And then, you know, what we've said is we'll be treating patients by the end of this year and have data, our own data, in the second half of 2027. So obviously that's a critical milestone for the company is to generate our own safety and potentially efficacy data in 2027, nominate 8143, and get that moving into the clinic as well. So those are some of the questions.

Operator

Fantastic. A lot to look forward to. Well, great. Thank you so much for joining us here today. Thanks for having us.