Good morning, everybody. Thank you all for joining with us today at the TD Cowen 46th Annual Health Care Conference. My name is Athena Chin. I'm here as on behalf of the biotech team. I'm pleased to introduce Rob Barrow, CEO of Definium, who will be presenting on their company developing treatments for psychiatric disorders. Rob, please take it away.
All right. Thanks so much, Athena. All right. Definium Therapeutics, lead program in the clinic, DT120, is a proprietary form of LSD that we're developing in two of the biggest market indications in generalized anxiety disorder, major depressive disorder. We're in an incredibly exciting year. We've got three pivotal studies reading out across the course of 2026 and building on some really exciting data from phase II that we presented in 2024 initially and published last September in JAMA. When we talk about the market opportunity for these indications, a lot of times we don't have to tell anyone how bad the problem is. There are tens of millions of people with anxiety and depression in the U.S.
It is growing at mid-single-digit rates, which means every single year we're adding millions of people to the tally. The drugs we have, the mechanisms are old. The last real shift we've seen in psychiatry really in a, in a class-wide kind of way was 30 years ago with the introductions of SRIs. We see those drugs, while they help many patients, for the majority, they do not. Patients cycle through them rapidly. They have untolerable side effects. With some of the newer innovations, there's been some heightened focus on intranasal esketamine, which is growing pretty rapidly in adoption. Even there, the burden, the tolerability, and the efficacy are all marginal in the context of what patients and providers are really asking for.
We think there's an extraordinary opportunity to really have an entire change in the field and one that psychiatry has been asking for and that we hope to be able to deliver on. The two indications that as I mentioned, that we're going after are generalized anxiety disorder, which we had the phase II data on, and we launched shortly thereafter a pivotal program in major depressive disorder. Together, 50 million patients with these two diagnoses, the vast majority of whom are underserved by current treatments.
We also in the last year, launched a phase II study, an early signs of efficacy study in autism spectrum disorder with our second program, DT402, or the R enantiomer of MDMA, which we're looking at very differently, not as a sort of acute intervention with a long-lasting effect, but rather a normal sort of recurrent dosing model that would be more akin to how psychostimulants are used in treating ADHD, where the direct agonism, the direct activity of the drug drives an acute functional effect that represents the deficit in autism. With pivotal data coming for DT120 though, a lot of focus, of course, there. To summarize briefly, phase II data, almost every way we looked at it, we saw effects that were double or better the current standards of care.
We saw a standardized effect size, a Cohen's d of 0.81, which all of the approved drug classes show less than 0.4, 0.36, 0.38. We saw rapid change that was detectable on overall severity within 24 hours after single administration. This is a single administration of DT120 with no other psychotherapeutic interventions. There's been historically a discussion about assisted therapy or assisted psychotherapy alongside of these drugs. We took the approach going into phase II that in order to have a scalable product, we needed to look at the drug effects on their own. We're really encouraged by the robustness of those data in spite of the fact that we uniquely had removed that at the time.
Those effects were durable, so we saw almost 22, a 21.9 point improvement on the Hamilton Anxiety Rating Scale. That was 12 weeks after a single administration. It was statistically significant. I should say these results are all for the 100 microgram dose, though we'll talk in a second about the dose response and some of the interesting learnings there. We saw a 48% remission rate. So of every two patients that walked in the door, effectively one of them 12 weeks later was in clinical remission. All of those data are unprecedented in treating GAD and very similarly in treating MDD, where we saw a similar response pattern, similar magnitude of effect in depressive symptoms as measured on the MADRS.
In the context of currently approved therapies, we see really marginal efficacy under 4 points. The best data we have from approved therapies shows a 4-point magnitude of change versus placebo across multiple studies. There are some studies that are slightly higher than that, but the vast majority of SRIs show less than a 4-point change and often less than a 3-point change versus placebo on the Hamilton Anxiety Scale, where we saw a 7.7 unit change. The 21.9 point improvement was in excess of an extraordinarily large placebo response of 14.2 units, which is larger magnitude than the actual active drugs in most of the approved studies. The response pattern was also incredibly encouraging.
Again, on anxiety symptoms as measured by the HAM-A and on depression symptoms as measured on the MADRS, we saw this acute response as early as it can be measured that was durable for the entirety of the 12 weeks, and that didn't show any sort of reversion back to baseline. We weren't apparently losing effects on average when we got out to the 12-week time point. Now we stopped following patients at 12 weeks in phase II and have a much longer follow-up in phase III with opportunities for open-label retreatment. If these data were to hold, it would suggest that the durability is even perhaps beyond 12 weeks, which we'll of course be able to assess in the pivotal studies.
To contextualize this as well, there's been so much focus on the MADRS, many people are more familiar with that scale. Hamilton Anxiety Scale is one that involves many different body systems, many different domains. It includes both psychological and somatic changes that represent a high degree of disability in these patients. Patients in our study came in with an average HAMA of around 30 points at baseline, which is quite severe. We look at median changes. The average patient, how were they at the end of those 12 weeks? They went from being in the severe or very severe category on average down to being borderline in remission or the mildest category of the disorder. Just contextualizing the actual impact on these patients is extraordinary.
We hear this in qualitative research in some of the reports from patients in our phase II studies, just about both the magnitude and the significance of the change that they experience after receiving DT120. I mentioned before we did a dose-response study. Uniquely in the field, there's often an assumption that the perceptual effects that a dose that is perceivable is just going to be efficacious. We weren't willing to buy assumptions about dose selection. We wanted to actually characterize this and do a full dose response, which means not only testing a bunch of interim doses, but also extending beyond what you might expect to be the target dose, which is why we tested doses of 25, 50, 100, and 200 micrograms.
We had almost a 10-fold difference in that range that we characterized. There was direct learnings which showed us that the 100 microgram dose was the optimal dose. It was observational, of course, but what's shown here is modeled dose response, a model-based assessment, which was the primary analysis in the phase II. Observationally, we saw the maximal effect at the 100 microgram dose with no incremental efficacy at 200 micrograms, although an increase in the AE profile and the burden at 200 micrograms versus at 100, which again, gave us the confidence to choose this dose going forward into the pivotal studies. Some of the indirect learnings were equally as valuable and interesting, though.
We saw that at all of the doses we tested, 25 up to 200 micrograms, virtually all patients, 90% or more, correctly guessed that they were on drug. Everyone at every dose effectively knew that they were on drug. We had two low doses that showed no clinical separation from placebo and two high doses that showed the largest magnitude separation we've ever seen in the disorder. That gave us evidence and confidence too that these effects are real, that they're not just due. There's a lot of conversation about, quote, "functional unblinding." The fact that patients who take any psychiatric drug for that matter, whether we look at other classes like psychostimulants or anxiolytics, Xanax is a great example of this, where patients can have a clearly perceivable effect at clinically effective doses.
Given the unique nature and the, you know, reliable nature of high doses of psychedelics to induce these perceptual changes, there's been some sensitivity to making sure that the effects that are being reported on the outcome measures aren't just driven by patients knowing that they got the drug, and then, of course, one would have to assume that the patients aren't actually better and then are saying that they are better, which we don't believe to be the case generally. We actually had the data.
We were able to show that there was not a response across this dose range in terms of ability to perceive the effects of drug as a flat line. We saw a remarkable and statistically significant dose response on the clinical outcomes, which again, cannot be the case if functional unblinding is to be explaining the drug effect, which also allowed us a clear path forward and a way to cleanly design the phase III studies. In terms of adverse event profile and tolerability, remarkably well tolerated in the phase II study. There's of course been a focus on suicide risk in these populations. We didn't see any sort of suicide, suicidal behavior or suicidality signal in the phase II data.
There were no SAEs that were related to drug. Virtually all of the adverse events were mild to moderate severity and limited to dosing day. Effectively, the adverse event profile of DT120 looked like what one would expect the effects of taking a high dose of LSD. No surprises there, virtually all of them also resolved very shortly after treatment. We do a lot of work to characterize the temporal relationship on the day of dosing because of course, it's a model where patients are gonna come into the clinic, stay in the clinic for a period of time, and at the end of that day in that treatment session, leave the clinic.
We'll talk a little bit about that response pattern in phase II, but in phase III, we're doing a lot more to characterize, beginning at hour five, the resolution of those perceivable symptoms that would necessitate clinical monitoring. Overall, FDA came out with guidance a few years ago on the development of psychedelics. Our development program is very much in line with that guidance. We have complementary designs, again, a five-arm study in phase II and a two and a three-arm study in phase III in each of the indications we're pursuing. We've gone to great lengths to mitigate the effects of functional unblinding, again, to prove that out in phase II, to mitigate that operationally in phase III by using centralized raters who are blinded both to treatment assignment and visit number.
Even though we saw in phase II that patients could reliably correctly guess that they were on drug, we also showed that the raters could not. The raters remained completely blinded to the effects, which also speaks to the quality and the robustness of the data we've been able to generate. Now in our phase III program, which we started our first study at the end of 2024 and the other two in early 2025. We just gave an update last week that our first readout now is expected from our EMERGE study, a head-to-head study in major depressive disorder. 149 patients were randomized in this study.
Identical designs across the GAD and MDD studies, just different endpoints and of course, different populations, so different eligibility criteria for the disease we're trying to treat. In all the studies, patients who receive a single dose of drug are followed for 12 weeks, after which they continue to be observed for an additional nine months. If they have a return of moderate or severe symptoms, they're eligible for up to four open label doses with the drug, which allows us both to characterize the durability of a single response beyond 12 weeks, but also retreatment patterns and what we could expect to be more like real-world utilization of the drug over the course of a year. Our two GAD studies, VOYAGE, our first head-to-head study, is enrolling approximately 200 patients, randomized 1-to-1.
We expect data from that study in early Q3. For PANORAMA, the three-arm study, statistically still the same design, testing placebo versus 100 micrograms. We included a 50-microgram arm in PANORAMA and in our ASCEND study, which is there effectively to be able to tell patients in the informed consent process, just because you may feel the effects of drug on the day of dosing, you can't assume it's a clinically active dose. We have a dose that both of which we've shown previously feel like something, that they're perceivable, but one of those doses is clinically inactive. Just because you, patient, feel the effects of drug on dosing day, you can't assume you're getting the real thing. You just need to be honest and reliable in how you're reporting how you're feeling thereafter. It's a methodological control.
It's one that we don't statistically test. It doesn't change the interpretation or the outcomes of the study in any way. It just allows us to have that operational and build that robustness that we'll have three different study designs, that if we're consistently showing an effect, gives us a high degree of confidence that we're seeing a real and robust drug effect. Beyond the Part A of the study's 12-week double-blind period, we continue to follow these patients and regularly assess the outcome measures, Hamilton Anxiety Scale and anxiety in the MADRS and depression. By allowing for open-label retreatment, we're able to both show a the durability of a response pattern with retreatment, but also to characterize that response.
'Cause patients who don't take open label drug stay in their blinded status up until that point in time where they do receive open label drug. We can look at things, events such as a return of moderate symptoms or subsequent retreatments that'll allow us to characterize durability even beyond 12 weeks. It'll allow us to look at that response pattern. For instance, if an average patient were not to need a second treatment until six months later, we could reasonably conclude that a single dose has durability out to that period in time. Again, in MDD, very much the same study designs. We targeted enrollment of 140 patients in EMERGE. However, we ultimately enrolled 149 in that study.
ASCEND, our second MDD study that has the same design as PANORAMA, we have sites activated and expect dosing first patients in the next few weeks ahead by early Q2. From a regulatory standpoint, based on our phase II data, we received Breakthrough Therapy designation for this program. We have had an extraordinarily productive relationship and partnership with FDA over the course of the development program. That has allowed us to be very clear and thoughtful in our alignment with FDA, allowed us to go very quickly. From the time we opened the IND in early 2022 until we expect to have all of the pivotal data in hand will be under five years, which is a remarkably quick timeline for a program like this.
FDA have been great partners in that. Over the course of last year, we've gotten extraordinary clarity on what we expect to need and how we expect to approach the path forward with pivotal data in hand and moving quickly towards an NDA thereafter. Talk a little bit about commercial framework. There's of course, I think a renewed enthusiasm with the rapid growth and expansion of intranasal esketamine that we've seen now annualizing and progressing towards multiple billions of dollars of sales in treatment-resistant depression. Of course, if we're successful in pursuing both of these indications, this is an even larger population that we'd be able to target.
There are now about 7,000 clinics around the country that are set up to as sort of interventional psychiatry clinics that are able to bring patients in, keep them under observation. We certainly believe that based on the high unmet need, based on the enthusiasm by both psychiatrists, but also all of the mental health care practitioners, right? It's not just psychiatrists. There's clinical psychologists and clinical social workers who are very much involved in the delivery of psychological and psychiatric care today that are overwhelmingly engaged and enthusiastic about DT120 and the possibility of bringing psychedelics into clinical practice.
We do a lot of work to engage there, a lot of work to both understand and target and engage with the population of providers so that if we're successful in getting the product approved, that we're ready for a rapid adoption, a rapid expansion. We see an extraordinary need, an extraordinary opportunity in a world that is increasingly ready to adopt these drugs and DT120 in particular if we're able to launch it. In that context, there again is a focus on the temporal relationship. How much time do patients have to spend in a clinic? This is where we are incredibly excited about DT120 's profile. Right. With ODT formulation and our approach in phase III, we bring patients in, give them a dose of drug.
Those effects from the drug are perceivable within about 15 or 30 minutes, and that is significantly enhanced and shortened based on the ODT formulation. The maximum effects pretty much occur within the first couple of hours, and from there on, patients are having a resolution of those symptoms. We start measuring at hour five. We have a structured checklist that looks very much like what is used to monitor patients with intranasal esketamine, but also is used in a similar context for post-anesthesia care to assess when patients have a return of cognition and perception in a way that would allow them to be safely out in the world and to end a monitoring session.
Our measure from hour five on an hourly basis and get a high grain definition of the resolution of those symptoms, which we'll be able to assess and use to, of course, make regulatory arguments, but also to give comfort to providers that they can integrate, hopefully, this into their practice by reliably being able to predict when patients may come off drug. We've seen really encouraging signs from our clinical pharmacology program and in our phase III program that we'll be able to share as we get closer to clinical data later this year. We look at all of the stakeholders that need to be ready for this, that need to be excited. Again, Healthcare Professionals, we get an overwhelmingly positive response.
There's a massive perception and understanding of the unmet need in GAD and certainly in MDD. With 70% of the surveyed HCPs, we do a lot of research in these populations, say that they intend to prescribe or recommend DT120 for GAD if it should be approved. This is in a population that is 10% incidence. It's 25-26 million patients in the U.S. alone. We expect certainly as good of numbers in the MDD population, which also is a huge unmet need and it also has a high degree of urgency in treatment. From a patient side, high degree of dissatisfaction, a lot of cycling through medications. A thing that often gets overlooked is the sort of lack of hope, particularly in GAD.
The last approval in GAD was 20 years ago almost with Cymbalta. We've lived 20 years without anything new in a population that has been growing rapidly, that carries a high disease burden and really often doesn't show up for care because there's nothing available for them. There's not highly effective treatments that drive patients to care. Even when we look at the current population, the current numbers who are receiving care, which are extraordinarily large, that's really just the tip of the iceberg 'cause there are a lot of patients who are undertreated and under-cared for because of the lack of available and effective treatments.
Even there, when we go to payers, of course, with a drug like this, that there's a degree of inter-intervention, we need to make sure that it's going to get reimbursed, that providers can be paid to monitor these patients, to deliver it in their sites of care. Again, we've seen a high degree of encouraging signs. Payers have expressed a high degree of receptivity, a positive reaction to the profile, a high degree of intent to find paths to reimbursement. There's a clear understanding from all of these stakeholders of the need and the opportunity to actually bring something meaningfully different into the population and the treatment paradigm, and a desire to chart a path to make it possible.
I won't spend a ton of time on the in the weeds of what it takes to get reimbursement. I just wanted to say that there often are a lot of questions about how this will integrate into practice, how it can get paid for. That's where we'd like to point there are, while all of the pieces have not been uniquely combined the way that they would need to be for the adoption of DT120 or other drugs in the category, each component has a precedent. Bringing patients in for monitoring, getting that reimbursed and paid for at attractive rates is being done today at a pretty impressive scale. So there isn't anything that is entirely novel about that.
It's just kind of a new combination of these factors that have to come together and one that we're already very much involved in navigating and charting a path for. We frame up the commercial opportunity, of course, in 50 million patients with these disorders. Cannot express just how large that is. 27 million of those in MDD and GAD are receiving medication to treat these disorders. It's remarkably large, and sometimes it gets lost. Numbers that big can just be hard to comprehend. We always try to sort of make it a little bit bite-sized and just say, if we were to say, what would it take, what would it look like just to treat 100,000 of those patients? That wouldn't even be tipping the scale.
It wouldn't even actually be sort of turning over the curve, the growth in the diagnoses. Even just to go to 100,000 patients, at the price ranges that we see for intranasal esketamine, we're talking about a multi-billion opportunity. At that scale, we think there's even more upside from there. That would, I would just say, would represent a remarkably small penetration of this population, well under 1%. I guess we need to update this for every conference. We should have this for Boston. At the beginning of the year, we just talked about San Francisco, really, like trying to bring this back down to what it would look like in a more bite-sized way, how we think this is, there's a direct path to attainability here.
If we look at the population of San Francisco as an example, it's about 1.5%, 1.4% of the U.S. adult population. If we just boil that down and say, to treat 100,000 patients nationwide, what would that city represent? It'd be 1,400 patients. There's 44 interventional psych clinics and top psychiatric providers who we believe are when we talk to say that they're highly encouraged, highly motivated to be early adopters, to be adopters of DT120. That means it'd be 32 patients per site on average means treating two or three patients a month on average. These clinics are treating dozens of patients a month today with esketamine and ketamine and other interventional psych products.
Just to see a world where each of these clinics is treating one or two patients, three patients a month is hard to really conceive of. When you scale it up at a national scale and you pair that with the degree of enthusiasm that we hear from these providers, even many of those who are not involved in delivering these interventional psych products today, again, it just gives us this high degree of conviction about the opportunity and the ability to actually make this happen. There's always a temptation to sort of turn away from the fact that these drugs have these unique perceivable effects.
There's a temptation to point to the treatment model that exists today and say, "Oh, well, it needs to fit exactly into the model that exists into a two-hour treatment session." Of course, that two-hour treatment session didn't exist until a few years ago, right? Before that, the 15-minute med management meeting, visits didn't exist until the introduction of SRIs. Psychiatry over and over again shows a high degree of adaptiveness, a high degree of ability to adopt new treatments when there's actual meaningful change and efficacy, when it's something that patients want and when it represents a real new option that they can offer their patients.
Again, we just see an extraordinary potential here, a future that we want to chart a path and be in the tip of the spear of bringing into reality because psychiatry doesn't need another drug that works just like what we have today. If that was working, we wouldn't have growing prevalence of these disorders. We wouldn't have the kind of burden, the growth in deaths of despair. Despite what we have available, it's just not good enough. We look at that and say, "Necessarily, we need something new." We need to exactly embrace the kind of change that this is going to be. Fortunately, all of the stakeholders that actually need to be involved in this generally agree with us and, and show an inclination to try to get that done.
With only a few minutes, I'll just briefly spend a second in, again, in autism spectrum disorder. When we look at the analogy to psychostimulants in ADHD, we think it's an appropriate one. Patient workshops have been conducted even by FDA a few years ago to ask patients and caregivers with autism spectrum disorder, what do they actually want out of drugs? Right now, most of the drugs are suppressive, and they're used for agitation and behavioral control. That's not what patients say they want. They say they want something that actually improves core domains, that improves their ability to function and engage socially and engage in social communication.
It so happens that the mechanism of 402, of R-MDMA appears in early studies in healthy volunteers to align very closely with those desired effects. The pro-social effects of R-MDMA are very much in line with the deficit in autism spectrum disorder. We decided to look at this. We conducted a phase I study, and off the back of that started an early signs of efficacy study . This is 20 patients, open label, who have a diagnosis. These are adults with autism spectrum disorder. We're looking for a number of functional biomarkers, functional domains, things such as eye tracking, but also just self-reported improvements in social and social communication skills. Study's ongoing.
We dosed the first patient at the end of 2025 and are now progressing that study, and we'll have first data from it later this year. With all of that, we are laser-focused on getting to our clinical readouts. We see an exciting year ahead, both clinically and as we're progressing in parallel to that, really driving commercial adoption, a commercial framework. We've brought in incredible commercial leadership to navigate the complexities of market access to really chart a path to get this out in the world in a major way, and certainly going to be measured both by the quality of the clinical data, but also by the preparations for getting this drug out in the world.
Thank you, Rob. We are at time, but would like to take one or two questions, if the audience has any. Yep.
Thanks. Rob, can you just re-review in any more detail the actual payer codes that you let your providers get paid for having the patient in the clinic for eight hours instead of two hours? Or would those codes still need to be created?
Yeah. It's a great question, and it's, of course, one that, you know, the final dynamics there are going to be subject to, you know, approval and actually having the product out in the, in the world and navigating that with payers and the codes that are under development. You know, there's been some progress getting CPT III codes adopted and prepared such that there could be unique codes for this category of drugs. That does not necessarily need to be the case, right?
When we look at the landscape today, the unique thing here is not so much the reimbursement of time because this is being done today with an intranasal esketamine . I'll go back to these. We see 90215, 90415, 99416 add-on codes. Basically, these are hourly codes with 15-minute add-ons. The unique thing here would be that instead of having five codes on a bill, to cover a two-hour session, but having that spread over 56 visits a year, it might be more codes in aggregate in a single visit. Operationally, it could be easier to just end up with a dedicated code that then reimburses for a longer period of time.
We always point to this reality that there is opportunity for some forward progress with the CPT III codes, moving those to once on approval. We could just as easily rely on codes that already exist, are already negotiated, are already being billed today. They just have a little bit of more administrative dynamics that would be unique, not so much a whole novel approach in terms of what codes needed to be generated.
Thank you, everybody. With that, we're at time. Thank you, Rob.
Thanks, Athena.