Good afternoon, and welcome to the Arrowhead Summer Series of R&D Webinars, Part One. As a reminder, all participants are in a listen-only mode. A question and answer session will follow today's formal presentations. If you would like to submit a question, you may do so at any time throughout the webinar by using the Q&A text boxes below the webcast player. As a reminder, this event is being recorded, and a replay will be available on the Arrowhead website following the conclusion of today's call. I would now like to turn the call over to your host, Vince Anzalone, Vice President of Finance and Investor Relations at Arrowhead Pharmaceuticals. Please go ahead. Thank you, Sarah, and thanks to everybody for joining us today. We're excited to kick off this summer series of R&D webinars with the first one targeting or covering our muscle programs, ARO-DM1 and ARO-DUX4. Next slide, please. So I just want to remind everybody that we will be making forward-looking statements today, so please refer to our SEC filings for risks. Next slide, please. Okay, so I wanted to spend just a quick couple minutes talking about Arrowhead generally. So as most of you know, we are an RNAi therapeutics company. We have a very broad pipeline of both wholly owned and partnered product candidates. They're all built on what we call the TRiM, or Targeted RNAi Molecule platform. It's a proprietary delivery system that allows us to get to multiple tissues throughout the body. Our current pipeline has 14 individual molecules. 10 of those are wholly owned, 4 are partnered. We think we have a good, diverse set of early, mid-, and late-stage clinical programs, and an opportunity to have commercial drugs in the next year to 2 to 3, certainly. And the targeted RNAi molecule platform is designed to achieve deep and durable gene silencing. And what we think is that a big value driver for Arrowhead and a differentiator is that we think that we are leading the field in fulfilling the promise of bringing RNAi therapeutics to where diseases live. And that's multiple tissues throughout the body, not just the liver. And also, we think that our balance sheet supports drive up to commercialization. And, and we have non-dilutive or access to non-dilutive sources of, of funding, through existing partnerships with Amgen, Takeda, GSK, Royalty Pharma, and we're also committed to, to doing additional business development deals and structured finance deals, to further strengthen our, our balance sheet. Next slide, please. So this is our current pipeline, and there, there's a lot here. I put a, a red box around the two muscle programs, ARO-DUX4 and ARO-DM1. That's what we're gonna be covering today. But I think that this is... You know, it's important to, to understand that, that our targeted RNA molecule platform, can, can access or can address diseases across therapeutic area. We don't have to necessarily be disease area specialists in any one area. We have to be the best at RNAi, and that's what we think that we do. Next slide, please. So how do we talk about that? You know, why are we doing this series of R&D webinars? And I think it's mostly because we tend to like to do one R&D day per year, sometime in the summer, normally June, July. And that will focus on the platform, all the pipeline products, give some guidance on about where we're taking the company in the future. And we realize that with that enormous pipeline that I just talked about on the last slide, it's very difficult for us to go into detail in any one area. So as an alternative to one R&D day, we are doing this summer series of webinars. Today is the first one, again, targeting our muscle programs. Next month, we'll be going over the cardiometabolic programs, Plozasiran and Zodasiran, which includes our Phase 3 program at FCS. And our hope is that we'll have top-line Phase 3 data at that event. In July, we'll talk about our pulmonary programs, which include clinical molecules against ARO-RAGE, ARO-MUC5AC, and ARO-MMP7. In August, we'll talk about our obesity and metabolic disease programs, one which we've disclosed, which is ARO-INHBE, inhibin E is the target. And we'll also talk about some expansions we're making to the TRiM platform that allow us to get to adipose tissue, and we'll disclose what our first therapeutic target is with that adipose tissue platform. And then lastly, in September, we'll talk about our growing CNS capabilities. Next slide, please. So as I mentioned, you know, we have a lot that we're working on. And so this R&D series, or webinar series rather, is designed to accomplish a few things. We wanna give focused time to these underappreciated areas of our pipeline that we really don't get an opportunity to talk about that much. We wanna talk about where we have taken and where we will take the TRiM platform. We also want you to hear directly from the experts inside Arrowhead that worked to make the-- worked on these programs and make them what they are today. And then also give you some external perspective from some opinion leaders in the field. Next slide. So here's what we'll cover today. Well, James Hamilton, our Chief of Discovery and Translational Medicine, will talk about the TRiM platform. Dr. Lawrence Korngut will talk about DM1 and FSHD a little bit later, about the disease area, how patients present, and where there are still opportunities and unmet need... Jonathan Van Dyke, who is intimately involved with the development of both of these programs, will talk about the preclinical data that went into candidate selection and why we're excited about these programs. And then again, you know, James Hamilton will come back and talk about clinical trial design for both programs individually. Once that's done, we will have an opportunity for the questions to the panel. Please use the Q&A system on the web to submit those questions. I'll read those out loud, and we'll cover them. Next slide, please. So before James goes into the platform, I just wanted to introduce Dr. Lawrence Korngut. We are very lucky to have him joining us today. He is an expert in neuromuscular disease. He is a neuromuscular neurologist at the University of Calgary, the Cumming School of Medicine, and he's also a member of the Hotchkiss Brain Institute. He is an expert in this field, and he is insight personified when it comes to DM1 and FSHD, so we're very happy to have him with us today. Next slide, please. I'll turn it over to James to talk about the TRiM platform for muscle delivery. Thank you. Sure. Thanks, Vince. We could go to the next slide. So we haven't talked a whole lot about the TRiM platform and the conjugates we use to deliver siRNA into the muscle, so wanted to give an introduction to the platform. This is the same platform used for both ARO-DUX4 and ARO-DM1, and it's unique in comparison to our liver-targeted programs in several ways. First and foremost, we use a different targeting ligand, so we have a peptide ligand that is linked to the 5 prime, and as you can see here in the diagram, and that targets the alpha-v beta-6 integrin receptor. We also use a novel linker that improves siRNA loading and efficiency. And then you can see on the, the three prime and the PKPD modulator that improves delivery and cellular uptake, and this is a lipid moiety that we use to enhance delivery. We use the same TRiM rules and algorithms for sequence selection to identify potent gene sequences, siRNA sequences, that knock down the target of interest while avoiding off-target effects. If you go to the next slide. Here we show that really all three of these components are necessary to maximize knockdown of a given muscle target. This is work we did with a tool target. This is a mouse tool target that targets myostatin. This is a protein that's expressed by the skeletal muscle and can be measured in the blood. But the take-home here is that you really need the full conjugate, as you see on the far right, containing the integrin ligand peptide, the PKPD modifier, and of course, the siRNA, all required to maximize gene target silencing. If you go to the next slide. You know, one of the things that we get asked a lot about is, how are you different from transferrin receptor antibody targeting, or why didn't you go after the transferrin receptor with this platform? And, you know, we're really agnostic as to, to the targeting method, and we have deep discovery capabilities at Arrowhead. We've done lots of work with monoclonal antibody and Fab fragment conjugates, and we've looked at transferrin receptor targeting, and we chose the integrin-targeted approach, because in our hands it worked better, and it had better, some other advantages that we'll talk about in the next slide. But here, on the left, we're showing, again, this is an siRNA targeting myostatin in mice. So two different delivery platforms, the transferrin receptor-targeted monoclonal in the light green, and then in the dark green, the TRiM platform targeting the integrin, using the integrin-targeted approach. Same dose of siRNA, 3 mg per kg, and in this study, we're seeing better knockdown at the same dose of siRNA using the integrin-targeted approach versus our transferrin-targeted transferrin receptor-targeted conjugates. On the right, here we're showing DMPK gene knockdown, and this is in monkeys. Here we're showing total dose, so total conjugate dose of the drug given as a single dose, and with 15 mg per kg of ARO-DM1, or 15 mg per kg of the integrin-targeted platform conjugated to a different siRNA against DMPK, we're seeing better knockdown in the muscle comparatively against 22 mg per kg total conjugate of a monoclonal targeting the transferrin receptor linked to an siRNA. Next slide. The reason we went with the integrin-targeted approach and the advantages we see, one, potential for improved knockdown, which we showed in the previous slide in two different species. Then additionally, we think that less drug is always better, better for the patients, and the transferrin receptor-targeted approach... with an antibody oligo conjugate will require a higher total dose because the siRNA is linked to this large monoclonal antibody compared with the integrin peptide target approach. For example, if you normalize for the siRNA dose, the amount of siRNA in a 12 mg per kg dose of ARO-DUX4 is equivalent approximately to the amount of siRNA in a 100 mg per kg of a DUX4 antibody oligo conjugate. And we see that this is an advantage, potential efficacy advantage, potential safety advantage, and a potential advantage in terms of cost of goods. Next slide. So I'm sure there'll be a lot of questions about that, but first, I'd like to, to introduce Dr. Korngut again, who will walk us through disease background and unmet need in myotonic dystrophy. Dr. Korngut, the floor is yours. Thank you. It's wonderful to be with you all today. Next slide, please. So I'm gonna give a brief overview of myotonic dystrophy type 1. Importantly, to highlight, this is a multisystem disorder that while it primarily affects skeletal and smooth muscle, there's also more diverse impacts on the patient, including eyes, heart, endocrine system, central nervous system. And typically, and classically, we've characterized the illness into three sort of degrees of severity: mild, classic, and congenital onset. Next slide, please. And while this is a busy slide, I think it really captures well the different phenotypes, as I mentioned, mild, classic, and congenital on the left. The clinical signs that can range anywhere from very mild, just a bit of myotonia, which is a difficulty in relaxing muscles, typically in grip, when a patient will grab onto something, difficulty letting it go. And then into the classic, where there's weakness of the distal limbs, so the hands and movement around the ankle, around the neck, more proximally. But also having more diffuse, as you can see on the right, in terms of the images of the patients, even affecting balding, cardiac arrhythmia. In the next column, you can see, and we'll talk about the genetics a little bit more later, the CTG repeat size. So this is an expansion of the trinucleotide repeat. And as you can see, as the more severe the phenotype becomes, the more repeats you see over 1,000 in the congenital form. That congenital form, of course, presents at birth with hypotonia, intellectual disability, respiratory deficits. You can see the ages of onset. And important to highlight, you know, these patients do not typically live a normal life expectancy. In the mild form, you know, you can live up to a normal life expectancy, but as short as 60 years, and then, of course, reducing life expectancy with increased severity of disease. Next slide. In terms of the prevalence, the bottom line on this in terms of the most recent epidemiologic studies, you know, this one systematic review did a nice job reviewing things recently. One in about 10,800 people had myotonic dystrophy type 1. I think one in about 20,000 is the more sort of conventionally regarded number. But I think as diagnostic testing is more widespread as therapeutic as this emerge we may see more patients coming into our clinics, as is typical in the setting of these rare neuromuscular conditions. Next slide. So, so in terms of life expectancy, mean age of death is 53 overall in the cohort. Respiratory failure in 40%, cardiac failure in 30% as a cause of death. And then, of course, if we go to the next slide, there's, there's diverse cardiac abnormalities. This is a nice meta-analysis of over 1,800 patients. You can see there's sort of, ranging, cardiac arrhythmia, and rhythm changes. But most importantly, if you look at the bottom, the prevalence of cardiac involvement was two-thirds of the cohort, at the ten-year point. So, so certainly, considerable cardiac involvement and, and disease burden. Next slide. Other respiratory, respiratory, may even require mechanical ventilation at the severe end, but particularly in the congenital. Gastrointestinal complications, central nervous system complications, cognitive change, executive dysfunction, intellectual deficits in the congenital myotonic dystrophy type 1, and even a specific form of Christmas tree cataract. Next slide. In terms of severity of disability, I think part of my message that I like to speak when I'm, you know, I like to highlight as I'm speaking about myotonic dystrophy type 1 is, of course, as we've discussed, this is not a muscle-only disease, but also this is a progressive disease, as we're seeing. That speaks to the unmet need that we'll get into. On the left side, in the y-axis, you'll see the cumulative incidence. Of course, this is sort of the percentage of affected patients going up over time as age increases. You'll see the same curves for wheelchair use, walker use, you see pacemaker implantations. Don't focus on the dotted line, focus on the black line, 'cause that's myotonic dystrophy type 1. You know, prevalence of cancer, which is associated with this condition, and then the burden of disability in 60% of patients is striking over time. Next slide. So in terms of the genetics of the condition, the myotonic dystrophy type 1 is caused by an expansion of the CTG trinucleotide repeat in the non-coding region of the DMPK gene. Less than 35 repeats is normal, 35 to 50 repeats is intermediate, meaning asymptomatic, but of course, with subsequent generations, there can be anticipation, particularly in maternal inheritance. A mom giving... An intermediate affected mom giving birth to a congenital myotonic dystrophy baby is a classic presentation, and then over 50 being symptomatic, autosomal dominant. And next slide, please. And so in terms of treatment, I think, I think this is the clear unmet need. We do not have a disease-modifying therapy available. So you'll see all of the things that we do, ankle foot orthosis, braces, wheelchairs, pain management, management and identification of systemic manifestation, low thyroid, treating gallstones, hypogonadism, screening for skin cancer, cardiac pacemakers, but we're not able to modify the disease at this point. And then so certainly, you know, eager for positive results in that regard. And then screening for complications is a big part of sort of healthcare burden for these patients in terms of multiple appointments annually, for screening and blood work, et cetera. Next slide. And so in terms of the opportunity unmet need, myotonic dystrophy type 1 is an important cause of progressive disability and premature death in children and adults. There are systemic manifestations. There are no disease-modifying treatments available. It is 1 mutation type with variable repeat length. There are small previous Phase 1 and 2 trials that are evaluating outcome measures, which is helpful to this program, in my view. But also the community is ready. So importantly, what we did in spinal muscular atrophy, what we did in Duchenne muscular dystrophy, in terms of organizing on a global level, that is certainly well underway, and Project Mercury is a big part of that. And the next disease that I'll talk about, but myotonic dystrophy, we've been doing this work for essentially decades, preparing for these types of clinical trials. So, next slide, and thank you. Thank you, Dr. Korngut. My name is Jonathan Van Dyke. I'm a senior scientist, and I did a lot of the preclinical work, proof of concept work, and we're gonna hit the highlights for the DM1 program next. I'm gonna show two sets of data that really helped us select and build confidence in this program, select our therapeutic and build confidence in the program. We're gonna start with the non-human primate. Here we have non-human primate data, and I'm gonna talk to you about not only ARO-DM1, but another RNAi molecule that we're gonna call sARO-DM1. S, in this case, is gonna be our surrogate. The reason why we're talking about both of these today is that for most of the proof of concept work that we did in terms of disease modeling, we needed to use sARO-DM1 due to the localization of the target sequence with sARO-DM1 versus ARO-DM1, and that'll become apparent once I get into the next slide. But for now, let's just look at and focus on the non-human primate data. Here I'm showing you quadriceps and triceps brachii. These are biopsy samples that were repeat collected from non-human primates that were administered 13.2 mgs per kg IV of ARO-DM1 or sARO-DM1 on days 1 and 29. And you can see that we got very deep knockdown that maintained through day 85 in both the muscles that we that I'm showing here. For the quadriceps, we got down to 70% knockdown of total DMPK transcript, and in the triceps, we got down below 80, or I guess, greater than 80% knockdown with ARO-DM1. A little bit less so with sARO-DM1. And that's part of the reason why we nominated ARO-DM1 over sARO-DM1 when we were doing the selection process. And the reason for the day 1 and day 29 dosing is that that follows our intended dose regimen for human patients. And then, after that, clinical dosing is anticipated to be quarterly in order to maintain knockdown. Next slide. For proof of concept work, we use the transgenic DM1-like mouse. This is the TREDT960I mouse out of Tom Cooper's lab at Baylor. We refer to them throughout the rest of this section as the DM1-like mice or DM1L. And then we have the non-carrier control, so that is our control animal that doesn't express the human transgene. You can see in the top panel a map of the transgene that we have, a fragment of the human DMPK exons 10-14 or 11-15, depending on whether you're talking about DMPK variant number 1 versus number 2, and the 3' UTR, and then 960 CTG repeats, and all of that is behind a doxycycline switch. So, when we feed the animals doxycycline-laced chow, we get induction of the, of this transgene. And, so in the middle panel here, this is what I was talking about earlier. You can see that, with the limitation of the model, meaning the exons that are targeted by sARO-DM1, those are expressed in this mouse. But ultimately, we ended up nominating the ARO-DM1, which targets a region outside of what's included in this mouse. So that was why it was necessary to show both for this presentation. So these mice were crossed with a human skeletal muscle actin rtTA mouse line, which conveys the inducible expression in skeletal muscle specifically. And then, as I mentioned, we administered doxycycline-laced chow to these animals. What we were looking at just for initial characterization, proof of concept in our hands with this crossed line. We wanted, we were comparing animals at 15, 22, 29, 36 and 50 days post-induction, so post being provided with the chow, and then comparing that also with the non-carriers. So we were looking specifically at human DMPK expression in these mice. And as you can see, we saw an increase over time as the animals consumed the dox chow and, but, you know, we ended up with a kind of a plateau that began around day 22. And then, additionally, we were looking for mis-splicing. So the pathobiology of DM1 is caused by this accumulation of the DMPK CUG transcripts in the nucleus, which then leads to sequestration of splicing regulators in the nucleus. And then what you end up with is a whole portfolio of genes that are mis-spliced, many of which are skeletal muscle required for normal skeletal muscle function, and then the resulting phenotype. So one such gene is LDB3, which is known to have an exon eight inclusion. So this is an exon that's not normally included when the DMPK CUG accumulation is present. And so you can see that when we were ca... When we were measuring the total number of LDB3 transcripts, you know, in our, in our non-carriers, you can see that the majority of them were without the exon eight. And then as the doxycycline chow was provided to the animals over time, you can see that we had a correlating plateau with the accumulation of human DMPK, of, of the variant, I'm sorry, of the mis-spliced LDB3, which would be including the exon eight. Next slide. So, so one thing that we wanted to know, whenever we're looking at these animals and, and looking at the DMPK expression, the human DMPK expression, was whether we were looking at the nucleus or whether we were looking at a cytoplasmic population as well. So here I'm showing some RNA scope co-stain data in mouse TA from the previous study or from the study that I was just showing you the data from. And in the brown, you can see the brown puncta. Those are mouse endogenous DMPK, so obviously not mutant, since the mouse endogenous DMPK does not contain the CUG. And then with the red, you can see the human DMPK. This probe was designed specifically not to cross-react with the mouse DMPK. And you can see that the human DMPK with the CUG is localized exclusively to the myonuclei. Not every myonucleus has a DMPK CUG expression or a human expression. But where we see red is the human DMPK, and it's only localized in the nuclei, which gave us confidence that we could reasonably make an assumption that whenever we're looking at human DMPK expression, that would be a measure of nuclear expression, and therefore, if we could knock that down, we'd see nuclear knockdown. Next slide. So one of our studies, we did a multi-dose intervention strategy. So we started off with these animals, and we started them on doxycycline. Well, so the animals' mothers, so in utero, were on the doxycycline chow. They were able to receive doxycycline through the breast milk, and then once they were weaned, they were weaned on doxycycline chow. Throughout their entire lives, these animals have been on doxycycline. Once those animals were brought in-house and acclimated, we began our sARO-DM1 treatment. We started quite aggressively because we wanted to show proof of concept pretty definitively. We administered at 26.4 or 52.9 mg/kg, that's total conjugate. The siRNA dose for that is 20 and 40 mg/kg. The animals were then dosed weekly with this large dose of siRNA and then harvested day 36, we harvested the muscles and analyzed what we had here. We have several groups here. Many of them are control... Most of them are controls, in the white DM1-like mice, with no doxycycline, so this is without that human transgene induction. Black is our disease model, so they do have doxycycline chow. We normalized everything to that group. And then we have in the light blue, DM1-like mice that were administered sARO-DM1, 26.4 mgs per kg, and in the darker blue, 52.9 mgs per kg. And then we also had C57BL/6, which was one of the background mice, as well as the non-carriers, as additional negative controls. And you can see that, at 26.4, we had a little bit of an effect there. We had a significant effect in the gastroc, less so in the TA and tri, but once we had gone up to 52.9, we were able to show significant knockdown of the human DMPK, which suggests nuclear knockdown for us in all three muscles. Next slide. Next, we really wanted to focus on the mis-splicing, since that's the source of the pathobiology. So we started with this PCR-based competitive mis-splicing assay. And, I this is a lot of data here, but the important part is to just remember the previous slide and look at the repair trends. So here we're looking at the relative mis-splicing scores for ATP2A1, CACNA1S, LDB3, and MBNL1. You can see the same trend for all three muscles, for all four of these targets, that, with increased dosing, with increased dose levels, so up to 26.4, up to 52.9, we saw significant reduction back towards the wild-type levels of splicing. So, so a more dramatic splice correction with increased dose for all four of these, all four of these, these genes. Next slide. Additionally, we went and assessed mis-splicing repair by RNA-Seq composite scoring. So this is, this is, from Charles Thornton's lab publication with a 35 gene panel for mice, to, to look at, or to create composite scores and, and normalize and scale so that all of it can be compared as just a single score. So we did three different composite panels. One was the complete panel, 35 genes, one was the 20 most responsive genes of those 35 that we were able to measure repair in, and then we also selected eight muscle-specific genes. So these are samples from the same study that I was just covering. And here we're just showing the non-carrier, so the negative control in the gray. In the white, we have our non- or uninduced disease animals. Black is our diseased animals, and then in the light blue and the dark blue, we have the sARO-DM1 treated animals at 26.4 and 52.9. You can see that the mis-splicing composite scores, we got a modest amount of mis-splicing repair with a 26.4, but once we had gone up to the 52.9, we were right in the just a little bit outside the realm, but right at the realm of the wild type repair. So nearly complete, at least 60% mis-splicing repair. Next slide. Yeah, so in summary, we've just discussed our disease model of DM1, our DM1-like mouse model exhibits the mis-splicing. You know, it has the truncated human DMPK expression with the 960 CTG repeats behind that doxycycline switch. The repeats are primarily localized to the nuclei and the resulting RNAopathy definitely yield the mis-splicing pattern that we expected to see. Our human mouse cross-reactive trigger in the DM1-like mouse prevented and reversed mis-splicing caused by DM1... I'm sorry, by DMPK transcript accumulation, and that appears to be a dose responsive effect. And then, we were able to observe both using competitive mis-splicing and RNA-Seq. We were able to see that repair. And so that proof of concept work has demonstrated that a TRiM conjugate can be used to prevent and correct mis-splicing caused by this transcript accumulation in the myonuclei. And then, of course, as is probably well known, to this audience, it's been shown that in the clinic, at 17% mis-splicing repair, yields relevant, myotonia-reducing and health-improving functions in patients. So you know, what we're looking at is the ability to possibly increase dosing, increase mis-splicing repair, and potentially get a stronger or longer functional repair in patients. Next slide. So I'll turn it back over to James to talk about the clinical plan. Yeah. Thanks, Jonathan. If we go to the next slide, just do a quick overview of the clinical trial design. So this study has started, the ARO-DM1 1001 study, is in patients with myotonic dystrophy, and, we've dosed patients, we have patients on drug now in the first cohort, where we start at 1.5 mg/kg, and this is the total conjugate dose. Then we will dose escalate, single doses to 3 mg/kg, but then quickly progress to the multi-dose cohorts, where we'll study two doses of 6 mg/kg, and then dose escalate to 12 mg/kg. In the single escalating dose cohorts on the left, all patients undergo muscle biopsy at baseline, and then twice post-dose around day 30, and then also at day 90. So we'll get a good idea of single-dose depth and duration at the lower doses, and then at the higher doses, they also undergo muscle biopsies at similar time points post last dose, so we can again evaluate depth of knockdown and also duration of knockdown at 2 post-dose time points. If you go to the next slide. Key endpoints for the study, of course, safety, tolerability. We'll look at PK, both plasma PK and also tissue PK, since we're measuring siRNA levels in the muscle. And then some of the other pharmacodynamic endpoints that we'll look at will include total DMPK mRNA. We'll look at spliceopathy repair and video hand opening time, and then various functional tests, measures of muscle strength, and patient-reported outcomes. And as I mentioned, this study has started. We have patients enrolling and on study now at sites in New Zealand, Australia, throughout the Asia Pacific region, and also opening sites in Canada and in the European Union. Next slide. So we'll shift to FSHD and the DUX4 program, and Dr. Korngut will introduce us to facioscapulohumeral muscular dystrophy with a review of disease, background, and the unmet need. Dr. Korngut, I'll turn it over to you. Thank you. Thank you. Next slide, and next slide again. Okay. And so, so facioscapulohumeral muscular dystrophy, of course, affects the face, the shoulders, and the, the proximal upper arm. It also doesn't typically, it affects the distal lower legs in, in terms of ankle dorsiflexion. Next slide. In terms of the prevalence, if you, if you look at the sort of top part, this was a systematic review we, we performed a number of years back. Our, our pool total for all, all patients was... or all age groups, was approximately 4 per 100,000. Next slide. And then in terms of the presentation, the most typical course is onset during the teen years, but can certainly be variable in terms of, you know, congenital presentation or even later on into adulthood. There's a stepwise progressive course. The disease is heralded by asymmetrical proximal arm and distal leg weakness. On examination, bilateral facial weakness and certainly pain, particularly in the shoulder region, due to the scapular winging and periscapular weakness, is very common. And of course, scapular winging is the most common initial finding that often triggers the consideration of this as a diagnosis. Next slide. And again, just to show that, you know, this is a serious disease and a very disabling one. If you compare the age of onset on the left side, and then the median age of required wheelchair use on the right side, I think it paints a pretty progressive story of very considerable disability. Next slide. Then in terms of systemic symptoms, there are extramuscular manifestations in terms of hearing loss that can be progressive, cardiac arrhythmia, which is considerably lower risk than in the myotonic dystrophy population that we discussed initially, but is still present, and then respiratory dysfunction, although relatively uncommon, can be significant, and can get to the point where it requires non-invasive ventilation for patients, but that's an uncommon concern or presentation. Next slide. And then even including the eye, the most significant thing we often see is eye closure weakness due to facial weakness. Of course, this can result in drying of the eyes, and so, daily proper protection needs to be undertaken, particularly at night when the patient's sleeping, if they can't close their eye fully. But there's other important ocular manifestations, Coats' disease, retinal vascular changes, among other, necessitating annual ophthalmology screening, and potentially intervention. Next slide. So in terms of diagnosis, FSHD1 is inherited in an autosomal dominant manner. 10%-30% are de novo, so no family history. FSHD1, which comprises 95% of FSHD cases, is a heterozygous pathogenic contraction of the D4Z4 repeat array, as we'll go into, in the subtelomeric region of the permissive chromosome 4q35. Next slide. If you look at the sort of overall chromosome 4 up top, you focus on the subtelomeric region, and on the top version there, where it says, "No FSHD," you can see the triangles, which represent the normal D4Z4 repeat array. There's typically 8-100 of these repeat units. The line below is FSHD type one, where you have a contraction of the D4Z4 down to the range of 1-10 repeat units on a permissive 4qA allele. And then, through that, there is a normal genetic derepression of the DUX4 gene, that you can see the mRNA expressed there. So that's a normally silenced mRNA product, that's expressed in this setting. Next slide. And so in terms of treatment of manifestations, again, no disease-modifying therapies are available, so patients are managed through physical medicine rehabilitation, or our colleagues in physiatry, physiotherapy, occupational therapy. Again, the use of braces, surgical fixation of the scapula can be considered, although we don't use that very commonly in our practice. Eye lubricants, taping the eye shut during sleep to treat exposure keratitis of the ocular globe. And then, of course, screening in terms of pulmonary consultations, ophthalmology, cardiology if needed, and annually for audiology assessment. Next slide. And then in terms of the opportunity and unmet need, again, an important cause of progressive disability in children and adults. A recent study calculated approximately 870,000 patients worldwide. Systemic manifestations, as we discussed, one mutation type with variable repeat contraction length, no disease-modifying treatment. There are multiple Phase 2 and 3 trials ongoing, which we see, you know, as a positive in the sense of understanding the outcome measures that are required to detect difference. And again, there is an entire community effort on a global level in terms of Project Mercury, led by the FSHD Society, to promote readiness for clinical trials, but also for eventual market access of therapies to ensure every patient who could benefit from the treatment has access. Next slide. And thank you. All right. Thank you. And so for the next section, we're gonna talk about some human myocytes. This data, and then, as another disease model that we used for our proof of concept work for ARO-DUX4. So in this first slide, I'm gonna show you data that is all from an FSHD1 patient-derived myotubes. So these are from the Coriell Institute. And these are human myoblasts that have the short 4q35 EcoRI fragment, so about 21 kilobases, which is equivalent to about 6 or 7 repeats of the D4Z4, which, as Dr. Korngut just mentioned, FSHD is defined usually at less than 11. So in these cells, we were able to measure DUX4 expression using ddPCR. And then what we did was transfected these cells with ARO-DUX4. And on the left here, we have the DUX4 transcript, so the human DUX4 transcript, and you can see that we did have a dose-dependent knockdown of DUX4. And then on the right, we looked at a number of human genes that are targets of the DUX4 protein, and we're able to show a very dramatic knockdown of those genes. Sorry, not knockdown, but reduction of expression, being that the DUX4 protein upregulates all of these genes. So, we were able to show here that we could achieve a dose-dependent reduction of that panel of genes that is turned on by DUX4 as a marker of DUX4 expression. Next slide. For a disease model, we went with the HSA MCM FLExDUX4 mice. So these animals have DUX4, human DUX4 behind a tamoxifen-controlled skeletal muscle-specific switch. And so with tamoxifen administration, these animals increased expression of the DUX4 target genes, sorry, of DUX4 transcript. And then we were also able to measure increased expression of DUX4 target genes, one example of which is WFDC3 in mice. This gene doesn't have any application outside of the preclinical space, but it's a very well-known and reliable marker of DUX4 protein activity. With this study, we took two approaches in the same study. So, a prevention and an intervention strategy towards treating this FSHD-like phenotype in these animals. So in the bottom left, we have a cartoon or a timeline of this study. So we began tamoxifen treatment, starting with 2 times per week for the first week, and then on day 8, we started 3 times weekly dosing. On days 3 and 5, for the prevention strategy, we dosed with ARO-DUX4 on days 3 and 5, and then weekly thereafter. And for the intervention strategy, we dosed on days 10 and 12. In our hands, these mice started to show functional ataxia around day 10 and body weight loss, which I'll show some data for that in the next slide. Around day 10, and so we dosed day 10 and 12, and then weekly thereafter. Harvest on day 31. We looked at multiple different muscles, I think nine in total. We wanted to kind of cover all of the muscles that may be affected in DUX4 patients, so paraspinal, facial, as well as limb and diaphragm. And I'm gonna show just four here. We did see similar efficacy in the others, but it gets a little bit busy on a slide to have nine muscles for each of these parameters. So in the top, we have DUX4 transcript. And you can see that, with the black, that's our baseline control, so those are animals that did not receive tamoxifen. In the blue, we have increase in DUX4 expression. Oh, I should mention, there's a known leaky DUX4 expression in this transgene. So, while, you know, while we do have baseline animals here, they do have a little amount of DUX4 expression. At the ages of these animals, that leaky DUX4 expression doesn't present any kind of a phenotype, but I believe it's known, later in life, without induction, these animals will start to show some of the disease phenotype. But in our case, we're using tamoxifen to accelerate that. and show a very pretty severe version of FSHD, like a phenotype in these animals, and that's what the blue represents here, is DUX4 expression increase. And then with our prevention, either at 1 mg/kg of the antisense or 5 mg/kg of the antisense, we were able to prevent that DUX4 expression increase in all muscles. And then even with the intervention, at 5 mg/kg of the antisense, we were able to reduce the DUX4 increase that we saw with tamoxifen administration back to baseline levels. And then if we look at WFDC3, so this is the biomarker of the DUX4 protein activity, you can see that a little bit of DUX4 increase leads to a very large and dramatic increase in expression of WFDC3, and we were able to achieve a 90+% reduction with the prevention and intervention, by day 31, in these mice. Next slide. Looking at the body weight and functional rotarod data. Let's see. So the panel on the left is body weight. Same thing, we had the strategy of dosing for prevention, just after we started tamoxifen treatment. And with the green, that's the prevention, and then with the orange, that's the intervention. You can see that, with prevention, the animals didn't appreciably or significantly deviate from the baseline in terms of body weight loss. Any animals that were treated with the prevention strategy maintained their body weight more or less to baseline levels. However, in the blue alone, that's the tamoxifen, so our disease model, we started to see significant body weight loss by around day 10, as I mentioned previously. And in the orange, you can see that the animals were starting to show body weight loss. But once we intervened with ARO-DUX4 on days 10 and 12, by day 17, we saw a significant reversal or I guess, a holding of the body weight loss, and then by day 22, we saw a return to baseline with those animals. So this demonstrates to us in the body weight data that ARO-DUX4 was able not only to prevent FSHD-like phenotype, but also to reverse it. In terms of rotarod performance, this is a different study, similar design. Animals were conditioned to the rotarod for 11 days prior to the beginning of tamoxifen administration. So we administered tamoxifen on beginning day 1, twice weekly, for the first week, and then three times weekly thereafter, just like in the previous study. This time, we only did the loading dose. We didn't continue dosing the animals with ARO-DUX4 beyond this initial loading dose. So with the prevention strategy, just doses on days 1 and 4, and then with the intervention strategy, we dosed on days 10 and 12. You can see that the animals that were not treated with ARO-DUX4 started to show pretty severe loss of rotarod performance by day 10, and then, with ARO-DUX4 treatment in the intervention, they were able to return to more or less normal rotarod performance by day 15. Meanwhile, the prevention animals never lost performance throughout. So again, another nice piece of data showing that ARO-DUX4 is able to prevent and or reverse the FSHD-like change in function that we've observed. Next slide. Right, so this, what we've shown is that the TRiM platform was able to give us pretty deep target knockdown that lasted at least 3 months in the non-human primate. That's actually based on our DM1 data that I presented previously. So using the DMPK as a surrogate in non-human primates, we're able to show that deep target knockdown is obviously the non-human primates don't express DUX4. In the patient-derived myotubes, we're able to show then that ARO-DUX4 can silence the misexpressed DUX4 and correct the altered expression of DUX4 target genes. And then in our transgenic mouse model, we were able to show that ARO-DUX4 could knock down DUX4 and return to normal levels the expression of the DUX4 proteins target genes. And that was in both a prevention and an intervention application. Next slide. All right, now James will tell us about the clinical trials. Sure. Thanks, Jonathan. We'll go to the next slide. So this is the design for the ARO-DUX4-1001 study. This is all in patients with FSHD1, and this study is open for enrollment with patients on study. Similar to the DM1 design, but with some key differences. We still do biopsies, pre-dose and post-dose, in the single-dose escalation component of the study, where we dose escalate from 1.5 mg/kg total conjugate up to 12 mg/kg total conjugate as single dose. And then starting at 6 mg/kg, we start to enroll multi-dose cohorts at doses ranging from 6-12 mg/kg. And here we're looking at two different dose regimens. We're looking at quarterly dosing, so 4 doses over the course of a year, or 2 doses over the course of a year, so dose, either every 3 months or every 2 months. So we should get a good idea, about not only depth of knockdown, but duration of knockdown, and can we push the dosing intervals out to, to less frequent administration. Next slide. Similar trial endpoints. Of course, this is primarily a safety study, but we'll also get a good look at serum and tissue-level PK. We will look for, DUX4 mRNA expression. The, the gene is notoriously difficult to measure, but, we're gonna see what, what we can measure. We will also look at downstream gene expressions, which might be a better way to look at, at target knockdown. Then patients are all getting MRIs, baseline, and throughout the study, so we can investigate any changes in muscle fat fraction or muscle fatty infiltration based upon on MRI. We've also included several functional tests, such as the 6-minute walk and a reachable workspace, and measures of muscle strength. And the sites are similar. I think they're both studies are open at the same sites in some of these countries. Sites are in Asia -Pac, and then also, again, in Canada and throughout the European Union. Next slide. So Vince, I'll hand it over to you for the Q&A. Thanks, James, and thanks, Jonathan and Lawrence, as well. I appreciate all the input here. This is a lot to cover here. This is very data heavy. I think that kinda what we've... The takeaway here that we wanna send to everybody is that we feel like we have potentially differentiated products here for both FSHD and for DM1. We're very confident in our preclinical data. We clearly are getting a high level of knockdown, and then there's other markers of potential for the future of these clinical programs. And then also, there is significant unmet need for both of these diseases. These are areas where patients are in desperate need of new innovative therapies, and we think we have some potential solutions here. And then lastly, you know, James covered this in, you know, in pretty good detail. We think that we have designed effective, early, first-in-man clinical studies to get at some key questions. Are we getting knockdown of the target? Do we see downstream surrogate markers that are of activity? And so we are eager to move forward with these clinical programs and share these data with everybody as quickly as we can. So for Q&A, we have the whole panel here, and I'm trying to compile as many questions as possible. There's a lot coming in, so I'm gonna combine some of these into individual questions, but I will read them off. So multiple folks asked these similar questions, and these are likely gonna be for James and Jonathan as well. So what do we see as the downside and safety risk of targeting transferrin receptor? Why did we decide on integrin targeting versus transferrin? And how does our preclinical data compare to the other competing transferrin-targeted programs out there with respect to knockdown? So I'll turn that to James to start. Yeah, sure. I can maybe answer the first two, and then I'll hand it over to Jonathan. So we showed some of the comparative data that we have. It's in the deck using our platform versus the transferrin receptor-targeted platform in our hands. And as I mentioned, you know, we're capable of making those conjugates as well. And the knockdown was better in terms of knockdown of DMPK, but also looking at other target genes. We also look at tissue concentrations, and we've routinely seen at the equivalent siRNA dose, similar to better delivery of siRNA into the tissue with the integrin-targeted approach. From a safety perspective, I mean, one of the key things that I think has been shown with targeting the transferrin receptor, particularly with a monoclonal, is, I guess you'd expect, anemia. And we would not expect to see anemia with an integrin-targeted approach. So there may be some other advantages. I think all of the programs are fairly early, and the safety database is limited, but we'll see. I mean, at the end of the day, the clinical data will carry the most weight. Jonathan, anything else that you wanted to add regarding the comparison preclinically? I think one of the things that differentiates us, so if we're talking about DM1, in particular, is the fact that we've demonstrated a dose response, repair in mis-splicing, and the fact that in our data, at least in our disease model, it looks like there's a threshold that needs to be overcome before you can get, you know, really deep and rapid mis-splicing repair. You know, when we started this program, we weren't aware of any competitor data, initially when it came to mis-splicing. As you know, no other data had been really published, using an siRNA to look at mis-splicing, say, in a rodent model of DMPK. So, so when we were going for it, we were going for, you know, 80% or better mis-splicing repair. And, when, when the clinical data emerged that, that, you know, 17, 18% was clinically relevant, you know, it was, it was kind of the equivalent of jumping 10 feet to clear a 3-foot hurdle. And, and, you know, that, that gave us, some confidence that we could, that potentially going, going higher is, is actually gonna be better when it comes to this approach. And, and so, you know, with our much smaller molecule, you know, we think that we can achieve that safely in, in the clinic. And, you know, as you showed in the, in the clinical design, that's, that's something that, that's something that we plan to do. Thank you. Thank you both. Next question, actually, Jason Gerberry from B of A, and Mayank Mamtani from B. Riley, had very similar questions. So I'll just put those together. And these are both for—likely for Dr. Korngut, so I'll put these to you. What level of DMPK knockdown may be necessary in humans to alleviate DM 1 phenotype? And second, what's the importance of sequestration of MBNL in cardiac versus smooth tissue in addition to skeletal muscle? Thank you. Thank you for those questions. You know, I think importantly, I'm a neurologist clinical trialist, so I'll probably steer away from some of the deeper biology kind of questions and defer to the other members of the panel. But certainly in terms of, you know, DMPK knockdown, I think we've learned across other diseases, I think, quite a holistic kind of perspective. Certainly, you know, seeing, you know, positive knockdown is important, but I think looking at the downstream impacts in terms of other genes, expressions, and then certainly phenotype is really been... I think we've been misled in different directions over the years in terms of what to expect. But I think, you know, from what I've seen here, you know, this is compelling data to me. And the other thing I'll mention about, in terms of the cardiac versus muscle, you know, I'll defer on the biology of that, but I think, again, as we've seen in other diseases, there's unmet need, and you can sort of look at that unmet need holistically, across, you know, the human body, you know, the different systems that are involved. But you can also look at it in very specific, sort of compartmentalized ways in terms of skeletal muscle versus cardiac. I think, you know, in a situation where the unmet need is total, so we do not have a disease-modifying therapy, I think, you know, you know, as a clinician, I'm looking for a treatment that can hit any of these compartments, you know, skeletal muscle, cardiac, and certainly the more of them that you can hit, the more value there is to the clinical scenario. But I think it's exciting to have, you know, feasibility in these different compartments together. So, but I'll defer on the other question. Yeah, I can, I can take a, a shot at the question about knockdown. I mean, I think for DMPK, it's an interesting target. You know, we've certainly worked on other targets with other programs where you need to hit, you know, you need to get 80%-90% knockdown to have an impact on the disease, or even more, with some of the viral targets. But this does not seem like that. That, you know, I think others have shown improvement in functional measures, things like video hand opening time with, you know, 30%-40% knockdown, total DMPK. So you probably don't need to crush it. At least that's what the clinical data out there so far supports. Thank you both. Next question, this was also asked both by Luca Issi at RBC and by Mayank Mamtani at B. Riley. Very similar questions. Why is RNAi the right mechanism versus ASOs, which may cross into the nucleus? And then the corollary of that is: What do we know about the difference between nuclear and cytoplasmic expression, and what makes us confident that we can get enough knockdown? So similar to the last question, but the site of knockdown. Yeah. You know, Jonathan, you may have some thoughts on this. I'll, I'll, throw out my thoughts on the first question. I think, you know, siRNA versus ASO, both approaches seem to work based on what's out there now in what's been presented by others who are in the clinic. Both approaches seem to be able to reduce DMPK and improve spliceopathy and improve the functional readouts in a similar manner. So I think that's, that's probably what's most important and probably more important than understanding the exact mechanism through which knockdown is occurring. Jonathan, what do you think? Yeah, I think, I think you got it right there. You know, it's been long debated about siRNAs activity in the nucleus, and, you know, we're not the only ones that are using this approach. But, you know, at the same time, we don't have a clear view as to what exactly is driving that. I think that's still something that's under debate in the wider community. But one thing that, you know, I think is pretty clear is that we have mis-splicing repair, and, you know, getting to the actual mechanism by which siRNA is affecting that is something that, you know, we and others intend to, you know, certainly continue to chip away at. But in the end, the, you know, the proof is in the pudding in terms of mis-splicing repair, and since that is the root of the pathobiology for DM1, being able to demonstrate mis-splicing repair, I think, is enough and certainly enough for the patients. Thank you. And this question came from Ted Tenthoff at Piper Sandler, and I was going to read it, but I don't have it right in front of me. So the, this is for Dr. Korngut. He wanted your impression of the recent Dyne DM1 clinical data. Yeah, no, I again hesitate to you know, say too much other than, you know, this DM1 has been a very challenging disease, you know, for the past, you know, 10-20 years in terms of development programs. I think what we're seeing is the outcome measures, you know, have been evolving, as have the sort of targeting technologies. I think it's an exciting time from the perspective of us being, you know, sort of as a community, being able to measure these differences more effectively. So I think, you know, things look, you know, very promising from the perspective of, if there's a strong signal, we'll be able to detect it. I'll add on to that, Vince. I mean, you know, we're really encouraged by those data, that it looks like, as I mentioned before, that without having to get, you know, 95% knockdown in the target, that a knockdown approach is able to improve spliceopathy, and that has led to improvements in functional ratings. So that, you know, that seems like a great outcome. Yeah, and maybe I can add one additional sort of perspective on that from the clinical perspective: is that, you know, the skeletal muscle system is regenerative by design, right, in the healthy state. And I think and there's also a sort of safety factor built into the skeletal muscle in terms of you can lose a certain amount before you're even symptomatic. And so I think these things make sense in terms of, you know, the numbers that we're seeing resulting in clinical improvement from the perspective of that basic physiology. And the way we think about it, I think as clinicians, that again, you don't have to sort of repair everything perfectly to start seeing the benefits. And I think that does represent that. Thanks so much. So Will Pickering at Bernstein has a question. This is platform question. How selective is our delivery to muscle? And also contrast the structure of the TRiM muscle delivery platform with our pulmonary delivery platform, which also targets the alpha-v beta-6 integrin. Yeah. So I'll, I'll take the second one first. The receptor that we're targeting is similar to the alpha-v beta-6 integrin receptor. With the muscle platform, we use a peptide, and we looked at the small molecule, but in this circumstance, the peptide looks better for the muscle platform. And then the other key difference with the muscle platform is the PK, PK/PD enhancer that we do not use in the pulmonary platform. In the pulmonary platform, we're just using the siRNA covalently linked to a small molecule that targets the alpha-v beta-6 integrin receptor. So that... Vince, what was the first part? I think that's the second part of the question. How selective is this to muscle? Right. So this is a way to get into the skeletal muscle. It is not skeletal muscle specific. We do see distribution to, to other tissue types, you know, liver, spleen, that sort of thing. Thank you. Actually, Ellie Merle from UBS asked a similar question. So what’s the distribution of knockdown across different muscle types? And I know at some point we’ve shown biodistribution data. I don’t think it was in this presentation. And then, secondly, which are the most important muscle types for DM1 and FSHD? Maybe, Jonathan, if you can, talk to- Yeah. D istribution of knockdown. Yeah. So the distribution. Well, I'll start with just the skeletal muscle. So as I mentioned, during the DUX4 part of the preclinical data, we looked at 9 muscles. We, you know, that which is a lot more than we normally would do. There's a tendency to assume that all skeletal muscle is the same, but we wanted to make sure that that was not an assumption that we were making without any data to back that up. Having looked at paraspinal facial muscles, you know, we looked at masseter, we looked at trapezius, and then we looked at lower limb, we looked at hind limb, and we looked at forelimb. We're fairly confident that we have delivery across the entire body, the entire skeletal muscle system, with some variations, you know, muscle to muscle. But in general, we were getting, you know, deep and durable knockdown in all the muscles that were analyzed. And then in terms of the biodistribution of the muscle platform, the TRiM platform, we do see, as James mentioned, distribution to other tissues, like liver. We do see some to heart, we see some to... I'm blanking on many of the others. But in general, we were looking for skeletal muscle enhancement. It may be that, especially in the case of DM1, that some of the off target, I'm sorry, off tissue delivery that we see with the muscle platform may in fact be a feature, that's desirable based on the amount of discussion that we've had about the cardiac in this particular—for DM1. But for DUX4, being that that's a skeletal muscle specific expression of a misexpression of that gene, to deliver the siRNA to any other tissues, we really don't have any concern there, as there won't be any target for it to interact with. Thank you. So another, next question is from Patrick Trucchio at H.C. Wainwright, and then he is asking: What is the potential for off-targeting of the platform? And then there's a follow-up question after that, that I'll get to. So when we select our sequences, we screen them for off-target effects. So there is, say, very low risk that we are going to silence genes that are not intended to be silenced for both programs, DUX4 and DM1. Yeah, and that's based both at the algorithmic level, you know, when we're doing the trigger design, as well as empirical data that we generate once we've selected a final candidate. His follow-up question was on our expectations for the pace of enrollment for the DM1 program. Yeah, I don't think we've talked about timing for full enrollment. There's a lot of interest. There are patients lined up for screening now. So I don't expect any challenges, we'll just put it that way, enrolling the study. And same goes for DUX4, by the way, that I don't anticipate excessive difficulty in enrolling that study. Okay, next question. Maury Raycroft at Jefferies. He's asking: How are we gonna measure DUX4 expression and relate it, and the reduction in gene expression of downstream DUX4 reactive genes in the clinic? Sure. Jonathan, you wanna take that one? Sure. And I might, I might actually tag in Dylan a little bit here, too. So, so DUX4 itself, we're, we're approaching that, from the digital PCR. So we'll be using the MRI-guided, muscle biopsy. So the idea is to locate a muscle that's, heavily affected by, or sorry, demonstrating a, a disease phenotype, and then, and then to biopsy there, and then, and then be able to repeat biopsy after, some time of treatment. And, and then measure by digital PCR, the DUX4, mRNA. And, and that's, that's with some hope. I mean, you know, as James said, it's not our main endpoint by any means. It's more of an exploratory endpoint or secondary endpoint that we're gonna see if we can, if we can reliably measure in these biopsy samples. And the same goes for the downstream genes. I mean, as you saw with the WFDC3 in the mouse, we also have a panel of DUX4 genes, sorry, DUX4 target genes, genes that are targeted by the DUX4 protein, that that increase dramatically. And for those, we're looking at those using PCR-based assays and this—from the same sample, right? So, you know, using MRI-guided biopsy, look for that, you know, much, what do I say, louder signal, from, from these, genes downstream of, of DUX4 that are, you know, amplified by the activity of DUX4, in an, in an attempt to, to look at those, the, the effect that we're seeing there, and the, and then, and then be able to show the effect that ARO-DUX4 has on those genes, even if we can't see DUX4 directly. Now, Dylan, did you have anything else to add for that one? No, I would just say for some of our sites that does not have the capability to do MRI real-time, enough MRI-guided, then we're doing MRI-assisted. So patients undergo MRI to identify STIR positivity, and then, when that becomes available, then they're brought into the operating room or the clinic for the biopsy. So it's with the image assistance, and some of our sites are able to do real-time MRI-guided. So it would vary depending on the site's capabilities. Thank you. So Andrew Tsai from Jefferies had, actually, so part of this question is likely for us and likely for Dr. Korngut. Let me start with Dr. Korngut. What are the most relevant endpoints for DM1? And then, the second part of this question is for us, what's our regulatory strategy and what endpoints are important from a regulatory standpoint? Yeah, that's a great question. Thank you. You know, I think always, you know, functional outcomes in terms of, you know, the patient's ability to, you know, perform activities. I think in the case of myotonic dystrophy, myotonia is it's a very disruptive symptom of patients being unable to relax their muscles. You know, I—so I think there are, you know, a number of outcome measures that have evolved, you know, to sort of reflect the regulatory requirements across these. And so but I think, you know, we're always looking at the more clinical measures in terms of understanding the benefit of the therapy. And then all the other measures, of course, still support the fact that there's efficacy. So, I think that's how I would look at it. We can't really comment at this point on approvable endpoints. We just haven't had those discussion with the regulators yet. We're still pretty early. I think we probably only have time for a couple more questions. This is from Prakhar Agrawal at Cantor Fitzgerald, and I'm gonna give this to James, but he likely is not gonna be able to answer too much of this. Just so you know. Competitors are showing 40%-50% DMPK knockdown in the clinic, and what level do we think we can get in the clinic? So, I guess the setup to that question may be for Jonathan. You know, what was the comparison of knockdown preclinically? Not necessarily what do we expect in the clinic. But James, you want to take that first, and then Jonathan, follow up? Yeah. I mean, we don't know yet. I mean, we don't have data yet from the study, so we don't know what level of knockdown we'll be able to achieve. I mean, based on the preclinical data that Jonathan showed in the monkeys, I would expect that we can achieve something similar. Historically, for our other programs, the liver-targeted programs and the pulmonary programs, translation from cyno to human at a given dose level has been pretty good. So, you know, I think that maybe partially answers the question. Yeah, and I would say, you know, comparing us to some of our competitors, the preclinical, you know, total DMPK conjugate, sorry, DMPK, transcript knockdown, is pretty comparable. You know, so if you look at the NHP data from our competitors, you look at the NHP data that we just showed today, you... I think the knockdown levels are comparable, there at the levels that were administered. But, you know, if you were then to consider, and then I think I mentioned this a little bit earlier, if you were to consider the mis-splicing data that we showed in our disease model, it may be that going higher does get us more or quicker results than if we were to stay at lower dose levels. And so our design is, our clinical design is taking that into account. This is probably our last. We only have time for one last question. So Keay Nakae from Chardan was asking about the PK/PD enhancer on the molecule, and how much does that increase the size of the compound? And this was not a part of the question, but, you know, the, I guess we had talked a lot about the larger amount of drug required for an antibody strategy. The doses that we are selecting, are they quoted as full dose, full compound, or the weight of the full molecule, or are we talking about just siRNA dose? Sure. These are the doses that we presented in the clinical trial design, both for DUX4 and DM1. Those are total drug, that's total conjugate. And the PK/PD enhancer is a small molecule, so it really does not add much to the total weight of the molecule. Yeah, I believe the difference in overall mass is something like 30% increase compared to just the duplex by itself. Yeah, and that's with the targeting ligand and the PK/PD modulator. So, you know, you take an siRNA dose and multiply it times 1.3, and you get the total dose. Thank you. So that is all the time we have. So thank you so much to Dr. Korngut and to the Arrowhead team, and thanks, everybody, at home for, for watching this. And we will see you next month for our next in the summer series where we'll talk about our cardiometabolic programs. Thanks so much for joining us today, everybody. Thank you, Nick. Thanks, everyone. This concludes today's webinar. You may go ahead and disconnect your line.