Good afternoon, welcome to the Ultragenyx second quarter 2023 financial results Conference Call. At this time, all participants are on a listen-only mode. At the end of the prepared remarks, you'll have the opportunity to ask a question during the Q&A portion of the call. It is now my pleasure to turn the call over to Josh Higa, Vice President of Investor Relations. Thank you. We have issued a press release detailing our financial results, which you can find on our website at ultragenyx.com. Joining me on this call are Emil Kakkis, Chief Executive Officer and President, Erik Harris, Chief Commercial Officer, Eric Crombez, Chief Medical Officer, Aaron Olson, Senior Vice President of Corporate Strategy and Finance, and Ted Huizinga, Chief Accounting Officer. I'd like to remind everyone that during today's call, we'll be making forward-looking statements. These statements are subject to certain risks and uncertainties, and our actual results may differ materially. Please refer to the risk factors discussed in our latest SEC filings. I'll now turn the call over to Emil. Thanks, Josh, and good afternoon, everyone. It has been a year of increasing momentum marked by advances in our lead clinical programs, which we expect to result in multiple important data catalysts over the next few quarters. At the same time, our excellent commercial efforts continue to drive meaningful revenue growth across the portfolio, including Crysvita revenue in North America with our partner, Kyowa Kirin, and in Latin America as well. I'll spend a few minutes discussing the osteogenesis imperfecta and Angelman syndrome programs before turning the call over to Erik Harris to talk through our commercial update. Beginning with OI, in June, we reported exciting data from the Phase II dose-finding portion of the pivotal ORBIT study, showing statistically significant increase in levels of serum P1NP, a sensitive marker of bone formation. The bone production response to these patients was extraordinary. This led to a rapid bone-building effect following just three months of treatment with setrusumab, resulting in nearly 10% increase in lumbar bone mineral density. At baseline, these patients had very limited bone mineral density, with an average Z-score in the 20 mg cohort of -2.12, which means the bone mineral density was two standard deviations below the mean of normal patients for their age. After three months on therapy, the mean Z-score increased by +0.65 points, resolving nearly one-third of the deficit from normal in a relatively short period of time. As we've said before, patients are showing meaningful improvements in bone health, and we are highly encouraged with how they are doing. Improved bone health refers to the instance of fractures, bone pain, and relative global health and activity of the patients. In the ongoing Phase II, we continue to collect data to compare fracture frequency during the conduct of the study to show the impact of setrusumab and increase the bone mineral density on fracture rates. We expect to share this data at an Analyst Day in mid-October, around the time of ASBMR, the major bone-focused meeting. In July, we announced that we initiated dosing patients in two Phase III studies evaluating setrusumab in two different age groups. The Phase III portion of the pivotal ORBIT study is evaluating the effect of setrusumab compared to placebo on analyzed clinical fracture rate in patients five to 25 years old. The newly initiated Phase III COSMIC study is an active controlled study evaluating setrusumab compared to IV bisphosphonate therapy on analyzed total fracture rate in patients aged two to five years old. Enrollment in both of these studies is going well so far, in part because the Phase II data has generated a lot of excitement for the potential setrusumab for both the clinical sites and from the patient community. Moving on to our Angelman program. In May, we announced we received FDA agreement to expand the ongoing global Phase I/two trial of GTX-102 to patients with Angelman syndrome in the U.S. The protocol amendment enabled us to harmonize the dosing range of use between the U.S. and ex U.S. cohorts of the study. Since then, we've been working to activate U.S. sites that have been on hold for a couple of years. We continue actively enrolling the expansion cohorts globally. Enrollment expansion cohorts is going well, particularly over the last couple of months. As of today, we've enrolled more than 20 patients. While we're on track to have eight patients with a full six months data by the end of the year, we've noted that waiting just a few more months will enable us to report a more substantial update on well more than 20 patients with six months of clinical data, plus safety data on all enrolled. Though the trial is going well, it seems more prudent to wait for this larger set of expansion core data, which we expect to have in the middle of the first half of 2024, based on enrolled patients to date. We will also be providing the Angelman program update at Analyst Day event in mid-October. This is an opportunity for us to provide more context for the clinical meaningfulness of the changes that have been observed in the study. Now I'll turn the call over to Erik Harris to provide an update on our commercial efforts for the first quarter. Thank you, Emil, and good afternoon, everyone. On April 27, 2023, five years after we began our highly successful Crysvita commercialization efforts, we transitioned the North American commercialization responsibilities to our partner, Kyowa Kirin. In the second quarter of 2023, the combined teams in the US continued to generate new start forms and have provided continuity of care for the existing patients. As a reminder, a smaller Ultragenyx commercial team will remain in place, supporting the Crysvita program in the US, alongside their counter- KKC counterparts through April 2024. Even beyond that time, Ultragenyx will continue to retain the responsibilities to promote Crysvita to medical geneticists in North America. We are thankful for the successful collaboration and expect to continue expanding penetration in the adult and pediatric markets. Shifting to Crysvita in Latin America, the team has continued to build impressive momentum in the region. As of June 30, there were approximately 410 patients on reimbursed therapy, which includes approximately 65 new patients who began commercial therapy in the quarter. Latin America is beginning to approach the same rate of commercial patient approval as we saw last year in the US, which bodes well for the long-term potential in the region. Each country has its own process to obtain regulatory and reimbursement approval, but our team has been diligently working to facilitate broad access to Crysvita despite the hurdles. I expect the underlying demand for Crysvita in Latin America to continue growing at a steady rate and becoming an increasingly greater contributor to the Ultragenyx commercial story. Today, we are reaffirming the Crysvita guidance we issued at the beginning of the year. The range of $325 million-$340 million includes all regions and all forms of Crysvita revenue. More specifically, it includes Crysvita product revenue from Latin America and Turkey, the cash and non-cash royalties from North America and Europe, and the collaboration profit share revenue prior to the transition. I'll now turn to Dojolvi and begin in North America. In the second quarter, we modestly expanded the U.S. Dojolvi commercial team with seasoned personnel from our Crysvita team to support continued growth and adoption of Dojolvi. During the first half of 2023, we added 61 completed start forms. We also increased reimbursements to 54 reimbursed patients in the first half of 2023. We continue to expand the number of treaters of Dojolvi, adding 18 new prescribers, including some healthcare professionals in Centers for Neuromuscular Medicine. In Canada, we continue to make steady progress following the positive opinion we received from CADTH, completing pCPA pricing negotiations and signing provincial listing agreements. In Latin America, we are continuing to leverage our existing infrastructure to commercialize Dojolvi. The patient find efforts have generated a growing number of patients with a confirmed diagnosis across Argentina, Brazil, Mexico, and Colombia. We are continuing to work with the authorities across the region to ensure Dojolvi is available for all patients who could benefit from this therapy. Across Europe, we continue to deepen awareness of LC-FAOD with key stakeholders and address the high unmet need through named patient and early access programs. Requests are coming across all major European markets, as well as Greece, Israel, and the Middle East. We continue to expect 2023 global Dojolvi revenue to be between $65 million and $75 million, reaffirming the range we announced at the beginning of the year. Lastly, I'd like to touch on Evkeeza. The team is focused on unlocking access across all markets in the EMEA region, deepening the awareness of HoFH and the urgency to treat, and reinforcing Evkeeza's unique profile amongst stakeholders. Across the region, a steadily growing number of patients are gaining access to Evkeeza through various early access programs. We are on track to launch in certain key EU markets over the next six months. The field teams are preparing the markets accordingly. Outside of the U.S., we are continuing to prepare for launches in Canada, Japan, and other major markets around the world, further expanding global access to this important therapy. Across all regions, we have received overwhelmingly positive feedback for Evkeeza from KOLs and patients, and they have continued to highlight the significant unmet need for this treatment. Our teams will continue their efforts to bring this product to people living with HoFH as quickly as possible. In closing, we are reaffirming our 2023 total revenue guidance range, issued at the beginning of the year, of $425 million-$450 million. With that, I'll turn the call to Aaron to share more details on the financial results for the quarter. Thanks, Eric. Earlier today, we issued a press release that included financial results for the quarter, which I'll briefly summarize. Company revenue for the quarter ended June 30, 2023, totaled $108 million. Crysvita revenue for the quarter was $83 million, which includes $61 million from North America, $16 million from Latin America, and $6 million in European royalty and other product revenue. The Crysvita revenue figures for North America and Europe are inclusive of non-cash components as a result of our previous royalty financings. As we typically remind you, ordering patterns in Latin America can fluctuate quarter to quarter, but we are continuing to see significant growth in the underlying demand for Crysvita. Dojolvi revenue for the quarter was $16 million, with continued strong North America demand, driving 22% growth versus the second quarter of 2022. Mepsevii revenue for the same time period was $8 million. It's worth noting Mepsevii revenue maintained the same level we saw in the first quarter, largely driven by new patients in Brazil and strong ordering from the US. Even six years after launch, this ultra-rare product continues to grow in patient accrual and geographic reach. Our total operating expenses for the quarter ended June 30, 2023, were $256 million, which includes R&D expenses of $165 million, SG&A expenses of $81 million, and cost of sales of $10 million. Operating expenses for the quarter include non-cash stock-based compensation of $35 million and a one-time milestone of $9 million payable to Mereo upon initiation of the Phase III ORBIT study in OI. For the second quarter of 2023, net loss was $160 million, or $2.25 per share. We ended the quarter with approximately $618 million in cash, cash equivalents, and marketable securities. As expected, through the first half of the year, cash use in operations was disproportionately greater than what we expect in the second half of the year. This is primarily driven by the timing of annual bonus payments and changes in certain working capital accounts. Additionally, we expect operating expenses to decrease in the second half of the year, driven by realized cost efficiencies and substantially reduced because of the North America commercial expenses, with the conclusion of the profit share period in April. With the impact of these cost reductions, projected second half revenue growth, and the timing of the working capital changes previously mentioned, we expect 2023 net cash using operations to be around $400 million. Now I'll turn the call to our CMO, Eric Crombez, who will provide an update on our key clinical programs. Thank you, Aaron. Good afternoon, everyone. Emil has already discussed the progress in the quarter for the osteogenesis imperfecta and the Angelman programs. I will briefly touch on the latest progress in our gene therapy pipeline. Starting with UX701 for the potential treatment of Wilson disease. Earlier this week, we announced that we had begun dosing the second dose escalation cohort in our pivotal study following completion of dosing and data review from the first cohort. In this first stage of the pivotal study, we are evaluating the safety and efficacy of up to three dose levels to determine the dose for the second stage of the study that will support registration. In July, the Data Safety Monitoring Board agreed that it was safe to proceed with dosing patients at the higher dose of 1e13. The first patient in cohort 2 has already been dosed, and the other four patients have been identified. This gene therapy is designed to directly address the underlying cause of disease by establishing the normal trafficking of copper. This will address both the toxicity of free copper and the copper deficiency, driving many of the signs and symptoms seen in patients who are not well managed on chelators. In the first dose cohort, UX701 has been well tolerated, with no unexpected related treatment-emergent adverse events observed as of July 11th, and there are early signals of the establishment of normal trafficking of copper. Initially, study entry required well-controlled signs and symptoms of Wilson disease on current standard of care, which proved challenging and resulted in a large number of screen failures, as many patients, for example, still had elevation in liver transaminases despite optimized chelator and zinc therapy. This tells us that even with current standard of care, there remains real unmet need for these patients. After additional discussions with regulatory authorities, we have changed entry criteria, and enrollment has accelerated. We are now on track to complete enrollment in stage one around the end of the year and expect to share initial data in the first half of 2024. Moving to DTX-401 for the potential treatment of glycogen storage disease type Ia. It is important to remember that all patients in the Phase I/2 study responded and showed meaningful reductions in their dependence on oral glucose replacement therapy. These patients have demonstrated a durable response, with patients moving into their fourth and fifth year of follow-up, with more detailed data presented at ASGCT in May. As we have previously disclosed, the Phase III study was fully enrolled earlier in the year. We expect data from the 48-week primary analysis period to read out in the first half of 2024. We look forward to sharing the first Phase III data generated by a gene therapy portfolio next year. Quickly on DTX-301, for the potential treatment of OTC or ornithine transcarbamylase deficiency. Enrollment in the Phase III study began earlier this year. This is a 64-week study that is designed to enroll approximately 50 patients. We are gaining meaningful traction with recruitment of this study, especially as more healthcare providers and patients appreciate the Phase I/2 data, with durable responses lasting more than five and a half years, with more detailed data also presented at ASGCT in May. Currently, there are 15 active global sites, with additional site activations pending regulatory and IRB feedback in Italy, UK, Japan, and Australia. We look forward to providing enrollment updates over the coming quarters as this program continues to build momentum. I'll now turn the call back to Emil Kakkis to highlight the key upcoming milestones and provide some closing remarks. Thank you, Eric. I'll summarize the key upcoming clinical catalysts before we open up for Q&A. Starting with UX143 for osteogenesis imperfecta, enrollment in both the Phase IIIs is going well, supported by meaningful demand from patients. Our goal is to have both of these studies fully enrolled around the end of the year. We also plan to provide additional clinical data from the Phase II portion of the study, including fracture data, at Analyst Day in mid-October. GTX-102 and Angelman syndrome. We're planning to give an update on the program at the Analyst Day in mid-October. That would include some information about the treatment effects we have observed so far in the earlier dose cohorts. We expect to share expansion data in the middle of the first half of 2024, when we're able to share 6-month data on at least 20 placed patients. Closing with our gene therapy programs, UX-701 for Wilson disease, enrolling patients in the dose-finding stage. We're excited about completing the first cohort and starting the second. We expect this dose-finding stage to be completed around the end of the year, with data on safety and initial signs of efficacy expected in the first half of 2024. DTX-401 for GSD1A dosed the last patient in the pivotal study earlier this year. We're now in the 48-week window and expect to share this Phase III data in the first half of 2024. Through the first half of the year, we've made meaningful progress across all of our priority initiatives. We finished and opened our gene therapy manufacturing facility outside of Boston, and just weeks successfully completed the first manufacturing run. This is not a modular assembled plant or refurbished clean rooms, but a true ground-up designed and built, state-of-the-art GMP manufacturing plant. To build a great plant is hard, to do it during the pandemic, to stay on time and on budget is exceptional. We give great kudos to our team on this accomplishment. In the second quarter, the commercial team continued to deliver meaningful revenue growth, with the Latam Crysvita franchise doing particularly well, becoming a larger contributor to the company's financials. Across the globe, our development teams are advancing one of the largest late-stage, rare disease clinical pipelines in the industry, we expect to generate a number of important data class catalysts over the next few quarters. With that, let's move on to your questions. Operator, please provide the Q&A instructions. Thank you. Ladies and gentlemen, if you have a question or a comment at this time, please press star 11 on your telephone. If your question has been answered, or you wish to remove yourself from the queue, please press star 11 again. We also ask that you limit yourself to one question and one follow-up. One moment for our first question. Our first question comes from Gena Wang with Barclays. Your line is open. Thank you. One quick question regarding the Angelman program. In mid-October update, what clinical measurement will you be presenting? Is Bayley's your key measurement? If so, what is your bar for efficacy to move forward? Yes. Our plan with when we will talk about there is focusing only on, on the clinical means of the effects we're seeing. The information on the Bayleys and that comparison was something we'll focus on with the expansion cohorts, where we have a large number of patients compared to a larger number of natural history patients, to give you the kind of quantitation maybe you seek. The October will focus more on the clinical meaningfulness and not so much on the detailed quantitative information. We'll reserve that for the expansion cohorts. Okay, Emil. Maybe follow-up, quick follow-up questions. Yeah. Based on the natural history, what would be the Bayley's, say, the change that you consider will be clinical meaningful, that you would be looking for, for your expansion cohort? Well, we've already put forth that the size of change we've seen, we thought were clinically meaningful. The amount you've seen before is, is there. I think I'd rather not go deeper into it. I think we need to do it in a more deeper context with data at hand, and I'd rather not go deep into that discussion at this moment. When we put out the Bayley data and we put out the other data, we'll have the clinical means, clinical meaningfulness thresholds, quantitative data, the natural history data to, to look at. I would not focus only on Bayley. I see there's also other endpoints we're going to be looking at, because we're still working through the data from our expansion cohorts to help us really nail down what's the right answer. Still in the mix is the Global Impression Scale, CGI scores, which FDA has accepted as primary, which would allow you to cover more domains, essentially, and be more Angelman-specific. We're still looking at a number of those particular endpoints, but the truth is, we've had relatively small amounts of data from these escalating cohorts. The expansion data allows us to really get a large number of patients treated the same way and to give us kind of quantitation to really answer your questions in a robust way, which is not quite there yet. I feel good about where we're at in the program and the fact that we have a drug that works, and that we need to figure out how to move it to the Phase III. Thank you. One moment for our next question. Our next question comes from Lisa Bei with Evercore ISI. Your line is open. Hi there. Can you just give us a sense of, of kind of your level of confidence about, what you're seeing in the OI program and how the changes in, in bone mineral density relate to potential changes you might see in fracture? Yes. Well, we, we have a high level of confidence that the magnitude of, of bone mineral density we saw at 3 months was already sufficient enough to improve the strength of bones and probably reduce fractures at that level we saw at 3 months in. We have high confidence in the fact that bone mineral density, when improved by this mechanism, the anti-sclerostin mechanism, where you're getting anabolism or production of new bone will translate into fracture improvements. We've talked about the non-clinical data in the past, but we'll be able to talk more about this at the October Analyst Day to provide that support. We have a high level of confidence that the BMD produced by an anti-sclerostin like setrusumab will translate into fracture reduction. Just as a follow-up on that, I, I, can you explain to me the, the amount of sort of the bone mineral density levels of OI patients? How do they relate to those of osteoporosis patients? Because I'm just trying to kind of relate the two changes, the amount of changes you're seeing to what we outcomes we've seen in osteoporosis, and it seems to me maybe the bone mineral density levels are slightly different. Could you can you expand on that at all? Well, sure, Lisa. What we said for this population, this study, is that the mean bone mineral density was -2.12, which means 2 standard relatable to the mean of normal people. Now, osteoporosis patients have reduced bone mineral density. I don't have for you exact comparisons to put forth, but I would say the mean of -2 standard deviations is pretty low on the bone scale. If you look at the range, we had patients as low as -4 standard deviations. These patients have, I think, a more severe, on average, bone mineral density problem than an average osteoporosis patient would, and therefore have more need of bone production. What has been the misunderstanding is everyone thought that the defect in the collagen was why the bones were fracturing. What we're kind of trying to say is actually, while that may be a factor, it's in fact, the effect of that mutation on bone production appears to be a bigger factor, and that's something we can change with setrusumab, and that's why we think we're gonna have an important effect on OI. Thanks. Our next question comes from Maury Raycroft with Jefferies. Your line is open. Hi, thanks for taking my question. Based on the expansion data in first half 2024, is the timeline for the pivotal study start shifted out some? Have you received any preliminary feedback from regulators on your data so far and what the pivotal design and endpoint could be? Is this something we can learn more about in the mid-October update? Yes, I, I don't think actually the timeline changes the timeline for what the Phase III is gonna be, because we're gonna be setting up the protocol and the plan and endpoint even before the full data are available. We'll already have understood what's going on. We'll have our discussions with the FDA soon after that and have a full protocol ready to get kick in and get going in 2024. It doesn't really change that timeline. It changes the timeline of how much we know and when, but we're gonna be gaining ground during the year, and we expect to talk with the critical outcome group at FDA, the COA group, this year. We haven't talked further yet with FDA. We're looking at when we wanna get to them. They said we could go to them. We'll look at when we wanna start talking to them about endpoints. They appreciate that this will require a lot more discussion than an average program, being a first-ever and a very complex developmental disorder. With the first meeting with COA, we'll get some ideas and feedback. We'll gain our data as we go along this year, but I would expect in late in the year, early next year, we'll have a handle on what we think the endpoints will be. The data will then further finalize the decision on dose regimen and allow us to head to and then the Phase II meeting in the first half, is our expectation, and to think about getting to a Phase III study then next year. Got it. That's helpful. Thanks for taking my questions. Our next question comes from Joseph Schwartz with Leerink Partners. Your line is open. Hi, I'm Joori dialing in for Joe. Thank you for taking our questions. I have two on UX701 for Wilson disease. First, could you talk about your decision to move to an open label design and broadening the inclusion criteria in phase I? How do these two factors impact the efficacy results, if any, and if any, that we're gonna get for the data that we're gonna get in the first half of 2024? Secondly, I believe in your opening remarks, you mentioned timelines around cohort two, but I'm curious about cohort three. When can we expect the stage 1 cohort three patients to be dosed, and will the cohort three data be included in the update provided in first half 2020? Sure. Well, I'll start with the last part. It's our expectation when we talk about first half is to, is to talk include cohort three patients, and the point at that point would be to make a decision on dose and to then kick off enrollment to Phase III. Because it's a combination study, we go right to Phase III, we make the call, make the decision, and move. The beauty of that is it'll cut out any dead time. It's already agreed on the endpoints and moving forward. Let me let Eric Crombez talk through the open label and the criteria changes and the reasoning for those and in the conduct of the study. Yeah, no, I think in the context of a single study registration, you know, it's always tempting at the beginning to, to kind of go to a double blind format there. The truth is, we do want to learn in that initial stage there, and the blinding was really kind of hindering that. That was in large part the driver to moving to open label, and I think it was absolutely the right decision, reviewing the data and really looking at those early signals after the readout from our first cohort. As far as entry criteria, a gene therapy has never been studied in Wilson patients, and certainly, it makes good sense to want to put any liver-directed gene therapy into as healthy of a liver as possible.... You know, I think a lot of treaters out there would say, you know, their, their patients are very good, their team is good and does a very good job of managing the patients. The truth is, is once we started screening a large number of patients, we realized most of these patients do not have LFTs in the normal range, meaning that they're still really having effect on the liver from the toxicity of that free copper. We needed to collect that data and have that discussion with the agency in order to adjust those entry criteria to allow more patients to enter the study. Okay, got it. Thank you. Our next question comes from Yigal Nochomovitz with Citigroup. Your line is open. Yeah. Hi, thanks. Another one on UX701. I think, you mentioned that you're seeing early signals of normal trafficking of copper. Can you expand on that a little bit? Is the goal of this gene therapy to get patients back into the normal range of copper or just closer to normal range? Thank you. It's, it's a little bit early. I'll let Eric comment a little more on that, but it's a little bit early to go deep into the data since it's just the first cohort. The goal of the program certainly was to try to improve copper distribution sufficiently to remove copper deficiency, which we believe is occurring and not fully understood in many patients. Yeah, we haven't set a threshold requirement for how much that would be, but our goal is by having both detoxification and some improvement distribution, we think you can have a much bigger impact than you can with just chelation. Maybe you wanna talk about the early signals of copper. Right, I think that's, that's really the point here. I mean, chelators have been great for this patient population, but chelators buying copper that's freely in circulation, you're not pulling copper out of these hepatocytes where it's accumulating. Again, that the fact that you have elevated transaminases, it shows that, you know, you're not excreting copper into the bile, and you're not loading copper onto ceruloplasmin, which is how it traffics to cells for copper to act as an important cofactor for a lot of enzymes. When you look at how you're measuring coppers for a chelator, it's different than how we're looking at copper levels, whether it's urine, blood, or from whatever capacity, once you establish normal trafficking patterns. Then importantly, we are still are looking at activity-based assay, which shows the loading of copper onto ceruloplasmin. Really, a very direct measure of the effect of, this gene therapy. The trafficking is... We have direct measures, urine, blood they're looking at to give us that sense, which is what the description of improving copper trafficking comes from. It's early yet. It's cohort one. We have more cohort to go. Thanks, Emil and Eric. Then on Angelman, just operationally, can you comment for the update in October and then for the one next year, how many of the patients under the U.S. protocol are gonna be represented in each of those updates? Just ballpark. Well, you see, in, in October, most of the patients are in the program are ex-US. There's only a small number that were on 2 mg that are now shifting to a higher dose, that's Cohort E. It's a relatively small number of US patients are involved in that. Exact number, I don't think is worth knowing. We put it in the, in the data release, how many patients we have. You know, I think what's probably most important is, when we talk about expansion, we're saying, well, well more than 20. It'll be significantly more than 20 that we'll have 6 months of data. That's why we can do a little more statistical analysis and have a group of people all treated the same way, whereas in the exploration cohorts, they were treated different ways, different doses, and it's not as easy to analyze. There'll be a small number of US patients in the fall, but a larger number with loaded the correct way that will be represented in the first half update on the expansion cohorts. Okay, thank you. Our next question comes from David Lebowitz, Stifel. Your line is open. There's two from me as well. One, a commercial question. Just wanted to clarify with the revenue numbers, it seems like there was a jump in the EU-derived royalty. Am I misunderstanding something, or can you maybe delve into what happened there and what the rest of the year may look like from the EU side of things? Second, on the clinical side, looking at the press release, on GTX-102, you mentioned the encouraging dose and time-dependent clinical activity. Was wondering if you can speak to any interpatient variability here. Is there a certain duration of follow-up or certain doses that you're starting to converge on for deriving therapeutic benefit, or is this still very much individualized? Thanks so much. Well, I'll start with the second part, then either Eric or Aaron can talk about the EU part. What we said is that as we look through time, we even published some of that, presented some of that data in July, that the day 128 data is not as strong as it is at day 170. Going a little longer, particularly some patients have a significant improvement in that time frame. There's no doubt there's some variation between patients and responsiveness. Some are responsive at very low doses, some need higher doses, that will be true no matter what. Our goal in the expansion course is not to find the perfect dose for all patients, to find a very good dose that gives a good effect, a large number of patients. Our expectation in the long run is that there may be some need to be individualization and titration. It's just hard to run that in a Phase III program. The main goal of expansion is to find a dose that works, the majority of patients that works well, and we think we can, we can do that. We see changes in all patients. All of them have improvements, but there's definitely some variation in the degrees of sensitivity, and we're still learning more. Truth is, we've treated relatively small numbers of patients now. For a year, it's about, I think it's more than 13 that have a year or so. With the expansion cohorts, it's gonna allow us to get, you know, 40 patients on drug and really learn something about, at 40 patients treated the same way, right? Get a better handle on the range and sensitivity. Our expectation, there will always be some variation, and we'll manage it. I think if we can get a majority of patients having a good treatment effect, a significant transformative change of life, then we'll be able to manage an extension, getting to the right optimal place. Let me leave that with that and let Aaron, is gonna talk about the EU. On the EU, the non-cash royalty did not jump in Q2. As a reminder, there is a part of our North America royalty that is non-cash now, and we can follow up offline with any other questions. Thanks, Kevin. Let's move on to the next question, please. Our next question is from Yaron Werber with TD Cowen. Your line is open. Great, thanks for taking my question. Emil, I, I got two. One, just on, on Angelman, in, in, in a sense, how many patients do you think you want to have in Phase II, down the dose, nail down the powering for the Phase III, and secondly, and potentially even nail down the schedule, the dosing schedule? Secondly, on Sanfilippo, you know, the, the, the program, the gene therapy program that you licensed, based on that Phase I, Phase II data, is there any way you can file for accelerated approval, just given FDA's new overture on accelerated pathways, even though that data, you know, was, you know, still early, not perfect, while you're doing a Phase III confirmatory? Thank you. Yep. Thank you, Yaron. On the Angelman program, we do have a lot of patients from the extension that are on drug for a long time. That's a chunk of patients that help us in deciding the Phase III. We'll announce in the mid part of first half, data from at least 20. It'll be well more than 20 of data. We'd expect to have 40-plus enrolled, maybe even closer to 50 enrolled. By, you know, towards second quarter or so, we'll have a lot of data on all those patients that will help contribute to the final decisions on dose and regimen that we'll be making. That, hopefully, that gives you kind of an outline of how much data we expect to have. We definitely think you need more than a handful to make this kind of decision, and 20 or so, 20-plus will be a good number to make a handle on what we have. Before we actually pull the trigger on the Phase III, we expect to have 40 patients worth of data or more to be confident that we've got the dose exactly right and we're picking the right things. On Sanfilippo syndrome, you know, accelerated approval is near and dear to my heart. I've been fighting for it for inborn errors for, like, nearly 30 years. Read my book, Dave and Ryan. Anyways, the truth is that the FDA wants, and particularly Peter Marks, wants us to do accelerated approval, but it's hard to get reviewers kind of to agree. We are working with the FDA, potentially on a workshop to talk about that. What I'd say to you is on our own Sanfilippo program, it's not exactly licensed. I guess it was licensed, but it was handed off to us. You know, we're excited to help these patients get forward. We, we did have to put into play some of, you know, the CMC part of the story, making the product has to get made, and a lot of the timeline is driven more about getting CMC set up than the actual data part. In the end of the day, even if they said today, they could-- we could file, we're still not ready because of the CMC part, so. We're gonna work on getting accelerated approval. I do believe there's an appreciation, but we now need to get some degrees of science and start doing it. We're setting up with a group of companies to go to the FDA, have a workshop, and talk through that. I've been advocating the FDA, both in editorials and in meetings, about the need to start seeing the science differently, and we hope we can get that to happen. I think if we can get that to happen for Sanfilippo and other MPS disorders, it opens the door to us actually getting the benefit of precision medicines that we have trouble fully capturing today with a system that's just not designed for rare, complex neurological diseases needing treatment. Thank you. Our next question comes from Jun Lee with Truist Securities. Your line is open. Thank you for taking our questions. I have a couple. On setrusumab, what's the value of doing an active comparator study against IV, IV bisphosphonate, which is off-label? Are you looking for non-inferiority or superiority, and how did you power the study? On GTX-102, in light of the recent discontinuation of rugonersen, what gives you confidence that one or two can succeed in Angelman, where rugonersen, with all the resources that Roche has to offer, failed to advance? Thank you. Sure. on setrusumab, our original plan was to do the placebo-controlled trial as the gold standard without an approved therapy. The truth is, the really young patients, there was more concern that those patients who have very high fracture rates couldn't be on a placebo, and there was resistance to that. At the same time, people are using off-label bisphosphonates, and people have impression of them as being standard of care, even though it's off-label. our view, though, is that the potential effects of setrusumab should be far better, far superior to bisphosphonates. The best way to get that is to actually study it and prove it. With the bisphosphonates, 5 randomized studies have been completed. 3 failed, 2 succeeded. The treatment effect size is a 20% reduction in fractures, so it's not very much. Patients do seem to feel better with it, once, which is why it's being used. In our trial, we're planning to do superiority of setrusumab to bisphosphonates, and we think the high fracture rate in that population and our expected effect on those fractures should generate a successful study that throughout the world, in all global areas where there may be reimbursement questions, be able to show why setrusumab should be standard of care for OI and not just a second-line treatment. That, that's, that's what that study will do. It's also particularly important in Europe, where comparison to drugs that are being used is important part of getting good reimbursement. There's a number of factors in, on all that. Now, on the, on the GSD1a and Roche rugonersen termination, we've been saying from the beginning that there are many ways to go after the Angelman locus, but the locus-specific region that we're working on is more potent, and it's because it's near the 5′ end of the message. This is the work that Dr. Dindot had. Roche and the others are working in further downstream. When we've made those molecules, we do not feel they're as potent. The only data comparison was that Roche required 24 milligrams to do what we were doing with 1 or 2 milligrams. I think whatever happened to the trial, we don't know. We only know what's public, but they weren't able to achieve a dose level applied safely that would allow them to get their knockdown they required to achieve what their particular goals were. In my view, that was somewhat expected because I think the potency was not enough, and I don't think it speaks at all to the mechanism, which we know from our data in our own hands, that we're having a, you know, transformed effect on the Angelman patients, and one that I think will be extremely important to them. That's operating at the dose ranges of 5-14 milligrams. That is what I think. I think it shows why the science matters, sometimes one really smart guy can beat a company with large amounts of money. Thanks, Emil. Our next question comes from Salveen Richter with Goldman Sachs. Your line is open. For taking our question. This is Tommy on for Salveen. Just trying to understand maybe more of the format of the Angelman release at the Analyst Day. Is it going to be in a similar kind of presentation as, for instance, the update last year? Any more detail you can provide on follow-up or patient numbers. Just if you have any updates on how the OTC Phase III enrollment is progressing. Thank you. Sure. I'll start with the Angelman. Maybe Eric can comment on OTC enrollment. It's interesting you ask about what the release is gonna look like. You actually want the categories, the size, the treatment effects. We all want to know. It's not gonna be the same as July, because in July, we put out a lot of raw information, which we were personally quite excited about at the company, and that received... We had a complex response from investors because it wasn't well digested. What we're talking about on Analyst Day is not like that situation where there's a lot of granular data. It's gonna be more high level. It's gonna talk about clinical meaningfulness, information that will provide to help give people a better feel why we, as a company, are confident on the importance of this therapy. It will not be focused on the quantitative data, which we said we'll let drive the expansion cohorts to large amounts of data to be able to do what I would call the data-driven, statistical kind of look at what we're seeing. It's a little bit more about clinical meaningfulness, and it'll be higher level than what we saw last July. Then for OTC, I'd like to comment in, it's doing really well. Again, designed very similarly with a similar global footprint with clinical trial sites to GSD1A, so the truly global phase III study there. Really good enrollment rate, and really tracking well to, you know, finish up enrollment next year. Thanks. Next question, please. Our next question comes from Christopher Raymond with Piper Sandler. Your line is open. Hi, this is Nicole Gabreski on for Chris. Thanks for taking the question. Just going back to the Wilson program, and sorry if I missed this, but I guess I was wondering if you could just expand on the changes you made for the patient inclusion criteria in the current study. I guess, was this just primarily around baseline liver transaminase levels that were modified? Then I guess just beyond this, does this change your thinking at all about the potential addressable Wilson patient population for a gene therapy? Yeah. The 2 big parts of entry criteria that changed were the LFTs. After initial conversations with the FDA, really wanting these LFTs very close to the normal range, with patients not being able to achieve that in chelators, we were able to have that conversation and allow patients with, with somewhat, I would say, mildly elevated LFTs, and that was important. Also, stability of copper levels on chelators and zinc. I think most people would, would tell you that those are, those are relatively stable and easy to control. It turns out they are not. Quite a, quite a bit of variability in copper levels, regardless of, of where you're looking. Again, really changing that criteria to allow enrollments to, to really accelerate. I would say we've always had high expectations for this gene therapy. We do think with all of really kind of how we target these diseases, replacing what's missing is important here. Chelators have done a great job for these patients, you know, again, we want to affect both the toxicity of free copper, which chelators does a decent job of addressing. Again, with the signs and symptoms of patients who are not well managed on chelators, we think is really driven by the fact that copper is not able to traffic to cells and tissues that need copper DAC as a co-factor for some important enzymes. Again, addressing both parts of this disease, and I think, yes, you know, really broadly applicable to, you know, all patients living with Wilson disease. Yeah, I would, I would add that I think our view of the addressable market has gone up. We used to say it was a, you know, a fraction that might have severe disease, not managed by chelators. The Alexion/AstraZeneca chelator also has been pulled because it really wasn't helping. That probably opens up the addressable market because there's some view that maybe that chelator would be better, but it wasn't. Given our knowledge of how many people have transaminase and copper issues still and don't feel right, I do think the addressable market for Wilson could be higher. If we see a great effect in copper distribution and symptom improvement otherwise, I think there's a possibility that it turns out to be a more important player in Wilson, a bigger fraction of the population. We still have more data to collect. We're not there yet, I do think the possibility that this could become a more important and major that most or all patients with Wilson could be addressable, I think is a possibility, which I think, makes this a, really important program to push ahead as we are. Great. Thank you. Our next question comes from Kristen Stewart with Keefe, Bruyette & Woods. Your line is open. Everyone, thanks for taking my question. Just one on manufacturing. Given the size of your new facility, how much flexibility does this allow you to expand beyond the current pipeline? Maybe what are some of the mid to longer term goals with building this as well? Thank you. Yes, the plant gives us a lot more flexibility because we can flip and switch what we do. We're still in the build-up phase in terms of how many runs we can run, but that will, that will accelerate quickly. We also have a second suite that we can outfit and operate, which would get us to be running 32 runs a year. So I think we probably would have capacity to, for example, if we did partnerships or other deals, we could offer manufacturing plus the piece of those type of deals, is something we could do. I would say to you, we have really one of the larger AAV programs out there with three programs in phase III, Wilson, OTC, GSD1A. We also have potentially to put in the plant the UX055, the CDKL5 deficiency gene therapy, which is heading toward an IND and is actually the subject of the first run in the plant. We also have a program, I talk about too often, is the Duchenne program, which is coming, and potentially some others. We have a great use for the plant, but I do think it gives us the capacity to be able to do some other manufacturing for other programs as needed. I think the team will be a superb team, and given the challenges at CMOs, I think that it will become a valuable asset broader than simply making our own products. Thank you. Our next question comes from Anupam Rama with JPMorgan. Your line is open. Hi, everyone. This is Priyanka on for Anupam. We just have 1 quick question. Will the Analyst Day be only focused on the 143 and GTX-102 programs, or will the overall pipeline also have other various updates? Thank you. Yeah. The expectation is to have several other programs highlighted there. Some you know about, maybe some you don't. Could be interesting. Don't miss it. We have a great pipeline, and the hard part is that it's really hard for most people to handle more than one or two good things, but Ultragenyx has got half a dozen things, and we will have more than GTX-102 at the meeting. I think it tended to be exciting. We tend to bring what we're learning and new things we've put together and hopefully give people a better breadth of understanding of the value we're creating and what we can do as a company, as I think we will become the leading rare disease company out there. Thank you. Our next question comes from Joel Beatty with Baird. Your line is open. Hi, this is Ben on for Joel. Thanks for taking the question. I'm sorry if I missed it, but what are next steps for dosing the remaining 4 patients in cohort 2 for Wilson disease? Yeah, no. We do have a 2-week dosing interval that was required by the FDA for cohort 2. Those additional 4 patients are lined up and ready to go. They're all screened and waiting, so it's just a time clock now. Yeah, and then we will have another DSMB meeting, and then we're only required to have a single week between dosing for the third cohort, so the timeline will start to accelerate. Got it. Thank you so much. I'm not showing any further questions at this time. I'd like to turn the call back over to Josh for any closing remarks. Thank you. This concludes today's call. If there are any additional questions, please contact us by phone or at ir@ultragenyx.com. Thank you for joining us. Ladies and gentlemen, this concludes today's presentation. You may now disconnect and have a wonderful day.