Please stand by. Good day. Welcome to the Travere Therapeutics First Quarter 2023 Financial Results and Corporate Update Conference Call. Today's conference is being recorded. At this time, I would like to turn the conference call over to Vice President of Investor Relations, Naomi Eichenbaum. Please go ahead, Naomi. Thank you. Good afternoon, and welcome to Travere Therapeutics First Quarter 2023 Financial Results and Corporate Update Call. Today's call will be led by our Chief Executive Officer, Dr. Eric Dube. Eric will be joined in the prepared remarks by Dr. Jula Inrig, our Chief Medical Officer, Peter Heerma, our Chief Commercial Officer, and Chris Cline, our Chief Financial Officer. Dr. Bill Rote, Senior Vice President of Research and Development, will join us for the Q&A session. Before we begin, I would like to remind everyone that statements made during this call regarding matters that are not historical facts are forward-looking statements within the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements are not guarantees of performance. They involve known and unknown risks, uncertainties and assumptions that may cause actual results, performance and achievements to differ materially from those expressed or implied by the statement. Please see the forward-looking statement disclaimer on the company's press release issued earlier today, as well as the Risk Factors section in our forms 10 Q and 10 K filed with the SEC. In addition, any forward-looking statements represent our views only as of the date such statements are made, May fourth, 2023, and Travere specifically disclaims any obligation to update such statements to reflect future information, events or circumstances. With that, let me now turn the call over to Eric. Eric? Thank you, Naomi, and good afternoon, everyone. The first quarter of 2023 has been one of critical milestones, representing significant progress across the organization. These advancements have positioned Travere for sustained growth, led by the ongoing launch of FILSPARI in IgA nephropathy and bolstered by the continued progression of our pipeline. The most notable achievements in the quarter was the U.S. accelerated approval of FILSPARI or sparsentan for the reduction of proteinuria in adults with primary IgA nephropathy or IgAN at risk of rapid disease progression. The approval of FILSPARI marks the first and only non-immunosuppressive therapy for the reduction of proteinuria in IgAN. While we are only in the early stages, the commercial launch is progressing very well and in line with our expectations. Today, we'll focus on the important takeaways from the first 6 weeks, but I am very pleased with the early demand and the commercial organization's execution, which instills confidence that we will effectively position FILSPARI to meet or exceed our internal goals for the year. We were very excited to see the interim results from the PROTECT study published in The Lancet. These data further elucidate the clinical profile of FILSPARI, demonstrating a greater than 3-fold reduction of proteinuria from baseline after 36 weeks of treatment compared to the active control irbesartan. The compelling data set support our confidence in a positive outcome from the 2-year secondary endpoints in the fourth quarter of this year. It was a great quarter for our efforts to establish the foundation for FILSPARI to become a new treatment standard in IgAN for the addressable population. Earlier this week, we were disappointed to report that our phase three DUPLEX study of sparsentan in FSGS did not achieve the primary efficacy eGFR endpoints. FSGS is a very difficult disease to study. Despite this, sparsentan still managed to demonstrate a consistent profile characterized by sustained proteinuria reduction and a well-tolerated safety profile over two years. We will continue to analyze the data sets and engage with the FDA and EMA to explore the potential for future regulatory submissions in FSGS. Once we've completed this, we'll provide an update on our direction. With regard to pegtibatinase, we continue to be highly encouraged by the forward momentum in our program for classical homocystinuria or HCU. As many of you will recall, HCU is a serious and progressive metabolic disorder that can lead to thrombotic events, serious vision problems due to lens dislocations, bone malformation, and a constellation of mental and psychiatric complications. Importantly, pegtibatinase is well-positioned to potentially become the first and only disease-modifying approach to treat HCU. We have made recent strides in our program and remain on track to report data from cohort 6 in the second quarter. We are incredibly grateful to the patients, family members, and physicians who have supported us in our pursuit of therapeutic advancements for diseases with high unmet needs. Our team remains committed to our mission of improving the lives of those living with rare disease, delivering for our patients, for the rare disease community, and our shareholders. Now let me turn the call over to Jula for a clinical update. Jula? Thank you, Eric. Good afternoon, everyone. I'll start by highlighting our continued efforts to support the awareness and education of the FILSPARI clinical profile. As Eric mentioned earlier, we were very pleased with the recent publication of the interim results from the phase 3 PROTECT study in The Lancet. The rapid publication in this renowned journal speaks to the scientific relevance and strength of the PROTECT interim results in IgA nephropathy. The publication serves as a great platform to showcase the interim results from PROTECT, the largest interventional study of its kind in IgA nephropathy. The published results detailed the rapid and sustained reductions of proteinuria seen in PROTECT, along with the inclusion of significant new data on complete and partial remission. The new data highlighted that after 36 weeks of treatment in PROTECT, a significantly greater proportion of patients on FILSPARI achieved complete and partial remission of proteinuria. As recently published, most high-risk IgAN patients will face kidney failure within their lifetime, and reducing and maintaining lower thresholds of proteinuria, particularly to levels less than 0.5 grams per day, can impact long-term kidney outcomes. We also saw encouraging early trends on important kidney outcomes. Here, approximately half the number of patients treated with FILSPARI reached the confirmed 40% reduction in eGFR from baseline, kidney failure or all-cause mortality compared to irbesartan. Furthermore, important data were included that support our belief and the primary efficacy objective of the phase 3 PROTECT study that optimally antagonizing endothelin-1 and angiotensin II with sparsentan may lead to protective effects in the kidney structure and function beyond hemodynamics. Specifically, the authors drew the conclusion that the proteinuria lowering effect of sparsentan is unlikely to be attributable to differences in blood pressure, especially given the large differences in proteinuria reduction relative to minimal differences in blood pressure. Finally, the publication also included additional safety data from the interim analysis, which reported no cases of heart failure at the time of the analysis, no treatment discontinuations or serious adverse events of peripheral edema, and no significant difference in weight change between treatment arms. These published interim results and the preliminary eGFR data from the interim analysis and the clinical literature demonstrating the relationship between proteinuria reduction and eGFR benefit support our steadfast confidence for clinically meaningful and statistically significant treatment effect on eGFR after two years of treatment with sparsentan. I'm pleased to report that the PROTECT study continues to accrue patient data as expected and remains on track for the scheduled top-line readout in the fourth quarter of this year. Since FILSPARI's accelerated approval, we've also received solid support from the nephrology community, including physicians, patients, and advocacy groups. Following a discussion with an academic nephrologist at NKF, I learned that The Lancet publication was the primary reason behind their decision to start to prescribe sparsentan to a handful of eligible IgAN patients. We're receiving similar anecdotes that physicians intend to alter the way that they treat their patients by including FILSPARI as a key treatment option now that it's available. FILSPARI is now included in the treatment recommendations for IgAN in UpToDate, an industry-leading clinical decision support tool for physicians. The physician authors recommend that patients with persistent proteinuria after 3-6 months of RAS inhibitors be treated by adding an SGLT2 inhibitor or switching the RAS inhibitor to FILSPARI. We eagerly look forward to the confirmatory phase 3 PROTECT study data, which we believe will put us in a strong position to enable FILSPARI to become the new foundational therapy in IgAN. Since we recently hosted an update call, I'll only briefly touch on sparsentan's development in FSGS. While we were disappointed to report that the DUPLEX study did not achieve statistical significance on the eGFR endpoint, it did demonstrate consistent proteinuria reduction of 50% across studies. Importantly, we also saw that with a higher dose, sparsentan continued to be well-tolerated. Since we reported our results, we've had a chance to engage with both nephrologists and the patient community. The resounding feedback has been supportive and encouraging. This, combined with the positive trends seen in the study, further supports our motivation in seeking a path forward with regulators in both the U.S. and Europe. Beyond sparsentan, we continue to advance our pegtibatinase program in classical homocystinuria. As many of you will recall, in the first five cohorts of our ongoing phase 1/2 COMPOSE study, pegtibatinase demonstrated a dose-dependent response and ability to dramatically reduce total homocysteine to clinically meaningful levels with the 1.5 milligrams per kilogram dose. Importantly, pegtibatinase was able to show a generally well-tolerated safety profile. In the sixth cohort, we're examining a higher dose and lyophilized formulation, which will give us valuable insights for the program's next steps and aid our discussions with regulators regarding the design of a phase 3 study to potentially initiate in the second half of this year. Additionally, we've made recent progress on our manufacturing to support a pivotal program and commercialization. We hear now more than ever from physicians and the patient community that new disease-modifying treatment options are desperately needed in HCU. We look forward to sharing an update on those data later this quarter and plan to provide an update regarding next steps for the program later this year. With that, I'll turn the call over to Peter for the commercial update. Peter? Thank you, JoAnne. I'm pleased to report that we are making great progress in the early days of FILSPARI launch. Our results in the 1st quarter include only 6 weeks, and we are in line with our expectations. We are encouraged with the strong level of interest and engagements that we are seeing across stakeholders, including patients, physicians, and payers. Let me reflect on our progress and share some of the metrics that we saw in the 1st week, 6 weeks of approval until the end of Q1. Since our approval on February 17th, we have remained focused on our 3 launch priorities, educating nephrologists on the efficacy and safety profile of FILSPARI, enabling broad patient access by securing reimbursement coverage, and ensuring that both patients and physicians have a positive 1st experience with FILSPARI. First, looking at our physician education efforts. Our commercial field team of over 80 seasoned professionals is successful in getting access to nephrologists and educating them on the FILSPARI label. Our strategy is to ultimately reach a universe of 6,000 nephrologists, representing roughly 85% of the addressable IgAN patient population for FILSPARI in the U.S. We have face-to-face interactions with over 2,500 of these nephrologists in the first six weeks. These engagements are aligned to our profiling insights, we are reaching those nephrologists that have been and we believe will be the early adopters. The reception to FILSPARI's efficacy and safety profile has been strong. Physicians consistently mention the impressive proteinuria reduction with FILSPARI and the importance of having a non-immunosuppressive IgAN therapy. We are excited to see a strong increase in brand awareness now that our team is actively discussing FILSPARI with nephrologists. As mentioned on the last earnings call, we received our first Patient Start Forms on the first working day after approval, which was also the day that we started educating physicians about FILSPARI. The first product was shipped to the patient the week after, just 8 working days from approval. We heard from one of these early prescribers. Anecdotally, with his first patients treated with FILSPARI, over the first 6 weeks, he has observed a rapid proteinuria reduction consistent with what was demonstrated in the interim PROTECT analysis. These are the stories that energize our incredibly dedicated launch team. This team is going steadfast in serving and educating our stakeholders. It is encouraging that we are starting to hear how patients may be benefiting from FILSPARI treatments. In the first 6 weeks, Travere TotalCare received 146 Patient Start Forms. We see an increasing number of physicians getting enrolled in the REMS program as they have identified patients who can benefit from FILSPARI. Secondly, we are making robust progress in educating payers on IgAN as the leading glomerular disease cause for kidney failure. That most IgAN patients progress to kidney failure within 10-15 years of diagnosis. The meaningfulness of proteinuria is a prognostic indicator for disease progression. Within that context, our in-field account team is emphasizing FILSPARI's compelling value proposition to the payers. As a result of these educational efforts, we are seeing FILSPARI is being discussed at P&T committees. The first formularies start including FILSPARI in their policies. These product-specific coverage plans are aligned to the FILSPARI label indication. In the first 6 weeks, we achieved 38% payer coverage of the U.S. population. In the coming months, we anticipate coverage will continue to expand, and we will periodically share our continuing progress. Similar to other newly approved therapies for rare diseases, initial access to FILSPARI is mainly through prior authorization and if denied, through appeal processes. We are encouraged with the rate that patients are able to gain access. Should a claim experience a slow or delayed adjudication process, we have support programs to provide eligible patients with access to products. Finally, our third launch priority is providing IgAN patients, their caregivers, and the treating physician with a positive experience in the FILSPARI treatment journey. I'm proud of the comprehensive services offered through Travere TotalCare, which was designed with the patient in mind to offer easily accessible programs, including personalized education, assistance in the REMS process, support in the reimbursement process, and co-pay assistance for eligible patients. Initial patient feedback is rewarding as we hear through Travere TotalCare about patients' appreciation for these offered services. In addition to Travere TotalCare, we designed enhanced support services to streamline and simplify the REMS enrollment and implementation process for physicians and patients. We are hearing from nephrologists that the REMS process is straightforward. To my earlier point, we are seeing a significant number of physicians enrolling in the REMS program because they have patients identified that could benefit from FILSPARI. From a financial perspective, we finished the first quarter with net FILSPARI sales of $3.0 million. It is important to note that this is predominantly based on the specialty pharmacy's initial starting of the distribution channel. As you may recall, we utilized a small network of specialty pharmacies to maintain high services for our patients. One of these specialty pharmacies has multiple regional distribution centers that each elected to stock for the initial launch to be ready for demand. As a result of this, we anticipate that a meaningful portion of this stocking in the first quarter will be drawn down in the second quarter and impact our second quarter revenue. We anticipate that it will begin that we will begin to see a more representative trajectory of both demand and reimbursement in the third quarter and a clear view by the fourth quarter. Overall, I believe that the launch is off to a strong start. We are seeing steady demand building. The initial metrics that I shared indicate the nephrology community's excitement for FILSPARI's potential for IgAN patients. With the recent planned publication of the PROTECT interim analysis, inclusion of FILSPARI in the treatment guidance tool UpToDate, the personal experience that nephrologists are getting on the rapid and sustained proteinuria reduction with FILSPARI in their own patients, and the number of nephrologists that are now involved in the REMS program gives me confidence that we will continue building the momentum. With respect to the commercial performance outside of FILSPARI, I am really pleased how our team is continuing the strong execution in connection with our established commercial portfolio. Our bioasset products reported $26.1 million in net product sales for the first quarter, which is consistent with our expectations of single-digit organic growth in 2023. For Thiola, we reported $21.2 million in net product sales in the first quarter, which is comparable to the same period last year. We continue to be reaching patients despite the competitive market dynamics. Summarizing, we are really pleased with the commercial performance to start the year. Most importantly, the initial adoption of FILSPARI is progressing well and in line with our expectations. We expect the second quarter to work through the stocking from the initial launch, and then we look forward to the true launch trajectory becoming more visible beginning in the third and fourth quarters. Let me now turn the call over to Chris for a financial update. Chris. Thank you, Peter, and good afternoon, everyone. Our first quarter performance was highlighted by continued strong execution across the organization, as well as the strengthening of our financial position. For the first quarter of 2023, net product sales were $50.3 million compared to $46.4 million from the same period in 2022. The increase is primarily attributable to the first reported sales of FILSPARI and growth in sales of the bile acid portfolio. As for FILSPARI, we utilize a sell-in methodology where we recognize revenue when products are delivered to our small network of specialty pharmacies. As you heard from Peter, that has resulted in a large amount of the FILSPARI sales recognized this quarter being related to stocking anticipation of demand. For the legacy products, as we've seen in previous years, gross and net discounts in the first quarter were higher as a result of insurance coverage changes in the beginning of the year. As we move through the balance of the year, we expect these to normalize, but they will continue to be higher for the Thiola business than in previous years. During the quarter, we also recognized $6.7 million of license and collaboration revenue. This compares to $2 million in the same period last year. The increase is primarily driven by a sale of drug product to our partner CSL Vifor as they prepare for a potential launch of FILSPARI in Europe. This activity also resulted in a nearly proportional increase in cost of goods sold for the quarter. Research and development expenses for the first quarter of 2023 were $59.9 million, compared to $56.6 million for the same period in 2022. The difference is largely attributable to the continued advancement of our sparsentan and pegtibatinase clinical programs, including clinical trial expenses, manufacturing, and increased headcount. On a non-GAAP adjusted basis, R&D expenses were $53 million for the first quarter of 2023, compared to $53.2 million for the same period in 2022. Selling, general, and administrative expenses for the first quarter of 2023 were $72.2 million compared to $46.8 million for the same period in 2022. The difference is largely attributable to the onboarding of the FILSPARI field team and supporting staff, as well as launch-related activities, including the initiation of our REMS program and patient services with the approval of the FILSPARI launch in the first quarter. During the quarter, we also began to amortize the $23 million milestone payment paid to Ligand upon approval of FILSPARI. On a non-GAAP adjusted basis, SG&A expenses were $55.8 million for the first quarter of 2023, compared to $35 million for the same period in 2022. Total other income net for the first quarter of 2023 was $0.8 million, compared to total other expense net of $9.8 million in the same period of 2022. The difference is largely attributable to a recognized loss on extinguishment of debt relating to the refinancing of our convertible notes in March 2022, partially offset by an increase in interest income. Net loss for the first quarter of 2023 was $86.3 million or $1.27 per basic share, compared to a net loss of $76 million or $1.20 per basic share for the same period in 2022. On a non-GAAP adjusted basis, net loss for the first quarter of 2023 was $56.2 million or $0.82 per basic share, compared to a net loss of $51.6 million or $0.82 per basic share for the same period in 2022. As of March 31, 2023, the company had cash equivalents, and marketable securities of $561.5 million, which includes $216 million in net proceeds from our underwritten offering of common equity in early March. It also reflects the $23 million milestone payment we made to Ligand as a result of the FILSPARI approval in February. Looking to the balance of 2023, we anticipate that our operating expenses will increase moderately and may be variable quarter-to-quarter as we advance our programs. Importantly, we will be focusing our investments in the FILSPARI launch and IgAN and the advancement of pegtibatinase as the potential first disease-modifying therapy for HCU. We will remain disciplined in our investment in FSGS while we work towards further regulatory guidance later this year. With our strong financial foundation, we anticipate that our cash balance can support our operations into 2025. This takes into account the investments I just highlighted in FILSPARI and pegtibatinase, as well as potential further competitive dynamics for Thiola and potential milestone payments related to achievements for the programs. I'll now turn the call back over to Eric for his closing comments. Eric? Thank you, Chris. We began the new year with the first FDA approval from our rare disease pipeline. The accelerated approval of FILSPARI marks the first and only non-immunosuppressive treatment indicated for the reduction of proteinuria in patients with IgAN. I am very pleased with the execution so far in the launch. Most importantly, following the first six weeks of launch, we are well in line with our expectations for demand, patient access, and reimbursement. I am very pleased with how our team is executing on our launch plan. We will remain focused on building momentum as interest amongst nephrologists continues to grow, and we look forward to providing regular quarterly updates on the FILSPARI launch. We also have a number of exciting milestones ahead of us this year. We look forward to the top-line results from the PROTECT study in the fourth quarter of this year and remain highly confident in the final results achieving a statistically significant treatment effect on eGFR, as we know physicians are excited to see those data. We believe positive results will lead to traditional approval of FILSPARI and catalyze the next phase of growth. Furthermore, we are pleased with the ongoing EMA regulatory review and look forward to a potential approval of sparsentan for IgAN in Europe in the second half of the year. Finally, we are very excited about the opportunity in HCU. The HCU community has been highly underserved, and they are eagerly seeking effective treatment options. Pegtibatinase has the potential to become the first disease-modifying therapy for this population if approved, and we look forward to providing an update on the program later this quarter. Let me turn the call back over to Naomi for Q&A. Naomi? Thanks, Eric. Operator, can we now open the line for Q&A? Yes. If you would like to ask a question, please signal by pressing star 1 on your telephone keypad. If you are using a speakerphone, please make sure your mute function is turned off to allow the signal to reach our equipment. Again, press star 1 to ask a question. We will take the first question from the line of Maury Raycroft from Jefferies. Maury, your line is now open. Hi, congrats on the progress with the launch, and thanks for taking my questions. Based on the Lancet paper, PROTECT is powered at 90% to detect an underlying treatment effect of 2.9 mil per minute per year. That translates to 5.8 mil per minute over a 2-year treatment period. Can you clarify if that is the delta versus irbesartan or is that, is that only the sparsentan treatment effect? Maury, thanks for the question. I will turn that over to Jula. Thanks, Maury, for the question. To clarify, we have greater than 90% power to detect a difference in slope of 2.9 mLs per minute per year with 380 patients. Just to give some more color, this is based on historical data and achieving a 30% difference in proteinuria. Recall, we achieved a 41% relative reduction in proteinuria, giving us a geometric mean ratio of 0.59. When you put that on the ANCHOR curve, it predicts a slope difference close to what we originally modeled, and it shows a very high positive predictive probability for a difference in eGFR slope, even with a modest-sized trial. I'll point you, if you want more details, I'll point you to the ANCHOR appendix so that you can actually do some of this analysis yourself. Got it. That's helpful clarification. Based on the new DUPLEX data and the view that IgAN is a progressive disease, is there anything additional you can point us to for how we should think about irbesartan arm treatment effect size on eGFR in PROTECT? Remember the irbesartan arm in PROTECT was already essentially optimized on RAS inhibition. They were at least 50% label, max 3 tolerated RAS. Essentially, they were treatment failures 'cause they had persistent proteinuria despite this. There was still an incremental reduction in proteinuria on those on IRB, but, you know, we had a 41% relative reduction in proteinuria compared to the irbesartan arm. I would imagine that we can anticipate those on irbesartan to progress similar to what we've seen in other studies, maybe slightly better. You know, in the Tarpeyo study, they progressed at 6 mils per minute per year. Maybe they'll do slightly better than that just because we had a slight reduction in proteinuria, but that is what I would say compared to the historical control. Got it. That makes sense. Maybe last quick question. Similar to DUPLEX, I'm wondering, do you have any feedback from FDA on whether it would be okay if you miss on total slope but hit stat sig on chronic slope for PROTECT? Bill, why don't you take that question? We don't have a specific dialogue from the agency addressing that with PROTECT. In the discussions around the design of the DUPLEX study, they did say that in the end, while the study is designed around total slope first and chronic second, they certainly wanna look at all of the elements of the study. I think that my expectation is they'd be consistent with each program with that type of approach. Got it. Okay, thanks for taking my questions. Thank you, Maury. We will take the next question from the line of Greg Harrison from Bank of America. Greg, your line is now open. Hey, good afternoon. Congrats on the FILSPARI number, and thanks for taking the questions. Are you able to give any additional color on what part of the $3 million sales number was patient demand and maybe how many patients are on treatment? What portion of the 146 Patient Start Forms have transitioned into paying patients, or at least maybe what should we expect that rate to be over time? Greg, thank you for the questions. We would be in a position to be able to share, as we mentioned at the approval, to be able to talk about the Patient Start Forms as well as revenue. We recognize certainly that early on in any phase of launch for specialty medicine, you're going to have variability in terms of the stocking as well as how quickly you get that through. I think as both Peter and Chris mentioned, it is gonna take some time to have that. While we did have some reorders or orders that reflect underlying demand, you can largely think about that $3 million as channel stocking for the first quarter. We are not gonna be providing any specifics at this point with regard to the breakdown of or conversion of Patient Start Forms to reimbursement. They're very in line with our expectations. We're really pleased with all aspects of the launch so far. Those metrics really are lumpy in the first part of a launch, and we wanna make sure that we can provide a consistent set of metrics over time that are gonna be predictable and consistent throughout the launch. Stay tuned. We may evolve in being able to share some of that as we have an underlying trend emerge in the launch. At this point, I would say that, you know, you should rely on the 146 reflecting the underlying demand from nephrologists. Okay, fair enough. The 146 number, it's pretty impressive. I think it's above most people's expectations. Do you think that reflects at all a bolus of patients that was maybe waiting for treatment or do you expect, you know, more of a steady ramp throughout from here? Peter, why don't you take that one? Yeah, happy to do that, Eric, and thanks, Greg, for that question. Yeah, you don't really see a bolus, and you have to realize IgA nephropathy is still a rare disease. Even though every nephrologist has at least a handful of IgA nephropathy patients, it's not like a physician has top of mind, like, "Hey, all those patients should come in at a certain day." I have to say, especially after spending some time in the field and seeing how busy those community practices are, IgA nephropathy is for us is top of mind. But for nephrology in all those patients they are serving, it's only a small fraction. I don't think there is a bolus. We're happy with the steady demand that we're seeing, and there is a building demand as well. I wouldn't say there is a bolus of patients that you're seeing initially. I think you will see a constant and steady growing demand, with regards to IgA nephropathy as patients are coming into the office, as we progress in the launch. Okay, great. Thanks for taking the question. Thank you, Greg. We will take the next question from the line of Joseph Schwartz from SVB Securities. Joseph, your line is now open. Hi. Thanks so much. I was wondering if you can give us any insight into how many physicians have written a FILSPARI prescription to date, and if you can describe the earliest adopters for us. Peter, why don't you take that question? Yeah. At this point, to your earlier point, we won't be disclosing, like, how many prescribers we have. We have seen repeat prescriptions already. I think it's in line with what you may have expected given the 146 Patient Start Forms. We're very pleased with the way physicians are receiving the product right now. To your point, like, what is the profile of the prescribers so far, well, we have really been targeting, based on three aspects. One is volume, patient volume in the clinic, as well as the physician's behavior and adaptation of new innovation, as well as the influence. We see that, especially the physicians in large community practices, are key to prescribe FILSPARI. Okay, thank you. Then, maybe a question on your HCU program. We hear that these patients can be somewhat elusive, so I was wondering if you can describe your relationship with the patient community and the physicians that treat them. How has that evolved since running the COMPOSE study? How challenging was that to enroll, and do you think it could be to enroll a larger phase three study? Yeah. Joe, thank you for the great question. I'll start by sharing a little bit about the relationship and how the community has evolved, and then I'll ask Jula to share some of the insights that her team has gathered in conducting the COMPOSE study. You know, this is a patient community that really has been underserved. When we took over the program. Many of them were actually served by connecting with the phenylketonuria or PKU community because of a lot of the similarities in how the conditions are managed. I think as we've started to really build our relationship with them, they really start to build their own community online as well as, you know, with kind of the standard patient advocacy organizations, both here in the U.S. as well as abroad. I think that we're starting to see a much more concerted and organized effort to articulate what the needs of that community are with regard to earlier diagnosis, improving newborn screening, helping to understand better management of the disease, as well as I think for us, educating about the importance of engaging in clinical trials as a potential for innovation in the future. I think largely we've been really pleased with how quickly the community has evolved, and I think we've really gained a lot of good learnings with regard to clinical trial enrollment. With that, I'll turn it over to Jula to share more. Thanks, Eric. Well, you know, in any rare disease it can be challenging to recruit because there's very few patients per site. It can take a bit longer, and you often have to go to where the patients are, and you really do need to engage with your advocacy partners and with the patient community to understand what's important to them, simplify the trial design and provide them a lot of support. That's what we're doing moving forward. I would say also importantly, we have significant engagement with the key opinion leaders to make sure that what's important to them and their patient community is what we incorporate into the design of the study. We also have a natural history study that helps us with having access to patients who, if they're interested in participating, that can provide us with additional patients that can help to enroll a bit quicker. Thank you for the insights. Thanks, Joe. We will take the next question from the line of Carter Gould from Barclays. Carter, your line is now open. Hey, this is Leon Wang, on for Carter. Thanks for taking my question, and congrats on the results. On FILSPARI, any early signs of the patient profile that docs are prioritizing versus those that they may be waiting for more confirmatory eGFR data? Any profiles of docs that may be perhaps waiting for the data, and not as receptive to the commercial launch? Yeah. Thanks for the great question. You know, maybe I'll start by saying with any launch, you typically will see a spectrum of adoption by physicians where you have some that are early adopters and those that are waiting. You know, it's not surprising that there will be some physicians that want to wait. What I will say is that we're very pleased, and the performance thus far from physicians is absolutely in line with our expectations and also in my experience with launches. I'll ask Peter to share a little bit more about the types of patients that we're seeing prescribed FILSPARI in the first 6 weeks as well as the profile of physicians that we see adopting. Yeah. Thanks, Eric. Happy to provide some color on the patients that we are seeing. The majority, the vast majority of the patients are those patients that are on rapid path of progression with consistent high proteinuria levels. Many of those are above 1.5, but we also have some prescriptions for patients with lower proteinuria levels than 1.5, but have additional indicators for rapid progression. I think largely in line with how the indication is written, mainly above 1.5, with some also below 1.5 gram per gram. Maybe the other thing that I'll, Peter, that I'll add is that the payer mix is very consistent with what we had assumed, with the majority of these patients having commercial insurance. I think a lot of the work that Peter's team did to really profile what this looked like, you know, what the launch uptake could look like is again, very much in line with our expectations and planning. Great. Thank you. Thank you. We will take the next question from the line of Liisa Bayko from Evercore ISI. Lisa, your line is now open. Hi there. Thanks for taking my call, congratulations on the initial good start here. Just, I know you wouldn't have this right now, but as we think about sort of, you know, later in the year, what kind of gross to net can we expect? What would it be initially, and not, I'm not talking about this quarter, but, and then what do you think it will stabilize around? Yeah. Great question, Lisa. You know, certainly as you allude to, the first part of a launch is going to be quite lumpy. You know, we've been reluctant to provide any estimates at this point. I'll ask Chris to comment on where we think we may be landing once we get to that steady state. Yeah. Thanks for the question, Liisa. Really, at stable state, we're gonna be looking at mid to high teens, and I think what we're seeing now is reflective of us getting there once we do get to that stable state. No change from our expectations on that point. Okay. Just back to the PROTECT and your powering. Jula, can you just clarify? You're powered for a 2.9 milliliter difference in slope. That was assuming 30% difference in proteinuria, but you actually got a bigger delta than that. You should have a greater difference. Is that the right way to think about that? Could you just... I didn't hear everything you said. It was a little confusing. Yeah. Jill, would you like to take that? Well, our initial power calculation was based on historical data, and then you can map it based on the ANCHOR data. Based on the ANCHOR data, we fall in line with our original power calculations to be able to predict a statistically significant and clinically meaningful effect at two years. The other thing I do wanna add to this is that as part of our review for accelerated approval, the FDA was very focused that we'd be able to confirm our benefit at the two years. They asked us the likelihood of achieving statistical significance, both on the chronic and total slope endpoints for the two years. We provided conditional power calculations that looked at our available eGFR data at the time of the interim, as well as the information from the trial-level analysis to address their request. Importantly, the conditional power calculations provided a very high level of confidence on achieving statistical significance at the two-year confirmatory analysis. Okay. Thanks. Thanks, Liisa. We will take the next question from the line of Mohit Bansal from Wells Fargo. Mohit, your line is now open. Thanks for taking our question. This is Amon for Mohit. Could you discuss whether you think naive patients or patients switching to FILSPARI is the bigger driver of demand in the first year of the launch? Separately, on the 3% of insured lives being covered, is that ahead of your expectations? How could we think about that going from here, the type of cadence from quarter to quarter? Sure. Peter, why don't you take those two questions? Eric, thanks for that question. When you think about, like, where is the main demand coming from with regards to patients, naive or switched, it is very consistent. Like, the majority, the vast majority of those patients have been on ACE or ARBs in the past and have switched to FILSPARI. I think that is quite consistent. I think ultimately you will start to see naive patients as well. I think it's a small fraction of the total patient population because the majority of those patients are prevalent, are already in the offices of the physician. What we are seeing right now is much of that phenomenon, patients that have not been managed to the proteinuria levels that the physician wants, and ACE or ARBs are being replaced with FILSPARI. That was the first part of your question. With regards to the second part of the 38% coverage, it's a good number, and it's much in line with our expectations, especially if you take into consideration that it was only after 6 weeks. 38% coverage by March 31st. I think it's a good number that we feel quite proud of, and I think is at the high end what you see with benchmark products. Yeah. Thank you for that, Peter. The only thing I would add with regard to actually both of those questions is the quality of the payer coverage. It's really important to think not just about coverage. What's the quality of the coverage relative to the labeled indication? We're really pleased to see that there's a high degree of quality when we think about, you know, the access for patients aligned to the label. You know, we do see a number of those payers that have stepped through ACE or ARB. Again, as Peter alluded to, the majority of these patients are already on ACE and ARB. In fact, many of these patients are referred to their nephrologist on ACE or ARB. When we look at the actual quality of the coverage, it's not just the 38%, but it's actually the quality of that access, and we're really pleased. Again, early days, but I think it's a great foundation upon which to build throughout the rest of this year. Any further questions, sir? We will take the next question from the line of Laura Chico from Wedbush Securities. Laura, your line is now open. Hey, thanks very much. I guess I wanted to talk a little bit more about the cadence of ordering here. I guess, Eric, maybe said differently. Could you just walk us through what are the expectations around the timing from receipt of a start form to when product is actually gonna be dispensed? Like, what is the timeframe there? Sorry if I missed it. Yeah. No, it's a great question, Laura, and it's an important dynamic to think about any specialty launch, where there is a range of timelines for from prescribing. I'll ask Peter to talk a little bit about what we're seeing and also what we expect to see throughout the rest of this year. Peter? Yeah. Thank you, to respond to that. Thanks, Laura, for that question. I think to Eric's point, as is typical for many rare disease product launches, there's a wide range of what I call the time to fulfillment, especially in the early days as payer access may take longer. I would say in these early days, the FILSPARI time to fulfillment is in range what is typical in rare diseases, which is typically in a 20 to 60 days range, I would say. We anticipate that this pull-through will decrease as we get more payer coverage. I'm sorry, Peter, just to verify, you said it's ranging from 20-60, but over time would likely to be closer to a typical 30-day range. Do I have that correct? Well, let me clarify that, Laura. I was talking about what is common in rare disease in general. I would say- Okay. We are in that race. It's more historically what I've seen in rare disease and specialty launches, so it's not reflective of FILSPARI. Understood. Okay. Yeah. I think the important aspect, Laura, to keep in mind is, you know, the... We won't provide any specific numbers 'cause it really is only the first 6 weeks of experience after approval. What's important is, as we get more broader coverage and high-quality coverage, that lead time should shrink. I think what's important in the experience that Peter's team has had is that we've already, you know, one, we're off to a great start with regard to payer coverage and reimbursement, but we're already starting to see that average time to fill reduce. I think that as Peter's team continues to execute, and we continue to get growing coverage, we'll continue to see that average time as well as the range reduce. Again, really early days, so we don't wanna give numbers 'cause it is lumpy, but the dynamics that we're seeing are exactly what you would expect to see with a successful launch. Okay. That's helpful. Maybe I'll sneak in one quick follow-up. Again, apologies if I missed this, but, did you quantify yet how many physicians have signed up for the REMS at this point? Peter? You know, we haven't given a number there, but we're very pleased, as with the Patient Start Forms, that we see a steadily increase in REMS certifications and enrollment. I think it speaks to the physicians that they understand the value that FILSPARI may have for their patients, also that they understand that the REMS process is relatively straightforward. All right. Thanks, guys. Thanks, Laura. We will take the next question from the line of Tim Lugo from William Blair. Tim, your line is now open. Hey, guys. This is Lachlan on for Tim. Thanks for taking the questions. I guess heading into the launch, you know, one of the headwinds you guys had mentioned, or potential headwinds was just that the physicians wouldn't really have, or wouldn't know the data very well because obviously not much had been released. I'm just wondering I guess how that has played into the launch so far. Have you seen that sort of affecting any of the interactions or the speed at which physicians are maybe starting to prescribe, or is that really not affecting that rate, I guess, compared to what you expected? Yeah. It's a great question, Lachlan. I think first I'll point to what Jula mentioned in having a high-profile publication of the interim data that I think really gives, you know, physicians a better understanding about the data. Peter, why don't you share a little bit more about what you're hearing from your team about, you know, the data on FILSPARI? Yeah. No, happy to do so. Indeed, like, nephrology in general is not as much inclined with innovation as maybe some other specialties, given that there has been so little innovation to nephrology in general. I think that's a phenomenon that we have seen with other nephrology launches, in particular rare launches. To Eric's point, I think having new data, and this is kind of like a rolling launch because we launched in the first 6 weeks without having a publication or without having further data, which is not very common to launch a product without that specifics. We launched basically on the PI, also given the promotional restrictions in a Subpart H product with accelerated approval. Now that we have the lens of publication and you start inclusion in medicine guidance like UpToDate, and as Jula mentioned in her part of the prepared remarks, I think that further provides confidence and provides more insights in that process as well. I'm very pleased what I'm seeing, both on the intent to prescribe, but also the actual prescriptions already, and that's the 146 patients so far that we were in Lorito. I think as we get more data and we have those publications, this will continue to help bring confidence to the nephrology community and allow for continued and accelerated scripts. I think that's absolutely right, Peter. I can share with you two maybe additional observations. Like Peter, I spent quite a bit of time in the field meeting with customers. I think there's a real eagerness to understand the profile and the data of FILSPARI more so the publication and guidelines are gonna really help provide some of that independent or third-party perspective. The other aspect is that it really helps understand the REMS better and the profile of a low rate of ALT, AST elevation. 'Cause I think in the absence of that information, it was hard for physicians to put into perspective what the level of risk really is. I think it's been very reassuring for physicians when they see the actual rates in the publication and in the label. Got it. Thanks. On the topic of reimbursement, Peter, I think you mentioned that most of it had gone through, but there were, you know, some delays for the patients that you're seeking reimbursement for. I guess to the extent that there have been delays, can you maybe talk about what pushback you're getting or from payers? No, I wouldn't say it. I mean, as you don't have inclusion in the formulary yet, I mean, it goes through the prior authorization pathway. That generally takes longer. I mean, I think that's a common process in rare diseases in particular. I wouldn't indicate this as like particular obstacles that we are seeing for FILSPARI. Go, thanks. Thanks, Lachlan. We'll take the next question from the line of Vamil Divan from Guggenheim Securities. Vamil, your line is now open. Great. Thanks for taking the questions. I think most of mine on the launch have been answered or asked and answered. Just one more, just in terms of the patients that are getting FILSPARI so far. Obviously, it is early. I'm trying to get a sense that you mentioned sort of the ACE and ARB dynamic, but in terms of SGLT2s, if you can comment on are most of these patients already on SGLT2s or not? Also curious, you know, with the label mentioning the greater than or equal to 1.5 gram per gram, is that sort of metric that physicians seem to be sticking with, or are they, you know, just using their judgment and maybe giving it to patients even below that threshold? The second question is more on the expense side, I guess, for Chris, just how we should think about, especially SG&A, the spend this quarter. First quarter was a little bit more than we were expecting. Is this sort of a reasonable amount to assume going forward, or is there still a little bit of build-up? We should expect, you know, sort of higher ramp-up as we get to end of 2Q and 3Q this year. Thanks. All right, Vamil, thanks for the questions. Peter, why don't you take the first on the patients? Yeah, it's a good question. Maybe I'll start answering the question by giving a broader perspective on the patient profile. This is often a younger patient population. Like, many of those patients are being diagnosed in their late teens, early twenties. That's what we're seeing as well. Many young patients that are on a path of rapid progression. To your point, like, what we're seeing is many of the current available medication doesn't bring patients to the level, the target level that physicians would like to see. ACE and ARBs didn't do that. We have SGLT2. I think that's something that you mentioned as well. We see that increased utilization in SGLT2. The physicians feel very comfortable in combining if needed or if appropriate, with SGLT2 as it's mechanistically synergistic, but also FILSPARI has that very rapid progression of 50% proteinuria reduction that physicians haven't seen with other medications. Especially the non-immunosuppressive nature of FILSPARI with or without combination with SGLT2 makes physicians very comfortable, especially when you talk about the younger patient profile that have been. The side effect profile of immunosuppression is not very pleasant, especially for this patient population. Chris, for expenses. Yeah, absolutely. Thanks for the question, Vamil. What I would point back to is in the prepared remarks, I talked about for overall expenses, we anticipate moderate increases for the balance of the year. Really, when I think about the breakdown of SG&A and R&D, that's probably more pointed towards R&D as we look to, you know, continue both the DUPLEX and PROTECT studies that are gonna continue on for the balance of the year. Also the pegtibatinase work that's gonna go into, you know, the potential initiation of a phase 3, as well as the supply CMC work that all needs to be done to scale up for both phase 3 and commercial. I think that's where you'll see likely the larger magnitude of increase come for the year. I think from a, an SG&A perspective, there may be some modest increase from this point, but I wouldn't expect it to be of any significant magnitude. Really what we've gotten to in this first quarter is the first time in which you've had the full sales force fully in place doing all the promotional activity and, you know, putting that right investment behind FILSPARI to make sure we can position it appropriately for IgA. Okay, great. Thank you. Thank you. We will take the next question from the line of Alexander Thompson from Stifel. Alexander, your line is now open. Hey, great. Thanks for taking my questions. I got one IgA question and one FSGS question. I guess on IgA, I'll try to ask another sort of commercial dynamics question. I guess given that you're starting by targeting a lot of higher volume prescribers, can you talk a little bit qualitatively about whether, you know, a majority of the start forms that you're seeing so far are coming from, you know, single physicians or multiple physicians writing multiple start forms for patients, or is it broader than that? Then on FSGS, you know, can you comment on sort of historic flexibility within the cardiorenal division and, you know, if there's any good precedence for them, sort of, you know, looking towards subgroup analyses in rare disease especially? Thanks. All right, Alexander, thanks for the questions. Peter, would you like to take the IgA question? Yeah. Thanks, Alexander. If I understand your question correctly, your question was like, do you see mainly prescription from prescribers that have multiple prescriptions or more single, and if it's mainly in the, in the higher volume centers? I think- Yeah, correct. It's too early to make a specific statement on that. I think we see the majority of the prescriptions coming from community centers, especially from larger community centers, but we also see prescriptions from academic centers. We see a mix of physicians that have prescribed a single time or a second time. Again, it's early days. I'm describing this for the first 6 weeks. I wouldn't read too much into it. We see a large prescriber base. We see both single as well as multiple prescriptions among those prescribers. Bill, why don't you take the question on regulatory flexibility? Yeah. No, happy to. The, I think the one that comes to mind quickest is Entresto for congestive heart failure was approved by cardiorenal, I think in 21, if my memory is right. That was a drug that missed their primary endpoint. The decision in the agency was that there was clear benefit and across the trial based on totality of evidence and unmet need, that that was something that they were interested in approving. I think that, you know, there have been other instances across rare disease indications, and I think the most recent work that I read was in JAMA, where they said in about the past 5 or 10 years, about 10% of the drugs approved by the FDA were ones that missed their primary endpoint in their pivotal study. It's not the norm, but it's also not something that's unheard of. Jules, anything further that you'd like to add on that question? I would also point to Fabry, is another potential indication for migalastat to look at as another reference. Great, helpful. Thanks so much. Thank you. We will take the next question from the line of Ed Arce from H.C. Wainwright. Ed, your line is now open. Great. Thanks for squeezing me in here. Congratulations on the early progress on the launch. I see here, obviously, first six weeks, $3 million is, as you said, represents mostly stocking, and 146 PSFs, mostly demand. I recognize, as you pointed out, that it's, you know, highly variable at the beginning. I'm wondering as we get through the next few quarters and years, if there are specific launch metrics that you intend to report regularly. For example, we've already discussed sort of the fulfillment conversion rate, or number of prescriptions or patients on drugs, and then perhaps later on, you know, numbers around persistence or compliance rate. Just, so that's first. Secondly, just wanted to ask as well on the readout later this quarter in HCU with the higher dose and the lyophilized formulation. The focus clearly is at least partly on the efficacy look from that dose as well as the PK with the new formulation. What other aspects to the data readout could we expect later this quarter? Thanks so much. Yeah, thanks. Thanks, Ed, for the great questions. I'll take the first one. I think we certainly are looking at a number of different metrics, and it's important for us to make sure that the metrics that we provide regularly are ones that we have confidence in the sort of trendability and the predictability. We believe that's why we focused on Patient Start Forms and access, because they really are robust predictors of underlying demand as well as the ability to pull through and have those reimbursed. I think as we look forward, you can imagine that there likely will be others like the persistence rates or the reimbursement rate. You can, you know, look to our commercial business where we have talked about persistence, the high rate of persistence, et cetera. As we start to understand the underlying dynamics of the FILSPARI launch, we'll look to evolve what those are. But again, we wanna make sure that we really focus on those fundamentals this year that we believe are gonna be most important in the first year of launch. With regard to the readout of the cohort six in the COMPOSE study, Bill, I'll turn to you to provide some further perspective on what we'll be looking for and possibly what we would be disclosing. I will say we haven't yet committed to what we will disclose specifically. Bill? Sure. The cohort six, we utilized the highest dose to date on a mg per kg basis in the study in what we view as the final cohort in the COMPOSE study. It also gave us the opportunity to utilize a lyophilized formulation and evaluate that in patients. What we're looking for is, you know, the most predominant biomarker is gonna be the reduction in homocystinuria or total homocysteine over time in the 12-week double-blind portion of COMPOSE. In addition to that, of course, we're looking at safety and tolerability. It's a phase 1/2 study and evaluating that for those individuals at that dose. Those patients will roll over into the open label extension. That will give us the data then to select the dose and help us with the design of the phase 3 study. Sounds good. Thank you so much. Thank you. Mm-hmm. There are no further questions at this time. Ms. Eichenbaum, I will turn the conference back over to you for any additional or closing remarks. Thank you, everyone, for joining us for our first quarter of 2023 financial results call. We look forward to providing additional updates on our progress. Have a great rest of your day. Thank you. This concludes today's call. Thank you for your participation, and you may now disconnect.