Hello and welcome to the Travere Therapeutics First Quarter Financial Results and Corporate Update. My name is Brandon and I'll be your operator for today. At this time, all participants are in a listen-only mode. Later, we will conduct a question-and-answer session and instructions. [Operator Instructions] Please note this conference is being recorded. And I will now turn it over to Chris Cline. You may begin sir.

Great. Thank you Brandon. Good afternoon and welcome to Travere Therapeutics first quarter 2021 financial results and corporate update call. Thank you for joining us. I hope you all remain well. Today's call will be led by our Chief Executive Officer, Dr. Eric Dube. Eric will be joined for the prepared remarks by our Chief Medical Officer, Dr. Noah Rosenberg; Peter Heerma, our Chief Commercial Officer; and our Chief Financial Officer, Laura Clague. 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 6, 2021. And Travere specifically disclaims any obligation to update such statements to reflect future information, events or circumstances. Let me now turn the call over to Eric. Eric?

We remain dedicated to the key priorities that we believe will enable us to strengthen our position of leadership in the rare disease community. And the first quarter of this year was another example of our organization's ability to execute. For us this centers on developing our pipeline for potential first-in-class programs targeting rare diseases that have significant unmet need. Earlier this year, the Everylife Foundation published the national economic burden of rare disease study. The study found that on average it takes approximately 6.3 years for a person living with a rare disease to find a diagnosis and that patients typically see upwards of 17 specialists along their diagnostic journey. Overall the study estimated that the direct medical costs associated with rare diseases in the U.S. was more than $400 billion in 2019. This is especially relevant given the challenges the rare nephrology community faces due to the limited innovation over the past few decades for diseases like FSGS and IgA nephropathy. For example, FSGS is considered to have one of the worst prognoses amongst primary glomerular diseases. It is estimated that more than 50% of FSGS patients with persistent nephrotic proteinuria will reach end-stage kidney disease within 10 years. This translates to over 2,000 people each year reaching FSGS-related end-stage kidney disease in the U.S. Patients today have a long diagnostic journey, experience progressive loss of kidney function and become dependent upon transplant and dialysis. This is why we have great urgency in pursuing our goal of developing sparsentan to become a new treatment standard for FSGS and IgA nephropathy if approved. We remain encouraged by the interim proteinuria data that we reported from the DUPLEX Study in February. The data showed that treatment with sparsentan resulted in a 60% greater relative likelihood of achieving FPRE when compared…

Thank you, Eric, and good afternoon, everyone. We continue to be encouraged by our engagement with the nephrology community, as we work towards the goal of developing sparsentan in a new treatment standard for FSGS and IgA nephropathy if approved. As Eric referenced earlier, there is a clear recognition that FSGS is a leading cause of end-stage kidney disease and subsequent kidney failure. Unfortunately, the incidents and prevalence of FSGS is believed to be on the rise. And there are no approved medicines indicated for this disorder. As a result, patients living with FSGS often require aggressive treatment options, such as, immune suppressive therapy, dialysis and/or transplantation. Even if these treatments are successful, they come with challenges for people to go about daily living. This significant unmet need provides us with a sense of urgency each day, as we continue to advance our program. Following the announcement of the interim results from the ongoing pivotal DUPLEX Study of sparsentan in FSGS, our medical team has continued to receive broad support, from the nephrology and advocacy communities. As we previously mentioned, sustained proteinuria reduction is recognized as a primary treatment goal amongst nephrologists in managing FSGS. This is driven by the well-accepted link among the nephrology community that lowering proteinuria results in improved kidney outcomes in this population. We are at the forefront of development with the first pivotal study demonstrating a meaningful reduction proteinuria, compared to currently available treatments. If approved, we believe, that sparsentan can become an important new treatment option that physicians can use as the base of their treatment paradigm. As Eric outlined earlier, we are in the process of discussing our plans to pursue accelerated approval submissions for FSGS with regulators. And we continue to expect, that we'll be in a position to provide an update,…

Thank you, Noah. Our team has begun the year with great motivation to deliver our approved therapies and to prepare for the potential futures for central launches. The commercial organization has performed well through a challenging period and have provided a solid foundation for us to build upon throughout through to 2021. During the first quarter, we saw a new patient initiate therapy for all three of our approved products. However, COVID-19 related dynamics resulted in a flat year-over-year net product sales performance. At the onset of the pandemic in the first quarter of last year, we experienced increased demands from patients who have product performance. This is over in a revenue above expectations of approximately $1.5 million to $2 million in the first quarter of last year. As expected, this did not mature in the start of this year. Another important dynamic is a cumulative effect the COVID-19 has had from patients visiting their physicians. And surprisingly, when COVID-19 cases accelerated in the fall and in the beginning of 2021, we did see fewer patient referrals for our approved products. This industry-wide trend has had an impact on our January and February demand and created a modestly slower-than-expected start to the year. That said, in March we started to see stronger new patient referrals than the first two months of the year. And we have seen that momentum now continues for April. So we are encouraged by the underlying strength that is present. Also during the quarter, we experienced a higher gross to net factor, driven primarily by the insurance resets in the beginning of the New Year. This is expected in our business and consistent with previous years and we anticipate this to return to our normal levels for the remainder of the year. Taking all of this into account, we believe we are in a sound position to identify and treat new patients through the balance of the year. As Eric mentioned before, we continue to expect mid-single-digit growth for our approved products in 2021. We are also continuing our work to prepare for launches in FSGS and IgA nephropathy if sparsentan is ultimately approved. We continue to strengthen our understanding of the patient journey and what it will take to provide broad access to therapy. We are continuing to do the foundational work to put the pieces in place to launch a product in a space that has seen limited innovation over the last few decades. We are confident that our established commercial infrastructure ecology, our rare disease expertise and our ongoing insight generation and longstanding preparations will ultimately enable us to be successful in delivering sparsentan to people living with FSGS and IgA nephropathy if approved. I'd like to turn the call over to Laura now for the financial update. Laura?

Thank you, Peter. For the first quarter of 2021, we reported net product sales of $47.4 million from our commercial portfolio, which was comparable to the same period in 2020. We reported a GAAP net loss of $53.9 million for the first quarter of 2021. After adjusting for non-cash expenses and income cash, we reported a non-GAAP net loss of $31.2 million for the first quarter of 2021. On a GAAP basis R&D expenses were $47.9 million for the first quarter of 2021. The increase compared to 2020 is largely attributable to increased patient enrollment in the ongoing pivotal DUPLEX and PROTECT studies of sparsentan, as well as the integration and advancement of the pegtibatinase program in classical HCU. On an adjusted basis R&D expenses were $44.7 million for the first quarter of 2021. Relevant non-cash expenses for the first quarter included $3.3 million of stock-based compensation and amortization. On a GAAP basis, selling, general and administrative expenses for the first quarter were $36.8 million. The increase over the same period in 2020 is largely attributable to increased compensation expense to support the growth of our organization and initial investment in launch preparation activities. On an adjusted basis, SG&A expenses for the first quarter were $26.3 million. Significant non-cash adjustments for the quarter consisted of $10.5 million in stock-based compensation and depreciation and amortization. Looking ahead, we expect our operating expenses to increase modestly from Q1 levels. This may be uneven quarter-to-quarter but is expected to occur throughout the balance of the year, as we continue to support the ongoing pivotal DUPLEX and PROTECT studies of sparsentan, which will advance as planned to their respective confirmatory two-year endpoints. It also accounts for investing in the success of the pegtibatinase program in classical HCU and preparing our organization for potential commercial launches. Our financial foundation to support this activity remains strong. We ended the first quarter with $520.9 million in cash and cash equivalents. Notwithstanding additional business development, this total cash balance is expected to support our current operations beyond the next two years. I will now hand the call back over to Eric for his closing comments. Eric?

Thank you, Laura. Execution remains a core strength for our organization and I would like to thank all of our team members and partners for their continued commitment to our mission. We have started off the year well. Our performance is in large part driven by the sense of urgency that is created by listening to patients' perspectives and the clear need for new treatment options. We will channel this as we continue our work with leaders in the rare nephrology community to break new ground in the pursuit of bringing the first innovation in decades to people living with FSGS and IgA nephropathy. And it will continue to drive our efforts to further develop and deliver the potential first disease-modifying therapy for classical HCU. Let me now turn the call over to Chris for Q&A. Chris?

Great. Thanks, Eric. Brandon, can we please go ahead and open up the line for Q&A?

Yes. Thank you, sir. We will now begin the question-and-answer session. [Operator Instructions] And from SVB Leerink we have Joseph Schwartz. Please go ahead.

All right. Thank you so much for all the insightful commentary and for taking my questions. I guess my first one is just – you referenced a lot of the continuing literature that supports the use of your analysis that you'll be doing in PROTECT in IgA nephropathy. And I know you worked really hard to hammer out a variation on that in FSGS years ago with the FDA. So I'm just wondering just given it seems like there is a continuous string of surprises from the agency due to various reasons, such as personnel shifts or maybe the same people looking at things differently now than years ago, and some unknown reasons granted. I'm wondering if you could just characterize for us, how much commonality is there between like the personnel that you're dealing with now and how they might look at things versus when you establish the analysis plan in FSGS? Thanks for hearing my long question.

Thanks Joe. Very clear question. And I'll have a few comments and then I'll ask Bill to provide further information. So I'd say that overall, as we look at our programs how they were designed years ago and where we are today in a very innovative trial design looking at proteinuria 36 weeks and eGFR in the longer-term over two years, the literature to support that link has only grown. And as you mentioned, certainly, so for IgA nephropathy with some of the recent analyses. And I think that FDA certainly recognizes that, I don't want to speak for any regulators, but we believe they understand on top of the literature. Bill, do you want to provide further comments on how things have evolved with the agency from your perspective?

Certainly, and thanks for the question, Joe. I've been on these projects for almost 4.5 years and the group across the table from us at cardiorenal has been relatively quite consistent. There's been very little change in turnover. We've seen some members in the team be seconded to other areas of the agency for COVID specific tasks, and then return after a period of six to nine months. And the agency in that period shuffled the way they allocated statistical professionals and that resulted in a change in some of the people on the team. But from the medical and leadership positions within the review division, we've been dealing with pretty much the same people the whole way through.

Great. That's super helpful. Thanks for the color. And then you mentioned – actually, Laura, I think that mentioned the starting to build out enhanced commercialization capabilities on top of what you already have. Can you just parametrize that for us both in the US? And then at what point do you think that it might make sense to build outside the US if ever given you don't currently have much of a presence there, but this could be a global brand?

Certainly, and our -- thanks Joe. Our plan certainly for sparsentan is to commercialize in both the US and Europe. And the approach that we take in Europe is still under review whether we do that our own or whether we partner. But I'll ask Peter to talk a little bit about the activities that this team is undertaking to prepare for commercialization.

Yes. Thanks Eric. So to start with the latter part of the question with regards to Europe. So we think the unmet need in Europe is equally high as in the US, but the dynamics in Europe are quite different. So what we are really focusing right now is to get a good understanding of the addressable patient population in Europe as well as what is the burden of disease and what does it take what is the requirement to gain [indiscernible]. And we're making the disciplined investments right now and I think we are quite pleased with the progress. And as Eric said, we haven't made a public statement on if we will commercialize ourselves. With regards to the first part of your question what are we doing from a commercialization perspective. Well last year and we gave a little bit of a display of that during our R&D Day. We invest mainly in insight generation patient journey addressable patient population the value framework. And this year we are continuing that looking also on field force sizing certain patients to ultimately say, like what is the field force required. We also look at the distribution model and what is the best way to bring the product to patients as well as educational initiatives both to patients as well as physicians, because FSGS is an underserved disease and I think educational efforts are needed to really gain understanding of the study that we conducted but also FPRE is our endpoint.

Thanks again for insights.

Thanks, Eric.

From Bank of America, we have Greg Harrison. Please go ahead.

Hey, guys. Thanks for taking the question. Question is on the DUPLEX Study. Will there be an opportunity to see additional data from that study particularly eGFR? And is this something that there could be periodic updates for or medical conference presentations planned before you were to get an accelerated approval?

So Noah, why don't you take that one with regard to additional data and also any potential presentations?

Yes. That's a great question. So we -- in terms of the overall data for DUPLEX, as you know we really had to and continue to provide minimal data to protect the study integrity. We've got the ongoing two-year confirmatory endpoint and we recognize the desire to see additional data, but we have no plans right now to publish further. We continue to evaluate potential opportunities that wouldn't introduce bias and be acceptable to regulators. That's we'll update you as we get there.

Yes. Thank you, Noah. The only thing that I would say, Greg, in addition is that we have a the approach that we're taking with DUPLEX to do exactly what Noah said, which is to maintain the study conduct through to the end and to maintain the study blind, which is the utmost important to us. I want to share a little bit about how we're doing that and making sure that as we think about additional data, there is no plan for any additional unblinding at this point. And so there's a very small team that is working on those data to support the regulatory filings, but beyond that there is nothing else that we have planned until we complete the studies.

Got it. That makes sense. And then one other one. I know this one is also maybe a little early but -- and if you can't give specifics maybe we could just talk about the factors you'd consider, but I wanted to get your latest thinking as far as sparsentan's pricing. And just how you're thinking about balancing pricing for the value you provide to the patients versus providing broad access, especially I know you've talked about that it will likely be used eventually in combination with other treatments as other therapies are approved. So I just wanted to get your thoughts there?

Sure. So I think it is too early for us to talk specifically about pricing, but what I can say is that our goal is to make sure that we have broad access to this innovation. So many patients have been waiting and we want to make sure that does not become a barrier for these patients and that includes the potential to combine with other therapies. And we know that that may be a concern for payers. But I can say that Peter and his team are very much focused on making sure as he mentioned earlier on the value framework for access. Peter, anything else that you'd want to add?

I think you mentioned it at all. I think it's good to take a step back and say like if you think about FSGS disease it comprises about 125,000 patients in the US and the costs associated is about $50 billion. So these patients are among the most expensive patients for society. And if you look then at FSGS and IgA nephropathy they are almost fast that of progression and they are disproportionately represented in that end-stage kidney disease patient population. I think there's a good base in that respect for -- to come up with like a solid value proposition and that's the work that we're doing right now.

Great. Super helpful. Thanks for taking the question.

Thanks, Greg.

From Barclays, we have Carter Gould. Please go ahead.

Yes. Hi. This is Justin on for Carter. Thanks for taking our questions and congrats on all the progress. Just a couple from us on PROTECT. Can you remind us of the data and the decision-making process that inform the selection of the 400 milligram dose? Sort of what gives you confidence that that's the dose level that will be sufficient to drive a benefit? And then just to confirm given how quickly you had enrolled should we still expect the interim read to be around 280 patients, or could it possibly exceed that number?

Justin, thanks for the questions. And I'll answer the second one and that is the planned analysis is when the 280th patient gets the 36-week visit. And because we've got complete enrollment it will be plus or minus 280 depending on what enrollment was at that time. And as I mentioned we're on track to be able to provide that analysis in the third quarter of this year. And I'll turn it over to Bill to talk about dosing in PROTECT.

Thanks for the question, Justin. We believe that the data from DUET show us and also now from DUPLEX that 800 milligrams is the right dose for the FSGS population. As you recall both 400 milligrams and 800 milligrams were used in the DUET study and they had largely overlapping results. When we looked at the PK/PD curves we also saw a high degree of overlap. Essentially, the 400 and the 800 are both at the top of a sigmoidal dose response curve. So while you have a larger numeric difference between the two, the effective difference isn't doubling between 400 and 800. Specifically to IgA nephropathy and FSGS, they are different diseases and they present differently. Starting with FSGS, it's a highly proteinuric disease and has a high degree of nephrotic proteinuria. With that comes a loss of albumin and other plasma proteins and sparsentan is highly protein bound in circulation. So when you lose protein, you're also losing sparsentan. The 800 milligram dose in FSGS patients is designed to compensate for that potential loss. Contrast that to IgA nephropathy patients where proteinuria is lower the rate of nephrotic proteinuria is much less. And so we don't see the need to have a higher dose there to compensate for that event. That along with our modeling and the -- where those two doses fall on the sigmoidal dose response curve give us confidence that 400 is the right dose for the IgA nephropathy patients.

Okay. Thank you so much for your color there.

Sure.

From Jefferies, we have Maury Raycroft. Please go ahead.

Hi, everyone. Congrats on the progress and thanks for taking my questions. I know you mentioned you're not providing a regulatory update, but I'm wondering if you can clarify if you had an initial pre-NDA meeting and you're now in a back and forth dialogue, or is the ongoing engagement related to preparation ahead of a formal meeting scheduled for 2Q? And then as a follow-up can you comment on potential scenarios for outcomes from the regulatory engagement?

Maury, thanks so much for your questions. And our typical practice is that we don't provide specific dates for our regulatory interactions. But as we've guided to previously we are in the process of engaging with both EMA and FDA and we're on track to be able to provide an update on those interactions by the end of this quarter. And with regard to your second question around scenarios I would say it's probably -- we're not in a position to be able to speculate where that might be. We'll be able to provide updates on those interactions and any implications on our business later this quarter.

Fair enough. Understood. Okay. And then maybe one other question just on IgAN and PROTECT. You mentioned it's close to fully enrolled. Can you comment on baseline proteinuria range or anything else on baseline characteristics and whether it's in line with expectations? And if you can remind me if you expect greater proteinuria improvement in patients with higher proteinuria at baseline, or how do you think about that in IgAN?

Sure. Noah, would you like to take that one?

Sure. Great question, Maury. So as far as the approach that we take keeping in mind that the PROTECT Study is currently blinded. So any analysis we're doing -- really both groups together are blinded analyses, all the data probably going through -- making sure that the data is high quality is reflecting that is consistent with our expectations for baseline factors. So I think that's as much as I can say about the baseline characteristics. And Maury there was another part to your question?

Yes. Just your expectations for patients with higher proteinuria at baseline, do you expect them to have a greater magnitude of benefit or improvement?

Yes. Yes. And I'll just add also -- in IgAN you would expect a slightly lower proteinuria level right due to lower [indiscernible] exist in first question, right? And as far as the net reduction we did see a slightly -- we saw proteinuria reduction in DUET and DUPLEX above and below the product range, but it was slightly diminished in the higher group compared to the lower group. So we might expect that, but remember that in IgAN we're having a less proteinuric population than there are in FSGS. So probably wouldn't have as much of an impact that we had predicted, but again we'll have the data back in August and we'll know that for sure.

Got it. Okay. Thanks for taking my questions.

From Evercore ISI we have Liisa Bayko. Please go ahead.

Hi. Yes, just -- I just want to clarify, is your expectation that you're going to file an accelerated approval? Just to clarify, because it's just the way you phrase it, I want to make sure that is your expectation that you are going to file for accelerated approval based on the data you have, correct?

Hi, Liisa. Yes, so accelerated approval is our base case and we're currently planning the -- and writing the NDA for that. But, obviously, that's going to be subject to the ongoing interactions with regulators and that's something that we'll be able to provide updates later this quarter. And I think, that's also why we want to make sure that we're engaging very closely with FDA, so that we understand their expectations for the package and reviewing the data with them prior to submitting, so that we have an aligned approach on accelerated approval.

Okay. And then, can you maybe just review like, kind of, for -- separately for FSGS and for IgA nephropathy, what kind of -- what gives you confidence that you can file an accelerated approval, notwithstanding the data, but using proteinuria -- this idea of using proteinuria? Can you maybe review kind of what's in the public domain, or what's been kind of communicated with FDA that leads you to believe that that's the base case?

Yes, certainly. And I'll ask Bill to take that one.

Certainly. If we start with the public domain there is a growing body of literature that links reductions in proteinuria to preservation of renal function in the long term. And specifically the work coming out of Dr. Inker's lab and others, Throost [ph] is another out of Michigan and [Indiscernible] all are showing a consistent story that reductions in proteinuria confer a slowing of the decline of renal function. In all of us, we have a lower GFR year-by-year as we age. In these patients with glomerular diseases that rate is faster. If you're able to reduce the proteinuria in these patients, that's expected to and has been shown to confer a reduction in eGFR over time. I think the other element of -- to answer your question, we've been in discussion with the agency as well as the EMA in Europe around trial design, with the surrogacy of proteinuria at an interim endpoint being used to predict the reductions in eGFR at the two-year confirmatory endpoint. So the combination of both what's in the public domain and the dialogue we've had with regulators, gives us confidence that this is a path that they are aligned with that could be used for accelerated approval.

And I think the other aspect Liisa is that there is consistency in how other sponsors, who obviously engaged with FDA, have designed their programs in the use of proteinuria. So I think that consistency, while we can't speak to other programs, I think is reassuring in the approach that we've received and the guidance that we've received.

Okay. Thank you.

Thanks, Liisa.

From William Blair we have Tim Lugo. Please go ahead.

Hi, guys. This is John on for Tim. Thanks for taking our questions. I was just wondering, if you guys could provide some commentary on how payer discussions are going for sparsentan in FSGS. And maybe a bit more specifically, if you could provide some color on how the payers are responding to and thinking about the interim proteinuria data? Thanks.

John, thanks for your questions. And Peter, would you like to take this one?

Yes. Thanks for that question. I think, it kind of like builds on the conversation that Bill was just outlining, how the relationship between proteinuria reduction translates into reduction of progression of disease and ultimately delay end-stage kidney disease. And I think some of the work that we have done is informative to have those conversations with payers. You may remember the R&D Day where Dr. Barratt was presenting, how 30% reduction in proteinuria actually translates in IgA nephropathy on patient level base to about over 10 years delay in end-stage kidney disease. And we are in the work right now to do similar work for FSGS and I think that's the kind of data that payers are very interested in issue, to gain an understanding what the translation of proteinuria reduction is into ultimately hard endpoints and delay of progression of disease.

All right. Thanks so much for that color.

From Canaccord Genuity we have Michelle Gilson. Please go ahead.

This is Michael [Indiscernible] on for Michelle. Congrats on the quarter. So for the DUPLEX filing and I guess some questions about Michelle Gilson, it seems like you are engaging with the regulators. I guess more specifically, do you anticipate the filing for FSGS would come before or after the interim PROTECT data in IgAN? And then, sort of, a little more broadly, do you see any read-through to the FDA recently accepting other applications for rare glomerular disease, to the agency's view of what the complete data package would be for these diseases?

Michael, thanks so much for your questions. And with regard to your first on the timing of filing and whether that would occur before or after the PROTECT interim, we're -- we wouldn't be in a position today to comment on the sequencing of that. But we are on track to provide both the data from PROTECT in the third quarter and then we'll provide an update on our regulatory interactions later this quarter. So that may be something that we can provide greater detail on very soon. With regard to read-through of recent regulatory filings, I would say, a couple of things. One is that, certainly, there is recognition of significant unmet need, very much in what I shared in my prepared remarks, with regard to rare kidney disorders. And we believe based on our interactions that regulators clearly understand this need and we're encouraged by other progress in other programs, just given that it's several steps closer for patients to potentially have an approved therapy. But each program is different and so we can't really make comparisons between those and I certainly wouldn't want to draw conclusions anyway to our programs. Our focus is to continue the trials and to continue our NDA preparation. And as I mentioned, we're in the process of engaging with regulators. So, we'll be able to provide an update soon.

Excellent. Thank you. Just switching gears just one more actually switching to TVT-058 or now newly named pegtibatinase. So, it looks like there is a potential delay due to COVID. You mentioned an impact on opening new sites. Is there any other way that COVID is affecting the trial? Perhaps issues with already open sites or anything else you haven't discussed? Thank you so much.

Great. Thanks for the question. Bill, would you like to provide your thoughts on that?

Certainly. The trial has not been free of impact from COVID as you note. I think with -- to your question of specific sites, it depends on the site and it depends on the timing. There are certain times during the past 12 months where some of these centers, some of which are children's hospitals have not been open for anybody except for specific patients. And in that exclusion list would be somebody in a clinical trial potentially that might be on placebo, as an example. This is something that's dynamic as our lives have all been throughout the last year with COVID. We are seeing these restrictions ease as the rates of COVID have come down around the nation, but it's very individualized center-by-center and month-to-month. We've responded to these by looking at the protocol and changing some of the visit schedules. For example, using nurses that go to the home to collect samples as opposed to patients having to come into the hospital or a visit in order to maintain the progress the forward momentum in the study and also, not to miss key samples or key data points.

Excellent. Thank you. That’s all for me.

Thanks,

From Wedbush Securities, we have Laura Chico. Please go ahead.

Thanks very much for taking the question. Apologies if this was already asked, but I know you mentioned the Inker publication. I just wanted to circle back with one on PROTECT. So, one of the limitations mentioned in the Inker paper was the heterogeneity of the trial data that they examined. And so, I was just wondering if you could talk to how you've tried to address that with the PROTECT Study and also maybe your assumptions around statistical powering. Thanks.

Thank you, Laura. Bill, I'll ask you to take this one.

Sure. I think the challenge with the Inker paper is not unusual in the rare disease community in that there aren't a lot of clinical trials to draw from. If you're doing a meta-analysis in a cardiovascular space, you're going to pull 75 studies and whittle it down to an exclusion criteria to the 50 that really matter. In the case of the Inker publication, they basically took all the treatment studies, interventional studies in IgA nephropathy and group them together. Taking out those that might be different for this reason or that, would leave them with too small a sample set. So, the end result was the input was a fairly heterogeneous group. I think the consistent message coming -- well and the result of that is, they cited as one of the potential weakness of the analysis but also it results in a greater uncertainty in the measure when you start to look at the correlation and draw a regression line. If you look at the signal overall and the consistency of the message, it's clear with the analysis that have been done by others as well as the work that we have done internally with registry data and other data in that reductions in proteinuria are linked to preservation of renal function. So, I don't think that the heterogeneity cited in the Inker paper is something of concern. I think it was an app description of their input data, but I think the output message in it was really quite clear.

And Bill, to the question around powering?

In powering, we're powered at 90% to show a 30% relative reduction in proteinuria, on the interim analysis endpoint. And that is -- gives us what we believe to be a very clinically relevant reduction in proteinuria, and more importantly, predicts a clinically relevant reduction in eGFR loss or preservation of eGFR slope. So that's how the study is powered. And I guess the other piece that I would mention. When we talk about on your first question around heterogeneity, with our study we have inclusion/exclusion criteria that really are designed to control that heterogeneity on the entrance to the study, so that we get a pretty even group of patients with similar baseline characteristics.

That's great. Noah, is there anything else that you wanted to add on that one?

Yes. I think I agree with everything that Bill said, and I think when you're in the setting of a clinical trial randomized Phase 3 study, we have the opportunity here to take patients with specific inclusion/exclusion criteria. So having UPC greater than one, enriches us on doing things like having an irbesartan standardized control is critical to ensuring that we have a stringent interpretation of the results. In that studies the backgrounds and standards of care are different and they're variable. So I think by providing that standard of care, standard irbesartan dose for every patient and by enriching again with UPC and getting population, it's a little more uniform. I think we feel like we're in pretty good shape. If you compare across the DUPLEX, we felt we were going into after shift it was a much more diverse population, heterogeneous population. And we were able to show the similar numbers in effect. And so I think the size of the study is also important to point out having 380 patients gives us that ability. A lot of those studies that Bill cited are really smaller studies. And so I think those are some [Technical Difficulty] why we feel confident we'll be able to address it. Then also the statistical analysis are very robust as well. So I think those are some of the keys.

Thanks, Laura.

From BMO Capital Markets, we have Do Kim. Please go ahead.

Hi everyone. Thanks for taking my question. I was hoping that you could go over your expectations for what the FDA is looking for just during these interactions. Back when you or the company had the end of Phase 2 meeting and the FDA ended up requesting a Phase 3 study they confirmed that proteinuria reduction is potentially approvable endpoint, but they wanted a longer treatment duration. What drove that? Are there other aspects of the interim data that they are specifically interested in like safety or eGFR turn?

Do, let me take this one and I'll ask Bill to provide any further comment. The expectation that we have for a regulatory submission on FSGS is a clinically meaningful statistically significant reduction in proteinuria which we provided in February. As we mentioned, the confirmatory endpoint will be on eGFR. And certainly, we believe that they're going to be looking at safety and the totality of evidence. And I think because in many ways we're charting a new path in the use of proteinuria in this trial design, this is why very much we're engaging with them and sharing with them the data, so that we can align on what they need to see for accelerated approval. I think at this point that's as much as I would be able to say in terms of expectations, but I'll ask Bill to provide anything further from his perspective.

Eric, I agree with everything that you say. I think the only color that I would add to that is in this situation with accelerated approval being based off of the surrogate endpoint in addition to the totality of the data, the agency is going to need to see or want to see enough evidence that provides a clear picture of the prediction of reduction in proteinuria to a preservation of eGFR that would be significant at the two year endpoint. Then that's part of why we're currently engaged with the agency making sure that the submission that we put forward meets their needs.

Great. That's helpful. And a question for Laura. Could you provide some additional color on the quarter-over-quarter step-up in R&D expenses? Is it broadly from all the clinical studies, or is it primarily from the addition of the HCU program?

Hi, Do. Yeah, really it's a combination of all of that. So yes, you're correct. As far as the pegtibatinase program this is the first full quarter that we've had that program here at Travere. And then in addition, it's the continuing study progression for DUPLEX and PROTECT. And just recall that those studies continue on to their eGFR endpoints in 2022. So there's continued monitoring assessment so that requires continued investment. So it is across those programs that you mentioned.

Perfect. Thanks for taking my questions.

Thanks, Do.

Yes.

We have no further questions at this time.

Great. Thank you, Brandon, and thank you all for joining us today. This concludes our call for the first quarter. We look forward to providing you updates on our progress in the near future. Thank you and have a great rest of the week.

Thank you. Ladies and gentlemen, this concludes today's conference. Thank you for joining. You may now disconnect.