I am pleased to have with us next, Travere Therapeutics. With us, representing the company is CEO, Eric Dube, CFO, Chris Cline, and the Chief Medical Officer, Jula Inrig. Thank you everyone for joining us. It's a pleasure to have you.
Ed, thanks so much for hosting us.
Great. So, let's start then with for those folks who may not be fully familiar with the company, just a brief background and overview of Travere.
Sure. Well, Travere Therapeutics is a company that is based exclusively in rare disease, with a particular focus on rare kidney disease, as well as rare metabolic diseases. We believe that we're in a very great position to really have a, a, an exciting path ahead of us, both for our employees, investors, but most importantly for the rare communities that we serve. We expect in the near term and in the years ahead, to create significant value from where we stand today, based primarily on, FILSPARI and the successful launch that we have. This is a medicine that we believe is unique in its ability to replace the current standard of care in IgA nephropathy, and our launch is progressing very well.
We've made great progress in establishing FILSPARI as a new foundational treatment that is superior to those therapies that physicians have been using to treat these patients for many, many years. And we're on track to receive full approval with the PDUFA date September 5th. We also are looking at adding an additional indication, FSGS, and exploring what that pathway looks like with regulators. And then finally, we have a phase 3 program with Pegtibatinase that's underway that really is the first and only disease-modifying therapy for this disease, classical homocystinuria, or HCU, with a significant market opportunity. So we believe that we're very well-positioned, again, to deliver significant value and growth between now and the end of the year, and in the years to come.
Excellent. All right, so with that, let's start with the ongoing launch of FILSPARI. Most recently in the first quarter, you reported over 500 PSFs, and nearly $20 million in net sales, representing a 35% sequential growth rate. How would you describe the progress so far, through 2Q and into, you know, early days of the third quarter, in terms of patient demand and persistency and satisfaction? Yeah, and I'll stop there.
Sure. Well, we're gonna be reporting our second quarter earnings here in the near future, so we won't be able to speak in detail about that. What I can say is consistent with what we've shared from our Quarter One earnings call, in that we had a strong start to this year, and we were very pleased with the progress that we made to begin Quarter Two. So we believe that those trends of strength in our launch continue. And really what we said is, from the beginning of this launch, is that with accelerated approval, we really expect to see that first year of setting the foundation for us to replace the traditional role that ACEs and ARBs have played.
We had a strong first year, but we really indicated that in year two, that we would expect to see ourselves apart from other rare kidney launches. That's exactly what we believe we're on track to do for this year, and in the years to come. Now, I think, you know, it's not just in the demand that we're creating and finding new patients, and with very high compliance rates and a very positive experience that patients and their treating clinicians are having, but we also expect to see a lot of that growth come from two really important inflection points between now and the end of the year. The first is the full approval, as we mentioned, the PDUFA date of September 5th.
The reason that's important is because, one, we would expect to see an expansion of our indication statement, and full approval is important for some clinicians as well as some payers. It also allows our commercial teams to talk about the long-term safety and efficacy data from the only head-to-head trial in this space, the PROTECT trial. The second inflection point is the KDIGO guidelines. These are the global treatment guidelines for kidney disease, and we expect the IgA nephropathy guidelines to be provided in draft form this summer and completed by the end of this year.
We understand that that will include FILSPARI as a new foundational therapy for IgAN, but also will be lowering, likely, the target for proteinuria, making it really imperative for clinicians to be more aggressive in the treatment, really not being satisfied with the traditional role that ACEs and ARBs have played as that kidney-directed therapy for IgA nephropathy.
Right. Okay. And since you mentioned the upcoming PDUFA and potential full approval later this quarter, I wanted to ask about the typical patient journey from PSF to fulfillment, how you're viewing it now, and how you might expect that to change in terms of barriers, if and when full approval comes?
Sure. Well, our Chief Commercial Officer, Peter, who's not on the call with us today, has really done. He and his team have done an outstanding job of really helping to define and refine that journey for patients. And he's also done a nice job outlining some of what this looks like. If I go through what the process looks like, the first thing is that a nephrologist needs to determine that they've got a patient that would be right for FILSPARI, and they complete a patient's start form, or PSF. That would then be signed by the physician and the patient. That would then kick off the REMS certification process, where typically a physician's already signed up. That really takes, you know, a few minutes for the physician.
It also then requires the patient to review the requirements for the REMS to be treated by FILSPARI. And essentially making sure that they understand that they need to have monthly monitoring for their liver function and pregnancy if they are of childbearing potential. In parallel, they will have a prior authorization or claims processing from their payer. And we've really seen great progress in the approval rate, as well as the speed to getting both patients through the REMS, as well as authorized by their payer. And, you know, ultimately, there may be some back and forth with payers, but largely we see that there's about 95% of patients have a clear pathway to get approval by their payer with FILSPARI.
You know, at that point, they would then be cleared from a specialty pharmacy to dispense, and then they would go through the regular monthly monitoring with their lab and with their clinician. Now, perhaps, you know, to answer your question around what's the experience been like, it has been exceedingly and consistently positive, both from a clinician standpoint as well as patients, where what we hear most consistently is that patients, for the first time since they've been diagnosed with IgA nephropathy, when they're on FILSPARI, they feel like they're winning. They're seeing their proteinuria levels go down, which is having a profound impact on, you know, their mental health, their overall sense of their progress in treating this disease.
We believe this is a critical part to why we see such a high compliance rate once these patients are on FILSPARI. A great experience. We expect that to only continue to improve as we get more data, more experience, and ultimately, full approval later this year.
Well, great. Okay, and then I wanted to ask as well about the feedback that you're getting on the field. You just mentioned the REMS, but in particular, the money... the, the monthly liver monitoring requirement. Because that's also something that I think has the potential to change if you get full approval.
So we do see that, you know, the REMS has been very straightforward for most nephrologists. It's not really a meaningful horrendous hurdle for many of them. As I mentioned, it's a straightforward certification process. They basically need to read the prescribing information as well as what the process is for REMS. Once they sign up, they are then able to prescribe FILSPARI for their patients. And, you know, I think it's important to keep in mind that for nephrologists, when they're treating these patients with IgA nephropathy, the way that they treat is through looking at regular labs. And the additional monitoring requirement through the REMS is very much aligned, again, with their practice of treating them. They, of course, now need to look at liver function test.
From the patient side, it does require them to go in for monthly testing. Some patients, particularly the more severe patients, are already doing that. But again, this is the one change: the monthly liver monitoring or pregnancy tests. Once they have that, there are... You know, for most patients, we hear that, you know, perhaps surprisingly, not only is it not an issue, they actually see a lot of reassurance for having that regular checkpoint with their clinician. For some patients, we learned early on in the launch that you know, they didn't really understand the need for this, and so we saw there an opportunity for better education, making sure that they understood why do we have a REMS, what is the real risk of liver events with FILSPARI?
So there were some challenges with a segment of patients, but we've been able to work through that with additional education, as well as our ability, after 120 days, to be able to actually have something more than the prescribing information to engage them with. So we see that this is less of a challenge. And as you mentioned, with full approval, not only will we be able to talk about two-year safety data, which is consistent in that we don't have any events of drug-induced liver injury, which should be reassuring to clinicians and their patients. But also, we will be engaging with the FDA about whether we could make changes to simplify or potentially remove the REMS as we move forward. So again, a great experience so far that we expect to only continue to improve as we move forward.
Okay. And then perhaps to put a little finer point on it, the September 5th PDUFA date, as you look towards potential full approval, what label changes are you expecting or perhaps hoping for? And what impact would you think that has on physician uptake and sales growth?
Jula, do you wanna take that one?
Yeah. So the FDA review of our SNDA, it's going well. We're on track for our full approval date of September 5th. And specifically about the label, there's precedent for how the FDA, and specifically the Cardio-Renal Division, changes a label when they have accelerated approval versus full approval in IgA nephropathy. So we anticipate that we will have a broader indication statement, which removes the 1.5 gram per gram threshold, and instead states that FILSPARI is indicated for treatment of IgA nephropathy patients at risk of disease progression. This broadening of our label indication statement is really timely, given the expected update of the KDIGO IgAN guidelines, which Eric mentioned earlier, which we anticipate to reflect lower ranges of proteinuria, both for initiation of treatment as well as a treatment target.
We also believe that our label will have eGFR data incorporated, and that's gonna be very helpful for our education initiatives to be able to speak to the accrual of benefit on kidney function year over year, which really differentiates FILSPARI from other treatment options. All these label updates we anticipate will provide further confidence and context for a nephrologist to prescribe FILSPARI to more of their patients, and will further our progress towards achieving FILSPARI as a foundational treatment option.
Great. And perhaps this is also for you, Jula. Given that expected shift in the KDIGO guidelines, and potentially others, I think the perspective is that it could be lower to 0.5. How receptive do you think physicians are treating to this new, more aggressive, lower target?
Well, I think it might even be lower than 0.5. It might be 0.3, which is complete remission. So to answer your question, I would say that there's really a concerted effort across academics, industry, and patient organizations to raise the awareness of the fact that IgAN is a progressive disease that warrants earlier interventions. And the KDIGO guidelines will really help to both to educate, but also to provide support to implement earlier diagnosis, earlier treatment, as well as a need likely for combination treatment. And I would say the RADAR data, which was published a little over a year ago, was a really very important first step to inform around the need to treat to lower levels of proteinuria to preserve kidney health. And importantly, we continue to see more data from other registries that validates this. And this isn't a novel concept.
Nephrologists, we all believe that lower proteinuria is better. I think what was not realized was just how detrimental letting an IgAN patient continue to smolder along with lower levels of proteinuria could be to their time left with functioning kidneys. We know now that it's less than 10 years of kidney life that they would have on average, even at the lower levels of proteinuria. So I really have no doubt that with all the concerted efforts educating about the need for earlier diagnosis and treatment to save kidneys, in combination with these new guidelines, that we're gonna see nephrologists adapt, and what's gonna follow is prescriptions to more aggressively manage IgA nephropathy.
Okay. All right, fantastic. One other area I wanted to bring up is Travere has been quite active recently in generating and publishing additional and supplementary data. So I wanted to get your take on the feedback you've been getting from physicians on three in particular. One is the SPARTAN study in newly diagnosed IgAN patients who are also RAS naive. The second is in the combination with SGLT2 inhibitors. And then thirdly, and most recently, the data on eGFR slope comparisons with TARPEYO. Jula, why don't you take those?
Okay. Well, we continue to hear very positive feedback and really a groundswell of enthusiasm for the potential of FILSPARI to be a foundational kidney-targeted medicine to preserve kidney function in patients with IgA nephropathy. We think nephrologists are gonna look to diagnose earlier. They're gonna be looking to get their patients even closer to complete remission, particularly if that's where the KDIGO guidelines go. This means that they're gonna treat earlier and look to use combinations of therapy. That's why this data is so important. Couple of things that you pointed out of this data, let me walk through some of the evidence that we've been generating, really to place FILSPARI as a foundational treatment. First, you mentioned the SPARTAN study. This is a de novo treatment option for newly diagnosed RAS inhibitor-naive patients.
And what we showed in this group is that we can get 80% reduction in proteinuria if you treat early. We also got more than two-thirds of patients reaching complete remission. We also saw a stable eGFR out to nearly one year. This data is very compelling and comparable to the phase II data of APRS and BAFF with regards to efficacy. But more importantly, it's the first study that shows first-line treatment in any therapy, everything else is in addition to standard of care, and says that FILSPARI should be used early to optimize outcomes. I've also talked about combination treatment, and that that's likely to be the future. And we've shown data demonstrating that if you combine SGLT2 inhibitors with FILSPARI, it's safe, and there's an incremental benefit on proteinuria.
And I would say this is important for the practicing clinicians to understand that there's no safety concerns using these in combination, as neither are immunosuppressive, and that you can have an incremental benefit that can accrue when you use both together. The last data that we recently presented was we did a comparison with the NefIgArd trial active arm of TARPEYO versus the treatment with FILSPARI. What we were able to demonstrate was greater proteinuria reduction with FILSPARI, both early and later, compared to TARPEYO, so a durable treatment effect. And what did this translate into? What we would predict: numerically greater preservation of kidney function, and this was based on the two-year eGFR slopes. I would say the one other important point, and Dr.
Barrett pointed this out, is that when you look at our active irbesartan control arm, it far outperformed the placebo arms in all the other studies, and yet FILSPARI beat that. This is the most rigorous study out there, and really gives us greater confidence that FILSPARI can be foundational treatment. So I'd say based on this data that we're generating, we're seeing more guidelines adopt FILSPARI, publications adopt FILSPARI as a treatment paradigm, and then we're also hearing from physicians that FILSPARI is one of the best treatment options available for treating IgA nephropathy.
Fantastic. Okay, and with that, I wanna switch then to FSGS. You had briefly mentioned that has been a long-standing effort. I just wanted to get your take on the current status of that program and, you know, learnings to date from the DUPLEX trial.
Sure. Well, before I hand it over to Jula to talk a bit about the status and potential outlook, let me start with why we believe it's so important for us to find a way forward for FSGS. FSGS is perhaps the most aggressive of the rare glomerular diseases. It certainly is the most proteinuria. These are patients oftentimes who are diagnosed as kids and have, you know, less than 10 years of kidney life left before they get into kidney failure. These patients are treated with off-label therapies, oftentimes that are not effective in staving off that progression of their kidney function decline. And so they really are desperate to find something that is developed and more effective for their condition.
We believe that in the U.S., if approved, there would be about 40,000 patients that would be addressable and could potentially benefit from something like FILSPARI. So this is one that is a high unmet need, and one that we are very committed to looking for a potential pathway. And with that, I'll turn it over to Jula to talk about our current status.
Thanks. In our Phase 3 DUPLEX trial, you might recall we showed clinically meaningful improvements in proteinuria, in kidney function, and in the composite kidney failure endpoints with FILSPARI versus irbesartan. So with a 50% reduction in proteinuria with FILSPARI and more patients reaching the modified partial remission endpoint versus irbesartan, we were able to demonstrate close to a 1 mL/min/year treatment effect on chronic slope. However, given the high variability and the wide confidence intervals around the eGFR estimate in FSGS, the eGFR endpoint was not statistically significant.
This data is really important because while we know in our minds greater GFR decline should result in a faster time to kidney failure, if that benefit on eGFR can't be shown within a reasonable timeframe in a clinical trial, then it may not be the right endpoint, and perhaps a proteinuria endpoint would be better. With this background, NephCure, which is a patient organization dedicated to patients with rare kidney diseases, the FDA, and academia came together to create an initiative called PARASOL, with a goal of bringing together datasets of patients with FSGS to define what should be the right endpoint for regulatory approval. What I can share is that this group has been in place for a little over a year.
They've collected and collated and are analyzing multiple longitudinal FSGS datasets, with a goal to present a data-driven endpoint for regulatory approval at a two-hour session at ASN in October. We're pleased with the speed at which this group is working. There's clearly an urgency because there's such a high unmet need here, and we continue to be hopeful that we can identify a path for approval for FILSPARI, and we'll provide more updates later this year.
Great. Thanks for mentioning that. And as you may know, our last session today features Josh Tarnoff, the CEO of NephCure, and we will certainly be discussing PARASOL. Lastly, before time runs out, I did wanna turn to pegtibatinase. That is currently enrolling patients for the phase 3 HARMONY study. Could you remind us of the disease-modifying data that you generated previously in HCU, and why you believe this opportunity could surpass $1 billion in-
Sure. Well, I think it's important to recognize that these patients are typically only treated with a very restrictive diet with high doses of vitamin B, which is essentially you know, a cofactor for any remnant enzyme that they have. There really is nothing that is disease-modifying. When we looked at our phase 1/2 data at the target dose... We saw that patients were able to reduce their total homocysteine levels by an average of 67%, and 100% of the patients were able to get below the target threshold of 100 micromolar. Half of the patients were able to get below 50, which is really the target that physicians are looking for in order for them to guide patients on introducing more protein into their diet.
We had 1 case that was quite surprising, that normalized their homocysteine levels and was able to resume a normal diet. This is a profound set of results that really excited us as we moved into phase 3, and designed a trial that essentially is looking to replicate that, as well as very innovatively look at how we can guide and show evidence on how patients would be able to introduce protein into their diet. And so, you know, we're looking to be able to provide data in 2026. We're now, you know, enrolling patients as well as doing a manufacturing scale-up for commercialization.
We believe this is an incredible opportunity as we look to about 7-10,000 patients between the U.S. and Europe, that would be addressable currently, and potentially more as there is typically with rare disease, greater awareness, earlier diagnosis, and better engagement with our clinicians, that could see significant growth in the years to come.
Great. Actually, lastly, I didn't want to leave Chris out. So I would like to leave a final question. Two parts, one, just asking about the cash runway as it stands now, but also perhaps any update that you could share in terms of potential, you know, partnerships with either drug?
Sure. So I'll, I'll start, and then maybe, Eric, I'll leave it to you on the... anything on the partnership front. But just from a cash perspective, what we reported at the end of Q1 was $441 million in the balance sheet, and we expect that to be able to support operations into 2028. And so we're in a, in a strong position financially, and really we're excited about the, the growth potential of FILSPARI to really lead that way. And from a, just from a partnership perspective, and, and one thing I would say is that we're always evaluating how we can create value for the company and for patients and our shareholders. And Eric, I don't know if there's anything you might want to add there for anything we're thinking about for the, the drugs.
Sure. Well, certainly we are open to partnerships if we believe that they're going to be generating value, as well as being able to reach patients outside of the U.S. We have partnership with CSL Vifor for FILSPARI in Europe. We have a partnership with Renalys for the development of FILSPARI in East Asia. So, you know, we believe that with FILSPARI, we're well-served to reach patients globally. And with Pegtibatinase, we're currently evaluating, you know, how are we able to reach these patients where we know that they are in Europe, as well as in very specific aspects of the Middle East. This is a much more targeted population, so it's foreseeable that we could do this on our own, but we certainly would be looking at the potential for partnership to reach those patients most effectively.
Great. Fantastic. Eric, Jula, Chris, thank you so much. I appreciate the time and perspectives.
Thanks, Ed.
Thanks, Ed.