Travere Therapeutics - Q3 2023
November 7, 2023
Transcript
Operator (participant)
Welcome to the Travere Therapeutics third quarter 2023 financial results and corporate update conference call. Today's conference call is being recorded. At this time, I'd like to turn the conference over to the Vice President of Investor Relations, Naomi Eichenbaum. Please go ahead, Naomi.
Naomi Eichenbaum (VP of Investor Relations)
Thank you. Good afternoon, and welcome to Travere Therapeutics' third quarter 2023 financial results and corporate update call. Thank you all for joining. 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 statements 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, November 7, 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?
Eric Dube (CEO)
Thank you, Naomi, and good afternoon, everyone. During the third quarter, we executed our key corporate priorities to further strengthen our leadership position in the rare disease community. Notably, during the quarter, we made progress with our launch of FILSPARI in IgAN and reported two-year data from the PROTECT study that we believe will position FILSPARI to play an important foundational role in the IgAN treatment landscape. Additionally, we completed a successful end of phase II meeting for our pegtibatinase program, putting us on track for the phase III study initiation of pegtibatinase by year-end. We completed the divestiture of the bile acid product portfolio, enabling us to further focus on our key priorities. Regarding the ongoing launch of FILSPARI, we continued to execute our strategy for FILSPARI to become a new foundational treatment in IgAN.
In the third quarter, we helped reach even more patients, and every week we hear stories from physicians and patients of how well FILSPARI is working for them. Over the course of the quarter, we identified that additional patient education and support could improve the performance of the launch, specifically in onboarding new patients after a patient's start form has been submitted, and we quickly adjusted. Notably, we are seeing early positive trends from these adjustments through October, and Peter will provide additional details shortly. Overall, we have built a solid foundation of physician demand, with growth in new patient start forms and payer coverage. And together with the initial signs of a positive impact from our enhancements in the quarter, we have confidence in the successful future of the FILSPARI launch. We are just returning from ASN Kidney Week, the largest nephrology congress of the year.
It was truly exciting and humbling to have both of our phase III studies of sparsentan in IgAN and FSGS presented as late-breaker oral presentations and published simultaneously in The Lancet and New England Journal of Medicine, world-renowned peer-reviewed scientific journals. Key opinion leaders who were at the Congress spoke positively about these groundbreaking results and recognized the role of sparsentan in providing deep and durable reductions in proteinuria and kidney function preservation compared to an active comparator for patients with IgAN and FSGS. This, in conjunction with The Lancet publication on the PROTECT study, should further lay the groundwork for potential inclusion into KDIGO guidelines for IgAN and should enable FILSPARI to become a new foundational therapy for this disease. Consistent with previous guidance regarding our U.S. regulatory engagements, we remain on track to provide updates for both FSGS and IgAN this quarter.
In parallel, our team is compiling the supplemental new drug application, or sNDA, for IgAN so that we're in a position to submit in the first half of 2024 for full approval in the U.S. In Europe, the conditional marketing authorization evaluation for sparsentan in IgAN is progressing. Together with our partner, CSL Vifor, we continue to anticipate a review opinion around year-end from the CHMP. Regarding our exciting pegtibatinase program, we are on track for an expected phase III study initiation by year-end. In late October, FDA hosted a patient-focused drug development panel on classical HCU. We are grateful for the HCU patients and their caregivers for sharing their stories about living with HCU. The need for better therapies, the ability to improve diet and improve testing was incredibly clear, and we feel the sense of urgency to execute our phase III program.
Our confidence in the potential for pegtibatinase to become the first and only disease-modifying therapy for people living with classical HCU continues to grow, and we're looking forward to sharing additional updates on the program in the near term. Lastly, during the quarter, we completed the sale of the bile acid portfolio to Mirum Pharmaceuticals. This transaction further strengthens our balance sheet and our focus on our key priorities of achieving success with FILSPARI and advancing pegtibatinase into phase III. Let me now turn the call over to Jula for a clinical update. Jula?
Jula Inrig (Chief Medical Officer)
Thank you, Eric, and good afternoon, everyone. Before walking through our recent data presentations at ASN Kidney Week, I'd like to recognize and thank our internal teams and external collaborators. Their significant efforts led to us achieving an impactful ASN Kidney Week and world-renowned peer-reviewed publications of both DUPLEX and PROTECT in a very short period of time. This rapid dissemination of data will help educate nephrologists on the strong clinical profile of FILSPARI and expeditiously provide the published data required for inclusion in clinical practice guidelines, such as an up-to-date KDIGO. We are empowered by the data shared in the 11 ASN abstracts, including two high-impact, late-breaker oral presentations with simultaneous publications on the phase III studies of sparsentan in IgAN and FSGS. Dr. Rovin, a globally recognized rare kidney disease expert, presented our late-breaking phase III PROTECT study data that demonstrated the significant effect of FILSPARI in slowing disease progression in IgA nephropathy.
These results were met with broad support by the nephrology community and provides us with increasing confidence in FILSPARI's prospective position as a foundational treatment in IgA nephropathy. Simultaneously published in The Lancet, these data demonstrate that long-term treatment with FILSPARI has the potential to preserve kidney function and thereby significantly delay the time to kidney failure. Faced with limited, safe, effective, and approved therapies without significant side effects for IgAN patients, this represents a significant medical advance. Let me highlight select data from the presentation and publication. Treatment with FILSPARI provided patients with an absolute 3.7 mL/min higher eGFR at two years versus irbesartan.
This, in conjunction with the -2.7 and -2.9 mL/min/year chronic and total eGFR slope, respectively, tells us that treatment with FILSPARI can provide patients with meaningfully slower rates of kidney function decline, particularly when compared to historical or recent phase III IgAN trials. Additionally, these treatment effects on eGFR slope were consistent across baseline eGFR and proteinuria, supporting the potential for FILSPARI as a foundational treatment across different stages of kidney disease. Treatment with FILSPARI demonstrated lower rates of the composite kidney failure endpoint, a 40% decline in eGFR, kidney failure, or death compared to irbesartan. FILSPARI resulted in a significant reduction in proteinuria and higher rates of complete remission compared to irbesartan, and the reduction in proteinuria with FILSPARI was durable over the two-year study.
The safety profile of sparsentan was consistent across all clinical trials conducted to date and comparable to irbesartan, importantly, with no drug-induced liver injury and no safety concerns related to fluid overload. We also presented important new data at ASN that we believe help further build understanding and confidence in the clinical profile of sparsentan. These include the SPARTAN study, which is evaluating sparsentan in newly diagnosed RAS-naive IgAN patients. Initial results to date indicate treatment with sparsentan was well tolerated, and we've seen an approximately 80% reduction in proteinuria over 36 weeks and with minimal to no change in kidney function. In the ongoing PROTECT open label extension, when SGLT2 inhibitors are added to stable FILSPARI treatment, the combination has been well tolerated, with a consistent safety profile and showed incremental proteinuria reduction benefits.
These data strengthen the growing body of evidence that sets FILSPARI apart from standard of care in IgAN, suggesting early initial treatment with FILSPARI therapy alone or in combination with other medications, has the potential to preserve kidney function, with this benefit accruing over time in patients with IgAN. Looking to next steps in IgA nephropathy, we believe these data from PROTECT should support an sNDA for traditional approval, potentially with label expansion, to reflect the broader population and long-term benefits of FILSPARI. Also, at ASN, Dr. Rheault, a leading rare kidney disease expert, presented the full phase III DUPLEX study results in a late-breaker oral session that was also simultaneously published in the New England Journal of Medicine.
The broader results show a consistent and durable effect of sparsentan on reducing proteinuria, greater rates of complete remission, positive trends on eGFR, including fewer sparsentan-treated patients reaching the kidney composite endpoint, including kidney failure as compared to irbesartan. While the DUPLEX Study didn't meet statistical significance on the eGFR endpoint, the totality of data continued to build on our previously announced clinically meaningful results and showed a consistent and a well-tolerated safety profile. With no FDA-approved medicines indicated for FSGS and a growing incidence, the unmet need in FSGS is incredibly high. We remain on track to provide an update on our regulatory discussions this quarter. Shifting to pegtibatinase for the treatment of classical homocystinuria or HCU, we made advancements on our clinical and regulatory objectives.
At the leading International Metabolic Conference, or SSIEM, we presented additional data from the phase I/II COMPOSE study that showed that pegtibatinase provides a clinically meaningful reduction in total homocysteine of 67.1%, and that the treatment effect was consistent across patients. One patient achieved normalization of total homocysteine to less than 15. This threshold allowed for increased dietary protein, which can significantly enhance quality of life for patients who are otherwise on highly restrictive, low-protein diets. Additionally, our teams had the opportunity to engage with global HCU thought leaders who are eagerly anticipating the study initiation. We have recently completed a successful end-of-phase II meeting with the FDA, and final preparations are underway in anticipation of a pivotal phase III study initiation by year-end. At that point, we will also look forward to sharing the key study design elements.
With that, I'll turn the call over to Peter for the
Peter Heerma (Chief Commercial Officer)
Thank you, Jula, and good afternoon, everyone. We continue to make sound progress in establishing the commercial fundamentals for FILSPARI to achieve our ambition of making it a new foundational therapy for IgA nephropathy patients at risk of rapid progression. Since the beginning of the launch in February, we have engaged with over 5,600 nephrologists, who are becoming increasingly knowledgeable on the promising clinical profile FILSPARI. These face-to-face interactions have resulted in new prescribers and additional users within practices. Physician demand continues to increase, and in the third quarter, we have 430 new patient start forms. This represents nearly 1,000 patient start forms since the initiation of the launch. This speaks to the confidence nephrologists have in the clinical profile of FILSPARI and how they are using it to help reduce their patients' proteinuria.
Notably, this patient start form growth occurred even with the slower summer season, when fewer patients typically visit physicians, as is common, a common dynamic observed in benchmark launches, and we observed growth following the summer months. As you heard from Jula, her team of medical science liaisons have received positive feedback from the recent two-year results from the PROTECT study, and that is consistent with our market research. In fact, recent market research conducted after the top-line press release of the PROTECT two-year data analysis shows that after reviewing the two-year data, a significant number of nephrologists that prescribe FILSPARI expect to increase their utilization. 60% of surveyed nephrologists that do not yet have the prescriber experience indicate a plan to prescribe FILSPARI in the next three months based on this new data.
Nephrologists also mentioned that they are encouraged by the rapid and sustained proteinuria reduction and that the eGFR results indicate a clinically meaningful long-term benefit on kidney function and delay in disease progression. The market research also indicates that the two-year safety profile could provide confidence for physicians furthering their intent to prescribe. This feedback gives us confidence that we will continue to see growing demand through the balance of the year and into 2024. During the quarter, we also continued our progress in payer engagement, with 67% of the U.S. lives covered for FILSPARI by the end of Q3. Importantly, we nearly doubled our FILSPARI-specific formularies from 50 by the end of the second quarter to more than 90 by the end of Q3. And we continue to be very pleased with the quality of these specific formularies and authorization criteria.
From a revenue perspective, we reported FILSPARI net sales of $8 million for the third quarter. We are beginning to see the expected upward inflection in revenue, but it is not yet closely matching demand seen from patient start forms. The main component of this is that there is a segment of patients who, without increased education and support on the REMS, either have not yet initiated therapy or have taken longer to receive their first shipment. Importantly, our teams recognize the need for additional patient education and support in the fulfillment process for this segment of patients, and we adjusted quickly during the quarter. We enacted targeted approaches to enhance communication and increase patient support, including physician guidance materials for their conversations with patients that are candidates for FILSPARI. We provided educational, patient-friendly communication materials in print and online.
Additional patient support through Travere Total Care's nurse educators to walk patients through the REMS certification process. Notably, we are seeing early signs that these efforts on providing additional support for this segment of patients are working. Both the number of patients completing their REMS certification shortly after receiving a patient start form and patients initiating paid therapy have been increasing. As we discussed on our approval call in February, FILSPARI's launch would be a rolling one that unfolds over the first nine to 12 months, punctuated by important milestones such as the two-year data and peer-reviewed publications.
Looking ahead, we see further growth opportunity with the growing body of sparsentan evidence and in combination with SGLT2, the potential inclusion in prescribing guidelines such as KDIGO, to be updated next year, and most importantly, the planned submission of an sNDA for the full approval of FILSPARI in IgAN in the U.S. To close, we have great confidence in the future launch trajectory of FILSPARI, based upon key fundamentals. First, FILSPARI's profile. FILSPARI has a superior treatment profile compared to active, compared to irbesartan, and addresses the needs of patients with IgAN and risk of rapid progression. Two, demand from nephrologists. Prescribers are excited about the FILSPARI profile, which is demonstrated by the high patient start forms and the increasing new and repeat prescribers. Three, the payer progress. Quarter-over-quarter, we have shown increasing payer coverage growth.
Now, 2/3 of the lives are covered, and we're seeing high level of payer approvals for FILSPARI. And four, patient experience and adherence. We continue to hear feedback that patients on therapy have positive clinical results in their proteinuria levels, and once a patient starts FILSPARI, we are seeing that both compliance and persistence is high. Importantly, our team is focused on delivering a strong first-mover, and we will continue to adjust based on ongoing learnings to achieve our ambition of FILSPARI becoming the foundational treatment for IgAN patients at risk of rapid progression. Let me now turn the call over to Chris for the financial update. Chris?
Chris Cline (CFO)
Thank you, Peter, and good afternoon, everyone. Following our third quarter results, we're in a very strong financial position. From an operational perspective, we continue to grow revenues, and we focused our investments for the future. We also completed the bile acid portfolio transaction, which has brought forward several years of value from the products and meaningfully strengthened our balance sheet. In our financials, the transaction is being reflected as discontinued operations, and as a result, the following discussion will be focused on our continuing operations, unless otherwise noted. For the third quarter of 2023, net product sales were $33.9 million, compared to $25.4 million for the same period in 2022. The increase is primarily attributable to an increase in net product sales from the ongoing launch of FILSPARI and IgA nephropathy.
THIOLA and THIOLA EC also continued to perform well and contributed $25.9 million in net product sales in the third quarter. This growth continues to be driven by organic patient demand. During the quarter, we also recognized $3.2 million of license and collaboration revenue, which translates to $37.1 million in total revenue for the period, compared to $228.1 million for the same period in 2022. Research and development expenses for the third quarter of 2023 were $60.6 million, compared to $57.1 million for the same period in 2022. The difference is largely attributable to the continued advancement of the company's pegtibatinase's clinical program as it prepares for phase III initiation, including clinical trial expenses and manufacturing, as well as increased head count.
On a non-GAAP-adjusted basis, R&D expenses were $53.8 million for the third quarter of 2023, compared to $51.9 million for the same period in 2022. Selling, general, and administrative expenses for the third quarter of 2023 were $67.8 million, compared to $52.4 million for the same period in 2022. The difference is largely attributable to commercial launch-related activities following the accelerated approval of FILSPARI in February 2023, as well as legal fees. On a non-GAAP-adjusted basis, SG&A expenses were $51.8 million for the third quarter of 2023, compared to $43.5 million for the same period in 2022.
Total other income net for the third quarter of 2023 was $3.4 million, compared to total other expense net of $1.3 million in the same period in 2022. The difference is largely attributable to an increase in interest income during the period. Net income, including from discontinued operations for the third quarter of 2023, was $150.7 million, or $1.97 per basic share, compared to a net loss of $69.7 million, or $1.09 per basic share for the same period in 2022.
On a non-GAAP adjusted basis, net income, including from discontinued operations for the third quarter of 2023, was $173.5 million, or $2.27 per basic share, compared to a net loss of $55.3 million, or $0.86 per basic share for the same period in 2022. As of September 30, 2023, the company had cash, cash equivalents and marketable securities of $634.6 million. This includes gross proceeds of approximately $210 million received during the quarter in conjunction with the closing of the bile acid portfolio divestiture maintain our strong cash position, we're following a disciplined capital allocation approach that is expected to reduce our cost base from this year, while ensuring the appropriate investments are made in the ongoing FILSPARI launch and advancing pegtibatinase into phase III development.
Importantly, with these efforts and our reported cash balance at the end of the third quarter, we believe we can manage our balance sheet to support operations beyond 2026. I'll now turn it back over to Eric for his closing comments. Eric?
Eric Dube (CEO)
Thank you, Chris. The Travere team has accomplished and executed on a remarkable number of milestones, making significant progress towards delivering innovative treatments for patients with rare diseases. Overall, for the third quarter, I remain incredibly proud of our team's execution. We have successfully delivered a quarter demonstrating demand for FILSPARI, and with the PROTECT phase III data in hand, we remain confident in our goal of enabling FILSPARI to ultimately become the foundational therapy in IgAN. Feedback from the scientific community at ASN is deeply encouraging as we continue our FILSPARI launch and continue our plans to pursue an sNDA to convert FILSPARI for traditional approval. We remain on track to provide an update on our FDA engagements for both IgAN and FSGS this quarter.
Additionally, the data packages from the phase I/II COMPOSE study for pegtibatinase continues to support its potential to become a transformative disease-modifying therapy for the HCU community. We are excited to continue our efforts in this program, and we remain on track to initiate a pivotal study by year-end. As we approach the end of the year, our efforts are concentrated on finishing strongly. We are focused on executing continued progress with the FILSPARI launch, advancing pegtibatinase forward, and remain committed to delivering on our promise of making profound differences in the lives of individuals living with rare disease. I'll now pass the call over to Naomi for the Q&A question. Naomi?
Naomi Eichenbaum (VP of Investor Relations)
Thank you, Eric. We can now open the line up for Q&A. Operator?
Operator (participant)
Thank you. If you would like to signal with questions, please press star one on your touchtone telephone. If you're joining us today using a speakerphone, please make sure your mute function is turned off to allow your signal to reach our equipment. As a reminder, we ask that you limit yourself to one question. If you have another question, please rejoin the queue. We'll now take the first question from Joseph Schwartz with Leerink Partners.
Joseph Schwartz (Managing Director and Senior Biotechnology Analyst)
Hi, all. This is Will in for Joe. Thanks for taking our questions today. To just start for us, are there any notable patterns among the nephrologists that you have interacted with after the PROTECT readout? Just wondering if there are any groups of physicians that seem to appreciate the totality of the data more, as compared to those who may not be fully comfortable with the profile yet. Then I have a quick follow-up to this. Thanks.
Eric Dube (CEO)
Will, thanks for the question. I will turn that over to Jula for her thoughts in the early reactions. What I can say is that I walked away from the ASN meeting with a very consistent view that nephrologists are excited about the profile. Jula, why don't you share what you heard?
Jula Inrig (Chief Medical Officer)
Yeah, I would agree with what Eric just said. I think people were excited to see the results and the full data presentation that shows that sparsentan has the potential to preserve kidney function and significantly delay the time to kidney failure. The other important thing that was demonstrated is the rapid and the durable and sustained reduction in proteinuria. And when people get to see the totality of data, they feel like it's very promising and has the potential to be foundational treatment in patients with IgA nephropathy.
The additional thing that I would say is looking to the future, the additional data that we showed with regards to earlier treatment were from the SPARTAN trial data, that shows if you treat people early, even before they've seen ACE inhibitors or ARB, you see even more reduction in proteinuria and preservation of kidney function. And if you use it in combination with, we presented some of that early data as well. It's safe and effective. So, I believe we saw a fairly consistent response to what we were able to demonstrate and show.
Joseph Schwartz (Managing Director and Senior Biotechnology Analyst)
Great. Thank you. I just quick follow-up here. Given the literature suggests that the 40% reduction in proteinuria should lead to around a 2.7 mL/min/year benefit on eGFR, but we saw a bit of a different relationship in PROTECT, have you heard any concern from docs on this? And now that you have the published data and have had some more time to review the results, do you have a better idea for what may have drove this outcome? Thank you.
Eric Dube (CEO)
Jula, I'll pass that one over to you.
Jula Inrig (Chief Medical Officer)
Yeah, happy to, to answer that. When you look at the meta-analysis and all the data in combination, you're looking at drugs with different mechanisms of action, some that acutely increase eGFR and some that decrease. This is a two-year study, where over two years we saw an absolute difference in benefit of 3.7 mL after two years, favorable for sparsentan, and that's a really important point to take into consideration. Obviously, the slope data is a modeled treatment effect, where we see an annual benefit of greater than 1 mL/min/year. And with drugs that have a slight acute effect, we know that that stabilizes kidney function over the long term, and the important thing to take away is that benefit accrues over time. So each year you get a benefit.
It's 1.1 mL/min/year in one year, it's 0.2 mL/min/year, and in two years, it's 3.3 mL/min/year the next year. That's the important take-home message that you get, is it, it accrues over the long term, which is very different than other drugs, which might increase eGFR and don't have production over the long term.
Joseph Schwartz (Managing Director and Senior Biotechnology Analyst)
Great. Thank you so much.
Operator (participant)
Our next question will come from Anupam Rama with JPMorgan.
Anupam Rama (Executive Director of Biotechnology Equity Research)
Hey, guys. Thanks so much for taking the question. On the patient start forms, maybe you can give us a little bit more color beyond the opening remarks on what you're seeing on the month-over-month growth here. Was there any particular headwind in the quarter beyond the summer seasonality that you talked about? Or, you know, was there a group of physicians that were kind of on the sidelines until they saw the two-year PROTECT eGFR data? Maybe give us a little bit more color on that. Thanks so much.
Eric Dube (CEO)
Yeah. Thanks, thanks so much for the question. I will have Peter talk about what he is seeing in terms of prescribing.
Peter Heerma (Chief Commercial Officer)
Yeah, thanks, Anupam. I would say overall, we see good continuation of growth during the quarter, and we had a little July inflection when less patients see their physician, and that's what I commented on in the pre-prepared remarks. But overall, we're seeing continued growth from both new prescribers as well as repeat prescribers. And most of these patients are being managed through the community physicians, and that's why we see the majority of the prescriptions coming from as well. But other than what I was talking about from a seasonality perspective, we didn't see any other headwinds, and I'm really pleased with the continued growth that we show today in continuation of demand.
Eric Dube (CEO)
Yeah.
Operator (participant)
Our next question will come from Maury Raycroft with Jefferies.
Maury Raycroft (Equity Research Analyst)
Hi, thanks for taking my question. I think Jula just alluded to benefit occurring over time in the PROTECT study. Since patients on sparsentan in PROTECT washout prior to starting the open-label extension, how does this impact ability to show that treatment effect occurs beyond the two-year period in case FDA asks for longer-term data like this? I guess, is there a way you can account for the washout?
Eric Dube (CEO)
Maury, thanks for the question. Jula, I will pass that one over to you.
Jula Inrig (Chief Medical Officer)
Yeah, Maury, it's a fair question because in reality, that's not how we're going to treat patients over the long term. You would keep them on, but that was a question that wanted to be asked because the acute hemodynamic effect. I would say the important thing is that what we saw was a durable treatment effect after patients went back to standard of care, where you saw an absolute overall favorable eGFR in patients on sparsentan washout. Now, we can continue to monitor those patients when they resume sparsentan, and I think the important data that we'll have that comes out of open label is what is the trajectory for those patients who are on irbesartan versus when they switch over to sparsentan. It'll be incrementally important information that we'll provide over the long term.
But to your point, we believe that the data that we have from the double-blind will be supportive of our sNDA filing, at this point in time.
Maury Raycroft (Equity Research Analyst)
Got it. Okay. Thanks for taking my question.
Operator (participant)
Our next question will come from Greg Harrison with Bank of America.
Greg Harrison (VP and Senior Research Analyst)
Hi, guys. Thanks for taking the question. Are you able to give any color on the volume of patient start forms in the periods before and after the announcement of the PROTECT data? And what feedback are you hearing from physicians on their appetite for prescribing FILSPARI in light of the data?
Eric Dube (CEO)
Greg, thanks for the questions. I would say, before handing it over to Peter to provide a bit more perspective on what he's hearing, including some market research that his team quickly did. It's really too early to be able to look at projections sort of before or after PROTECT in terms of prescribing. What I can say qualitatively coming out of ASN, where, you know, there was much greater exposure to the actual data, was a real excitement, you know, particularly for those that attended ASN, much more academic. Peter's team did some really great research quickly to understand that. So Peter, why don't you share a little bit more about what your team learned?
Peter Heerma (Chief Commercial Officer)
Yeah, thanks, thanks, Greg, for that question. I would say, first of all, the patient start forms of 430 in the third quarter, I think is a really good number, and that leads to like 1,000 patient start forms in only the first seven and a half months. So I think we're making really good progress there. To Eric's point, it's too early after the top-line data announcement to see any change in inflection. But I think overall, what we saw in the market research, and this was a post-market research right after the press release of the top line, is that there is good confidence in the profile of FILSPARI.
Having been at the ASN and having had many of the conversations with physicians, I think there was a really good reception of the FILSPARI profile, the totality of the data, and what FILSPARI can mean for those patients, those physicians' patients. I think overall good reception and, yeah, more to go.
Operator (participant)
Our next question will come from Vamil Divan with Guggenheim Securities.
Vamil Divan (Managing Director)
Hi, great, thanks for taking my questions. I'm just curious if you can share some more feedback on the REMS and safety side of things. I think you said you've now touched about 5,500 nephrologists, I believe, was the number you shared. Can you share anything in terms of how many nephrologists are now sort of, you know, worked their way through the REMS program or are certified to prescribe it?
And then again, just kind of in the theme of some of the other questions, just any feedback on the safety side of things now that we've seen, you know, now doctors have seen the full data both on PROTECT and as well as DUPLEX?
Eric Dube (CEO)
Vamil, thanks for the questions. I'll, before I hand it over to Peter, what I'll just share is that we can provide some qualitative and directional feedback on the REMS as well as the safety profile. We are not providing metrics on REMS certification, but, you know, we continue to see that grow. Peter, why don't you talk a little bit about what the reaction and what directionally you're hearing, both from the physician and the patient perspective? And certainly, Jula, you know, if there's anything further you want to add on reactions to safety coming out of ASN, by all means, add that. Peter?
Peter Heerma (Chief Commercial Officer)
Yeah, certainly, Eric. And I think you were referring to the amount of nephrology that we have seen in face-to-face interactions. And indeed, I did call out 5,600 nephrologists that we have seen in face-to-face interactions with our field force since the launch. And that is, I think, a very good progress, because as we announced during the launch call, we are consistently want to call on about 6,000 nephrologists, and it's covering about 85% of the patient population. And so I think we are making really good progress, and we are nearly there from overall nephrology perspective. With regards to the safety profile, I think that was the second part of your question. Maybe, Jula, that's a more an appropriate question for you to answer.
Jula Inrig (Chief Medical Officer)
Yeah, I think that I would respond, significant reassurance with regards to the safety profile around sparsentan across the program to date, both PROTECT and DUPLEX, where we saw the exact same safety profile with regards to the liver elevations of three times upper limit of normal, and really no new elevations since our interim from PROTECT. And so where physicians rapidly move to is, can this be changed over time? Which, of course, we'll readdress this as we continue to accrue data and go back, but that's where physicians quickly move to. So we feel reassured by the safety profile at this time.
Eric Dube (CEO)
Well, maybe I can just add one other insight that I think is... might be helpful, and it's really behind some of the comments that Peter shared in his prepared comments. And that's really the reaction of physicians versus patients to the REMS. Most physicians are familiar with, you know, how to read prescribing information, what a box warning is, and what a REMS is. And in fact, you know, many nephrologists have familiarity and are accustomed to REMS. For patients, on the other hand, some of them may just be accustomed to going to their local pharmacy and picking up a prescription for, you know, an ACE or an ARB or others. So for some patients, it requires a bit more education, a bit more hand-holding through the process.
For that segment of patients that Peter talked about, it really does require a bit more information, education, and support. And so there is a segment, as we refer to, where the REMS does take a little bit more time. But overall, what we're hearing from physicians is the REMS doesn't take that much time. It's very straightforward. For many patients, it works incredibly well. But I think we do need to make sure that we're providing all patients the information that they need to be able to move from patient start form to actually fulfilling their prescription. So I think that was the key insight and the pivot that we had this quarter to make sure that we're able to move all patients as quickly through the process as possible.
Vamil Divan (Managing Director)
Okay. Thank you.
Operator (participant)
Our next question will come from Liisa Bayko with Evercore ISI.
Liisa Bayko (Managing Director)
Hi there. Thanks for taking the question. Can you just give us a little detail on things like, gross to net, for example, where you're at there? And then actually, how many patients did you have on therapy by the end of the quarter?
Eric Dube (CEO)
Chris, why don't we have you go through gross to net? And Liisa, I'll say that we are not yet in a position to be able to comment on number of patients on therapy or other types of KPIs that you might be looking for. Because as you can imagine, in the first year of launch, it is quite variable. You've got patients that are on, you know, free drug, as well as just working their way through the reimbursement process. So, we're not in a position to be able to comment at this point.
What I can say is that we continue to see very strong demand, and we continue to see that inflection in revenue that we expect to continue and become more closely aligned with the underlying demand of patient start forms. Chris, do you want to comment on gross to net?
Chris Cline (CFO)
Sure. So Liisa, consistent with our prior guidance, we expect that stable state sparsentan or FILSPARI gross to net to be mid to high teens, and, you know, that's, that's consistent with what we see today. There's going to be some variability quarter to quarter as we're getting all of the processes, and as Eric highlighted, the different elements of reimbursement, et cetera, in place. But overall, we, we feel very confident that we're going to end up in that mid to high teen range, and, and that's, consistent with how we're operating now.
Liisa Bayko (Managing Director)
Okay. Great. And how many patients did you have on, at the end of the quarter, roughly?
Eric Dube (CEO)
We did not report on numbers of patients on therapy, because again, during the first parts of launch, it is variable. And so, you know, getting to a steady state would allow us to be able to report on a consistent basis to be able to project forward. So at this point, we're going to continue to report on those three metrics since that we shared and guided to on in February of patient start forms, payer coverage and revenue. And I think as you see from the revenue inflection that we had from Q3 to Q4, that we have many more patients that are on reimbursed medicine, and we would expect that only to continue through the fourth quarter and beyond.
Liisa Bayko (Managing Director)
Okay. And then any commentary on, or update on the, the new guidelines coming out, the KDIGO guidelines?
Eric Dube (CEO)
Jula, do you want to take the latest on the guidelines?
Jula Inrig (Chief Medical Officer)
Yeah. We're very pleased that we were able to get our PROTECT results published and in peer-reviewed. We knew that our interim data was going to be included in the KDIGO guidelines, and now that we have the complete data, they will also be able to be reviewed and included in the guidelines. Those will be available for publish or public commentary in the very first quarter of 2024.
Liisa Bayko (Managing Director)
Okay, great. And then just final question for me, kind of as we see the landscape evolving, and I was really kind of struck by the eGFR results that Otsuka presented for sibeprenlimab, which is, you know, one of the B-cell modulators targeting APRIL. I guess, in the context of having, you know, that kind of effect on eGFR, like, how do you see kind of the need for other mechanisms on top of that, if you're able to keep eGFR relatively flat, or is there still, like, you can do better and what about proteinuria and all those other things? But just curious how you're thinking about, kind of, you know, sparsentan in the context of that kind of a remarkable change in eGFR. Thanks.
Eric Dube (CEO)
Yeah. I'll have Jula talk about, you know, the view of maybe hers or of nephrologists in kind of the evolving treatment landscape. What I'll share is that the thing that really excites us about the profile of FILSPARI is the ability to combine with all of these new classes of therapies that are being developed. And, you know, each of them are being studied on top of RAS inhibition that occurs to address the overactivation in the kidney. I think now what we've seen with our two-year data is the superiority of FILSPARI versus RAS inhibition alone. So it really is the question of how and when and in what patients do you combine, is really the way that we think about it in the positioning, and that's what we mean by that foundational therapy.
I know that a lot of this data is early, but Jula, do you want to comment on how you view as a nephrologist and what you're hearing from your peers in this emerging treatment landscape?
Jula Inrig (Chief Medical Officer)
Yeah, I think it's important. As Eric said, you need a foundational treatment. When you get diagnosed with IgA Nephropathy, you have already damage that's ongoing, and you need to reduce the proteinuria to preserve kidney function. And what we demonstrated with PROTECT is if you replace your RAS inhibitor with sparsentan, you can get incrementally closer to a normal kidney function in the twos. If you want to then add additional treatment on subsequently, if that patient either doesn't get into complete remission or continues to progress, certainly that's an alternative treatment option to add on. With regards to the sibeprenlimab data, you know, that's one-year data. We showed similar 36-week data. If you start treatment very early, the SPARTAN trial data, 80% reduction in proteinuria, 2/3 of patients getting into complete remission and no change in eGFR. Early data.
So again, we do need to follow the data that we're seeing from these phase IIs to further out. But I do believe that sparsentan as foundational treatment with the increment of other therapies, we want to preserve kidney function as much as we can, and combination therapy is absolutely the future of treatment for patients with IgA nephropathy.
Operator (participant)
As a reminder, please limit yourself to one question. Thank you. Our next question will come from Mohit Bansal with Wells Fargo.
Speaker 18
Hey, this is Aman for Mohit. Thanks for taking our question. Would you briefly touch upon the early persistence data you have for patients on FILSPARI and how you think REMS contributes to this? And then separately, would appreciate an update on what you're seeing in terms of step edits and prior auths that let you have more formularies covering FILSPARI.
Eric Dube (CEO)
Yeah, thanks for the question. Peter, I'll turn to you in just a moment to talk about, you know, to explain a little bit more about persistence, compliance, as well as step edits. But before I do, I want to share a story that I heard from a patient who really talked about their journey with IgA nephropathy, and he shared this at ASN last week, where I think initially he had, you know, some questions or really uncertainties about what a REMS would mean for him. And this was a patient that struggled to get his proteinuria down for years, and his physician offered him FILSPARI. And you can imagine that, like for many patients, having to go and do additional testing and starting a new therapy, there were many questions.
What he shared, and I think was really an aha for many of us in the audience, was that he looked forward to those monthly calls with the nurse from our total care center and the ongoing monitoring and support that he felt from our hub services, our patient services, as well as those regular check-ins from his physician. So actually, you know, that may be, for many patients, a real additional support for that longer-term compliance, persistence with therapy. And we know that for many patients, particularly those that are otherwise young, healthy, working, busy, it can be a challenge. So I think that it really is a real benefit. We've heard lots of questions about the challenges of REMS.
I think he did an incredible job to articulate what he found in value of that regular monitoring and really people looking after his health.... Peter, do you want to share, you know, anything further on the persistence as well as the payer coverage?
Peter Heerma (Chief Commercial Officer)
Yeah, absolutely, Eric, and thanks, Maury, for that question. I think your question was on three components. One was on payer approval, one was on compliance persistence, and one was on REMS, if I understood you correctly. So let me go one by one. I think really pleased with the payer approval rate that we are seeing for FILSPARI, which closely matches the progress we're making in the overall coverage as well. So I think we have made really good progress there. And also the compliance and persistence. Patients that are on products, see clinical results and remain on product. And I know this is one of the questions initially with the monthly monitoring, will patients remain on therapy? And what we are seeing so far, and it's still early days, we see strong compliance and persistence rates.
With regards to the REMS, and patient perception of the REMS, I think for a large amount of patients, the process is working very well, and these patients receive FILSPARI well within benchmark numbers. But as Eric mentioned earlier, and I was alluding to that in the prepared remark, there's also a segment of patients that need a little more handholding through education and support. I think you have to realize that it was only until the second half of June if we had the opportunity to educate physicians and patients other than the package inserts, as part of the FDA guidance for accelerated approval. So really, by the end of June, we were able to provide that additional educational support for patients. And with the additional support, we are seeing that the early REMS certification for that group of patients is already improving.
That also translates then into an increase in paid FILSPARI shipments to patients.
Speaker 18
Thanks so much.
Operator (participant)
Our next question will come from Carter Gould with Barclays.
Edwin Delfin (VP of Biopharmaceuticals Equity Research)
Hey, guys, you've got Edwin Delfin on the line for Carter Gould. Thanks for squeezing us in here. We have a question on pegtibatinase for HCU. I know you've completed the end of phase II meeting, but have you guys received clarity from the agency on amount of follow-up and any impact on clinical measures beyond the biomarker impact for the primary endpoint? Thanks.
Eric Dube (CEO)
Edward, thanks so much for the question, and we are really excited about our HCU program and moving into phase III here very soon. Bill, why don't you take that question to share a little bit more to answer those questions? But before I turn it over to Bill, I will say that we'll be sharing, you know, much more detail once we initiate the trial on you know aspects of the trial design. But certainly, Bill can share what we've shared publicly at this point.
Bill Rote (SVP of Research and Development)
Certainly, now that I'm off mute. We've completed the end of phase II, as you noted. We had very collaborative discussions with the agency, and I'm happy to report that we've aligned, as we intended to all along, on total homocysteine as the primary endpoint for the study. There are various aspects of the program that look at clinical benefit. Some of those are measures of function, some of those are quality of life, some of those will be looking at what we're able to do with diet. And as Eric said, we're going to have more detail about this. Once the study starts, we'll give you a full picture of the phase III program. I think you also asked around overall study duration.
If we look at the range of other enzyme replacement therapy studies, the period of observation ranges from six months to 18 months, and we'll be in that window, and most of those studies are less than 100. So I think that gives you kind of a ballpark of where we're headed, and you know, we'll have more once the study has started.
Edwin Delfin (VP of Biopharmaceuticals Equity Research)
Appreciate that. That's helpful. Thank you.
Bill Rote (SVP of Research and Development)
Sure.
Operator (participant)
Our next question comes from Laura Chico with Wedbush Securities.
Laura Chico (Managing Director and Senior Biotechnology Analyst)
Hey, good evening, guys. Thanks very much for fitting me in here. I wanted to go back to the patient start form for a moment for FILSPARI. You know, 430 over 417, I guess the question I've got is, have you plateaued in terms of how high you can go with patient start forms? If I look back, for example, at the first year of Tarpeyo's launch, I believe they peaked out at 589 enrollments during those first four quarters. So I'm curious as to whether you think you can actually grow this much more beyond 430. Thank you very much.
Eric Dube (CEO)
So, Laura, I think the question is unequivocally yes. We have nearly 1,000 patient start forms through the third quarter of this year, and as we think about the number of patients that we believe are addressable, that will increase. I'll turn it over to Peter, but I want to be able to emphasize our confidence and be able to identify those patients, but equally the enthusiasm that we hear from nephrologists, not just that anticipate prescribing, but those that have prescribed. We're seeing repeat prescriptions and new prescriptions, new prescribers added every month. That's a really important lead measure for any launch. In my experience, those are critical. Those and the clinical experience, the feedback anecdotally we're hearing, we are seeing really positive results there.
So we do expect it to grow, and Peter can talk a little bit more about what he's seeing and where we expect to go from here.
Peter Heerma (Chief Commercial Officer)
Yeah, thanks, Eric, and thanks, Laura, for that question. I think there's really three components here that I would like to, to highlight. To answer your question, like, how far can you go and how many patients are out there? The first one is I would say there has been limited, innovation in nephrology in the last 30-40 years, and that's what you see as well with physicians. Nephrologists are relatively, conservative in adaptation of new medicine, and part of that is also the education. In particular, in IgA nephropathy, where there have been little, investments in education. And I think the RaDaR publication that we, discussed actually at the last earnings call, and Jula can provide a little more context on that, really is providing that, that increase in urgency of, of to treat.
Because historically, a lot of the physicians thought like IgA Nephropathy is a relatively slow progression, progressive disease. But what we are seeing right now, based on new data and registry research, is that those patients actually progress much more rapidly. So I would expect that the patient population over time will be increasing also with new guidelines and new guidance. So within that context, I would say I'm really pleased with the progress we have been making. To Eric's point, we have now nearly 1,000 patients in the first 7.5 months of FILSPARI. And I see with all the continued investments and education in the community, there is that recognition that these patients should be treated more early and more urgently.
Gio, maybe we can provide a little more context on your perspective on, for example, RaDaR.
Jula Inrig (Chief Medical Officer)
Yeah. I think that as we educate the physicians and they realize that what they historically understood and were trained in their educational programs 10, 20, 30 years ago, that IgA is a benign disease and they can send them back to their primary care physician and see them every few years, is not the case. That patients, even with 500 milligrams of proteinuria, are at risk of progression to kidney failure within their lifetime. We had additional data presented at ASN that confirmed the RaDaR data, and this was U.S. registry data that showed similar results. Patients, even with lower ranges of proteinuria, are at risk of progression to kidney failure. That dissemination of information needs to get out to the community physicians who don't always go to these kidney meetings and don't always read the journals.
As they see this information, that urgency to then treat their patients increases. To Peter's point, then that translates into the need to treat them with a foundational medication such as FILSPARI, which reduces proteinuria and preserves kidney function.
Operator (participant)
Our next question will come from Tim Lugo with William Blair.
Speaker 19
Hi, this is John on for Tim. Thanks so much for squeezing us in. So with the recent atrasentan data, I was wondering if you could just give us some thoughts on that data and how you might think that might impact the regulatory landscape moving forward?
Eric Dube (CEO)
Yeah, I mean, we certainly expect that there are going to be additional data, potentially new therapies that are going to be approved. I think, you know, it's hard for us to comment because there were no data disclosed. And so I think we'll have to wait to see what is presented from Atrasentan for us to be able to comment. I mean, our working assumption is that it is an endothelin blocker, so it should show benefit. We certainly have seen demonstrated that with PROTECT, with sparsentan, and we've seen that proof of concept with other endothelin blockers. But we've got to see the data on benefit and safety before we can comment.
Operator (participant)
Our next question will come from Alex Thompson with Stifel.
Alex Thompson (Director of Biotech Equity Research)
Hey, great, thanks for taking my question. I guess in the past you've commented sort of with this uptick in, in sales in the second half of the year, that you're comfortable with, with consensus numbers for the year, which I think on Bloomberg are in the low $30 million range at this point. I guess maybe if you could reiterate your confidence there, that would be great. And then could you also maybe comment on, you know, the impact at all of, stocking in the revenue this quarter? Thanks.
Eric Dube (CEO)
Yeah, thanks, Alex. I'll take the first part of that question, and then I'll turn it over to Peter to talk about the impact of stocking throughout the year. What I can say is that I'm incredibly proud of the progress that we've made on the FILSPARI launch and the ability to continue to grow demand to be able to show the early signs of that inflection that we expect. And as we've guided, in the back half of this year, we'll start to see revenue track more closely with that underlying demand or the number of patient start forms. I think as Peter alluded to, you know, we still have some room to go in terms of aligning that more closely. We expect that we're going to make that progress in the fourth quarter.
In fact, when we look at other rare renal launches, we've seen that there's a meaningful proportion of their first-year sales in that fourth quarter. We fully expect that to be the case with us as well. We've seen the inflection so far, and in terms of providing specifics on guidance, we've not provided that this year. We won't for the rest of the year. But we are confident in the continued deflection of both patient start forms and of revenue.
Operator (participant)
Our next question will come from Allison Bratzel with Piper Sandler.
Allison Bratzel (Equity Research Analyst)
Good afternoon, guys, and thanks for the update and for taking my question. So just one on the SPARTAN Study update at ASN, and this is kind of a follow-up to a prior question and prior discussion. But just based on your interactions with nephrologists and KOLs, could you help us understand what kind of additional clinical data you think you need to generate to really catalyze or just drive widespread first-line use of FILSPARI in IgAN or just earlier line use more broadly? Thanks.
Eric Dube (CEO)
So, first, let me take part of that, and I'll turn it over to Jula and then to Peter. What I would say is, you know, our focus right now is within under accelerated approval. We've got to focus very much on the label at hand. You know, we would expect that with traditional approval, that we would expect to see that expansion. But, Jula, do you want to comment on, you know, what additional data you're hearing from nephrologists, and Peter, then perhaps, you know, further, what you're hearing in market research?
Jula Inrig (Chief Medical Officer)
Well, to Eric's point, right now, we're primarily being utilized in prevalent IgA Nephropathy patients who remain at risk for progression per our label. Physicians are very excited about the SPARTAN data because we're one of the only ones that's generating this data. Patients who are newly diagnosed, who haven't failed RAS inhibitors yet, and the potential for sparsentan to be used as a first-line treatment and the magnitude of proteinuria reduction and kidney function preservation. So I think that the SPARTAN data can incrementally show that. The other important data that we're going to have in this is some of the biomarker data, the fluid data, the bioimpedance that shows the safety profile, as well as some of the novel data that's going to come out from this study is the repeat kidney biopsies in these patients.
Incrementally, the information that's going to come out of SPARTAN will further give confidence with regards to the place of therapy that sparsentan can play in patients with IgA nephropathy.
Peter Heerma (Chief Commercial Officer)
Yeah, thank you. Building on that, I would say we have very strong data now for patients that basically have failed RAS inhibition, both ACE and ARBs. And we know from market research that over half of the patients that are on ACE and ARBs are not getting to the target levels of proteinuria as a physician would like to. So we have still a lot of patients to go in that segment. But now we also have patients information and very strong data in patients that are RAS naive. And then I think the third category is really building upon the evolving treatment landscape and being prepared for combination therapies, as Jula was mentioning. And I think the combination data that we presented last week at ASN with SGLT2 provides that additional context as well.
So I think we are building the data and the evidence across a broad patient population that could benefit from FILSPARI treatment.
Operator (participant)
We'll take a question from Ed Arce with H.C. Wainwright & Company.
Ed Arce (Senior Research Analyst)
Great. Thanks for squeezing me in. And, Peter and Jula, it was great to see you this weekend in Philadelphia. Three questions for me. First of all, in one of the sessions at the conference, I saw Eliza Thompson discuss the chronic versus total slope and basically acknowledge that there's a hemodynamic effect there early on. And so in light of that, I'm just wondering if you could, you know, discuss your thoughts as you approach the meeting with the FDA and discuss all the other supportive data in the context of the totality of the data for full approval. And then two more, just in terms of the ongoing launch of FILSPARI. Firstly, can you discuss the PFS in October, if there is any further acceleration from the third quarter?
And then lastly, I'm wondering if you can discuss the conversion timeline from PFS to treatment initiation, perhaps now and then also eventually steady-state expectations? Thanks so much.
Eric Dube (CEO)
Okay, thanks, Ed. So, Bill, I'll have you comment on the regulatory perspective and how we are thinking about, you know, the totality of data. And Peter, you can talk about, you know, directionally, what we're seeing in October as well as conversion. Bill?
Bill Rote (SVP of Research and Development)
Certainly. Thanks, thanks for the questions, Ed. I thought that was a very good session on IgA nephropathy endpoints, and the question was put to Dr. Thompson about, you know, how is the agency looking at assessing all the different drugs that are in phase III studies now for approval or moving toward that? And her remarks, one, they were very consistent with the discussion that we've had over the years around endpoints. That, you know, there are different ways to measure kidney function. eGFR, she pointed out, is a surrogate in itself, but it's a validated surrogate. And for those patients with, you know, a high risk of kidney progression, they want to see a compound showing a meaningful effect on the rate of loss across the body of evidence.
And they're also looking for compounds that show an accumulation of benefit across various stages of the disease, whether they are early in the disease progression or later in that. I think that the data package that we have with the chronic slope, the total slope, measurements pre and post, the overall absolute difference at 2.5 years, the reduction in hard endpoints, the kidney failure endpoints, the increase in patients that get to complete remission, all of this on a background of a very safe therapy. It's clear, you know, mechanistically, there's two things going on in these kidneys, angiotensin and endothelin, both driving negative effects, and blockade of both together is really required to have the best outcomes in these patients. I'm very confident in the fact that we have a very strong case to make with the agency, and I look forward to the review.
Eric Dube (CEO)
All right, Peter, would you like to comment on, you know, direction of what we're seeing in October and the conversions, which we're not providing metrics on, but directionally?
Peter Heerma (Chief Commercial Officer)
Yeah, I would say to your point, Eric, we have the practice not to comment on metrics within the quarter. But with regards to demand, I would say that we see a continuation of new patient source funds coming in, so I'm really pleased with that. And also to what I mentioned in the prepared remarks, we start to see, like, the increase in patient shifts. So I'm really pleased with the progress and also expect to have that, the further inflection on revenue in the fourth quarter and moving into 2024.
Operator (participant)
And that does conclude the question and answer session. I'll hand the call back over to you.
Naomi Eichenbaum (VP of Investor Relations)
Thank you, everyone, for joining us for our third quarter's 2023 financial results call. We look forward to providing additional updates on our progress. Have a great rest of your day, and thank you.
Operator (participant)
Thank you. That does conclude today's conference. We do thank you for your participation, and have an excellent day.