Operator: Welcome to the Ardelyx First Quarter 2026 Earnings Call. [Operator Instructions] I would now like to turn the conference over to Lisa Caperelli, Senior Vice President of Corporate Communications and Investor Relations. Lisa, you may begin.
Lisa Caperelli: Thank you, Ross. Good afternoon, everyone, and welcome to our first quarter 2026 financial results and business update call. Earlier today, we issued our earnings release, which can be found on the Investors section of our website at ardelyx.com. Slides that accompany today's call can also be found on our website. On today's call, I'm joined by Mike Raab, President and CEO of Ardelyx, who will share our Q1 progress towards our 2026 priorities. Eric Foster, Chief Commercial Officer, will provide an update on the performance of IBSRELA and XPHOZAH. And Sue Hohenleitner, our Chief Financial Officer, will provide some key highlights from our financial results. Before we begin, I'd like to remind you that some of the statements made during the call today are forward-looking statements, which are subject to a number of risks and uncertainties that may cause our actual results to differ materially, including those described in our annual report on Form 10-K, our quarterly report on Form 10-Q, which was filed today and from time to time in our other documents filed with the SEC. While we may elect to update these forward-looking statements in the future, we specifically disclaim any obligations to do so even if our views change. I will now pass the call over to Mike. Mike?
Michael Raab: Thank you, Lisa. Good afternoon, everyone. It's great to be with all of you today. Before we dive in, I want to take a moment to welcome Lisa to the team. We're excited to have her on board leading our IR efforts as our new Head of Investor Relations. 2026 is poised to be another significant year of growth for our company, and we're already off to a great start. At Ardelyx, we're building an innovative pipeline of medicines for patients with unmet medical needs. Our first quarter's performance reinforces our confidence in the strategy we've laid out and in our ability to capture the opportunities ahead to create long-term value. As we build on this momentum, our focus is on executing on our 4 key priorities: accelerating the growth of IBSRELA, maintaining the XPHOZAH momentum, building and expanding our pipeline and delivering strong financial results. Starting with IBSRELA. In the first quarter, our disciplined commercial execution drove 58% year-over-year revenue growth. With more than 7 million prescriptions written for IBS-C-indicated medicines last year, IBSRELA is well positioned as a differentiated mechanism for patients who continue to experience symptoms despite treatment with secretagogue. Our strategy continues to positively impact demand drivers. And today, IBSRELA is helping tens of thousands of patients with IBS-C, and we remain on track to deliver at least $1 billion in annual revenue in 2029. With XPHOZAH, our patient-first strategy continues to guide our execution with demand growing. Today, more patients have access to XPHOZAH than ever before, and we remain committed to supporting patients irrespective of payer coverage. Next, our pipeline. As a result of our performance and execution, we are at a stage where we have the financial flexibility to further invest in our pipeline, positioning our company for durable long-term growth. Earlier this year, we initiated the ACCEL trial, a Phase III clinical trial evaluating IBSRELA for chronic idiopathic constipation or CIC, as part of our efforts to expand our label and to reach more patients. This trial has rapidly gained attention from clinicians and patients alike. And all pre-identified sites have been initiated in under 4 months and are engaged in patient recruitment activities. We remain on track to complete enrollment by year-end and to announce top line data in the second half of 2027. If ACCEL reads positive, IBSRELA will expand treatment options for more patients. In addition, we have a strategy to expand the use of IBSRELA, which may help pediatric patients with IBS-C and has potential to extend tenapanor's patent life for an additional 6 months. Our ongoing pediatric program consists of several studies evaluating IBSRELA in patients with IBS-C and functional constipation, pediatric equivalent of adult CIC. This effort is an example of our ongoing strategy to extend tenapanor, which includes our recently announced Orange Book listed 2099 patent covering the commercial formulations of IBSRELA and XPHOZAH, building additional value for these franchises. Also included in our pipeline is our development program for our next-generation NHE3 inhibitor, 531, which continues to progress through IND-enabling studies, building on our foundational experience in NHE3 inhibition. And 531 may extend our reach into other therapeutic areas, which will be driving additional value for shareholders. We're excited for this next phase of Ardelyx's evolution as we execute on our pipeline and explore various external opportunities that align with our mission and core capabilities and meet our disciplined capital allocation approach. We've been growing our team at Ardelyx and now have a deep bench of talent at the executive level. I'm excited with the 2 newest additions who've joined the executive team, Felecia Ettenberg, our Chief Legal Officer; and Dr. Rajani Dinavahi, our Chief Medical Officer. Felecia's broad legal training and experience as a business partner as well as Rajani's experience in advancing innovative therapies from development to patients will be beneficial to Ardelyx as we build upon our commercial foundation, invest in our pipeline and focus on delivering meaningful outcomes for patients. I'd also like to take a moment to thank Dr. Laura Williams, our Chief Patient Officer, who's been serving the dual role as CMO and CPO while helping to guide us on this journey and has done an outstanding job advancing our clinical programs. Thank you, Laura. Finally, we remain in a position of financial strength. Our Q1 revenue performance position us to reiterate our previously communicated full year 2026 revenue guidance for IBSRELA and XPHOZAH. We have the flexibility to allocate capital to both near-term commercial execution and investments that will expand our pipeline to drive long-term growth value for the company, our patients and our shareholders. I am confident in our strategy and our team's ability to deliver on our key priorities. Together, we are advancing a growing, differentiated, innovative pipeline of medicines that address unmet patient needs. And with that, I'm pleased to turn the call over to Eric to walk you through our commercial success. Eric?
Eric Foster: Thank you, Mike. It's great to be with you all again. In Q1, we continued to build upon the incredible commercial momentum and execution and performance from last year. IBSRELA grew in total writers, new and refill prescriptions and total prescriptions year-over-year. For XPHOZAH, we continued to ensure patient access regardless of payer coverage, which drove an increase in total dispenses and paid prescriptions year-over-year. Our commercial team remains focused on expanding adoption among HCPs, creating greater brand awareness for patients and ensuring the fulfillment of written prescriptions. Our investments to improve the HCP and patient journey and expand access to our medicines have turned into consistent year-over-year growth for both IBSRELA and XPHOZAH. Let me start with IBSRELA. IBSRELA continues to be our main revenue driver, and our commercial execution generated 58% product revenue growth year-over-year. During the quarter, we saw robust demand trends, notwithstanding expected first quarter market dynamics and temporary disruption from 2 severe winter storms. Our growth in demand is a result of our efforts to capture more of the IBS-C market in 2026 by driving IBSRELA as the first-line therapy following a secretagogue failure. IBSRELA is a first-in-class innovative medicine with a winning and sustainable position in a growing market with nearly 7 million prescriptions written last year. Through research, we know that as many as 77% of patients on a secretagogue continue to experience symptoms despite treatment, demonstrating a high unmet medical need for additional options. I'll now walk you through our key demand drivers, which include growing both breadth and depth of writing, increasing patient activation; and lastly, improving prescription pull-through and fulfillment. Beginning with growing breadth and depth of writing. We are focusing on high-writing health care providers who are responsible for approximately 50% of the IBS-C total prescriptions, and our field sales team is driving greater reach across those targets. These efforts resulted in an increase in the number of writers in Q1, underscoring the effectiveness of our commercial activities. We are also seeing deeper prescribing within existing accounts. When an HCP is familiar with the access path and sees positive patient experiences, they are more likely to prescribe IBSRELA more broadly. Our in-market messaging focused on IBSRELA's differentiated mechanism of action and its established safety and efficacy profile is resonating and continuing to drive HCPs to prescribe IBSRELA. With respect to patients, the IBS-C population is highly engaged in managing their condition. As awareness of IBSRELA's effectiveness and safety increases, patients are more likely to initiate conversations with their physicians, which in most cases, results in a prescription. We continue to focus on identifying and reaching patients through multifaceted marketing efforts. We are currently seeing robust engagement across digital and social channels, while we continue to explore new channels to reach and engage with the sizable IBS-C patient population looking for something different. One such initiative is through our partnership with the LPGA, where we will educate, empower and mobilize patients to take control of their IBS-C by seeking new information and talking to their doctor about their symptoms and the treatment options that are available. We chose to partner with the LPGA due to their clear strategic alignment between the LPGA's legacy of empowering women and Ardelyx mission to empower patients to proactively manage their health. Patients deserve open dialogue about their symptoms and their options, and we are excited to partner with the LPGA to accomplish this goal. Lastly, our full commercial organization is focused on driving prescription pull-through to help ensure that all patients prescribed IBSRELA get on treatment. Based on prior success, we are increasing the presence of our field reimbursement managers who support patient access. This team is talking directly to prescribers and supporting them with account education and patient pull-through to improve patient access. To drive further adoption, we are continuing to encourage HCPs to send prescriptions to the IBSRELA Pharmacy network, a limited group of specialty pharmacies that offer a patient-centric, high-touch experience and who are best equipped to handle prior authorizations and the payer hurdles that can restrict patient access. As prescriptions go through our specialty pharmacy network, fulfillment rates are higher, and we see on average an additional refill per year for patients. This is a high-value opportunity that we will continue to help achieve our projected revenue growth. We are united in our purpose to make a meaningful difference to patients impacted by IBS-C, and we are moving with urgency to capture the opportunities ahead and realize our full potential. Moving on to XPHOZAH. Our high-performing patient-focused XPHOZAH team is committed to achieving the full potential of XPHOZAH and bringing this important medicine to patients in need. I continue to be proud of the team's ability to improve patient access and drive growth. As a result, we saw an increase in total dispenses by 32% and paid prescriptions by 19% compared to the same quarter in 2025, which is important as the overall prescription market declined by 10% over the same time period. We are broadening our reach by employing targeted sales initiatives and a cross-channel strategy to increase HCP and patient engagement. We saw solid growth across key metrics in Q1 with notable increases in total writers, new and refill prescriptions and total prescriptions across the non-Medicare segments compared to the same time period last year. This growth shows progress against our key strategic initiatives, which includes optimized HCP targeting and enhanced access messaging to support pull-through. XPHOZAH continues to be an important contributor for Ardelyx, and we remain focused on supporting and ensuring access for all patients regardless of payer coverage. With the majority of patients treated with binders not having fully controlled phosphorus, the high unmet need is clear. I'm confident in the team's ability to deliver on our priorities for both IBSRELA and XPHOZAH this year. The entire organization is executing incredibly well at a high level in a fast-paced environment, consistently achieving our shared goals as a result. At the same time, we are making prudent investments across the commercial organization to strengthen our position in the market, support patients along their journey and accelerate long-term growth. I will now turn it over to Sue. Sue?
Sue Hohenleitner: Thank you, Eric. As you heard from Mike and Eric, we are continuing to advance our commercial momentum to drive significant value creation. We are leveraging disciplined capital allocation into a clear strategic advantage by investing with purpose and commercial growth and building our pipeline. We are driving towards profitability and meaningful cash generation, allowing us to strengthen our balance sheet, invest in growth and build long-term shareholder value. Now let me walk you through the financials. Our quarter-over-quarter total product revenues were $93.4 million compared to $67.8 million in the same period last year, representing 38% growth. That growth was driven by a significant increase in IBSRELA demand with Q1 2026 revenues of $70.1 million, an increase of 58% compared to Q1 of 2025. The Q1 2026 demand for IBSRELA increased despite the expected Q1 seasonal dynamics that were further exacerbated by the winter storm. We continue to expect IBSRELA revenues to grow quarter-over-quarter for the remainder of the year. Revenue for XPHOZAH during the first quarter of 2026 was $23.3 million and on an as-reported basis remained consistent with the prior year revenue. However, it's important to understand the underlying business results we're seeing. As you may recall, in Q1 2025, we recorded a $3.8 million favorable adjustment related to product returns. Taking that adjustment into account, our paid prescriptions of XPHOZAH revenue actually grew 19% year-over-year. Now turning to expenses. R&D expenses for the first quarter of 2026 were $20.2 million compared to $14.9 million for the same period in 2025. This increase primarily reflects development activities for the ACCEL Phase III trial for CIC. SG&A expenses were $102.3 million for the first quarter of 2026 compared to $83.2 million for the same period in 2025. This increase was reflective of the ongoing investments to drive commercialization demand and adoption of IBSRELA. Our net loss for the first quarter of 2026 was $37.6 million or a loss of $0.15 per share compared to a net loss of $41.1 million or $0.17 per share for the same period in 2025. The net loss for Q1 2026 included $14.2 million for non-cash expenses from share-based compensation compared to $12.1 million for the same period in 2025. We are in a position of financial strength with $238.1 million in total cash, cash equivalents and short-term investments as of the end of the first quarter. To capitalize on the favorable market conditions, we recently refinanced our existing debt with SLR. You may recall, we entered into a loan agreement with SLR in 2022 that provided a total of $300 million of cash, which $200 million have been drawn down. The remaining $100 million of cash is available for drawdown this year. We are pleased with the positive outcome of this refinancing with SLR, which extended the maturity and interest-only period of our loan by 2 years and lowered our overall cost of capital and annual interest expenses throughout the term of the loan. Now turning to guidance for 2026. We are reiterating our 2026 revenue guidance for IBSRELA between $410 million and $430 million. That represents a 50% to 57% year-over-year growth. We expect the growth to be driven by quarter-over-quarter increases in demand, along with improved prescription pull-through. Our long-term growth expectation for IBSRELA remains to reach at least $1 billion in 2029, representing a 38% CAGR. Now turning to XPHOZAH. We are reiterating our revenue guidance between $110 million and $120 million in 2026. We continue to invest at an appropriate level to ensure that XPHOZAH remains a contributor of financial growth for Ardelyx. Our full year product revenues are expected to grow between 38% and 46%, outpacing our operational expenses, which will grow by approximately 25%, consistent with prior guidance. We are at a stage in our development where it's necessary for us to prudently invest in our growth accelerators, our commercial operations and our pipeline, all of which require high-impact investments in R&D and SG&A. In 2025, we grew our cash balance year-over-year even as we increased investment in both commercial execution and pipeline development. As we transition into more steady and measurable cash flow positivity in the near future, I think it's important to begin to share our capital allocation priorities as we head into this new era. Our priorities include: one, accelerating IBSRELA growth as this is our highest ROI use of capital today; two, investing in our current pipeline to create additional growth drivers and expand with external business development opportunities; and three, maintain our financial strength. Importantly, we are funding current operations and pipeline from our revenue base, which demonstrates the growing financial maturity of Ardelyx. In addition, as I stated previously, we have proactively refinanced our debt and reduced our cost of capital while preserving optionality for BD, partnerships or other future opportunities. Ultimately, all of this builds towards sustainable profitability. We hope this view of our capital allocation priorities is helpful as you continue to support the strategic value of Ardelyx now and as we evolve into the future. With that, I'll hand it back to Mike.
Michael Raab: Thank you, Sue. As you heard, we're focused on executing on our priorities, significantly grow IBSRELA, maintain XPHOZAH momentum, further advance our pipeline and continue delivering strong financial results. We are moving with purpose, urgency and discipline against these priorities, and we look forward to demonstrating continued progress as the year unfolds. To our investors and employees and especially the patients, thank you for your continued engagement and support. We're encouraged by the progress we've made and excited about the opportunities ahead. We remain focused on disciplined execution, long-term value creation, and we appreciate your continued confidence as we move forward. And with that, we'll open the call for questions. Operator?
Operator: [Operator Instructions] And our first question comes from Roanna Ruiz from Leerink Partners.
Roanna Clarissa Ruiz: A couple for me. First one, I thought it was interesting, you mentioned IBSRELA demand increased despite the storms and seasonality. How should that flow through to the next quarters and in light of your current guidance?
Michael Raab: Sure. I'll ask Eric to comment a bit on it. But for us, seeing what we all went through in the first quarter, which is normal seasonality in those 2 storms, seeing that continued growth in demand only strengthens our conviction in terms of where we're seeing this business grow and very, very pleased with those results. Eric, anything to add?
Eric Foster: Yes. Thanks, Roanna, for the question. Very pleased with what we saw in terms of demand in Q1 and very similar to the patterns that we've seen in the past. We expect to continue to see quarter-over-quarter growth as we move forward. I feel very confident with the team that we have in place and continuing to invest in access and making sure that all patients that are written a prescription can get fulfillment. So I feel very comfortable about the strategy that we have in place and our ability to be able to continue the strong execution, and you should see that continue to grow as we move through the year.
Roanna Clarissa Ruiz: Great. And the other question I had, I was curious about any color you could share about OpEx throughout 2026? How should we think about this with the Phase III CIC study ramping up as well?
Michael Raab: Sue?
Sue Hohenleitner: Yes. Thanks, Roanna. Yes, I would say that we've said before we were going to guide and we are up to about $520 million in total OpEx, and that would be consistent throughout the quarters. So you saw in the first quarter that we recorded about $122 million of that OpEx expense. So what I would see is a bit of a ramp-up then as we move through. And yes, as we continue to enroll the patients in the study, you will see more of those expenses come through the rest of the year.
Michael Raab: And then to be clear, that was all factored into the guidance that we gave, the expectation of the spend that we would have on CIC.
Operator: And our next question comes from Yigal from Citi.
Jin-Wook Kim: This is Jin-Wook Kim on for Yigal. Congrats on the progress. Maybe just a quick one from us. As you track towards your December enrollment completion target for the Phase III CIC trial, can you provide any color on the pace of enrollment relative to internal expectations so far? And are there any learnings from the IBS-C TEMPO enrollment experience that are helping you optimize recruitment?
Michael Raab: Interesting question with regards to TEMPO. As I stated in my comments that we have all the preconceived sites up and running, right? And that pace of enrollment of the sites was wonderful to see and it was on par with what we expected out of the TEMPO program. As I also noted, the enthusiasm both by treating physicians and patients is evident, and that enrollment continues at pace. So we're very confident with the time frame that we have shared where we'd be able to expect both for it to be completed and the data to be shared.
Operator: And our next question comes from Dennis Ding from Jefferies & Company.
Yuchen Ding: I had several questions around IBSRELA. So number one, so Q1 has some seasonality. And on a quarter-over-quarter basis, there was a bigger step down relative to last year, which is totally fine because it's a bigger base. But in terms of the recovery, should we also expect a bigger recovery than what we saw last year as well? I believe consensus for Q2 assumes about like a $30 million quarter-over-quarter recovery for Q2. Question number two, just specifically around the specialty pharmacy dynamic. Can you share if that shift away from retail is working out in terms of better fill and reauthorization rates relative to last year? The channel is around 30% of the mix, but how much higher can that go? And then I have one more follow-up.
Michael Raab: All right. Let me just quickly address some of those and I'll ask Eric to comment. I think the Q2 recovery, I think, rather than recovery is just a normal course of business. And I think that term is an important one to think about. It's what we expect and what we plan for given the predicted and expected dynamics that everyone sees in Q1. Now the surprise was the storm, the 2 storms, both the Mid-Atlantic one and the in the Northeast. And that clearly had a meaningful impact in that sector of the country. And if you think about where many distribution centers are, they were smacked out in the middle of Ohio River Valley, where much of that was hit. So one can't predict. We're not weather people and they are wrong 50% of the time at least. So we don't try to predict storms, but it is one thing that's notable. I'm very confident with the data that you show every week, that we're on the path to what we expected out of Q2. And I do think, again, just to reemphasize, it's not a recovery rather just the pattern of the business. I'll ask Eric to comment a little bit more on that in terms of what they saw in the field. But the IPN, IBSRELA Pharmacy Network, is a fundamental important part of our strategy moving forward, given Eric's comments in his opening statements. It is better for patients. And I'll let him talk about the dynamics in terms of the shift. And I think at this point, it's early for us to say what we think the ultimate potential of percentage of the business that would go through that. It's probably a little bit too much to tell that will become evident through the data that we know is imperfect, but that will become evident over time. Eric?
Eric Foster: Yes. Thanks, Mike, and thanks for the question, Dennis. As far as Q1 goes, we had talked about the seasonality. And as Mike said, for us, we've got the experience and the knowledge to know most of that that's coming. What we were not aware of, obviously, were the storms. So we feel like the team planned accordingly. We were able to push through the temporary disruption there. And just like we saw last year, we really started to see the acceleration in the back half of the quarter, and we certainly see that, which gives us great confidence as we moved into Q2. With regards to the IBSRELA Pharmacy Network, we continued to be very excited about that opportunity and really to bring IBSRELA to patients that are prescribed IBSRELA. So if we think about the fulfillment rate, and your question around, is there better fulfillment, absolutely, there is when it goes to the IBSRELA Pharmacy Network. And that's really the driver for us to make sure that patients that are prescribed IBSRELA can get access to the treatment. So we'll continue to work on moving business into the IBSRELA Pharmacy Network. We expect that to continue through the year. And also, it's important to note, when that happens, there is an additional on average prescription written or refill written in that year. So it's really great for patients. You get a higher fulfillment rate, you get better refill rate as those prescriptions go through the IBSRELA Pharmacy Network.
Sue Hohenleitner: Yes. And the one thing I would add, Dennis, you kind of talked about the guidance. I think we were pretty overt about Q1 with kind of a soft guide, but that was all factored into our full year, and that's all factored into our full year guidance. But we aren't going to provide similar color. We felt like that was appropriate for Q1 just given the storms and some of the volatility. But I think as we go forward, as we said, we're going to continue to grow quarter-over-quarter.
Yuchen Ding: Okay, perfect. And then as my follow-up. So Lilly is running a Phase II with its GIPR agonist for IBS-C, data might be in 2027. So I'm curious how you're thinking about that study and the durability of the IBSRELA franchise over the long term in 2030 going to be well north of $1 billion in revenue?
Michael Raab: Yes. I mean, I think for us, what we need to do is follow the data. And anything that helps patients is a good thing. I think that is just a fundamental way that we and I look at this business. Anything that's going to help patients is the right thing to do. The realities are, if you look at the potential patients that could, should or might be taking GLP-1s, it's a relatively small percentage who actually are versus those who would benefit from it. So I wouldn't imagine there's going to be a massive degradation of the market given the positioning that we have for IBSRELA in that market. I don't see that as a massive threat on the horizon. Is it better for patients if it works? Of course, it is, and that's something we should all cheer.
Operator: And our next question comes from Chris Raymond from Raymond James.
Christopher Raymond: So we've talked to some KOLs who indicate they're already using IBSRELA to some extent in CIC. Mike, I know you don't want to -- you're not going to want to give too much color here, but just maybe in broad strokes, can you guys talk maybe about what kind of CIC use you're seeing in the field? I mean, Linzess, Trulance, Amitiza, they all have CIC on their labels already. So maybe a second part of that question is, would the competitive dynamic in this indication be maybe similar to what we've seen with IBS-C or are you thinking something different?
Michael Raab: So yes, what's important about what you said is all the others have dual indication. And clearly, we have heard and understand what you've described as well in your KOL clinician discussions. As you know, physicians in the art of what they practice can prescribe things off label. We cannot promote things off label, and we won't and don't. That is a fundamental part of this business as everyone understands. If a physician feels it's appropriate for CIC, they should. And what's really interesting, if you haven't looked at Rome V, which was just published, the changing definition of CIC, functional constipation, IBS-C, which we know given our experiences on the front lines, is a continuum of care. And understanding how the Rome Foundation has evolved its definitions is one of the fundamental reasons why we moved into the CIC program is it's a natural course. And I think as we've spoken over the years, would we have loved to had both indications at launch, of course. But as you know, I'm cheap and we didn't have the money to invest in both indications. And now that we are in a place that we can, we are to provide those benefits and try to eliminate some of the barriers in the way that physicians think about this and the further hurdles that the prior authorizations will put them through if it's an off-label indication. So I agree with everything that is the genesis of your question. And I think what we're doing with the CIC program is specifically designed to address that, coupled with what's happened with Rome V.
Operator: And our next question comes from Allison Bratzel from Piper Sandler & Company.
Ashley Aloupis: This is Ashley on for Ally. Congrats on the quarter and all the progress made. So just 2 questions from us. You talked about it in your prepared remarks, but could you talk a little more about the IBSRELA pediatric trials and just the workings of the potential 6 months of additional patent life and how meaningful those additional 6 months could be for IBSRELA? And then also just wondering, once the IND is filed, do you have any line of sight into time lines around getting 531 into the clinic? And how quickly do you plan to move if the IND studies are positive?
Michael Raab: We will work at pace if those studies are positive because it's the right thing to do. But fundamental, again, to what we do is we follow the data. And all this pre-IND work is really critical for us to understand. Remember, Ashley, let me remind you that when we created tenapanor back in 2009, it was based upon a huge amount of preclinical work that we had done to understand all aspects of where this molecule engages certainly with animal models and ultimately into man. So we have good experience in this, and there are very tried and true approaches that one takes in order to make the decision to or not to file an IND. And the data tell us what the right thing is to do. With regards to the pediatric indication, this is a tried and true practice that everyone does in the industry. One of the things that the FDA put in place was the pediatric act to encourage companies to develop drugs for the pediatric populations. Now it is pretty hard in IBS-C given different age groups, the inability or challenge to describe pain, it's subjective. So it's a harder population. It's a smaller population. But the mere operational effort to put this in place primarily to show safety is one of the fundamental tenets of pediatric development is it allows you flexibility to treat the younger patients if you demonstrate the safety that we expect to demonstrate given our long history of utility of this molecule. So the benefit of that 6 months, you look at whatever peak it is that you guys have modeled, just look at each incremental month of value that, that will generate and that will tell you the value in your modeling of what those 6 months are worth. It's significant.
Operator: And our next question comes from Joseph Thome from TD Cowen.
Joseph Thome: Maybe a little bit of extension of a prior question, but can you walk through the physician touch point differences between CIC and IBS constipation? I guess, if you are successful in CIC, would you need to go a little bit more maybe into a primary care segment or anything like that with your sales force or by the time they're presenting to the level of getting IBSRELA, they may be in a GI office? Anything around that would be helpful. And then you mentioned a couple of times, obviously, on the call, can you talk a little bit about the company's willingness to maybe lever up the balance sheet given what your expectations are for the growth of IBSRELA to do something maybe a little bit larger in size?
Michael Raab: Sure. Let me address the first one and then ask Eric to comment, too, is I think as we said when we announced the ACCEL program is the CIC market is significantly larger than the IBS-C market. However, the vast majority of those patients are effectively treated with over-the-counter medications. So I think that's an important distinction as you look at the epi in these populations as to what the differences are and not get over your skis in terms of what that market sizing might be because it's an important distinction of those that are not served by OTC meds are the ones that end up going and being referred to other offices. And Eric, do you want to comment a little bit on what we would do in the field, if anything, differences?
Eric Foster: Yes. Thanks, Joe, for the question. So as you know, today, we focus on high-writing GIs, APPs and high-writing non-GIs. So that does put us in more of the primary care setting and feel really confident about the targeting that we have right now for IBS-C, and you can see a lot of the great momentum that we have. With regards to CIC, I do think you're correct. As Mike mentioned, it is a bit of a larger patient population, and we do see and expect more patients to be going to their primary care. So at some point, as we're continuing to look at that patient population and making sure that we have the right reach, we'll make that decision at that time. But certainly, I can see that there is more utilization in the primary care market, and that's something that we definitely will consider as we look at the rightsizing of the team as we get closer to product being approved in the market.
Michael Raab: And Joe, I think a fundamental part of that is, Eric has talked about this in the past, we call on 50% of the HCPs today that write for IBS-C and frankly, CIC indicated drugs alike, and that's the 14,000 HCPs. The other 50% is 182,000 HCPs, and we're not going to cover them all, right? So it's going to be an optimization of those who might be writing disproportionately amount for CIC, which you can find through the data. But a little bit of a cautionary note not to take this as though we're going to double or triple the size of the organization, but rather an optimization as you've seen us do this year. With regards to levering the balance sheet, we're at such an incredible pivotal time for the evolution of the company, where not really reading between the lines, Sue has said explicitly, we're going to generate more top line than expense. So that journey that we're on, that horizon is not that far away with what we're trying to do. So I'll ask Sue to comment. I'm not sure how much leverage is needed versus execution in the way we're doing. But certainly, we're not afraid of doing the right thing for opportunities that present themselves.
Sue Hohenleitner: Yes. And as Joe, you heard that we already did do a refinance of our debt. We still have access to an extra $100 million of that loan. So we've got that. We've got plenty of options to do that if and when it's necessary or a great opportunity presents itself.
Operator: And our next question comes from Laura Chico from Wedbush Securities.
Laura Chico: Three for me. First, I thought I heard Eric mention an expansion of the field manager level. And I'm just trying to understand if that's more impactful on the depth of prescribing or the breadth of prescribing? And which of those 2 levers impacts hitting the upper range of guidance or kind of impacts the guidance swing there? And I have 2 quick follow-ups.
Eric Foster: Yes. Thanks for the question, Laura. So I hate to say, but both actually. It's very hard getting the physician to write that first prescription. And so we want to make sure when they write the prescription that they have confidence that it will be filled. And that's what the field reimbursement manager does. They work with the physician's office to ensure as they navigate the payer dynamics that they're able to pull through and get that prescription filled. With regards to physicians as they continue to increase their depth of prescribing, that same confidence is important that not just the first one goes through, but subsequent ones. So that team is really focused on helping the prescriptions get pulled through, whether it's the first prescription or subsequent ones. I think you heard me say in my prepared remarks, we saw increase in writers as well as increase in depth of prescribing as well. So we are having impact across both of them, and that's why I kind of go to both of them to say that it's important to make it happen across both.
Michael Raab: Laura, when Eric first started talking about hiring the skill set, one of the things that really opened my eyes is really a very simple example. If I'm a salesperson, I worry that, that script is going to be filled. That's the way you're going to compensate me. So if I'm spending my time looking at Dr. Foster and whether or not that script is actually getting filled, I'm not calling on Dr. Raab because I'm worried about that. So bringing on the field access managers allows the ABDs to have confidence that they can drive the top of the funnel and that there will be those there to help pull through at the bottom of the funnel, resulting in compensation ultimately in incentive comp, right? So it is -- I don't think I would ever imagine not having both in the launch of a drug going forward.
Laura Chico: Okay. And I guess 2 quick follow-ups then kind of related to that. I think in the prepared remarks, I heard that the XPHOZAH paid rate was also up. Just curious if you could quantify that. And then with respect to ACCEL, the site activation on the pre-identified sites has moved really rapidly. How are you monitoring, I guess, any conversation around quality checks that you can do to ensure you're getting the sites to adhere to protocols and recruiting the right patients would be helpful? But also, what are your assumptions around discontinuation rates?
Michael Raab: Once the site is up and running, we don't pay any attention to it. No, you're right. I mean for the quality of the patients, it's really, really important, right? And as you get the enthusiasm of start-up, there's training and reminding people of why you started in any clinical trial, you have screen failures that happen and then the sites get better and better at identifying the patients. So that's just a natural progression of clinical development and recruitment. So Rajani, a couple of weeks now on to the job is into this with both feet and both arms, and we all feel very good about both the quality of the sites as well as those sites learn and get better at enrollment that we see those failure rates begin to taper, which is something you factor into your projections of how you enroll. So I think we all feel very good about what we've said, and ultimately, the quality of the patients are going to be there defined by our inclusion/exclusion criteria. So we feel very good about that quality that Rajani's team is ultimately and our CRO is following through with. And with regards to your first question, I think what's important is on a GAAP basis, of course, the year-over-year quarters look similar. It is so important what Sue reminded everyone is that $3.8 million return reserve reversal that we did in Q1 should be excluded as you look at the base business that we've defined, which is a non-Medicare business, which grew by 19%. And if you look at our sequential growth, even since we started in this effort to not participate in TDAPA because we believe what we are now seeing is ultimately what was going to be true, is proving out. And the growth that we're seeing in that non-Medicare segment with all the challenges that dialysis organizations are facing further emphasizes the value of this program and the product for patients in the phosphorus management. So it's an opaque and difficult business that we've chosen to partake in the way that we have. But the numbers are showing that actually we're helping the patients that we anticipated that we would.
Operator: And our next question comes from Prakhar Agrawal from Cantor Fitzgerald.
Prakhar Agrawal: Congrats on the quarter as well. Maybe firstly, on XPHOZAH, maybe I missed this, but I did not hear you reiterate the long-term guide of $750 million. I know the Street is a little bit more conservative, but I just wanted to check if you are reiterating that. And you talked about investing in high-value opportunities as well. So has there been a change in the level of investments for XPHOZAH this year and maybe in the future, too? Secondly, maybe if you can talk about the gross to net for both products for 1Q and trends for the rest of the year? And last question, given the investments you are making both on the R&D side and SG&A, how should we think about the cash flow profitability?
Sue Hohenleitner: Thanks, Prakhar. That's a lot for me. So let's see if I can hit it all. So in terms of the high-value opportunities with XPHOZAH, yes, we ensure that XPHOZAH continues to be a contributor. So we don't necessarily tease out separate product P&L. But rest assured, we continue to ensure that all of the spending that's done and the investments we make behind those patients and that growth makes them a financial contributor. So that's good. In terms of the GTN, you probably saw in what we filed, we're a little over 36.4% of GTN, and that's a blend. We don't necessarily split that out. And what I'd say is first quarter is going to be really probably your highest quarter in terms of GTN, just given all the dynamics with co-pay assistance, et cetera. So -- and what we've always said before is it's about low-30s when you think about a blended total GTN rate for the year. So -- but I would say that -- so you'll see that high in Q1 and then kind of taper off as we go into further quarters. Before I leave XPHOZAH, yes, we will reiterate the $750 million, and I am reiterating that. So within the guidance, we've given $1 billion for IBSRELA and the $750 million for XPHOZAH. In terms of R&D and SG&A, it was more around the expenses for the rest of the year. Yes. So I would say -- and with cash flow, it is something that we're continuing to monitor. As you can see with the top line guide, being $520 million to $550 million and our OpEx only at $520 million, there is a possibility we'll get to cash flow positivity. But certainly, we want to continue to see how the year unfolds and make sure that we're hitting on all cylinders. And then we will likely come back with an update if it's appropriate on cash flow.
Michael Raab: We appreciate the question of wanting trajectory quarter-to-quarter, but we're not going to get into the practice of quarter guidance. I think the yearly guidance that Sue just went through is really important.
Operator: And our next question comes from Matthew Caufield from H.C. Wainwright.
Matthew Caufield: With the investor focus on sales execution, is there further granularity that you could share on IBSRELA growth between the new patient starts versus refill persistence trends? And then where things may stand presently for the total penetration among target prescribers there? Just thanks for any color there on execution overall.
Michael Raab: Yes. I think that's getting into detail that we probably wouldn't get into specifics on. You can begin to look through your script data in terms of NRxs versus TRxs and tease that out to some extent with what you do. I recognize that it's going to be imperfect data. But suffice it to say, with Eric's prepared remarks that we're seeing both with the other question that was asked, breadth and depth. So we're seeing great refills and we're seeing lots of new prescriptions coming through as well. Eric, anything to add?
Eric Foster: No.
Operator: And our next question comes from Julian Harrison from BTIG.
Andrew Kassin: This is Andrew Kassin on for Julian. Congratulations on the results this quarter. On IBSRELA, which are the growth drivers would you say do you believe still has the most room to grow writers, new prescriptions, refill or pull-through?
Michael Raab: I think Eric will probably say yes. It's all of the above. I think what's interesting is for the 7 million prescriptions for IBS-C-indicated products that I referenced in my opening remarks, it's a very small percentage of the market that one needs to penetrate in order to get to our guidance of peak. So there is massive opportunity out there. And I think, Eric, any granularity around the specifics would be great.
Eric Foster: Sure. Yes, I'm very excited about all of them as you list them. So as we think about the IBSRELA opportunity, as Mike said, there are 7 million prescriptions written for IBS-C on an annual basis, and we continue to see that market grow. We feel very confident in the position that we have, a winning position sustainable over time that we've had for the past 3 years. And we continue to see an increase in writers, total writers, new writers as well as depth of prescribing, and that's really important. So what that tells you is physicians continue to have confidence in IBSRELA and look at it as a viable option for their patients that are in need. So of those patients, we know that 77% continue to have symptoms despite treatment with a secretagogue. So very healthy market, strong position for IBSRELA, continuing to go writers as well as depth of prescribing and feel really good about the opportunity we have moving forward. When you think about the IBSRELA Pharmacy Network and being able to improve the fulfillment rate as well as the number of refills for patients, it really is -- really leads to success across the business in those important drivers of the business. And that's really what gives us that confidence to that $1 billion in 2029 and beyond.
Operator: There are no further questions at this time. This now concludes today's conference call. Thank you for joining. You may now disconnect.