Good day, and welcome to the Ardelyx First Quarter 2024 Earnings Call. Please note, this event is being recorded. I would now like to turn the conference over to Caitlin Lowie, Vice President of Corporate Communications and Investor Relations at Ardelyx. Please go ahead.

Thank you. Good afternoon, and welcome to our first quarter 2024 financial results call. During this call, we will refer to the press release issued earlier today, which is available on the Investors section of the company's website at ardelyx.com. During this call, we will be making forward-looking statements that are subject to risks and uncertainties. Our actual results may differ materially from those described. We encourage you to review the risk factors in our most recent quarterly report on Form 10-Q that was filed today and can be found on our website at ardelyx.com. While we may elect to update these forward-looking statements in the future, we specifically disclaim any obligation to do so even if our views change. Our President and CEO, Mike Raab, will begin today's call with opening remarks and an overview of the company's progress during the first quarter of 2024. Next, Susan Rodriguez, Chief Commercial Officer, will provide an update on the performance of IBSRELA and XPHOZAH. Justin Renz, Chief Financial and Operations Officer, will conclude today's prepared remarks with a review of the company's financial performance during the first quarter ended March 31, 2024, before we open the call to questions. With that, let me pass the call over to Mike.

Good afternoon, everyone, and thank you for joining us on this call. Q1 earnings always seem to come quickly after we report our Q4 results. And yet, as usual, a lot has happened since we last provided you an update. First, XPHOZAH's performance out of the gate following the launch in November continues at a remarkable pace. This is a first-in-class product in a therapeutic area that has seen no innovation in decades. The response from the prescribing community clearly demonstrates the significant unmet need among this patient population. XPHOZAH is an important new option for physicians to help patients whose serum phosphorus remains elevated despite best efforts. All demand indicators are favorable. Prescribers are eager to learn more about XPHOZAH's blocking mechanism and are working to identify potential candidates for therapy. Like IBSRELA, Ardelyx assists in supporting prior authorizations and helping patients take advantage of our affordability programs. Patients are accessing the drug, and the feedback is that they are seeing sustained reductions in their serum phosphorus. We are focused on ensuring prescribers are aware and educated on XPHOZAH and ensuring patients have access to treatment. As you can see by our performance, it's going very well. IBSRELA continues to perform strongly, providing an important option to address the large unmet need among IBS-C patients. We believe that this can be a $1 billion product, and on the path to achieving that piece, we expect full-year net sales revenue for 2024 to be between $140 million and $150 million. As I consider the first-quarter performance, the underlying demand metrics and fundamentals of the business are robust and continue to demonstrate growth in new and repeat writers and new and refill prescriptions. Our reported revenue reflects demand growth, offset by the impact of seasonality, which is standard across the industry that we experienced during this first quarter. Importantly, our cash position remains strong, resulting from our revenue, the third tranche of debt from our partnership with SLR, and thoughtful management of our expenses. We are at an exciting time in our evolution as a company, and our top priority is to build upon the growth momentum of IBSRELA and XPHOZAH. Now I will turn the call over to Susan to discuss first quarter performance for both of our products. Susan?

Thank you, Mike. It is great to be here today to discuss the commercial performance for IBSRELA and XPHOZAH. Our performance reflects strong execution of our disruptive commercial approach for both first-in-class products, which centers on targeting the high-volume writers in our disease areas, driving identification of patients in need of a novel treatment option as their response to existing treatment options is deemed inadequate, and enabling patient access and affordability with favorable coverage policies that define the path to access prior authorization support and patient support programs. Let me begin with IBSRELA. Our confidence in this product is driven by the strength of the fundamentals driving IBSRELA's performance. HCPs are evolving their treatment practice now that they have expanded treatment options for their IBS-C patients following the launch of IBSRELA. Based on the favorable clinical response they are seeing and confidence in the path to access, HCPs are increasingly identifying patients in need of a novel treatment option. During the first quarter, we saw increases across all key demand parameters for the product, including growth in new writers and repeat writers, as well as growth in new prescriptions and refill prescriptions. We are very encouraged by the continued growth of these key demand metrics despite IBSRELA being impacted by first-quarter seasonality that is commonly seen across the industry linked to insurance plan resets and prior authorization renewal processes. During the first quarter, we began the process to expand the IBSRELA dedicated salesforce footprint from 64 territories to 124 territories. We experienced a strong response to the job posting, attracting sales talent with extensive GI experience who are motivated and enthusiastic to join the IBSRELA sales team and be part of disrupting the IBS-C market with an innovative therapy. Hiring, training, and full deployment of this team is on track to be completed by the end of the second quarter. This salesforce footprint puts us in a strong position to capitalize on the promotion sensitivity we have seen across our high-writing HCP targets to further drive increases in new writers as well as drive expanded use across our growing writer base, who are continuously broadening their view of patients who are candidates for IBSRELA. The fundamental drivers behind IBSRELA are strong, and we anticipate continued quarter-over-quarter growth with our expectations for the 2024 performance consistent with our stated guidance. Turning to XPHOZAH. We are extremely pleased with the nephrology community's response to this first-in-class phosphate absorption inhibitor. It is clear that patients have been in need of a new option to manage their phosphorus when binders were insufficient or not well tolerated. Our dedicated nephrology sales team, comprehensive blocking messaging campaign, speaker and promotional programs, and omnichannel initiatives are driving high interest and early uptake of XPHOZAH. Nephrologists are responding favorably to the novel blocking mechanism and clinical data profile, are pleased with their early clinical experience, encouraged by the defined coverage policies, and increasingly integrating this novel blocking mechanism product into the therapeutic regimen for their patients. The feedback we regularly receive from the field is that physicians are seeing that their XPHOZAH treated patients, many of whom have been continuously outside of target ranges, are reflecting consistent improvement in serum phosphorus levels and that these levels are being maintained. We are also hearing that patients are responding favorably to the dosing profile and that HCPs are pleased with the flexibility they have in adapting the patient's treatment regimen where they can add XPHOZAH to the patient's existing binder regimen, reduce the patient's binder regimen, or fully discontinue the patient's binder regimen. HCPs are adopting XPHOZAH and are adapting regimens based on the needs of the patients. We are very pleased with the $15.2 million in sales we reported for XPHOZAH during the first quarter. This performance is consistent with the uptick indicators we are seeing in the field. Our salesforce is experiencing highly engaged meaningful discussions with our target HCPs who are eager to learn about XPHOZAH. Nephrology HCPs are rapidly identifying patients who they believe can benefit from therapy, reporting to us that they may have many patients outside of target ranges despite treatment with binders or are intolerant of binders therapy. HCPs are pleased with the clinical response they are seeing, and patients are responding favorably to the treatment experience. Coverage policies are being defined that outline a path to access by our prior authorization attesting to the fact that the patient has been treated with binders and inadequately responding or unable to tolerate the therapy. HCPs are seeing that when prior authorizations are submitted for patients meeting the criteria, patients are gaining access to XPHOZAH. Nephrology HCPs and their office staff are responding favorably to our specialty pharmacy distribution network as well as to our comprehensive patient services offering, Ardelyx Assist, that further enables patient access through prior authorization support and patient engagement with the affordability programs available to them. Our own internal metrics are supported by external research conducted by Spherix, who is tracking the launch of XPHOZAH. According to the April 2024 launch dynamics report, nearly all of the 77 surveyed nephrologists, 98% rate XPHOZAH as an advance over currently available hyperphosphatemia therapy. In addition, 56% of the surveyed nephrologists reported using XPHOZAH, and of those, again, 98% report satisfaction with treatment. The research demonstrates that awareness is high among the nephrology community, interest and intent to adopt is high, and satisfaction with the treatment is high among users. We will continue to build upon our launch momentum, capitalizing on the high nephrology awareness of the number of patients that are in need of a new treatment option despite treatment with binders and their intent to adopt XPHOZAH for these patients. Our go-to-market strategy is working. We have established a strong presence in nephrology offices across the country, and HCPs are responding favorably to the novel blocking mechanism and clinical data profile. They are identifying patients that could benefit from XPHOZAH therapy, and with coverage policies in place, patients are gaining access and responding favorably to treatment. We are pleased with the performance thus far and are focused on continuing this growth momentum. We have several exciting months ahead as we will have a strong commercial and clinical presence across key annual medical conferences for both IBSRELA and XPHOZAH, where we'll have the opportunity to present more clinical trial data on our products, connect with the prescribing community, and deepen our relationship with patients. I look forward to continuing to share updates with you in the future. With that, I will hand it to Justin.

Thank you, Susan. I'm very pleased to be with you today to discuss the first quarter performance we reported, which included meaningful progress towards our IBSRELA net sales revenue guidance, a strong launch of XPHOZAH, careful management of our finances, and a strong cash position. Let's start with revenue. As you saw in this afternoon's release, we reported significant year-over-year growth, bringing our total first quarter product-related revenue to $45.6 million compared to $11.4 million in the first quarter of 2023. Net product sales revenue for IBSRELA was $28.4 million during the first quarter of 2024, more than doubling the $11.4 million in revenue we reported during the same period in 2023, and 1% quarter-over-quarter growth compared to the fourth quarter of last year. Volume demand grew for IBSRELA during the first quarter, which was offset by deductions associated with the reset of annual prescription drug plans. Most notably, this was related to our commercial co-pay program. The impact of the commercial co-pay program is most significant in the first quarter when most commercial healthcare plans reset, and patients have higher out-of-pocket requirements. As patients fill prescriptions throughout the year and begin meeting their deductible requirements, our expenses related to the commercial co-pay program declined. Our gross to net deduction for IBSRELA during the first quarter was in line with our expectations at 33.5% and comparable to the 33.7% we saw in the first quarter of 2023. We expect this percentage to improve as the year progresses as it did last year. In addition, we saw the anticipated impact of the prior authorization renewal process that occurs at the start of the calendar year for many healthcare plans. The strong demand and expected improvement in gross to net deductions reinforce our confidence in the ongoing performance of IBSRELA. As such, we continue to expect that full-year U.S. IBSRELA net product sales revenue will be between $140 million and $150 million. XPHOZAH had an exceptional first full quarter performance as we are reporting $15.2 million in net sales revenue, driven by the meaningful demand for this product. Our gross to net deduction came in favorably for XPHOZAH at 23.8%. As we progress into the launch of XPHOZAH and learn more about the patient mix that drives the associated gross to net deduction, we will share more. In addition, we had $2.5 million in combined licensing and product supply revenue. We are very pleased with our top line results during the quarter, which demonstrated the growth momentum Mike and Susan both spoke to. At the same time, we continue to be thoughtful about how we manage our expenses. Research and development expenses were $10.6 million compared to $9.1 million during the first quarter of 2023. Selling, general and administrative expenses were $53 million for the first quarter compared to $26.8 million for the same period of 2023. The increase was related to launch activities for XPHOZAH as well as continued investments to grow IBSRELA, which we made throughout last year. Importantly, our costs were comparable to our spending in the fourth quarter of 2023. We expect to complete the current expansion of the IBSRELA salesforce that Susan previously mentioned by the end of the second quarter. Substantial top line growth, combined with thoughtful cost management, resulted in a net loss of approximately $26.5 million or $0.11 per share in the first quarter of 2024, compared to a net loss of $26.8 million or $0.13 per share in the same period of 2023. The net loss for the first quarter of 2024 included $9.3 million in combined noncash expenses from share-based compensation and noncash interest expense related to the sale of future royalties. As of March 31, 2024, we had total cash, cash equivalents, and short-term investments of $202.6 million compared to $184.3 million at the end of 2023. This includes $49.8 million in net proceeds that we drew in March from our term loan agreement with SLR Capital. We are very pleased with our performance during the first quarter, driving top line growth across all reported revenue lines, planning for success, investing in our supply chain, managing our operating expenses, and strengthening our cash position. We will continue to be thoughtful about how we deploy capital while focusing on maximizing shareholder value. And with that, I'll turn it back to Mike.

Thanks, Justin. I hope that what you took away from our performance during the first quarter is, one, we continue to have high expectations for IBSRELA, including $140 million to $150 million in net sales revenue this year and on the path to at least 10% market share and $1 billion in annual revenue. Two, XPHOZAH's launch progress is exceptional, and it is already beginning to disrupt the hyperphosphatemia market where there remain significant unmet needs among patients. And finally, we're in a strong cash position to invest in growth. We have a lot of important work ahead of us, and we have the team in place who is able to deliver. I look forward to sharing our progress with you over the coming quarters. And I will now open the call to questions. Operator?

The first question comes from Chris Raymond with Piper Sandler.

Congratulations on the tremendous success with XPHOZAH. I have one question about that and a follow-up. I understand you are early in the launch, and you've established a pattern for guidance after several quarters with IBSRELA. However, the speed of adoption is clearly exceeding expectations. Can you share any insights on this? It's noticeable in the script data, and even those closely monitoring it seem surprised by the figures. What can you tell us about the uptake and its potential implications for the upcoming quarters? For my follow-up, I know you’re not in the business of predicting legislation, but given the lack of progress on including phosphate binders into the bundle, at what point do you start planning for that possibility?

So Chris, thank you for the questions. I guess, first of all, I hope by now you can tell that we're not quitters, and that we see what we're doing for patients and the uptick that we see with XPHOZAH is and has been absolutely worth the fight that we're fighting. I think as you see with what we've done with IBSRELA, these IBS-C patients as well deserve the attention that we're giving them. What you saw with IBSRELA is we need and we expect to have roughly four quarters under our belts before we give guidance. We don't want to get over our skis. We're excited and thrilled by this performance. The anticipation for the drug out there, the enthusiasm our sales team are seeing in the field is remarkable. The ability that we have in helping people through the prior authorization process through Ardelyx Assist is working extraordinarily well based on so many learnings that we gathered through with IBSRELA. So although I would like to give you a clear answer on both of those, I'm sorry, I'm sure you understand that I can't.

The next question comes from Yigal with Citi.

Congrats as well on a very strong launch. Susan, I just had a few questions on the commercial franchise. Regarding IBSRELA, can you comment on the percent that were new writers versus repeat writers in the quarter? And then with the almost doubling in the territories, how do you expect that to scale in terms of the size of the base of the prescribing physician community? And then with XPHOZAH, you nicely articulated three buckets, the ones where you add XPHOZAH and get them to go, and ones where you can add and then reduce the binder and then you can add XPHOZAH and potentially remove the binder altogether. Do you have any anecdotal or early evidence or data to discuss sort of roughly what percent fall into each of those three scenarios?

Thank you, Yigal, for your question. While we haven't shared specific percentages regarding new and repeat writing, I can emphasize that monitoring the consistency of new writers appearing on a weekly, monthly, and quarterly basis is crucial. Since our launch, we've noticed a steady generation of new writers, which bolsters our confidence in the momentum and our forecasts for this year. Regarding repeat writing, as we have progressed through several quarters, we can now demonstrate that new writers continue to write again. This repeat writing is also consistent, and our growth potential lies in further increasing the number of new writers while encouraging greater depth of writing within that expanding writer base. These repeat writers have the opportunity to write more frequently and for more patients. Our salesforce is focusing on broadening their approach based on the positive experiences reported by patients who are now viable candidates for IBSRELA. These patients typically have persistent systems, have tried other treatments, and physicians are recognizing that there is a pathway to access and that patients are responding positively. Therefore, sales representatives are identifying more potential candidates, presenting us with a significant growth opportunity. Additionally, we believe investing in our salesforce is essential, as our experience suggests that our sector is highly responsive to promotion. The deeper our engagement with doctors, the more they prescribe IBSRELA, as evidenced by our relationship. By expanding our footprint from 64 to 124, we can visit healthcare professional offices more often, driving increased writing and taking advantage of their broadened view on patients who qualify for XPHOZAH, while simultaneously continuing to attract new writers. This dual strategy is key to our execution efforts.

Okay. Great. And then if you could comment on the XPHOZAH question, if you have any data there regarding the way it's bucketing and reducing the binder versus removing it altogether?

Yes, not specifically from a percentage standpoint, Yigal. But what we're hearing persistently is that all nephrologists, in general, are just commenting on the flexibility. And that's what's really exciting because that means that, that patient group that they identify, that they believe is inadequately managed on binders or don't tolerate binders, they see XPHOZAH because of its complementary mechanism of action as a drug that that patient could benefit from. And they don't have an ongoing concern around how it gets integrated because they can be flexible on initiating therapy and then perhaps some of them are initiating, tracking, and then taking them off some of the binders. Some of them just cut the binders right away. Some of the time, they just eliminate it entirely, as I mentioned in my narrative. So what we hear is that each doctor is actually using the drug with this level of flexibility and that they see that as a way to realize the benefits of novel mechanism XPHOZAH across their patients that they see are inadequately managed.

Yigal, it's Mike. Just one additional comment with that is, I think, as we spoke of earlier in other calls is you never had multiple mechanisms like you do with so many other diseases to manage what the drugs are trying to address. So it's not going to be a static ratio in any given patient. There's going to be intrapatient variability depending upon their serum phosphorus. There's now flexibility and tools for these physicians to finally get phosphorus in the target range that they're looking for. So I think that's an evolve. And as we understand that better in the coming quarters, we'll certainly share it.

The next question comes from Louise Chen with Cantor.

Congratulations on the progress this quarter. So first question I wanted to ask you about was XPHOZAH and the $15.2 million. Is that all demand sales? Or is there any stocking in there? And secondly, just back on the Buddy Carter bill, if it doesn't move through, then is that $1 billion of peak sales you have for IBSRELA at risk, or that is regardless of whether or not Buddy Carter happens?

Yes. I mean, there are two different product lines in different patient populations. So our guidance with IBSRELA is independent of that. But thanks for asking that. As it relates to stocking, let me ask Justin to address that.

Thank you, Louise. It has been really just in time, if you will, approach with XPHOZAH. So through our network, we've seen very low inventory rates since launch in November. So I would say, this is absolutely demand of the patients and not due to any stocking, very limited to roughly between one and two weeks at max in the channel.

The next question comes from Ryan Deschner with Raymond James.

Congrats on the strong early XPHOZAH launch. Two good questions from me. At this point, I was wondering what the breakdown is looking like so far between patients getting access to XPHOZAH through Medicare versus non-Medicare? And then comparing the how much of XPHOZAH's strong start are you attributing to the differences in market dynamics versus differences in your commercialization strategy? In other words, is your commercialization strategy for XPHOZAH markedly different from that of the early IBSRELA launch? Or is the main driver more related to differences in things like unmet need, patient visit rate, etc.?

Yes. Ryan, thanks for the question. The easy answer is, of course, it's our very, very unique and disruptive commercialization approach. No kidding, I think what we do here, and Susan can address it in greater detail, it truly is one about having really good drugs that are making a difference for these patients, having a commercial team that knows how to communicate that to the omnichannel initiatives, and a remarkable sales team with feet on the ground, talking to physicians about what these drugs can do for their patients because these drugs work.

Yes. To build on Mike's point, our go-to-market strategy shows notable parallels between IBSRELA and XPHOZAH, both featuring a novel mechanism of action and addressing the limited options available for patients in need. An important distinction is that with XPHOZAH, we entered the market with a high level of awareness among nephrologists and strong interest in adoption, along with a clear understanding of the challenges they face in managing serum phosphorus with binder therapy. This led to greater market awareness of both the product and the unmet need. In contrast, with IBSRELA, although it's a similar situation with patients having limited options and being inadequately managed, our approach involved more promotion and education for our target audience, which helped them recognize the inadequacy of patient management. Now, as we introduce this option, we are increasingly identifying these patients and engaging in discussions about their treatment needs. Thus, while more education on the market side was necessary for IBSRELA, the path to access and the favorable coverage policies are consistent across both products.

Got it. And then on the Medicare versus non-Medicare breakdown for the first quarter?

Susan?

Yes, thank you, Mike. Yes, so right now, it's actually really interesting being on the market now for a full quarter that we can see from our IQVIA data what the percent mix is for the XPHOZAH prescription. And on average, between 55% and 60% is Medicare, and the remainder is non-Medicare.

The next question comes from Dennis Ding with Jefferies.

Congrats on the quarter. Few questions from me, if I may. On gross to net for XPHOZAH, this was definitely better than what people expected in the first quarter. So how does this evolve through the year, and we should use the 23.8% as the new base going forward? And then secondly, I want to take another stab at this question. But on HR-5074, if the bill is to be signed into law in the first half of '25, XPHOZAH would need to go into TDAPA. But then, if the bill gets signed, XPHOZAH would need to come back out of TDAPA. Can you perhaps shed some light on that process and some of the logistics around that?

Dennis. Yes, let me just address that quickly. Currently, I think, as we've said, our intent is to enter TDAPA. I think the specifics of what you're just describing, that's going to play out over time. But our current intent is to go through the process, and as we hope and the work that we're doing and what Buddy Carter is doing and others on the Hill, is understanding how important this medicine is for patients. This is a good policy. It's the right thing to do to ensure that patients get access to a drug that's already beginning to make a difference in many, many lives of dialysis patients. So the work continues, and the specifics about how things come in and out based on these next six months or more, we'll get that to you as we also learn. And Justin, if you can address the gross to net.

Thanks, Mike. Dennis, in the first quarter, XPHOZAH's gross to net deduction was 23.8%. It obviously is very early in the launch and also the first quarter of the calendar year. So as Susan articulated, our Medicare and non-Medicare split is around 55% to 60% Medicare, and the rest non-Medicare. We're still assessing the patient mix. This is going to drive the gross-to-net ratio through the course of the year. So as a reminder, like I said, it's our first full quarter. We're currently estimating that maybe it will slightly increase over the next few quarters. But in general, we believe for the rest of this year, it will be in the mid-20s range. And we will obviously comment more for you to have greater clarity.

The next question comes from Roanna Ruiz with Leerink Partners.

One for XPHOZAH, could you talk a bit about what the early adopter patients look like in terms of their main features? And what's really encouraging physicians to find them and identify them as optimal candidates for XPHOZAH?

Yes, I'll ask Susan to address it, but the realities are, they are not that hard to find. When we know that patients are out of range. And they've been waiting for something like this. So it is clear that we have patients who are above the target range. The answer is, of course, yes, and then we move forward.

Yes, you're absolutely right. I appreciate your question about the early patients we are targeting. It's important to note that nephrologists closely monitor phosphorus levels in their patient populations. The patients currently being initiated on XPHOZAH are those that nephrologists have historically struggled to keep within the target ranges. This is the group we are focusing on now. As we move forward, it is crucial for nephrologists to adapt their practices and consider XPHOZAH for patients who are outside of the target ranges.

The next question comes from Laura Chico with Wedbush.

I have two questions. First, regarding XPHOZAH, what needs to happen for us to reach the high end of the guidance range for 2024? Secondly, I'd like to follow up on XPHOZAH and discuss the current mix of Medicare and Medicaid. Are you anticipating that at a steady-state level, there will be a roughly even split between Medicare and non-Medicare patients?

No to just briefly address the IBSRELA question, it's execution and everything that we have been doing is what we need to continue doing. Expanded footprint certainly is going to be a benefit as we said, trained in the field by the end of the quarter. So that's certainly a big part of it, too. But it's execution. The patients are there, they're waiting, and when you ask the right questions, if physicians identify them, then we help them go through the prior authorization process. Susan, do you want to address the first question?

Yes, regarding XPHOZAH, with only one full quarter of data available, it's difficult to make predictions. I don't want to imply that we are at a steady-state. However, given the patient demographics in the dialysis setting and the IQVIA data on binder therapies, these observations are not surprising. We need more quarters of data to provide a clearer picture. It's also crucial to note that the coverage policies have been established across all payer segments, which is a significant factor influencing the outcomes. These policies will remain consistent as we progress through this quarter and beyond, providing strong support across all segments.

The next question comes from Joseph Thome with TD Cowen.

Congrats on the strong launch. Maybe on XPHOZAH, can you give us a little bit of idea of the proportion of patients that are on free drug or using the patient assistance program as they weigh coverage? And maybe how long does it take to navigate that prior authorization process from a physician writing script to actually getting the drug? And then second, Mike, you mentioned the cash balance, maybe what's your appetite to invest in R&D, either internally in the pipeline or maybe externally and bring something in?

Let me address both the first and the last question. It's early days for us to be sharing what's on the patient assistance program. So we're going to wait until we've got more experience under our belts with that. And as you saw just under 1.5 months ago, we hired Mike Kelleher as our Executive Vice President, Corporate Development and Strategy. That should be the signal to your question, our willingness to invest in pipeline opportunities, whether it's organic development or opportunities we may find outside as I think what we are demonstrating is that the approach that we take to commercialization of drugs is clearly unique. Our ability to attract remarkable performers in the field, I think, is evident in both IBSRELA and XPHOZAH performance. So leveraging that and bringing Mike on board is certainly a big part of us going in that direction.

The next question comes from Ed Arce with H.C. Wainwright.

This is Thomas asking a couple of questions for Ed. Congrats on the strong early traction for XPHOZAH. Perhaps first question, can you discuss how many patients are on XPHOZAH therapy to date? And among these patients what's the split between GI gastro and then PCP prescribers? And then I have a follow-up question as well.

Yes, it's a little bit hard to hear the question, but I think you're asking about the split of patients in GIs versus PCP. I think as Susan has spoken about, our targets are high writing GIs and high writing PCPs who act as other GIs and have big practices. I don't know, Susan, if you want to add anything more to that?

Yes, exactly. We have identified our target audience as 9,000 healthcare professionals who represent 50% of the total market for IBS-C medications. While many doctors prescribe for IBS-C, we see significant potential in focusing on this concentrated group, which drives our IBSRELA opportunity. As Mike mentioned, we do not see a clear distinction between primary care physicians and gastroenterologists. We identify high-prescribing gastroenterologists and also high-prescribing non-gastroenterologists who are interested in treating IBS-C and use the prescribed medications to manage their patients. Thus, this distinction is not significant in our market strategy.

Got it. And also, can you discuss how many patients are on XPHOZAH therapy and also the script data could be a reasonable indicator for underlying demand of growth?

I think you're asking how many people are on 60-day versus 30-day scripts. I think, again, it's early days for us to be sharing that kind of information.

The next question comes from Matt Kaplan with Ladenburg Thalmann.

Great start with the launch of XPHOZAH. Congratulations on that. I want to explore XPHOZAH's performance in the quarter and what it could indicate for demand in 2024 and beyond, especially considering the strong interest highlighted in the Spherix survey. Were the initial doctors early adopters of new therapies? Will it be more challenging to recruit additional adopters later on since these doctors are among the first to show interest in new therapies?

A quick comment and then I'll let Susan address in more detail, is, nephrologists have been trying their entire careers with these patients to get their serum phosphorous levels in check. And they have been woefully unable to do that with a single mechanism of action of binders irrespective of the type of binder that it is. Patients don't want to take that amount of material. Low phosphorous foods are unpalatable. It's really a difficult life. And when a new mechanism of action just comes in, as Susan spoke in her opening statement about how this is being utilized, as you saw in our Adcomm, it's really heartening. And I think physicians see the opportunity to finally have a tool in their toolkit that may help their patients get into the target range that they've been trying to achieve. And as Susan said, we are hearing from patients and from physicians that these effects are sustained. That's heartening and extraordinarily rewarding that we're going to have that kind of impact on patients. It is early days. You always are going to have early adopters; that's not an uncommon phenomenon. But the difference here is there's not one nephrologist out there that has not struggled with, nor one patient that has not struggled with how to manage their serum phosphorus.

Yes. The Spherix data shows a 56% user base, based on information from April. What we're observing is that nephrologists are eager to work with our sales team. They are becoming familiar with our product, XPHOZAH, and thinking about their patients in relation to it. It’s not just about early adopters; all doctors have been tackling the challenge of managing phosphorus levels with limited treatment options and are now open to adding XPHOZAH to their treatment plans. This sentiment is widespread among nephrologists. To increase the adoption of our product, it's crucial to encourage them to think beyond the difficult cases they've always focused on. With a new treatment option available, they shouldn't wait for multiple phosphorus readings or rely solely on dietary solutions. They should consider treating these patients with XPHOZAH, as it provides them with a broader set of tools for managing their patients' needs.

This concludes our question-and-answer session. I would like to turn the conference back over to President and CEO, Mike Raab, for any closing remarks.

Thank you, everyone, for joining us this evening, including our investors who've been on this journey with us, the employees who drive our success, our partners who support us, and the patients that we serve. With that, we can close the call. Thank you, operator.

The conference has now concluded. Thank you for attending today's presentation. You may now disconnect.