Eric Foster
Thanks, Mike, and it's great to be with you all again. Q1 was another great quarter for both products. IBSRELA and XPHOZAH delivered meaningful year over year growth. Consistent with prior Q1's, we saw the IBSC market contract, and as you know, the hyperphosphatemia market was impacted by the elimination of Medicare Part D coverage for phosphate lowering therapies.
Despite these headwinds, we saw strong prescription demand for IBSRELA and demonstrated that both Medicare and non-Meddicare patients are able to access XPHOZAH, as we continue to meet the unmet need in the market. The team is focused on execution and building on our Q1 momentum as we enter an important second quarter in a position of strength.
Let me start with IBSRELA. IBSRELA grew 57% over last year. This is incredible growth as we enter our third full year of post-approval. We saw increases across key demand indicators, including new and total riders and new and refill prescription. As I mentioned before, the IBSC market historically contracts during the first quarter, and we saw clear evidence of it in Q1, especially early on. Despite that contraction, IBSRELA demonstrated strong prescription demand consistent with Q4 and exited the quarter with very strong momentum. This is further evidence of the confidence that HCPs have in IBSRELA and the value this medicine can bring patients.
As we look ahead, we remain focused on making progress against our strategic imperatives to drive growth and help more patients with IBSC. Which include raising awareness and favorable perception of IBSRELA, expanding target HCP's view of potential IBSRELA patients, positioning IBSRELA as the first action for appropriate patients who are not getting adequate relief or are not satisfied on a secretogog, and encouraging HCPs to send prescriptions to one of our specialty pharmacy partners or Ardelyx's assist.
These strategic imperatives are allowing us to create opportunities across all aspects of the physician and patient journey to improve HCP perception, drive consideration, and support prescription pull-through. Our expanded skill-based teams and our omni-channel marketing initiatives are focused on these areas, and we continue to see improvement. IBSRELA is an important treatment option for patients with IBSC, and we remain confident in our path to greater than $1 billion peak-year net sales revenue.
Now on to XPHOZAH. XPHOZAH had another very strong performance, delivering 30% revenue growth compared to last year when you exclude the returns reserve release. This demonstrates that XPHOZAH continues to be an important medicine to help patients achieve and maintain target phosphorus levels, despite the turmoil and disruption in the market.
It also gives us confidence that XPHOZAH strategy is working. Most importantly, the operational plan has allowed patient access to continue. We're driving a clear message to healthcare providers that is resonating. Prescribe as you always have, based on the patient need, and we will support access through our patient services programs.
As we look at XPHOZAH's performance during the quarter, there were several positive indicators that gives us confidence as we move forward. We saw new riders prescribing during the quarter as well as both new and refill prescriptions continue. In addition, our internal market research indicates that the vast majority of surveyed nephrologists recognize they are the decision makers for XPHOZAH prescriptions, and that they continue to believe that at least 30% of the patients are candidates for XPHOZAH.
To maintain the momentum that the team has established, we must remain focused on the factors that influence our ability to drive demand. There is a high unmet need among dialysis patients for tools to achieve and maintain target phosphorus levels. Physician satisfaction with XPHOZAH remains high. Access to XPHOZAH has been protected, and lastly, we have a strong share voice in the market.
The commercial team and all of team Ardelyx have been steadfast in our commitment to bring these first-in-class medicines to patients who continue to struggle with their conditions. We have a winning position in two markets with a high unmet need and a high performing team that consistently drives results, and we are eager to achieve our potential as quickly as we can. We are focused on executing our plan and maintaining the growth momentum for the remainder of the year.
I will now turn it over to Justin.
Justin Renz Renz
Justin, thank you, Eric. We were very pleased with the financial performance we reported earlier today, which demonstrated significant year-over-year revenue growth, careful management of expenses to support continued commercial excellence, and a strong cast position to continue building the business. We had total revenues of $74.1 million in the first quarter of 2025, an increase of 61% compared to the $46 million we reported last year.
The growth was driven primarily by strong performances and significant increases in net product sales revenue from both of our commercial products in the first quarter of 2025 compared to the same period of 2024.
During the first quarter of 2025, we recorded IBSRELA net sales revenue of $44.4 million an increase of 57% over the same period of last year. Our growth was driven by strong patient demand and the continued focus on commercial execution from clinical consideration to prescription pull through. As we've consistently shared with you in the past, our net sales were impacted during the quarter due to normal Q1 market dynamics.
In line with our expectations, the gross net deduction for IBSRELA for the quarter was 34.8%, and as we've experienced, we expect this to improve throughout the course of the year. We expect continued growth for IBSRELA. We reaffirm our 2025 guidance of $240 million to $250 million in net product sales revenue.
We also recorded $23.4 million in net product sales revenue of XPHOZAH in the first quarter of 2025, an increase of approximately 55% compared to $15.2 million in the first quarter of last year. As you saw in our press release, XPHOZAH net sales revenue includes a one-time $3.8 million release of our returns reserve. Excluding this returns reserve release, our year-over-year growth for XPHOZAH was 30%.
Our returns reserve considers our returns policy and the passage of time since launch. When coupled with zero product returns to date in our open return window in the very low number of bottles in our downstream distribution channel, it was clear that a returns reserve is unnecessary. As a result, our gross net deduction for XPHOZAH during the first quarter was approximately 18%, excluding the impact of this release, it was approximately 32%.
In addition to product revenue, we earned a $5 million milestone from our partner in China following the approval of tenapanor for hyperphosphatemia. We received payment from Fosun Pharma in April. We also recorded $1 million in non-cash royalty revenue during the first quarter of 2025 compared to $370,000 in the same period last year.
Research and development expenses were $14.9 million for the first quarter of 2025, compared to $10.6 million for the same quarter of the prior year. The increase in R&D expenses reflects increased engagement with the scientific and medical communities.
Selling, general and administrative expenses for the quarter were in line with our expectations at $83.2 million compared to $53 million that were reported for the same period in the prior year. The increase was related to commercial activities for IBSRELA, XPHOZAH, including the IBSRELA salesforce expansion, as well as growth of the overall corporate infrastructure to support our strategy.
In the first quarter of 2025, we also had $12.1 million in non-cash stock compensation expense and $2.1 million in non-cash interest expense. We had a net loss of approximately $41.1 million or $0.17 per share in the first quarter compared to a net loss of $26.5 million or $0.11 per share in the same period of last year.
As of March 31, 2025, our total cash, cash equivalents, and short-term investments was $214 million. The first quarter demonstrated strong demand for IBSRELA and clear evidence that the XPHOZAH strategy is working. We remain confident that there is a significant opportunity for both of our medicines that we are on track to achieving our peak sales expectations, more than $1 billion for IBSRELA and $750 million for XPHOZAH. We are building a great company and focused on delivering shareholder value.
With that, I'll hand it back to Mike.
Michael Raab
Thanks, Justin. It's been quite an eventful first quarter, and through all of it, we executed and created opportunities. That will continue to be our focus moving forward.
I will now open the call to questions. Operator?
Operator
(Operator Instructions)
Louise Chen, Scotiabank.
Louise Chen
Congratulations on all the progress this quarter. I wanted to ask you two questions here. First, for the IBSC market, do you expect this to improve as you go through second quarter and beyond versus the contraction that you historically see in the first quarter and how should we see that play out? And then secondly, could you explain in more detail the return reserve and how that impacts the sales and what that could look like going forward? Thank you.
Michael Raab
Sure, let me ask Justin to start with the second question first.
Justin Renz Renz
Thanks, Louise. Yes, so as part of our gross net, we have a returns reserve and our returns reserve, again, as contemplated from the beginning of launch. When you couple our progress over the last five or six quarters where we've had zero returns and very limited bonds in our downstream distribution, it was no longer appropriate to carry this reserve on our balance sheet. So we will no longer be doing this prospectively, and this, of course, would have modest improvement to our gross net prospectively.
Eric Foster
Yeah, thanks, Louise, for the question. With regard to the IBSC market improving as we go through the year, the short answer to that is yes. The IBSC market in the first quarter, we know traditionally contracts, and that's exactly what we saw early on in Q1. But we continue to remain very optimistic, given that we had our Highest prescription demand quarter in Q1. We were able to -- I'm sorry, in 4, and we were able to see that consistent in Q1. And certainly, we're able to finish the quarter with strong momentum that gives us a lot of confidence as we move into Q2 in the rest of the year that we'll continue to see that improve.
Louise Chen
Thank you.
Operator
Ryan Deschner, Raymond James.
Ryan Deschner
Hi, thanks for the question. Just wanted to ask a little bit more about the one contraction. What are you attributing this sort of the level of overall contraction in 1Q and looking different from prior, 1Q situations? And then, I have a follow up. Thank you.
Michael Raab
Sure, thanks for the question, Ryan. I think just for some context is the market has consistently contracted. I think in their first two years on the market, given the volume that we were generating, probably not as much of an impact, but as this business grows, as Eric, I'll ask him to address it, it's something that we are expecting as we move forward. I think if you compare us to others within that market basket, I'm pleased with the performance that we saw out of IBSRELA. Eric?
Eric Foster
Yeah, I would just add as we continue to grow, volume, we're starting to see a bit of a response similar to that of the market in the first quarter. But it's still a very healthy market continuing to grow double digit growth as it has over the past few years. And as I mentioned just a minute ago, we expect that to continue to grow in 2025 for the rest of the year.
Ryan Deschner
Got it. And then, what are you targeting for your long-term gross to net if you're disclosing a level for XPHOZAH at steady state? And also, do you have any color or a status update on the launch in in China now that it's approved? Thanks.
Michael Raab
Yeah, so the China first, once we get more perspective from our partner, we can share that. So probably not much to talk about there, and Justin, if you could address the gross net?
Justin Renz Renz
Sure, it's still early because we're in the new treatment paradigm, if you will, the coverage mix where is changing in 2025 compared to 2024. So we're not really fully there yet. I would say, we had 32% irrespective of the gross to net change we made for the returns reserve in Q1.
Michael Raab
I think it's fair to say, Ryan, and just correct me if I'm wrong, Justin, that generally our guidance for both the 30%, plus or minus 5%, is likely to hold true continually going forward.
Justin Renz Renz
It's a great place to start modeling.
Michael Raab
It's very helpful. Thank you very much.
Operator
Dennis Ding, Jeffries.
Dennis Ding
Hi, thanks for taking our questions. Two for me, on IBSRELA, I mean, how do you guys reconcile what's being reported through IMS and the $44 million in revenue that you guys reported because, based on scripts and I think through some reasonable assumptions? I think people were expecting around $52 million, so the $44 million was quite a surprise to us.
And then, question number two is on the CMS litigation on XPHOZAH. When do you expect the decision on the appeal? And I guess hypothetically, if there were a positive decision and XPHOZAH was given back Part D, how quickly can things be restored back to 2024 levels in terms of the underlying structural logistics at the DOC? Thank you.
Michael Raab
Well, that, I'll address the last question first. I mean, it's probably not healthy to get into hypotheticals, just given everything that we're seeing going on in Washington. All of the briefs that need to be filed are filed, and we're just waiting for the courts to set a date. And we will navigate through that and as we learn more, we will certainly bring it to your attention.
I'll ask Eric to talk a little bit about your question around scripts. But remember, as we talked about this over the years, that there are going to be fluctuations in scripts, which is why what we said consistently is you need to hold us to account for the guidance that we give you. And as you heard all of us say, we are confident that $240 million to $250 million. And the perturbations in the first quarter are part of the reason that we encourage you to look at it as such. Eric, any thought?
Eric Foster
Yeah, thanks, Dennis. Good question. As we think about demand, we were very pleased with what we saw in Q1. As I noted, consistent with what we saw in Q4, which was our highest demand quarter to date. Certainly, when you look at net sales, it can be impacted by market dynamics. When we think about Q1, we typically see things like the IBSC market contract.
We've got prior authorization renewals, insurance coverage resets, wholesaler buying patterns, and higher patient co-pays, and all that needs to be taken into consideration. But what gives us confidence is we've seen that in the past. We also see that it normalizes, and we feel like we really ended the quarter with strong momentum and certainly feel very confident as we go into Q2.
Michael Raab
And then, I think what's important about that strong momentum, Q1 was our second highest generation of demand to date, right? So what Eric just described certainly is I'm sure from the perspective that you're bringing frustrating, given the numbers that you thought. But we're extremely happy with the performance that we saw, particularly since this is the second highest demand. And we were not impacted by the contraction the way other products were in the IBSC market basket.
Dennis Ding
Got it, thanks.
Operator
Laura Chico, Wedbush Securities.
Thank you very much for taking our question. This is Dylan on for Laura Chico. I was just wondering what metrics are you monitoring to assess the impact of the newly expanded IBSRELA of field force and what gives you confidence that you're on a trajectory to meet the peak peak revenue expectations?
Michael Raab
Sure, first of all, is I think the caliber of the people that we've hired and what we're seeing already coming out of the first -- the fourth quarter, excuse me, fully on board and trained, gives us that confidence. As I just said, Dylan, that this was the second largest quarter of demand generation that we've seen since launch. That is part of the confidence I get in it. In the midst of that market contraction, as I said, we contracted less than the others. That gives me confidence. The incredible unmet need that's out there and the better access that we have with the larger sales organization, I think all comes together. Eric, other thoughts?
Eric Foster
Yeah, for me, I mean, what I think about it is really three things. Are we seeing an increase in activity? Are we seeing an increase in writers, whether it be total riders or new writers, and then are we seeing that lead to new and refill prescriptions? And as it relates to year over year, we certainly see significant increase in activity, we see an increase in new and total riders, and then we also see an increase in the new and the refill prescriptions.
As Mike mentioned, Q1, the second highest demand, prescription demand quarter to date. And there we saw an increase in total riders as well as new and refill, prescriptions, looked really good coming off of, what Mike said was, our highest demand quarter in Q4. So those are some of the basic metrics that we look at to make sure that we're getting the activity that we need. It's generating new and total riders that's leading to new and refill prescriptions, so that we can help the higher number of patients out there that need this treatment for their IBSC.
Michael Raab
Thank you.
Operator
Joseph Tome, TD Cowen.
Joseph Thome
Hi, there, good afternoon. Thank you for taking our questions. Maybe the first one, can you comment a little bit on the demand specifically in the commercial channel, and how that changed from Q4 to Q1 for exposure just to kind of get an idea of growth in that segment. And then a question on the financials, when we look at the R&D and SG&A spend for this quarter, should we use this as sort of a new base going forward? And maybe relatedly, how much wiggle room do you have in the spend for exposure to make sure, that business stays profitable going forward depending on what we see this year? Thank you.
Michael Raab
Sure, let me ask Justin to address the second part of your question first.
Justin Renz Renz
Great. So thanks, Joe. Yes, we have a modest increase in our SG&A in Q1 compared to Q4, so you might have seen an increase from $76 million to $83 million. And we expect to that will rise over the course of 2025 to around $90 million by the end of the year, making sure we have all the appropriate team members to support the commercial team, and to your point, make sure XPHOZAH and all the patient access and everything else is available through our either our patient assistance program, our field managers and everything between.
So, we feel like that is in good shape and some modest increase over the next few quarters. From an R&D perspective, we were approximately $15 million in the first quarter and we expect modest growth in that over the course of the year. So we're in great shape again. We finished the quarter with $214 million and we're in good shape for financial position.
Michael Raab
And Joe, just to clarify, your question is more than just commercial, it's the non-Meddicare segment, right?
Joseph Thome
Correct, yeah.
Michael Raab
Okay. Yeah, Eric, you get that.
Eric Foster
Yeah, thanks, Joe. What we saw in Q1 was we saw that Medicare had about a weighted average of around 13% of the total payer mix. We think about that, we saw that it was primarily in the first few weeks. Unfortunately, these patients had the benefit of a one-time transitional fill through CMS, and we saw that take place. And like I said, it was primarily in the first few weeks. But what we saw as the quarter continued to move was the rest of the mix was really predominantly through the commercial and the Medicaid side, which, as is the non-Medicare mix.
So we were able to see, a good momentum there as the quarter continued and feel really good about where things ended, at the end of Q1, and that's given us continued confidence as we move forward. And really focusing on being able to allow all patients, regardless of whether it's Medicare or non-Meddicare, be able to have access moving forward.
Michael Raab
Yeah, I guess I just want to follow up to the financial question is it's not that we're necessarily looking for wiggle room. I think we have incredible confidence on the trajectory that we're on with XPHOZAH in the way that we've approached the market. So it's not that we're looking for wiggle room, I think we're on track with what we anticipate, which is why we reaffirm the $750 million peak. And the hope is an expectation that in the not too distant future, we can give you more perspectives of what our views are for this year.
Joseph Thome
Great. Thank you very much, very helpful.
Caitlin Lowie Lowie
Thanks, Joe.
Operator
Roanna Ruiz, Leerink Partners.
Roanna Ruiz
Hey, afternoon, everyone. Follow up about XPHOZAH, I'm just curious, do you have any updates on the how the patient assistance program is operating right now and some of your plans to keep going forward into 2Q and 3Q? And the second part of it is I was also curious off the last question, thinking about commercial and non-medicare, how are those trends, possibly tracking into exiting 1Q and thinking about 2Q and 3Q?
Michael Raab
Sure. Let me ask Eric to address this for you.
Eric Foster
Yeah, so, thank you. So with regards to path, or the patient assistance program, we're very pleased with how, the ardelic assistance is being able to help patients in need, particularly those Medicare patients. We saw patients that were on XPHOZAH for Medicare Part D and Q4, they were able to continue accessing XPHOZAH in Q1 through our patient assistance program. So I would say, we were very pleased with being able to help those patients out and certainly new patients as they come on in first quarter.
We are in this for the long term. For us, it's paramount that we are able to provide access for those patients in need. And so we're not looking at it on a quarterly basis. It's not a Q2, Q3, Q4 decision for us. We're continuing to move forward so that all patients, regardless of Medicare and non-Meddicare have coverage for XPHOZAH.
With regards to the commercial business. Again, very pleased with what we're seeing there on the non-Medicare segments. As I noted, we saw really the vast majority of the Medicare transitional fields within the first few weeks, but really that dissipated. And we really aren't factoring that into our models as we look at things and forecast moving forward. It's really focused on driving that non-Meddicare business primarily through commercial, Medicaid, and the VA business that we saw. Really increase in that latter half of Q1, and that's what's given us confidence as we move into the remainder of the year.
Michael Raab
I mean, just a couple of comments on that, Ron, is if you -- the confidence that we have coming from January where, everything, everyone was wondering how this was going to work. And then as it progressed through to March, the strategy is working. I think no one can underestimate the impact on these patients of the turmoil that they're facing and suddenly having to get their binders through the DOs.
Some of the binders that they've been on for a long time aren't available, and ultimately, us having to work and choosing to work with the nephrologist at the center of the decision making. As they were before in the midst of all this turmoil, I'm very pleased the way that the team has actually helped them navigate through it and the strength of the Ardelyx's team in the program there in particular is paying dividends.
Roanna Ruiz
Got it. Thanks for the help.
Michael Raab
Thank you.
Operator
Julian Harrison, BTIG.
Julian Harrison
Hi, thank you for taking my questions. When you look at high volume IBSC prescribers, are you left with the impression that they generally know who the best candidates are for IBSRELA? And I asked this because I am aware of some recent survey data you guys have suggesting a disconnect between prescribers and patients on how large the unmet need is. And I'm also just wondering how you expect maybe the gap to narrow there going forward.
Michael Raab
Yeah, I mean, just one quick comment, I'll ask Eric to address it. A disconnect between prescriber and patients is probably a pretty traditional phenomenon across many therapeutic areas. And to me, at least with what I see, the significant untapped potential that's out. There is remarkable -- don't forget that all of our clinical work was first line therapy. And the fact that a new mechanism like this given payer dynamics is what forces you into making the decision we did, because we didn't want to negotiate with payers that we would be second line is what gets us to where we are.
The dissatisfaction when you talk to patients with what they have with GCC agonists kind of hard when a physician doesn't yet understand this new mechanism and what it is that we can provide that they may see a disconnect between the patients thing. But that's the work and why we expanded the field and the yields that we're seeing from that effort. Eric?
Eric Foster
Yeah, I would just add there, there's certainly is plenty of opportunity out there. You mentioned the disconnect and we're very much aware of that, and really take it very seriously and our responsibility to help connect the physician and the patient. I think, patients or physicians, they do recognize who these patients are. It's actually -- when we talk to physicians, it's patients that are diagnosed with IBSC. They're currently on a secretive god therapy, and yet they're not satisfied or they're not getting that relief.
For us, it's really trying to get the physician to act with urgency. They've been writing [notes] now for a decade. And so we need to continue to try to break these habits. It's getting them to recognize the appropriate patient. I think we're, we feel like we're getting traction there. But then it's really acting with urgency, so that they can be the first choice once that patient really is not satisfied or they're not getting adequate relief.
And we know that's quite a few patients because we know about a third of those patients out there, are satisfied. So that leaves, quite a few patients out there that are currently diagnosed on a treatment, not satisfied and getting adequate relief, that we're seeing IBSRELA being used really second line for those patients.
Operator
Aydin Huseynov, Ladenburg.
Aydin Huseynov
Hi, good afternoon, everyone. Congratulations with this quarter. I got a couple of questions. So appreciate explore this long-term guidance confirmation $750 million. So could you provide some dynamic of sort of how you plan to get there, sort of ramp up curve? And If possible, any 2025 sort of soft guidance kind of hints? And the long-term guidance not include Medicare and in case you'll be able to sort of include Medicare, further on would -- how would that actually affect the upside of [XPHOZAH] sales, peak sales?
Michael Raab
Sure, let me address that for you, we assume Medicare is not part of the mix in terms of paying for XPHOZAH for those patients. That's roughly 60% of the dialysis population is Medicare -- non-Meddicare is primarily Medicaid and commercial. And the comments from both both Eric and I that what we see already in the first quarter makes us feel confident that that is going to be what we are able to confidently get to $750 million.
As we said last year, as we were entering this year and reaffirmed in my opening comments, it's too early for us to be giving you guidance as to what 2025 is going to look like. We are -- once we have confidence, and I believe it will happen, in the not-too-distant future, we will provide you some perspective as to what we think 2025 will turn out to be.
Aydin Huseynov
Thank you. I appreciate that. And I won't for long question. How much of the decision making by nephrologists may affect the insurance coverage, and have you seen any pushback from payers so FAR for XPHOZAH given your sort of ongoing negotiations with CMS?
Michael Raab
Sure, well, [Pair and CMS] probably not correlated, two very separate things. The nephrologist and the HCPs are extremely important as it relates to getting prior authorizations through. Eric, other thoughts?
Eric Foster
Yeah, I would just say, right now, we're really not seeing any pushback on the commercial side. And it's good to see that the nephrologist still has the ownership and really is at the center of the decision making. And for those patients that need it, if they have commercial coverage, then certainly, the physician can write for it, and we've got confidence that the patient can get it on the commercial side.
Michael Raab
And our others in our adult assist program is extremely helpful in navigating that process.
Aydin Huseynov
All right. Thank you. Thanks so much.
Michael Raab
Thank you.
Operator
Allison Bratzel, Piper Sandler.
Hi, thanks for taking the question. This is Ashley on for Allie Bratzel. I have two questions. First one being related to XPHOZAH. It seems like we haven't really heard much about the Kidney Patient Act. It seems like this is kind of shaping up to be what you would call a call option. Do you have any updated color on that front, anything you've heard?
And then my second question is related to potentially bringing in a GI or renal adjacent external asset. You guys previously signaled some interest in doing that. Is that still the plan? Do you have any color on when we might hear about this? Are you kind of focused more on the ongoing launches with your commercial products? Anything on that phone would be really helpful. Thank you.
Michael Raab
Sure, thanks for the questions. In terms of bringing up assets as we've described, we've recently built out a team with Mike Kelleher to look at corporate development and licensing, acquisition of assets, certainly in direct, in our spaces in renal and GI and adjacent spaces as appropriate. And that work continues. We're excited about progress is being made. When there's something to talk about both in terms of internal development of some of the approaches we could have with programs that we have developed, we will announce that as anything that we bring in from the outside.
So it's an incredibly important part of our efforts to build this enterprise as we believe we can. As it relates to the kidney Patient Act, you hit the nail on the head. Think of it as a free call option. What we -- at the end of last year, we communicated is that you should hold our feet to the fire around the $750 million and that comes from 40% of the dialysis patients, which is roughly $220,000 would be our our TAM. So free call option is exactly what you think about it.
Great. Thank you so.
Michael Raab
Thank you.
Operator
Prakhar Agrawal, Cantor Fitzgerald.
Hi, this is (inaudible) on for Prakhar. Trying to get a better sense of the strategy around expanding and exposure up on Medicare channels, and, once you we expect to see the stronger uptake materialized within these medical channels?
Michael Raab
I'm sorry, I couldn't hear the the entire question. Expanding XPHOZAH to Medicare, did you say?
Non-medicare channels. What is the strategy around expanding XPHOZAH of taking non-medicare channels?
Michael Raab
Yeah, so with non-Medicare, that's that's going to be Medicaid, as I said, and commercial are the two main components of non-Medicare, and that is 40% of the patient population. They are seen by nephrologists, which are the people that we call on. And one of the important aspects of the way that we do it is we don't tell the nephrologist to discern who's Medicare and not in Medicare.
We have a closed distribution system that goes through Ardelyx's assist program, so that we adjudicate those who are Medicare and those who aren't Medicare. And those who are Medicare, transition into our patient assistance program. And if they qualify, they get free drug. If they aren't Medicare, then we work with them through the system if there's prior office or not to get their prescriptions filled.
Operator
That concludes our question-and-answer session. Now I'll turn the call over to our host for any additional or closing remarks.
Michael Raab
Thank you all for joining us this afternoon, and a special shout out goes to team Ardelyx, who I know is listening. Your hard work is invaluable in bringing our essential medicine to our patients. Thanks also to our shareholders. We are building a great company and focused on doing what is right for patients and creating long-term value. With that, we can conclude the call.
Thank you, operator.
Operator
That concludes today's meeting. Thank you for joining and have a pleasant day.
The host has ended this call. Goodbye.
