Earnings Call Transcript

Tarsus Pharmaceuticals, Inc. (TARS)

Earnings Call Transcript 2025-12-31 For: 2025-12-31
View Original
Added on April 06, 2026

Earnings Call Transcript - TARS Q4 2025

David Nakasone, Head of Investor Relations

Thank you. Before we begin, I encourage everyone to visit the Investor section of the Tarsus website to view the earnings release and related materials we will be discussing today. Joining me on the call this afternoon are Bobby Azamian, our Chief Executive Officer and Chairman; Aziz Mottiwala, our Chief Commercial Officer; Seshadri Neervannan, our Chief Operating Officer; and Jeff Farrow, our Chief Financial Officer and Chief Strategy Officer. I'd like to draw your attention to Slide 3, which contains our forward-looking statements. During this call, we will be making forward-looking statements that are based on our current expectations and beliefs. These statements are subject to certain risks and uncertainties, and our actual results may differ materially. I encourage you to consult the risk factors contained in our SEC filings for additional detail. With that, I'll turn the call over to Bobby.

Bobak Azamian, CEO

Good afternoon, and thank you for joining us. 2025 was a breakout year for Tarsus and for XDEMVY, the first and only FDA-approved therapeutic for Demodex blepharitis, an impactful disease that affects more than 25 million Americans. Among the key highlights for the year, we delivered more than $450 million in full-year net sales. We have helped more than 0.5 million patients living with Demodex blepharitis since launch, underscoring the meaningful real-world impact of XDEMVY. By creating and leading an entirely new category in eye care, we have established Tarsus as a differentiated company fully capable of translating scientific insight into commercial leadership. We believed from the beginning that XDEMVY could be a breakthrough medicine. Today, the data and real-world experience validate our conviction. In just two years since launch, XDEMVY has fundamentally changed the eye care experience. We see that transformation reflected in three clear proof points: First, XDEMVY is delivering consistent meaningful outcomes for patients. Second, eye care professionals have fundamentally changed the way they practice. And third, we've redefined the rules of launch and have succeeded in rewriting the biotech playbook. We're now ready to share what we've always believed: that XDEMVY can reach blockbuster status within the next couple of years with sales potential exceeding $2 billion. At the same time, we are intentionally building Tarsus for its next phase of growth. Our primary strategy is disciplined and built for repetition: identify diseases with clear root causes, significant demand for better solutions, and the potential to establish a new standard of care, and then apply the development and commercial playbook, we have proven with XDEMVY. We are already executing against that framework with TP-04 and Ocular Rosacea, and TP-05 and Lyme disease prevention: two clinical-stage programs where the biology is clear, the unmet need is substantial, and our approach has the potential to deliver a new standard of care. Importantly, we also intend to expand our pipeline in a measured way, targeting one to two new programs per year. This pace allows us to remain focused, leverage our existing infrastructure, and allocate capital responsibly while extending our long-term growth trajectory and patient impact. What excites me the most is that we have the right team in place to accelerate our goal of becoming the next leader in eye care. You may have seen last week that we welcomed David Pyott, a distinguished leader in the global biopharmaceutical industry and former Chairman and CEO of Allergan, to our Board of Directors. His experience building enduring global eye care franchises and driving disciplined growth at scale will be invaluable as we continue to expand Tarsus' reach. We have proven we can build and scale. We have a product that continues to grow. In a pipeline with tangible proof points that position us to do even more. Looking ahead, our ambition is clear: to build a company capable of repeatedly creating and leading new categories in eye care and beyond. Before I hand it over to Aziz, I want to thank the entire Tarsus team. Our performance in 2025 reflects extraordinary execution in our award-winning culture, laying the foundation as we become a leader in eye care.

Aziz Mottiwala, Chief Commercial Officer

Thanks, Bobby. We entered 2026 from a position of strength and momentum. XDEMVY is one of the best-selling prescription eye drops and, from a product line perspective, is now profitable and growing. This gives us the leverage and flexibility to continue investing in our proven growth drivers that we believe will best support this opportunity. We are still early in reaching the estimated 25 million Americans living with Demodex blepharitis, or DB. And as Bobby mentioned, we have fundamentally changed medicine. We've transformed the eye care experience, and now see U.S. sales potential exceeding $2 billion. Beyond the large untapped addressable market, this outlook is reinforced by three fundamentals: One, a highly effective medicine that delivers consistently positive outcomes for an easy-to-diagnose disease. Two, our top prescribers have a significant opportunity to increase utilization, and almost every doctor we talk to is looking for more patients to treat. And three, the tremendous growth in patient interest, with many coming in and asking for XDEMVY by name. We've seen a meaningful shift in eye care professionals' or ECP practice behavior and patterns. ECPs are continuing to deepen utilization across all of the patient types we've been talking about, including DB patients with congruent MGD, dry eye, and cataracts, where visual outcomes are so important. Furthermore, I constantly hear from ECPs that they're beginning to look beyond these initial 9 million patients we originally focused on and are now screening for DB patients being treated for glaucoma, receiving eye injections, or presenting with styes. At the same time, patients are becoming more proactive and are increasingly self-identified. Together with strong access, where we have more than 90% of coverage across commercial, Medicare, and Medicaid, these dynamics are expanding the funnel of diagnosed and treated patients. To further accelerate the depth of utilization among ECPs, we're making a targeted investment in one of the most impactful parts of our business: our sales force. In 2026, we plan to add approximately 15 to 20 key account leaders. This is a relatively modest investment that is strategically focused on increasing depth within high-opportunity practices, and we expect it to contribute meaningfully to growth in the second half of the year. Another critical growth lever is evidence generation. We plan to share additional clinical and real-world data to reinforce the consistency of outcomes, strengthen physician confidence, and further expand screening and treatment patterns. This will also feed another powerful amplifier of ECP utilization: peer-to-peer influence. Having been in the eye care space for a long time, I know that when ECPs hear directly from colleagues about XDEMVY's consistent outcomes, adoption accelerates. We see this dynamic repeatedly at conferences and across professional forums. In complementing all the great work we're doing with our ECPs, our powerful direct-to-consumer campaign and surround sound approach to patient education also continues to deliver a positive and growing return on investment. In 2026, we plan to execute with even greater precision, focusing on the channels and formats that we know drive the greatest return while maintaining a similar level of spend as in 2025. And you can feel the momentum of our campaign in the field. I was recently with a group of optometrists at a large eye-care conference, and they were blown away by how often patients are now coming in asking to be screened for DB. In many cases, making appointments specifically to ask about XDEMVY. It's also amazing to see the change in objective measures of unaided awareness of DB and XDEMVY, which has gone from just 2% at the start of our campaign to now 25%, or 1 in 4 patients surveyed. Finally, retreatment dynamics are continuing to progress. Weekly refills are trending in the low to mid-teens range as practices formalize protocols, moving towards our expected steady-state rate of approximately 20%. Taken together, these trends of sustained shifts in vision behavior, expanded screening, growing consumer awareness, and emerging retreatment practices are making diagnosing and treating new patients more efficient than ever. Before I pass the call over to Sesha, I just want to say how proud and thankful I am for our commercial team. At conferences and meetings, we constantly hear from ECPs about all the great work our team is doing and the impact they're having on patient lives. As you can clearly see, we have a lot more in store for 2026 and look forward to sharing our progress with you.

Seshadri Neervannan, Chief Operating Officer

Thanks, Aziz, and good afternoon, everyone. We are leading the way in category creation and have proven that our model works. XDEMVY is the first proof point, and we are now applying that same scientific and strategic framework for the next set of opportunities in our pipeline. Today, I'll share updates on two programs that reflect the attributes that drove XDEMVY success: clear biology, significant unmet need, and the opportunity to pioneer new standards of care. I'll start with TP-04 for Ocular Rosacea. Ocular Rosacea is a natural extension of our Demodex expertise. Like DB, it is driven by Demodex mites and can significantly impact how patients look, feel, and see. It is also easily identified during a routine eye exam by the hallmark signs of inflammation and redness. Ocular Rosacea affects an estimated 15 million to 18 million Americans, and there are currently no FDA-approved treatments. Importantly, this opportunity is highly complementary to our existing infrastructure. It involves the same physicians and the same diagnostic process, enabling us to build on what we've already established, lotilaner's positive clinical data across several related conditions. In particular, in Papulopustular Rosacea, a related inflammatory facial skin condition with similar pathophysiology, lotilaner demonstrated statistically significant improvements in inflammation and redness in a Phase II trial. The insights from that trial have further informed our understanding of and confidence in TP-04's potential in Ocular Rosacea. TP-04 is a novel lotilaner-based sterile investigational ophthalmic gel designed specifically for application to the area around the eye. In December 2025, we initiated the first-ever Phase II trial for the potential treatment of Ocular Rosacea, which we believe is the next blockbuster category in eye care. The goal of this trial is to evaluate safety and improvements in erythema and telangiectasis around the eye, two of the most impactful signs of the disease using novel and proprietary grading scales informed by feedback from the FDA. As with XDEMVY, this Phase II trial is designed to inform decisions on dose and endpoints for later-stage development. Importantly, the FDA has indicated that we are not required to show a cure, but rather improvements in the endpoint. We expect top line data in the first half of 2027. Turning to TP-05 for Lyme disease prevention, a significant and growing public health concern. I'm excited to announce that we plan to initiate a Phase II clinical trial in the second quarter of 2026; we plan to enroll approximately 700 participants at risk of Lyme disease in one tick season with the goal of generating data that gives us confidence in TP-05's potential to prevent Lyme disease. Top line data is expected in the first half of 2027. As a reminder, TP-05 is an investigational, on-demand oral tablet that is designed to potentially kill Lyme-infected ticks before disease transmission occurs directly targeting the root cause. Approximately 27 million Americans are at moderate to high risk of contracting Lyme disease with no FDA-approved preventative therapies and an annual healthcare burden of over $1 billion. Our approach is already established in Animal Health and is further supported by the results of our previous Tick-Kill trial, where TP-05 demonstrated greater than 95% tick-killing activity within 24 hours compared to placebo. Furthermore, our market research showed that patients and physicians alike are excited about the potential of a new oral preventative therapy, with 90% of patients willing to try it, and a majority of physicians willing to prescribe to up to 95% of their high-risk patients. We believe advancing this program ourselves is the right strategic decision at this stage given the foundation we have in place, which includes deep experience with the lotilaner molecule, patent protection projected through 2040, alignment with the FDA on a regulatory path forward, and engagement with and support from many of our top Lyme disease experts in the country. And with the data from our Phase II trial, we expect to generate a robust Phase III-ready package that will maximize the program's long-term value. Before I turn the call over to Jeff, we also continue to make progress in the potential of TP-03 globally. In Europe, TP-03 remains on track for potential regulatory approval in 2027. In Japan, we are engaged with regulators to define the development pathway. And in China, our partner, Grand Pharma expects approval later this year. These milestones represent potential long-term growth drivers as we work to establish TP-03 as a global standard of care. We have an exciting year ahead and look forward to sharing continued progress across our pipeline.

Jeffrey S. Farrow, Chief Financial Officer

Thanks, Sesha. 2025 was a year of strong financial performance and disciplined execution. For the fourth quarter of 2025, we delivered $151.7 million in net product sales at a gross-to-net discount of 44%. For the full year, we delivered $451.4 million at a gross-to-net discount of approximately 45%. Total operating expenses were $522.3 million, driven in large part by commercial investments supporting the XDEMVY launch. We ended the year with approximately $418 million in cash, cash equivalents, and marketable securities, providing meaningful financial flexibility as we scale the business and expand our pipeline. Turning to 2026. With more than 2 years of revenue history, a clear understanding of seasonality, broad and stable payer coverage, and proven DTC effectiveness, we are providing full-year guidance for the first time. For 2026, we expect strong net product sales in the range of $670 million to $700 million, or annual growth of more than $230 million and 50% at the midpoint of our guidance. It is important to note that projected annual revenue growth is not anticipated to be linear throughout the year. Consistent with what we have seen across eye care and other therapeutic areas, we expect typical first quarter seasonality to impact growth, including deductible resets that increase out-of-pocket costs and temporarily reduce new patient visits. We also expect this dynamic to increase the gross-to-net discount for the first quarter. Additionally, given that XDEMVY remains primarily driven by new patients, holidays, medical meetings, and this year's severe weather disruptions are influencing near-term trends. As a result, we expect first quarter 2026 revenues to be flat to slightly below our Q4 2025 revenue. Further, sequential growth through 2026 is expected to be similar to what we observed in 2025 and consistent with broader sector dynamics. We expect strong growth in the second quarter, more tempered growth in the third quarter, and robust growth in the fourth quarter. Turning to expenses. For 2026, we expect gross margins to remain strong at approximately 93%, SG&A expenses to be in the range of $545 million to $565 million, which includes stock-based compensation of approximately $40 million, continued investment in our DTC campaign, XDEMVY-related marketing, and commercial support at levels consistent with 2025 or approximately $80 million, the incremental planned 15 to 20 new key account leaders, anticipated utilization of patient support services, and variable costs that scale with higher sales, including pharmacy administration fees and the branded prescription drug fee. We also expect R&D expenses to be in the range of $115 million to $135 million, which includes stock-based compensation of approximately $20 million. The Phase II trial of TP-04 for the potential treatment of ocular rosacea is expected to cost between $7 million and $10 million, with the majority planned to be recognized in 2026. The Phase II trial of TP-05 for the potential prevention of Lyme disease, as Sesha noted, is a relatively large trial, and is expected to cost approximately $25 million to $30 million in total. Given our expertise with TP-05 and lotilaner, we believe we are best positioned to run the trial and generate the most value for this program by developing a Phase III-ready package for our potential partner. Importantly, and as Aziz mentioned, XDEMVY is profitable and growing from a product line perspective today. As revenue continues to scale, we expect increasing operating leverage and maintain a clear line of sight towards potential company-level profitability while maintaining the flexibility to invest in other high-return opportunities. Overall, our 2026 plan reflects a balanced approach: extending XDEMVY's leadership while advancing pipeline programs that expand our long-term growth potential and value creation. In summary, we believe we are entering 2026 with strong revenue visibility, a scalable cost structure, and a disciplined investment plan. We look forward to sharing more updates with you in the coming quarters. I'll now turn the call back to Bobby for closing remarks.

Bobak Azamian, CEO

Thanks, Jeff. In just two years since the launch of XDEMVY, we have driven a fundamental shift in eye care and expect a clear path to peak sales potential of more than $2 billion. And as you heard today, Tarsus is not a single product story. XDEMVY is proof of a repeatable model: one that integrates science, commercial execution, and disciplined investment to create and lead new categories in underserved disease states. The foundation is built; the model has proven. We've rewritten the biotech playbook and are on our way to becoming a leading pharma company. Operator, please open the line for questions.

Operator, Operator

Our first question comes from Eddie Hickman with Guggenheim.

Eddie Hickman, Analyst

Congrats on the progress. Can you give us a little bit more detail into what is going into your expectations beyond Q1 for that $370 million to $400 million guidance in terms of a little bit more about like the bottles and the refill and sort of what your expectations are around the cadence of that? Appreciate it.

Jeffrey S. Farrow, Chief Financial Officer

Yes, are you talking about Q1, Eddie, in particular?

Eddie Hickman, Analyst

Sort of beyond Q1, anything you can give us to get you to that full-year guidance that you gave us in terms of the number of bottles and sort of how you expect retreatments to work throughout the year?

Jeffrey S. Farrow, Chief Financial Officer

Yes, the big picture guidance that we provided in the prepared remarks is we do expect flat to slightly down in the Q1, just given the typical dynamics that you see with deductibles resetting. Historically, we've seen a nice bump up in Q2. And then as you think about eye care space in general, you typically see some tempered growth in the Q3 summertime frame. In the fourth quarter, with FSAs expiring and deductibles expiring, you see more robust growth there. So all of that, the gross-to-nets and the bottles dispensed are baked into our guidance. We're not going to really provide that typical bottle guidance or gross-to-net guidance that we've historically done, now that we've given the full-year guidance here. But absent a material change, we're probably not going to comment on those types of things. If there is something that changes dynamically, we'll be sure to make sure the street knows.

Eddie Hickman, Analyst

Got it. And then one clarification is, as the launch continues and docs and patients get more familiar with how this is administered and maybe some getting refilled, do we expect sort of the impact of those seasonal disruptions for conferences and weather and holidays to continue to be as impactful from a magnitude perspective going forward?

Aziz Mottiwala, Chief Commercial Officer

Eddie, it's Aziz. Yes, thanks for that clarifying question. I think as you move further in the launch, you are going to be more susceptible to the typical seasonality. That's pretty typical for most brands. We see this across the eye care space and actually areas outside of eye care as well. So we're seeing that now in the first quarter. I think the dynamics you're referring to give us confidence in the continued growth of the brand and to eventually achieve the peak that we provided today. The fundamentals there are really strong, as you alluded to. We've got a strong and growing base of prescribers that are actively deepening their utilization. They're looking for other use cases. We're meeting that with a strong consumer effort. We're now one in four patients aware. So if you think about our DTC, even at a similar spend level, we're likely going to be able to convert patients more quickly and more effectively as we progress on that effort. And then, of course, the refills will continue to help drive that. But I do think from time to time, conferences, weather, et cetera, are certainly going to affect it, considering that even at our steady-state 20% refill rate, we're still primarily NRx driven. So you'll see that across every brand. We're probably just as susceptible to it, given the NRx dynamic. But certainly, the long-range view here looks really great, given the drivers I've outlined.

Operator, Operator

Our next question comes from Jason Gerberry with Bank of America.

Bhavin Patel, Analyst

This is Bhavin Patel on for Jason Gerberry. First on the gross to net side, you landed at about 44% for Q4. I know that Q1 typically has the reset pressure. But as we look at full-year 2026, where do you see that steady-state gross to net settling out? Are there any favorable dynamics potentially offsetting the Q1 pressures?

Jeffrey S. Farrow, Chief Financial Officer

Yes, you are right, we do expect some pressure on the gross-to-net discount in Q1 as most manufacturers will face this quarter. But we do expect it to fundamentally be around where we have guided for long-term gross-to-net discount, which is in the 43% to 45% range. As you highlighted in the fourth quarter, we exited at 44%. We'll probably get to that range in the middle of this year. So we'll see a stepwise decrease in Q2 and then fundamentally get to that sort of lower end of the 43% to 44% to 45% range.

Bobak Azamian, CEO

And Bhavin, this is Bobby. Thanks for the question about $2 billion. We have gotten a lot of people interested in what's the potential of XDEMVY, and we're really excited to be able to talk about that today. What’s really changed there is that we have a great view of how XDEMVY is performing now two years in. We know that this is a breakthrough. We've served only 0.5 million patients with this medicine. There are 25 million Americans with DB. So that represents less than 10% penetration, that $2 billion-plus figure. We also have transformed the practice of eye care in general, and that's allowed doctors to look beyond those segments to all their patients. They're starting to look at all their patients and recognizing the importance of DB. And then, to your point, there's just continued flawless execution across the board with our commercial effort, education, access, and evidence. You mentioned a couple of things there that we're going to continue to execute flawlessly on. So that's allowed us to rewrite the playbook and confidently say this is a $2 billion-plus medicine.

Operator, Operator

Our next question comes from Lachlan Hanbury-Brown with William Blair.

Lachlan Hanbury-Brown, Analyst

I guess the first maybe on the DTC campaign. You said that you've seen a great response. It's got a positive ROI, and it's probably achieved that earlier than you had expected. So just curious on the thoughts of is it worth putting more behind that, investing more money in a DTC campaign, and how you thought about that and sort of land on $80 million being the right level of spend for that?

Aziz Mottiwala, Chief Commercial Officer

Yes, thanks, Lachlan. You're absolutely right. The DTC campaign so far is performing exceptionally well, ahead of our expectations in terms of timing to reach that positive ROI, which confirmed our rationale to continue to advance that in 2026. When you think about what's driving the improvement in ROI in '26 and why we're excited about that, there are a couple of factors. One, now you've got one in four patients aware. Two, you've got doctors actively looking. These two things, along with our ability to execute, are going to allow us to really scale that ROI impactfully. It's a compounding effect, if you will. We should be able to convert those patients more quickly and more effectively. $80 million feels right. Ultimately, where we're making a slight incremental investment is actually with the sales force because ultimately, the physician writing the prescription. We think that getting the patients into the practice is important, but continuing to support that deepening of prescribing and utilization is another factor. So we're sort of hitting on both sides of the funnel, if you will. We're driving patients at the top and really investing in converting as many of those patients as possible. As we sit today, we feel really good about the outlook on converting patients from DTC, but also improving the physician dynamics and building on that momentum as well. So TBD, I think long-term, we feel really good about the investment level, and we've got the right things in place to capitalize on it.

Lachlan Hanbury-Brown, Analyst

Great. And maybe a second on the Lyme disease program. Can you give any more details on what that study looks like, what the endpoints might be, how long it would be, and what sort of duration of treatment is?

Seshadri Neervannan, Chief Operating Officer

Yes, Lachlan, this is Sesha. Thanks for the question. So Lyme disease is a Phase IIb trial, as we said, about 700 participants. We plan to enroll them in one peak season. Beyond safety, which is an important part of a prophylactic program, we are looking to measure other measures. One of the key ones is the blood level of lotilaner, which we want to see that could really translate into our confidence in the overall effectiveness of TP-05. The purpose of the study is to generate data that gives us a strong Phase III readiness package, gives us additional confidence on the program, and in a large enough population that can give us directional input to a Phase III study.

Operator, Operator

Our next question comes from Jenna Davidner with Barclays.

Jenna Davidner, Analyst

Just on the operating expenses, which I think came in a little bit ahead of what people were modeling, and it makes sense given the R&D and the investments in sales and marketing. I was just curious, maybe looking beyond 2026, would you expect a similar level of step-up going forward? Or is there a point in time where maybe the increase in OpEx spend would moderate a little bit?

Jeffrey S. Farrow, Chief Financial Officer

Thanks, Jenna. This is Jeff. Great question. We don't expect a big step-up, absent a major change in the business. The only thing I would continue to think about is certain variable costs that will continue to increase with revenues increasing. There are certain things that we pay in terms of pharmacy fees, fees to run the co-pay program, and also patient support programs that will increase with increasing revenue. So that would be the main item there. The other thing that we could explore in potential out years is maybe a reduction in DTC spend. We'll have to see how that experiment plays out, but there could be potential for us to pare back on it or pulse it or something like that. But that's more of a '27 and beyond type of question. But big picture, no material step-ups in the out years, absent a material change in the business.

Operator, Operator

Our next question comes from Matthew Caufield with H.C. Wainwright.

Matthew Caufield, Analyst

Great to see the continued progress. I appreciate the question. There was obviously a mention of the European preservative-free formulation in 2027, the discussions in Japan, and the potential partnered approval in 2026 in China. Can you tell us a little bit more about these opportunities and how these markets compare in terms of anticipated prescriber receptivity overall?

Aziz Mottiwala, Chief Commercial Officer

Yes, thank you for that question. When we look at ex-U.S., what's really interesting is the overall dynamics are very similar to the U.S. The prevalence of the disease is pretty consistent regardless of the geography. In most of the markets, the treatment paradigm is very similar to what we saw in the U.S. prior to the launch of XDEMVY, where doctors are aware, they're typically using palliative approaches, and are really eager to have a definitive cure or treatment for the disease. Furthermore, the positive U.S. experience is getting out there. As we mentioned, doctors like to hear from each other. I've been to a few of these European conferences, and the European doctors are really excited about what they're seeing their U.S. colleagues do with XDEMVY. So there's a lot of interest and excitement around the market opportunity. The market dynamics are very similar, albeit there are always differences in pricing and reimbursement, but the patient and physician dynamics are very similar. Ultimately, the pricing and reimbursement dynamics will sort of dictate our go-to-market approach, which we're currently evaluating in each of those markets.

Operator, Operator

Our next question comes from Dennis Ding with Jefferies.

Unknown Analyst, Analyst

This is Anthea on for Dennis. Congrats on the quarter. In terms of the peak sales guidance, can you talk about when you expect to achieve that $2 billion in sales? And if that would be before 2032 and when your composition of matter patent expires? Is there some more room beyond that based on your secondary patents out to 2038? And then secondly, on ocular rosacea, can you talk a little bit more about what a meaningful trend on erythema would be and if there's a scenario to hit stat sig there?

Bobak Azamian, CEO

Thank you very much. This is Bobby, and I appreciate the question. It's a little early to say exactly when that peak is going to be hit. What we see is we're two-plus years into the launch, and we've seen continued incredible growth and continue to see no slowing of that growth. So we're about a couple of years from $1 billion plus, and we see no signs of slowing down. All these metrics that we've talked about on the commercial side continue to be very, very strong. So that's what I can say about the peak, and I'll pass to Sesha to talk about ocular rosacea.

Seshadri Neervannan, Chief Operating Officer

Yes, thanks, Bobby. Can you please repeat that question so I can clarify that?

Matthew Caufield, Analyst

Yes, for sure. In terms of ocular rosacea, what do you see as a meaningful trend on erythema and if there’s a scenario to hit stat sig on that endpoint?

Seshadri Neervannan, Chief Operating Officer

Thank you. This is the first-ever trial in ocular rosacea, and we are not new to this paradigm. We have done this well before, developing new clinical measures. In addition to erythema, we are also looking at telangiectasia, which are prominent blood vessels. These are the hallmark signs of the disease. When we talk to the ECPs, given that there are no approved treatments, what they're looking for is any improvement in these conditions. It’s very meaningful for them, and that’s exactly what we are focused on. We have alignment with the FDA on these two measures. What we are striving to show is an objective improvement on these measures. We'll continue to evaluate the data and move it forward with continued conversations with the FDA.

Operator, Operator

Our next question comes from Andreas Argyrides with Oppenheimer.

Andreas Argyrides, Analyst

Congratulations on your success and progress in 2025. Most of my questions have been addressed, but I have a couple more. You mentioned the seasonal dynamics while providing your strong sales guidance. Could you share more insights on those seasonal trends? Also, if you make advancements in both the ocular rosacea and Lyme disease programs, what do you estimate the costs of those pivotal studies will be?

Aziz Mottiwala, Chief Commercial Officer

Yes. The seasonal dynamics are what you typically see across the industry. As we move further down the launch curve here, we'd expect XDEMVY to be part of that typical seasonality. There are a few dynamics here: There's resetting co-pays, there's deductible resets for both patient visits. So you're thinking about fewer patients going into the office, and those that are going in the office are paying more out of pocket. It affects both the demand as well as the gross-to-net, which Jeff alluded to earlier. What we do see is that, that is already starting to work its way through. If you look at the most recent weeks in the IQVIA data, which most people track, we are seeing a positive trajectory in the last few weeks, and we expect that to continue outside of anything unexpected. Once you're past the bulk of the season and the weather, you start to see people come back into the eye care offices, and you start to see conversion of those scripts. All the signs we're seeing are great. When we go to the conferences, the doctors are telling us there’s no end in sight. You've seen a lot of utility and success with the product, and we see that in the numbers that we analyze. The doctors are looking for more and more cases. We think rolling out our key account leaders will help facilitate that, and they'll be out there in the back half of the year. We expect that to pay for itself. These are some key drivers, and we've talked a little bit about DTC earlier as well. We'd expect all the things we're doing to continue to amplify the growth. The Q1 dynamics are going to play through, but absent that, we expect a really strong year in line with the guidance that Jeff provided.

Bobak Azamian, CEO

And Jeff, do you want to talk about the pivotal potential costs for OR in line?

Jeffrey S. Farrow, Chief Financial Officer

Yes, so Andreas, the OR study is expected to cost somewhere between $7 million and $10 million, with the majority of those costs incurred in 2026. For the Phase III or Phase II Lyme study, somewhere in the range of $25 million to $30 million with most of those costs coming in during 2026 and a few trailing over into 2027.

Operator, Operator

Our next question comes from Graig Suvannavejh with Mizuho.

Graig Suvannavejh, Analyst

Congrats on the quarter. Two questions, if I could. Just one, could you just go into XDEMVY current prescribing trends and differences happening between the two segments, ophthalmologists, and optometrists? And then secondly, just a follow-up on the peak sales guidance. Any way you can provide color on the U.S. versus ex-U.S. kind of split there?

Aziz Mottiwala, Chief Commercial Officer

Yes, great, it's Aziz. I can provide a little bit of color on both of those. In terms of the prescribing dynamics, what we're excited about is the continued depth of prescribing. We’re seeing this across both ophthalmology and optometry. I'll remind folks that our split is roughly two-thirds optometry and about one-third ophthalmology, with both segments growing strongly. When we think about depth of prescribing, we've seen some really good movement there. In the most recent quarter, we hit a stat of about 40% of our core target now prescribing weekly, meaning they're prescribing at least five a week. We saw a 20% growth in those that are writing at least five a week or what we call a daily writer. They're writing at least once a day. That grew 20%. So you've got about 40% of your total audience writing this with good regularity, and the fundamental heavy users are growing even more at 20%. There are good signals there, and that’s across both of those segments. We feel good about the prescribing dynamics. We think about the utility of expanding that effort further with the key account leaders. Of course, thinking about the effort that DTC has there, right? Every time a patient comes in from DTC, that’s actually pulling from our 25 million TAM into that 9 million TAM. So you're expanding the funnel, as we mentioned earlier. So that's going to help continue to facilitate that depth of prescribing.

Graig Suvannavejh, Analyst

Got it. As a follow-up, is there any way to provide insight on what the ex-U.S. component might look like? I understand it's early days, but any information would be helpful.

Jeffrey S. Farrow, Chief Financial Officer

Graig, it's Jeff. Yes, it is a little bit challenging, particularly given some of the dynamics that we're facing with MFN. What we're doing is making thoughtful investments along the way to do ECP education, get engaged with patient groups, and do everything we can before crossing the Rubicon and really launching over there. So we're monitoring that. Big picture, I think a good proxy is typically 90% U.S., 10% rest of world. That could be something you can think about. I would say Japan is probably a little bit higher on the opportunity scale than maybe Europe is, but I think that for modeling purposes, that would probably be a good model.

Operator, Operator

This concludes today's question-and-answer session and the conference call. Thank you for participating. You may now disconnect.