Mirum Pharmaceuticals, Inc. Q4 FY2025 earnings call

2025 was a year of disciplined execution and growth. Merham is entering 2026 with confidence, expecting net product sales of $630 to $650 million. They advanced their pipeline through important clinical and regulatory milestones, like the approval of Citexly for CTX and enrollment completion of the VISTA study of Elixabat and PSC. They expanded the pipeline with the Phase 3 Brolovitac Program for Chronic Hepatitis Delta Virus. Integration of the recent transaction has progressed smoothly. There are four potentially registrational clinical readouts expected in the next 18 months, and enrollment in various studies continues to exceed expectations.

In 2025, Merham Pharmaceuticals delivered $521 million in net product sales. Litmarli had net product sales of $245 million in the U.S. and $115 million internationally, while bile acid medicines contributed $161 million. The fourth quarter of 2025 had net product sales of $149 million, compared to $99 million in the prior year. Full - year 2025 net product sales were $521 million, representing 55% year - over - year growth. Total operating expense for the year ended December 31st, 2025 was $543 million, with R&D expense of $186 million, SG&A expense of $257 million, and cost of sales of $100 million. The commercial cash contribution margin in 2025 was approximately 55%.

Merham expects to deliver net product sales of $630 to $650 million for 2026. In 2026, R&D expense is expected to increase, primarily driven by investments in the Berlowitac Clinical Program and manufacturing validation and scale - up for an anticipated BLA submission next year. Merham expects a return to positive cash flow in 2027.

Forward - looking statements involve risks and uncertainties that may cause actual results to differ materially from those discussed. Refer to the risk factors in the latest Form 10 - K and subsequent SEC filings for more information about these risks and uncertainties.

Q: Hey, thanks for taking my question and congrats on all the progress. I actually wanted to ask one on Belixibad and specifically as it relates to the commercial opportunity. You know, obviously, Velixibat's coming first. And I think generally a lot of people are thinking about pricing in the context of Velixibat around the PPARs in terms of the PBC opportunity. And just curious as you guys are, you know, getting closer to data and potentially commercialization, kind of how you're thinking about the right way to price Velixibat and if, you know, pricing specifically around the PSE opportunity is kind of on the table or makes sense.

A: Yeah, thanks, James, for the question. This obviously is something we spend a lot of time thinking about. And kind of as you're saying your question there, the PPARs and PBC really are a good planning benchmark to think about, but that's certainly not our final guidance or decision on it. We'll take that as we have data in hand and are closer to launch to make the final decision. And one of the big factors to keep in mind here is that unlike in PBC – There are no other approved medicines, so really unique positioning for Velixibat. But, you know, we'll take that decision when we're at launch.

Q: Hi there. Good afternoon, and thank you for taking my question. Maybe one on the upcoming PFC trial, our care wells are hinting that maybe the itch associated with PFC patients can be a little bit more episodic. Maybe do you see that as providing a little bit more risk into this study versus what you're seeing in PBC? And maybe what have you done in the study, whether in terms of the patients that you're enrolling or monitoring, do you think that can maybe help limit any variability there?

A: Yeah, thanks for the question there. A couple things to comment on that I'll lead in. I'll let Joanne speak a little bit to some of the study design elements. And what we find in market research that's more directed at patients and some of the advanced practitioners that may spend more time with patients is a different perspective on pruritus than what you get from some of the top KOLs who may actually just be seeing the patient episodically when there are other more complicated factors. And in conversations with patients and some of the advanced practitioners, you do get a different picture of how persistent the pruritus can be and also just the proportion of patients that are actually dealing with it being quite different than, you know, might be the perspective of a KOL at a top center. But then on study design, I'll let Joanne speak to some of the things that we've seen from screening and the overall operational side. Yeah, thanks. Thanks for the question. A couple things. Actually, we know that pruritus is an issue for a lot of patients. And then this is really from some work that we did with, you know, Chris Cowley a few years back presented to EASL that, you know, a really high proportion of patients do complain of pruritus and fatigue as the main symptoms associated with their PSC. And then perhaps about half of them said that it's disrupted their daily life activities. So pretty significant. Within the study, we are enrolling patients with persistent pruritus. And so, you know, we're careful to have that as eligibility, and therefore we track the pruritus response throughout the study. So, you know, understand kind of the basis for your question, but I think, you know, between study design and also understanding the patient population a bit better, we feel comfortable that this is really designed to address a significant symptom for patients, a significant impact in terms of their daily lives.

Q: Hi, everyone. Thanks for taking my question. I wanted to dig more into the study design for PSC. If you could highlight some the key similarities and differences between VISTAs and the Vantage study designs. And you mentioned that you expect general patients with persistent pruritus, but just wondering whether we should expect the baseline pruritus scores for the PSC study to be in a similar range to what we saw in the PBC interim data.

A: Yeah, so thanks for the question. So I think, you know, the commonality is that we're really studying closed - static pruritus. which is something that we know well and have characterized, you know, with the other indications that we have for Merylixibat, for instance. So, you know, we know how to measure this. We know, you know, how to implement that within a clinical trial. You know, PSC and PBC are different diseases in terms of the etiology, but we think the commonality here is the fact that there is cholestasis, intrapatic cholestasis, and then, therefore, cholestatic pruritus. So there's a lot of commonality in terms of how we implement it within the trial. I think, you know, probably the best guide in terms of what the baseline pruritus is is if you look at the PBC interim, and that shows significant pruritus. I mean, clearly within the range of moderate to severe pruritus for baseline. So I think that's kind of our expectation. We're selecting patients with moderate to severe pruritus at baseline to study in both of these studies.

Q: Hey, thanks for taking the question. Piggybacking on the PSC questions, can you talk a little bit about your interactions with FDA around safety database requirements for the and what follow - up you'll need and what that means for timing of a potential MDA submission?

A: Yeah, I can jump in on this one. Thanks for the question, John. A lot of this kind of goes back to some of the original pre - IND interactions we've had with FDA. And we've subsequently actually confirmed some of the safety database questions with them, in particular around PBC, in terms of what they want for overall safety database, and with acknowledgement that PSC is smaller. And so what we do expect that the current VISTA's PSC study has the sufficient safety database for the setting. So the idea is after our top - line data, we'll have an interaction with FDA on the submission plan, and I think we'll track to get it submitted in the second half of the year.

Q: Thanks a lot. Congrats on a big year. Looking forward to a busy cadence of catalysts this year. For the EXPAND readout coming later in 4Q this year, how are you – are you expecting to break out the data on pruritus by another second and other secondaries by indication? And are you looking at the pruritus bar here – how are you looking at the pruritus bar in general compared to what was shown in PFIC and AllerGel?

A: Yeah, overall, the mix of patients in this study, just as a reminder, we think it's probably ultimately going to end up being approximately half biliary atresia and then a much longer tail with other settings. So we'll look at whatever the most relevant ways to break it out are. Biliary atresia is an obvious one. The others are just much smaller, each of them individually. But I'd come back to the comment that Joanne was making earlier just on the commonality here being these are settings with elevated bile acids and cholestatic pruritus. So we see kind of the treatment objectives and the potential for response that we've seen in compassionate use examples having more in common than different across various settings.

Q: Hey, guys. You have Ryan on for Manny. Thanks for taking our question and congrats on the quarter. Maybe just sticking with expand, Chris, I'm curious how you think a positive readout here kind of plays out in terms of like the label expansion given it's more of a basket trial. And when we think about biliary atresia and the other indications, like how well diagnosed are these, or is this going to be more of a PFIC setting where you're going to have to improve diagnoses to really drive that additional growth?

A: Thanks for the question, Ryan. The thinking around label indication statement and the label, as you point out, it has some nuance because it's a basket. It's really defined by exclusion, right? I mean, we're The way that the protocol is written is it excludes the larger settings where you could run a standalone study to look at cholestatic pruritus and PSC, for example, as we're doing with Elixabet. So expect that to be reflected in the labeling. And could you remind me of the second part of your question? Yeah, just kind of like when you think about these additional settings, like how well - diagnosed. Are these, or do you think it's going to really take a lot of hand - holding and physician education to drive further uptake in these additional settings?

A: Yeah, actually, we think that, I mean, what we're seeing in particular in the pediatric settings is, you know, it's highly symptomatic, so it is diagnosed. And that's really what the origin for the study was compassionate use requests. So, you see, the demand is out there for something to help these patients. So I do see it as a pretty well - trapped patient population.

Q: Hi. Thanks for taking my question. This is Charles on for RK. So, I guess a question on the guidance from me. So, in 2025, the sales grew about 55%, and the guidance range implies a 21 to 25% annual growth. So, I was wondering if you could provide some color on how much of this is driven by Liv Marley versus the bile acid portfolio.

A: Yeah, I mean, the growth is definitely more Mali - driven. Keep in mind, though, that for Japan last year, we had $23 million in revenues, which was inventory buildup. And this year, we expect, therefore, lower revenues from Japan, although I should clarify that the launch in Japan is going as expected. In terms of the bile acid portfolio, we do expect continued growth, but it's more kind of steady growth, not accelerating the way the live model growth has been in the last few years.

Q: Hey, guys. Thanks for taking the question. Congrats on a great quarter and year. I just wanted to revisit the EXPAND study. Are there any learnings that you've taken away from Embark that you're going to be applying here based on the high proportion of biliary atresia patients? And could you just kind of help us contextualize the market represented by the EXPAND basket relative to PFIC and ALGS in terms of as well as the dose you anticipate using in this population.

A: Thanks for the question. And it's an important distinction from Embark, actually, to point out. As a reminder, the Embark study was looking at bilirubin levels in biliary atresia patients immediately after the CASAI procedure. So think of that as it's just a very acute setting where the goal would be to try to improve the immediate transplant rates. What we learned is in that very young infant setting after CASAI procedure, that the surgical procedure directed at bile flow actually is most determinative of outcome in those young patients. Now, what's different in EXPAND and in the biliary atresia patients in EXPAND is those are all patients that had a successful CASAI, and then over time they have what seems to be just a much slower progressing or persistent cholestasis that is not the kind of acute transplant - driving situation you see in the very young patients. So the biliary trees for patients that are enrolling into EXPAND are going to be, you know, think of it as toddler to school - aged that have a persistent post - casai cholestatic pruritus. So From the learnings there, it really comes back to what we saw in compassionate use, is that there are examples of patients being highly responsive to Lipmarly treatment with that profile. So that's kind of what inspired us to pursue this study, is seeing actual strong treatment responses in those older biliary atresia patients. And in terms of bridging that to market size, But because this is a basket, it's hard to – you can't use traditional epidemiology, so you can't look at literature or incidence rates, so to speak, because this is a long list of different potential causes of cholestatic pruritus. From the work we've done in the pediatric setting, it's clear that there's readily at least 500 patients in the U.S. that would fit the profile of this, potential for more. When we look at kind of the total peak Liz Marley potential of that billion plus that we see as the long - term potential for the brand, Xpand could represent a third of that overall.

Q: Hi, this is Rohit on for Mike. Thanks for taking our questions. Can you just talk about the current market for HDV and how you expect it to develop over the coming years? And then how much do you expect R&D to increase this year from the HDV studies?

A: Yeah, I'll speak to the market and pass it over to Eric to comment on the investment side. For the current treatment landscape for HDV, there really is nothing specifically labeled in the U.S. And one labeled medicine, Hepcludex, in Europe that actually has been performing well. We do expect that to evolve in the U.S. given from what we're seeing is that Hepcludex is up for review and potential approval in the U.S. and then also another dual - agent regimen looking at a HP surface damage and an SRNA approach in hepatitis delta. So this will be an evolving landscape. But what got us excited about Brilovitug as a potential for best - in - class profile is that with a single agent, you're seeing really impressive response rates, and a very attractive safety profile. It's 100% viral response at week 48. You know, that's 65% to 82% composite endpoint. It has a chance to really set the bar for treatment options in Delta, though there will be – we do expect to have other competitive agents in the market. I'm just excited about what Brilovatide can do compared to those. I'll pass it over to Eric on the P&L.

A: Great question. So the good news is that Brovovitac 4 Phase 3 studies are enrolling really well, which means that the expenses will be somewhat compressed into this year. It also means we need to make significant CMC investments to prepare for filing next year. So they are compressed, and in total, related to Brovovitac, we anticipate roughly $150 million increase. in R&D spend types to this program with, you know, about half being CMC.