Mirum Pharmaceuticals, Inc. (MIRM) Q2 2026 Earnings Call Transcript

Good afternoon, and welcome to Mirum Pharmaceuticals Second Quarter 2026 Earnings Conference Call. My name is Alexandra, and I will be your operator today. All lines are currently in a listen-only mode. There will be an opportunity for Q&A after management's prepared remarks. I would now like to hand the conference over to Andrew McKibben, Senior Vice President of Strategic Finance and Investor Relations. Please go ahead.

Thank you, Alexandra, and good afternoon, everyone. I would like to welcome you to Mirum Pharmaceuticals second quarter 2026 conference call. I am joined today by our Chief Executive Officer, Christopher Peetz; our President and Chief Operating Officer, Peter Radovich; and Eric H. Bjerkholt, our Chief Financial Officer. Lara Longpre, our Chief Development Officer, will be joining us for the Q&A portion of the call. Joanne Quan, our Chief Medical Officer, could not be with us today due to a family matter. Earlier today, Mirum issued a press release announcing the company's results for the second quarter of 2026. Copies of the press release and our SEC filings are available on the Investors section of our website. Before we start, I would like to remind you that during the course of this conference call, we will be making certain forward-looking statements based on management's current expectations, including statements regarding Mirum's programs, market opportunities for its approved medicines and product candidates, and financial guidance. These statements represent our judgment and knowledge of events as of today and inherently involve risks and uncertainties that may cause actual results to differ materially from the results discussed. We are under no duty to update these statements. Please refer to the risk factors in our latest Form 10-Q and subsequent filings for more information about these risks and uncertainties. With that said, I would like to turn the call over to Christopher. Christopher?

Thanks, Andrew, and good afternoon, everyone. At Mirum, we are growing a rare disease leader focused on delivering high-impact medicines for often overlooked diseases. This quarter demonstrates continued progress with strong commercial execution on our approved medicines as we head into the potential launch of our fourth commercial medicine later this year. We have a busy pipeline with multiple pivotal readouts in the quarters ahead, all delivered with the strength in capital structure and overall financial performance, giving us greater capacity to invest throughout the business. In the second quarter, our commercial business generated $176 million in net product sales, reflecting strong demand across the portfolio and excellent execution by our team. Based on this performance, we are increasing our full year 2026 net product sales guidance to $680 million to $700 million. Fueled by the strong commercial performance, we are driving towards the next phase of Mirum's growth with multiple milestones over the coming months. Our next commercial milestone will be the potential launch of zilurgisertib for fibrodysplasia ossificans progressiva (FOP) with the PDUFA date next month. This is fast progress for a program added to our rare genetics business only in the second quarter. Peter will cover more of the launch profile in his remarks. Moving to the pipeline for our rare liver business, it is important to spend some time today on volixibat and primary sclerosing cholangitis (PSC), which just had some key U.S. regulatory interactions. First, as a reminder of the background of the study of volixibat in cholestatic pruritus in PSC, we designed this adaptive study with input from the FDA as a pivotal trial for this difficult clinical setting, including alignment on study duration, endpoints, and analysis plan. As we have announced previously and presented at EASL this year, VISTA met its primary endpoint showing highly significant improvements in pruritus in the primary cohort, with consistent significant results also observed in a second cohort of patients with milder baseline pruritus. We are excited to share that the FDA has now granted Breakthrough Therapy designation for volixibat in cholestatic pruritus due to PSC based on these strong results. We see this as recognition of the potential for volixibat to address a serious unmet need in PSC. As planned, we recently held a pre-NDA discussion with the agency about the submission of an NDA based on the VISTA study. In the meeting, the FDA recommended conducting a Phase 3 study. We believe the VISTA study provides a robust and clear dataset to characterize the use of volixibat in patients with pruritus due to PSC, and is a clinically and statistically highly persuasive study. VISTA is the largest randomized clinical study conducted in patients with pruritus due to PSC with an extensive overall data package that includes more than 180 PSC patients, randomized 1-year safety exposure data for over 100 PSC patients and growing, results from an independent committee evaluating liver safety, all totaling over 600 subjects across the clinical program to date. So while we are not currently aligned on the NDA submission package, we will be engaging in discussions with the FDA on how to further supplement our planned submission based on the VISTA study. This engagement will delay the planned timing of our NDA submission, which we are now targeting for the first half of next year. We are positioned to move quickly once we have further clarity from the agency. We will provide updates as we work towards our goal of bringing a much needed therapy to this unaddressed clinical setting. In parallel, the VANTAGE study in primary biliary cholangitis (PBC) is progressing well and has completed enrollment, reaching over 330 patients randomized. In PBC, our earlier Breakthrough Therapy designation has enabled more dialogue with the agency during the conduct of the study. We have recent feedback from FDA for VANTAGE to serve as a pivotal study of volixibat in pruritus due to PBC if the study is successful at its Q1 top-line readout next year. Our next clinical readout for the rare liver business is expected to be volovitug's AZURE-1 top-line results later this quarter. This is the readout of the Phase III portion following strong results in the Phase IIb portion earlier this year, and we also continue to expect the AZURE-4 data in Q4, which keeps us on track for a potential BLA submission for this Breakthrough Therapy-designated program in the first half of next year. Rounding out the rare liver pipeline highlights, the Phase III EXPAND study of Livmarli in additional rare cholestatic conditions remains on track for top-line data in Q4. Putting this all together, we are advancing these clinical programs from a position of financial strength. Our commercial business continues to generate meaningful cash, providing the capacity to invest in potential launches, clinical development, and opportunistic business development where we see a compelling strategic fit and the potential to create value. I am proud of the team's progress and the promise of our current medicines and pipeline. I am excited about what lies ahead for Mirum. With that, I will turn the call over to Peter to discuss our commercial performance and launch readiness in more detail.

Thanks, Christopher. The second quarter was another strong quarter for Mirum's commercial business, with total net product sales of $176 million for Livmarli and the bile acid medicines. Both continue to perform well, and based on the demand we see, we are increasing our full year 2026 net product sales guidance to $680 million to $700 million. Second quarter net product sales for Livmarli were $129 million, with the U.S. contributing $92 million. Alagille growth remains durable, supported by continued new patient starts, sustained persistence on therapy, and weight-based dose increases. PFIC continues to be an important driver of growth, fueled by new diagnosis. We are particularly encouraged by the growing contribution from adult PFIC patients. We are seeing an increase in prescriptions from adult liver providers as awareness of later onset PFIC grows and genetic testing becomes more routine. Based on claims data as well as insights from two years in market, we now estimate an addressable adult PFIC population of at least 2,000 patients in the United States with likely a similar number in Europe. Because genetic testing remains less established in adult practice, these 2,000 addressable patients do not yet have a PFIC diagnosis, and we see a meaningful opportunity to continue expanding diagnosis through education. Internationally, Livmarli continues to grow across our direct and partner markets, contributing $37 million for the quarter. We are seeing contributions from established markets and expanding reimbursement in additional geographies. On the rare genetics side of the business, our bile acid medicines continue to provide steady contribution, generating $48 million in net product sales for the quarter. Our rare genetics business is also poised for growth with the recent addition of zilurgisertib for FOP. Data from the pivotal Phase II PROGRESS study of zilurgisertib presented at ENDO showed a compelling clinical profile in FOP patients ages 12 and older. Based on the strong efficacy observed and the convenience of oral dosing, we believe zilurgisertib has the potential to offer an attractive profile to patients with this severely debilitating disease. If approved by the FDA, the initial launch opportunity is expected to focus on patients ages 12 and older, with potential future expansion into younger patients supported by additional cohorts in the PROGRESS study. Following a recent late-cycle meeting with the FDA, we believe the NDA is proceeding as expected toward the September PDUFA date, and we are preparing for potential U.S. launch in Q4. The U.S. launch will heavily leverage the rare genetics team we have in place now that currently markets our bile acid medicine, as the physicians who manage FOP are largely concentrated in the same specialized centers where Livmarli and CHOLBAM are prescribed, building on the efficiency of our rare genetics business. Also, a marketing application for zilurgisertib has been submitted in Europe, and we will provide updates as this filing progresses. Overall, we are pleased with the continued execution across the commercial organization. We are seeing strong demand throughout the existing portfolio while making the investments necessary to support the next wave of potential launches. We believe that we are well positioned for the remainder of the year and beyond. With that, I will turn it over to Eric to discuss the financial results.

Thanks, Peter, and good afternoon, everyone. Today, I will walk through the financials of another excellent quarter from Mirum. Net product sales for the second quarter were $176 million compared to net product sales of $128 million in the second quarter of last year. Cash, cash equivalents, and investments as of June 30 were $561 million compared with $391 million at the beginning of the year. In the second quarter and first half of 2026, the cash contribution margin from our commercial business was in the high-50s percent, approximately a 5 percentage point improvement over the year before. Total operating expense for the quarter ended June 30 was $290 million, $19 million of which includes $16 million of in-process R&D expense associated with the upfront payment for licensing zilurgisertib. R&D expense was $76 million, including $29 million related to the development of volovitug; SG&A expense was $66 million; and cost of sales was $23 million, all excluding stock-based compensation expense and intangible amortization. Stock-based compensation, intangible amortization, and other noncash expenses totaled $37 million for the quarter. Operating cash flow was positive in the second quarter despite the expected increase in R&D expense. During the quarter, we significantly improved our capital structure through the issuance of $690 million aggregate principal amount of 0% coupon convertible notes due in June 2032. Net proceeds from the offering were $672 million. In conjunction with this financing, we settled 75% of the outstanding 2029 notes, added $197 million of cash to the balance sheet, and significantly reduced our interest expense. These transactions further strengthen our balance sheet and extend our financial flexibility to execute our strategy. Our commercial business continues to scale and our pipeline includes multiple near-term value drivers. With that, I will turn the call back to Christopher for closing remarks.

Thanks, Eric. Taking stock of where we are, we are continuing to drive our strategy to bring important medicines to underserved rare disease patients. Commercial business is thriving, now tracking towards $680 to $700 million in net product sales for the year. Livmarli is well on its way to realizing its over $1 billion peak revenue potential, and our rare genetics team is thrilled about the potential launch of zilurgisertib for FOP patients in the coming months. On the pipeline, we are focused on a collaborative discussion with FDA on the VISTA study in PSC. Clinical results are clear, and Breakthrough Therapy designation gives us further opportunity to engage with FDA. All said, we have a plan to advance volixibat for PSC patients. The balance of the pipeline is firing on all cylinders. Recapping our upcoming clinical milestones, we expect clinical readouts from the Phase III AZURE-1 and AZURE-4 studies of volovitug over the balance of the year, which will enable our planned BLA submission in the first half of next year. Next quarter, we also expect to announce top-line results from the EXPAND study of Livmarli in additional rare cholestatic diseases, setting up the potential for an sNDA next year as well. And into 2027, we expect top-line results from the VANTAGE study of volixibat in PBC in Q1. Finally, we are on track with MRN-338, with proof-of-concept data in fragile X syndrome next year. Importantly, we are building an organization capable of reaching many more people living with overlooked rare diseases while delivering strong financial performance. I want to thank the Mirum team for their continued focus and execution, and the patients, families, and physicians who continue to partner with us in this work. With that, operator, please open the call for questions.

We will now begin the question-and-answer session. Please limit yourself to one question and one follow-up. If you would like to ask a question, please press *1 to raise your hand. To withdraw your question, press *1 again. We ask that you pick up your handset when asking a question to allow for optimum sound quality. If you are muted locally, please remember to unmute your device. Please standby while we compile the Q&A roster. Your first question comes from the line of Ryan Deshner with Raymond James. Your line is now open. Please go ahead.

Hi. Good afternoon. Congrats on the strong results. Curious what your overall take is on the potential read-through from the BOLD study evaluating odevixibat in patients with biliary atresia? And I have a follow-up question.

Thanks, Ryan, for the question. The BOLD study and the study of note in our pipeline that includes biliary atresia patients, the EXPAND study, are asking very different questions. I would equate the BOLD study more to what we ran previously with EMBARK, looking at patients in the very acute setting trying to reduce bilirubin or extend transplant-free survival. The question we are asking in EXPAND ties much more to where we have seen IBAT perform quite well in other settings. We are looking at older patients than what was in BOLD and in EMBARK and evaluating pruritus changes. It is something that we have seen an impact from IBAT therapy repeatedly in different clinical settings. So we feel there is not really a read-through or connection between BOLD and what we are looking at in the upcoming EXPAND readout. I appreciate the follow-up. On the PSC regulatory discussions, we did extensively discuss the VISTA study design with FDA back in the pre-IND setting; the FDA acknowledged that pivotal intent, described the design as reasonable, and gave direct feedback on duration, analysis plan, and other aspects that designed the study we read out successfully earlier this year. In the meeting we recently held, there was a new team from FDA, so we think there is a lot of work to get them up to speed on the backdrop here — the history of designing and conducting VISTA and what the study means in a PSC setting. We think it will be an iterative approach to get them up to speed with the current data package and the history of the program. Very helpful. Thanks, Ryan.

Your next question comes from the line of Gavin Clark-Gartner with Evercore ISI. Your line is now open. Please go ahead.

Hey, thanks for taking the questions. First, what was this new FDA team's rationale to conduct an additional Phase 3? Was it more of a safety database question, or was it more around the efficacy side?

Thanks, Gavin. The comments about a Phase 3 recommendation from them were not specific, so we do not have great clarity on what specifically they are looking for. There were general comments across the board on efficacy, which we think VISTA very clearly addresses, and the agency actually commented on that in the meeting. On the safety side, in the discussion, the things that were brought up included IBS-like GI effects and liver safety. Those were designed into VISTA as key things to evaluate. So we think it is all there in the VISTA study; this is more about familiarity with the study design and some of the questions that were asked. Another thing to point out is that the Breakthrough Therapy designation was issued after the meeting, which gives us a great opportunity to go back in and build up familiarity with this dataset and work toward an NDA. In terms of prior engagement with this specific FDA team, often correspondences are written so you do not have perfect clarity on who is behind some of the written correspondence. Some interactions were written, others were in person. The pre-NDA meeting was in person. In terms of precedent for approval based on a Phase 2b-type data set, we have looked across IBAT settings — from Alagille approvals based on a short randomized withdrawal design to the more recent Livmarli approval in PBC pruritus with a six-month placebo-controlled study that looks similar to VISTA. There is clear precedent for IBAT in cholestatic pruritus settings that line up with VISTA, which informed how we designed the study in prior conversations with the agency.

Your next question comes from the line of Rohit Bhasin on for Mike Ulz with Morgan Stanley. Your line is now open. Please go ahead.

Hi. This is Rohit Bhasin on for Mike. Thanks for taking our questions. Just based on your conversation with the FDA, do you see any read-through to the PBC VANTAGE study? Is it possible they will request a Phase 3 trial for that one? And also, in terms of commercial prep for FOP, can you talk about where you currently stand and what is outstanding?

Thanks, Rohit. I will speak to PBC and then pass it over to Peter to talk about FOP. On the VANTAGE study, as you may recall, we were granted Breakthrough Therapy designation after the interim analysis in 2024, which gave us an opportunity to have conversations similar to what we expect to go through here with VISTA. In the correspondence after the Breakthrough designation on VANTAGE, we actually received pretty clear feedback from FDA on what we should do to consider VANTAGE a pivotal study, and we were able to address those. Primarily, the comments related to overall size, which is part of why we ended up with over 330 patients in VANTAGE, and also the analysis plan and specifics on how the pruritus endpoint is analyzed. I will pass to Peter to address commercial preparation for FOP.

Rohit, with regard to commercial preparation for zilurgisertib potential approval and launch in Q4, that is going very well. We were able to integrate it into our rare genetics team and have regional coverage in several territories. We have been doing typical prelaunch activities: profiling accounts and understanding where the treating physicians are. These patients are well identified; there are about 300 or so diagnosed and managed in the U.S. at highly specialized centers. We had a good presence at the ENDO meeting earlier this summer as well. So we are excited about the progress of the NDA review and working toward launch readiness in Q4.

Your next question comes from the line of Brian Skorney with Baird. Your line is now open. Please go ahead.

Hey. Good afternoon, team. I am going to be annoying and also ask about FDA's issues with VISTA, given that it seems like a pretty straightforward data set. Can you refresh our memories: is the review team here within the Division of Hepatology? Was Kati Donahue, the Office Director, involved in the meeting? Is Frank Anania still the Division Director and was he in the meeting? I mean, I hear they were not very clear about why they wanted Phase 3, but did they mention a need for replication? It just seems like the key value here is so robust that there is not really another question that could be answered with a Phase 3 other than maybe longer-term follow-up. Any guidance there is helpful. Also, maybe one thing on the PDUFA with zilurgisertib: I think you would have had the late-cycle review meeting in the last month or so. Any commentary on how that went and your level of confidence going into labeling discussions?

Thanks for the question, Brian. On specifics of who was in the room, office leadership may have changed and leadership was not in the room in our review meeting. Regarding efficacy, I think you are pointing out correctly that the VISTA data are convincing and address efficacy clearly. Given that Breakthrough Therapy designation came after the meeting, that is a nod in the direction of the data's strength. Some of the discussion points we see as addressable through iterative conversation with FDA. I hope that helps answer your question.

Brian, on the PDUFA: we did have the late-cycle meeting and it went very well. We feel the application is progressing well toward the PDUFA date, so it's all systems go to prepare for potential launch in Q4.

Your next question comes from the line of Yesha Patel with Wolfe Research. Your line is now open. Please go ahead.

Yeah. Hey. Good afternoon. Thanks for taking the question. One more on the regulatory interaction here. In your communication with the agency, has there been any dialogue so far on running a post-approval confirmatory study instead of running a Phase 3? Or should investors assume that a Phase 3 is what is in the works right now?

Thanks for the question. The direct answer is that the conversation with FDA did not get to the level of specifics for post-approval requirements. I can comment on the pathway: using pruritus as the basis for full approval means we do not expect a post-approval study in the sense of an accelerated approval confirmatory trial. What we would expect, and what has been added for other IBAT approvals, is some level of post-approval registry or long-term monitoring, which we think would be appropriate in this setting as well.

Your next question comes from the line of James Condulis with Stifel. Your line is now open. Please go ahead.

Hey. Thanks for taking my question and congrats on a great Livmarli quarter. Just one more on PSC. To clarify, is a Phase 3 on the table, or are you confident this can be resolved through iterations on the data? Just wondering what your base case is and what informs your confidence of guiding to a first half 2027 resubmission?

Thanks, James. As we considered the proposal for a Phase 3 given the VISTA results, the key question is what would you learn from another study in this setting. VISTA is the largest ever conducted in PSC pruritus with clear, definitive results and a substantive safety database for PSC. We do not see what would be gained by another large study. The weight of evidence is convincing, and Breakthrough Therapy designation provides a good platform to work through remaining items with FDA. That underpins our confidence that through iterative engagement we can move toward submission in the first half of 2027.

Your next question comes from the line of Lisa Walter with RBC. Your line is now open. Please go ahead.

Good afternoon. Thanks for taking our questions. One more on the NDA filing delay for volixibat: could this mean that we see more business development in the near term as potentially PSC revenues may now be pushed out? And could you add any clarity on whether the FDA is still accepting pruritus as an approvable endpoint?

Thanks, Lisa. On the second part first: there is absolute clarity that pruritus is an approvable endpoint. That is central to this discussion. On business development, we always approach BD as active and opportunistic, and this does not change our overall level of activity or criteria for opportunities we would consider. We will continue to evaluate BD when it aligns strategically.

Your next question comes from the line of Joe Schwartz with Leerink Partners. Your line is now open. Please go ahead.

Hi. Thanks. Hypothetically, if the FDA does not budge, does VANTAGE have any ability to strengthen the volixibat regulatory package for PSC? For instance, if a filing in PBC is an NDA and a filing in PSC as an sNDA, could that order of operations be successful without having to do another Phase 3? Also, did any baseline characteristics in the interim AZURE-1 cohort appear to correlate with better response in the Phase IIb portion? How do baseline characteristics for the full AZURE-1 population and AZURE-4 compare?

Joe, potentially. That is hypothetical and down the road, but the base plan is to get the PSC NDA submitted first. As we think about VANTAGE data, another large randomized study in a related pruritus condition could add weight, and how we approach parallel or sequenced NDAs is something we would consider if we end up in that scenario. Regarding the AZURE program and baseline characteristics: the quick answer is no, there was nothing obvious correlating with better response in the Phase IIb portion. We see response to volovitug across all patients and across baseline viral RNA levels, ALT levels, geography — consistently patients respond.

Your next question comes from the line of Jessica Fye with J.P. Morgan. Your line is now open. Please go ahead.

Hey, good afternoon. Thanks for taking my question. On volixibat, you referenced some options to supplement the VISTA trial. What could you supplement it with? Second, based on where things stand right now, what gives you confidence to outline first half of 2027 as the new PSC filing timeline?

Thanks, Jessica. In terms of supplementing the VISTA dataset, a straightforward element is the data cutoff timing: we can allow more safety data to accrue, for example reaching 100 patients at the 12-month mark in the open-label follow-up. That was one of the quicker items we could offer. Other items could include post-marketing registry commitments and long-term monitoring plans. On timing, we feel first half of 2027 is achievable because it allows room for an iteration or two with the FDA. It is less about time to prepare the submission — we can prepare quickly once we have the input — and more about the time needed for iterative dialogue with FDA based on our prior experience with similar submissions.

Your next question comes from the line of Joseph Thome with TD Cowen. Your line is now open. Please go ahead.

Hi there. Good afternoon, and thank you for taking my questions. Maybe in setting expectations, when should we hear next steps on the filing progress? What are you anticipating in terms of relaying your FDA interactions to the street? Also, your prepared remarks indicated that this necessarily will not flip over to PBC and that VANTAGE will be registrational; is this new group that conveyed the Phase 3 recommendation one point of clarification? And just one point on guidance: is there anything for FOP in your updated product guidance, or would that be above and beyond what you have outlined today?

Thanks for the questions. On updates, our view is this will be an iterative process; we will provide an update when we have a material update. We do not plan to share blow-by-blow written correspondence with FDA. On the PBC interactions, those were written correspondence, so we do not know exactly if it was the same exact people behind it, but the recency of the interactions gives comfort — they occurred over the past year. I will turn to Eric for guidance clarification.

On guidance: the $680 to $700 million full year 2026 guidance does not include FOP. So any revenue from zilurgisertib would be above and beyond that guidance, and we really expect the revenue to start more in 2027.

Your next question comes from the line of Jonathan Wolleben with Citizens. Your line is now open. Please go ahead.

Hey, Christopher. I am wondering if you could talk us through what this iterative dialogue looks like in terms of using Breakthrough Therapy designation or formal meeting status and scheduling of these interactions, just to set expectations on that flow of information between you and the agency.

Thanks, Jonathan. One of the benefits of Breakthrough Therapy designation is it allows for more frequent advice from FDA and more frequent interactions. That means we will be able to reach out more informally and also have more advice meetings. How those sequence out depends on how the dialogue progresses. We cannot be too specific at this point, but we will keep you updated as we make progress.

Your next question comes from the line of Ramakanth Swayampakula with H.C. Wainwright. Your line is now open. Please go ahead.

Thank you. This is Ramakanth Swayampakula from H.C. Wainwright. A couple quick questions: based on the interactions you have had so far for the PSC indication, are you planning to make any changes at all in your approach for the PBC indication once the VANTAGE data comes out? Also, if you do go ahead and submit in the first half of 2027 notwithstanding the recommendation, do you run the risk of a refuse-to-file situation? And if everything goes fine and you still continue to apply, would you expect an Advisory Committee?

Thanks, RK. In terms of PBC approach, given recent interactions we have direct input for that indication and feel it is on a good course; we would not make changes to what we are doing in PBC at this point. We have made recent adjustments to accommodate FDA's input, ensuring VANTAGE can be considered pivotal. Regarding the risk of an RTF, that is the reason for iterative interaction with FDA: to identify and address items that might pose an RTF risk. An Advisory Committee could be helpful given the significant clinical impact volixibat has shown in a terrible setting for patients; airing the case publicly could be informative. Thank you.

There are no further questions at this time.

We will now turn the call back to Christopher Peetz for closing remarks. Great. Well, thank you all for joining us today, and I hope you have a great afternoon.

This concludes today's call. Thank you for attending. You may now disconnect.