Thank you for your patience, ladies and gentlemen. The Mirum Pharmaceuticals Report 2023 Financial Results and Provide Business Update will begin in a minute. During the presentation, you have the opportunity to ask a question by pressing star followed by one on telephone keypad. Thank you for your patience. Ladies and gentlemen, welcome to the Mirum Pharmaceuticals Report Q1 2023 Financial Results and Provide Business Update. My name is Glenn, and I'll be the operator for today's call. If you would like to ask a question during the presentation, you may do so by pressing star one on telephone keypad. I'll now hand you over to your host, Andrew McKibben , to begin. Andrew, please go ahead.
Thanks, Glenn. Good afternoon, everyone. I'd like to welcome you to Mirum Pharmaceuticals Q1 2023 conference call. I'm joined today by our President and CEO, Chris Peetz, our Chief Operating Officer, Peter Radovich , and our Head of Research and Development, Pam Vig. Earlier today, Mirum issued a news release announcing the company's results for the Q1 of 2023. Copies of this news release and SEC filings can be found in the investors section of our website. Full details and updates from the quarter can be found in our news release and 10-Q issued today.
Before we begin, I'd like to remind you that during the course of this conference call, we will be making certain forward-looking statements about Mirum and our programs based on management's current expectations, including statements regarding Mirum's current and future business plans, development programs and regulatory expectations, strategies, prospects, market opportunities, and financial forecasts and guidance. Mirum is under no duty to update these statements, and they are subject to numerous risks and uncertainties, and actual results could differ materially from the results anticipated by these statements. Investors should read the risk factors set forth in Mirum's 10-K for the year ended December 31st, 2022, and any subsequent reports filed with the SEC. With that said, I'd like to turn the call over to Chris. Chris.
Thank you, Andrew. Good afternoon to everyone joining us on the call today. It's been another exceptional quarter for Mirum as we continue to advance our leadership position as a high-growth, rare disease company focused on life-changing medicines. Our clinical, regulatory, and business achievements in the Q1 , with total revenue of $31.6 million, are driven by our team's passion and expertise in addressing urgent unmet needs for patients with rare disease. With our five-part strategy to become a global leader in rare disease in place, we're pleased with the progress we've already made in 2023. First, we've continued to build on the successful launch of Livmarli in Alagille syndrome in the U.S., tracking well on our guidance of 50% year-over-year net product sales growth driven by new patient starts.
Second, our international business is also building well with the recent launch in Germany and early access programs in France and other international partner markets. We look forward to additional launches around the globe later this year and into 2024. Third, we've accomplished an important step in our strategy to expand the label for Livmarli. In the Q1 , we announced label expansion to include patients 3 months and older. In addition, we submitted a supplemental NDA and European equivalent with our positive Livmarli PFIC phase III data. Our team is preparing for the December 13th PDUFA date and is excited about bringing Livmarli as a new treatment option, advancing care for PFIC patients. We also anticipate providing top-line data from the EMBARK study in biliary atresia in the second half of this year, a third potential indication for Livmarli.
Fourth, in advancing into adult indications, we are conducting potentially pivotal studies for volixibat in Primary Sclerosing Cholangitis and Primary Biliary Cholangitis and look forward to providing interim updates from these studies in the second half of this year. In the fifth part of our strategy, we continue to evaluate opportunities across rare diseases to leverage Mirum's industry-leading capabilities. We also recently took a significant step towards enabling our strategy with convertible note financing of approximately $316 million aggregate principal amount. This financing enabled the repurchase of the nearly 10% royalty committed to our prior royalty investor and added additional growth capital to the balance sheet. We were excited to see the high level of interest in supporting our strategy in this well oversubscribed transaction. We continue to project that our balance sheet provides 3+ years of runway beyond cash flow breakeven.
We have started 2023 off with great momentum, and I'm excited about what the Mirum team is poised to achieve this year and beyond as we provide patients with life-changing medicines. With that, I'll pass the call over to Peter to discuss our commercial business in more detail before Pam gives an R&D update. Peter.
Thanks, Chris.
We are pleased with the $29.1 million in Livmarli net product sales in the Q1 of 2023, which included $24.7 million from the US and $4.4 million from international markets. The US growth was driven by the addition of new patients as well as a strong retail cadence. We're pleased to report that substantially all of the key pediatric liver accounts in the US have prescribed Livmarli. Based on their positive clinical experience and ease of access with Mirum Access Plus, healthcare professionals report that they intend to increase the use of Livmarli across their Alagille syndrome patients. Taken together, the US business performance is tracking well against our guidance for 50% growth in 2023 net product sales. Turning to international markets. In Q1, we launched Livmarli in Germany, and it's off to a great start.
We've already converted early access program patients to commercial drug. We have seen impressive de novo demand in line with what we saw in the U.S. launch. Pricing and reimbursement discussions are ongoing in major European markets, which we expect to unfold throughout 2023, with full launches in European countries beyond Germany starting in 2024. We expect name patient sales in European and distributor markets to continue throughout 2023, although we anticipate quarter-to-quarter variability in order patterns. In summary, Livmarli is in a strong position after a year and a half in market as the first and only treatment for Alagille syndrome that is providing rapid symptomatic relief and long-term improvement in outcomes. Livmarli is becoming standard of care in treating cholestatic pruritus with over 600 Alagille syndrome patients treated globally to date.
Clinicians have gained familiarity with and confidence in Livmarli's robust clinical profile, as well as its exceptional access and patient support. We believe this provides a strong competitive position, propelling a continued growth story in Alagille syndrome with exciting pediatric cholestasis indication expansion opportunities just on the horizon. On that note, I'll turn the call over to Pam. Pam?
Thanks, Peter. In the 1st quarter, we achieved important milestones in our pipeline that support the growth of our programs and ability to impact more patients. As a reminder, the central problem in all of these diseases studied in our pipeline is accumulation of bile acids. Across these cholestatic settings, IBAT inhibition has been shown to directly reduce toxic bile acid accumulation, the associated debilitating symptomatic burden. In Alagille, Livmarli showed improved long-term outcomes versus standard of care. The benefits of profound IBAT inhibition was shown by the impressive data from our MARCH-PFIC phase III study announced at the end of last year. We're happy to share that our supplemental NDA submission was accepted with the due date of December 13th of this year.
In April, we also submitted for approval of Livmarli in PFIC to the EMA for patients 2 months of age and older. The data from the MARCH-PFIC study proved our hypothesis, where greater IBAT inhibition using higher dosing regimens with Livmarli drove a highly statistically significant reduction in both pruritus and serum bile acids across the broadest range of genetic PFIC types studied to date. Early and statistically significant improvements in growth as well as in bilirubin were seen in patients treated with Livmarli, where 40% of patients with abnormal bilirubin levels at baseline normalized their bilirubin versus 0 in the placebo group. These data suggest an overall clinical improvement beyond pruritus for these patients, and we have heard strong positive feedback from the physician community, and if approved, look forward to the opportunity to expand Livmarli to a broad PFIC population.
We're also happy to announce that we remain on track for top-line data readout for our biliary atresia program for the second half of this year. This study will provide the first placebo-controlled data for an IBAT inhibitor in this setting. We're really excited to share more when the study is completed. As a reminder, the primary endpoint in the biliary atresia study assesses bilirubin at 26 weeks, as bilirubin is the most predictive marker of disease progression and transplant in this setting. The dosing regimen in the BA study is the same as the MARCH-PFIC study. The bilirubin improvements we observed in MARCH-PFIC are extremely encouraging as we look forward to our biliary atresia readout. Now turning to our pipeline programs in adult cholestatic indication.
We expect interim analyses from our studies of volixibat in both PSC and PBC in the second half of this year. We've previously shown that marked reductions in pruritus and serum bile acids can be achieved with IBAT inhibition in PSC, underscoring the potential for volixibat in this setting. Currently, there are no approved therapies for PSC, and roughly 60% of patients are being actively managed for pruritus with largely ineffective off-label therapies, none of which lower bile acids. Building off of our learnings from our pediatric programs, we are dosing at a higher level and BID dosing regimens, which adds to our confidence in these upcoming interim analyses. Finally, I'm proud of our team's academic and collaborative efforts as we continue to advance the benefit for patients from clinical studies to the real world.
We're committed to leveraging our deep experience across all of these cholestatic disease settings as we continue our scientific leadership. With that, I'll turn the call back over to Chris. Chris?
Thanks, Pam. Mirum is poised for continued growth throughout the years ahead. We anticipate that 2023 will be another transformative year with strong commercial growth.
Potential PFIC label expansion, top-line data of the first randomized data set of an IBAT inhibitor in biliary atresia, and interim analyses from our potentially pivotal volixibat studies. We remain excited about the growth prospects and potential of Mirum as we work to provide new medicines to patients with rare disease. With that, operator, please open the call for questions.
Thank you. Ladies and gentlemen, if you'd like to ask a question, please press star followed by one on your telephone keypad now. When preparing to ask your question, please ensure your phone is unmuted locally. We have our first question comes from Jessica Fye from J.P. Morgan. Jessica, your line is now open.
Hey, this is Nick on for Jess. Thanks for taking our questions. two quick ones for me. One, could you just talk about a little bit about the factors that resulted in that timing shift for the phase IIb VISTAS trial from mid-2023 to second half 2023? Is that more of a narrowing or a shift?
Yeah. Hi. I'm happy to answer that question. Thanks for the question. The reason for the delay in the PSC study is it's really a slight delay and mostly based on screen fails, there's a number of reasons why patients are screening out. One is a mix of lab values, some pruritus score compliance during screening, where they have to put in their pruritus scoring. If they're not compliant, they also get kicked out because we wanna make sure that they can remain in the study. Also some for itch score that is not meeting the minimum threshold to enter the study.
What we're doing with some of this is we've got plans on advancing tools and education on how we standardize training and interpretation of those itch scores and just continuing to drive forward, and we're starting to see more movement and good activity.
Great. As a quick follow-up, I know there have been some PBC trials in the past that have run into issues with high placebo responses on itch. Can you kinda just discuss how the VANTAGE trial is designed to help kinda mitigate those risks?
Yeah. Thanks for the question. In our PBC CLARITY study, as you know, we ourselves had a placebo response rate. We took those learnings, applied them into this study design. We baked some of that into the assumptions for our analysis, and we also adjusted our study design to accommodate for placebo failures and account for that. I don't think I can give specifics about the way that we're doing that in the trial, but we have thought very deeply about that and have taken that into account.
Great. Thanks so much.
Thanks for the questions.
Thank you. With our next question comes from Mani Foroohar from SVB Securities. Mani, your line is now open.
A quick question on biliary atresia. How should we think about the scale of the opportunity, both in terms of the number of patients, which I think is fairly well-defined, but also at what point would patients be treated, and how long would they be treated? Is the expectation here that you would pursue a lifelong study? Would you expect it from your clinical feedback that physicians, in the case of a successful study commercialization, would after 1 year, 2 years, some period of time, look to withdraw patients rather than leave them on drugs for life?
Thanks, Mani, for the question. I'll My one just kinda first comment, you know, biliary atresia is the most common indication for transplant in liver transplant in pediatrics. Really the, you know, in terms of scale of unmet need and impact it can have, this is a really important indication. I should ask Peter to maybe speak to a little bit of how to think about how this evolves over time and duration of treatment because there are some nuances on how we think this indication can build over time.
I think as you, as you think about that piece of it, Mani, the biliary atresia is, you know, more common than ALGS and PFIC by a fair bit when you think about it from an incidence perspective, probably on, you know, threefold more common on newborn incidence than ALGS. Because the dynamics that Chris is describing, there's much less of a prevalent pool there 'cause it's generally pretty rapidly progressive and heads towards liver transplant. So we'd envision in the kinda early years after approval, you know, the, you know, eligible patient population being, you know, kind of on the order of kids who are born, you know, within the last 12 to maybe 36 months.
As you know, if the drug does what we hope it does and get patients on therapy and again, hopefully, keep them from liver transplant, that would build over time and I think could be bigger than the other two indications.
That's really helpful. When we talk about what the drug hopes one can do, obviously there's a little less certainty around the regulatory dynamic here because you can't really ask trial stage. Give us a sense of how you think about target effect size, target product profile, and is there more certainty in your view on what you need to show for clinical uptake, or is that also a little bit up in the air as are regulatory questions?
Thanks for the question there. I mean, there's a couple of aspects to consider and, you know, in thinking about the regulatory conversations that we'll have after this data set is unblinded. Regulators are data-driven. They do have patient interest in mind. I think if we show a really convincing data set paired with advancing some of the understanding of the disease and the importance of bilirubin, which is some work we're also doing in parallel, that'll be the basis for a really good case and strong conversation on why the EMBARK study could potentially support approval in biliary atresia. We do need to generate that data, and that's all kind of baked into the study design.
I think the one thing that I'd point to in addition to the bilirubin data that Pam talked about from the PFIC study, just looking at mean change in bilirubin. There's also categories that are really well established on risk profile for transplant in terms of level of bilirubin at three months. We have a close eye on that, being able to down categorize patients on the bilirubin score. That's, you know, above 6, 2-6, and below two for bilirubin. You know, each step is a meaningful difference in risk of outcome. We'll look at those in a kind of responder or shift table format.
All right. That's really helpful. Thanks, guys.
Thanks for the question.
Thank you. With our next question comes from Steve Seedhouse from Raymond James. Steve, your line is now open.
Hi. Two questions from me. This is Ryan Deschner on for Steve Seedhouse. The first one, now that we're more than a year into the Livmarli launch, have you seen an appreciable step-up in sales due to the increases in average patient weight? How often are treating physicians adjusting, dose for growth and other reasons?
Thanks for the question. You know, what we see there is I think about once a year, patients are weighed and they're, you know, considered for dose increases. We do see dose increases in the real-world setting, consistent with the prescribing information for Livmarli. You know, really the majority though of the growth we're seeing is just de novo demand and new patient starts.
Excellent. Also, in what areas do you anticipate potentially being able to differentiate from competitor odevixibat in biliary atresia? Thank you.
Thanks for the question there. In terms of biliary atresia, you know, I think that, you know, time to having a randomized data set was a big part of our thinking and our strategy here. The EMBARK study on track to have data second half of this year will give us a really sizable lead in terms of having data on Livmarli, a really robust data set on Livmarli in this setting. We also have a feature of the study that is not in the bill-based study, where at six months, patients roll on to open label therapy. The effect of starting treatment later is really important to look at from the prevalent patients that are out there.
That's a really key part that we're looking at here. Lastly, you know, similar to what we've seen in the other settings, our higher dose of Livmarli, I think is, we expect to have a bigger clinical impact. I feel like we've really advanced our understanding of how to dose IBAT inhibitors and, you know, really think that that's gonna show up in our top-line data.
Thank you very much.
Thanks for the question.
Thank you. We have our next question comes from Debanjana Chatterjee from Citi. Debanjana, your line is now open.
Hi, and thanks for taking our call. I'm on for David Lebowitz from Citi. We were wondering if you could comment on the ex-US inventory build, and what should we expect in terms of the sales trajectory ex-US going forward?
Yeah. The, you know, In terms of the $4.4 million in sales we saw in Q1, you know, a lot of that was from Germany and Western Europe, where there's really very little, if, you know, effectively zero inventory, true demand sales there as we get started in those countries. We do have, you know, some other, the balance of the sales in international are named patient programs in distributor markets, so markets that we're not directly selling in, but our partners are. Think of, you know, Central Eastern Europe, Middle East.
Generally what happens in those dynamics is there's a, you know, a country-specific mechanism and an individual patient identified that the physician and our distributor partner works through a local reimbursement access mechanism. Oftentimes, those patients get 3, 6, and even, you know, some cases we've seen 12 months of supply ordered for 1 patient. You know, that's kind of where. Obviously you're not gonna see a consistent refill cadence every 30 days like you see in the U.S. with those kind of orders. That's kind of the dynamic we see. In terms of, you know, visibility and, you know, the guidance we have for 50% growth is based on the U.S. sales.
In the international setting, we're really excited about the feedback we're getting, and we're excited Germany's gone really well. I think from the sort of the patient-physician perspective, looks a lot like the US. It's just too early to provide firm guidance on international, given that we've just kind of getting started there.
That's very helpful. Thank you.
Thanks for the question.
Thank you. With our next question comes from Ed Arce from H.C. Wainwright. Ed, your line is now open.
Hi, everyone. This is Thomas Yip asking a couple of questions for Ed. First, congratulations on a very impressive quarter. Just trying to tease out this. Of the 600 patients with Alagille syndrome that's been treated with Livmarli globally, can you tell us roughly what % stay on chronic treatment and if you can provide some major factors for patients to stay on with Livmarli or vice versa, stay off with Livmarli as well? That'd be appreciated.
Thanks for the question. you know, the 600 number really we see as a really strong statement on familiarity with and interest in prescribing with Livmarli. That number comes from all sources over the history of the program for patients with Alagille syndrome who have been prescribed or been part of a clinical study protocol. It's really kind of all sources that feed into that. Not really a number that makes sense to parse out to the, you know, by country or by source. What I can say is that across all of the different ways that patients have found their way to Livmarli, clinical study, expanded access program, commercial products, compassionate use products in different formats, you do see the same profile of really high compliance, high persistence.
Some of these patients, 6+ years, staying with the program, because of the profound impact that it can have.
Thanks. Thanks for the clarification. Perhaps sticking with Alagille syndrome , with the U.S. label expansion down to three months of age and above, can you just tell us what your expectations are both for top line and also from a strategic standpoint as well?
On the label expansion for ALGS down to three months of age, you know, really important step because that's where most patients are diagnosed. It allows Livmarli as a treatment option early on. Overall top-line impacts, you know, keep in mind that these are younger, smaller patients. Really important for the long-term view, but staying consistent with our guidance of 50% year-over-year growth in the US and international as we get further in, we'll look at how we fold that into guidance as well.
Got it. Perhaps switching gear to PFIC with the application submitted to the EMA in Europe, when should we expect the next milestone including CHMP opinion, perhaps?
Yeah. The PDUFA date we shared in December, excited about that. The potential timing for an opinion would be from CHMP would be late Q3 or in Q4.
Got it. Perhaps one final question. This one is financial. With the convertible offering, closed in April, can you tell us what's your estimated cash runway out to?
Similar to as described in the prepared remarks, really are fully funded with the current business to cash flow, break even and positive. 3+ years really meant to just be an indicator of the strength that we have there, and see runway to operate the business for the long term here and continue to grow the products.
Got it. Understood. Thank you so much. Thank you again for taking our questions. Looking forward to the biliary atresia data.
Yeah. Thanks for the questions.
Thank you. With our next question comes from Brian Skorney from Baird. Brian, your line is now open.
Hi, this is Luke on for Brian. Just a couple on EMBARK. Do you have an update on the scope of detail you might expect to include, with the top-line readout beyond just bilirubin in particular or maybe any outcomes data? Then are you able to generally characterize the geographic dispersion of the enrolled patients in terms of US versus other territories? Thanks.
Thanks for the question. Overall, on top line, you know, other than the primary, we can't really speak to specifically what else would be in there other than getting material updates disclosed. The study is not powered for outcomes at that time point, unclear if we would have anything to share on that point. Geographic presence of sites really around the globe, and we're seeing activity across all geographies. Nothing really to point to there.
Great. Thanks. Just one on the PFIC launch. Do you think this will be a lean add-on, or do you see any need to invest further into the commercial team?
I'll ask Peter to maybe describe some of the launch plans.
Yeah. We don't see a need for incremental OpEx for PFIC. It's straightforward. In fact, the PFIC patients are probably taken care of a, by a subset of the prescribers who have prescribed Livmarli today for Alagille syndrome .
Great. I'll hop back in queue. Thank you.
Thanks for the questions.
Thank you. As a reminder, ladies and gentlemen, if you'd like to ask any further question, please press star followed by one on telephone keypad now. We have no further questions on the line.
Great. Thank you, operator. Big thank you to everyone for joining today's call. Hope you have a great day. Goodbye.
Thank you. Ladies and gentlemen, this concludes today's call. Thank you for joining. You may now disconnect your lines.