Mirum Pharmaceuticals, Inc. Common Stock Citigroup’s Biopharma Back to School Summit 2026

Yeah, great. Thanks for having us. First, point out that we make some forward-looking statements, so refer people to the SEC filings for more complete risk factor disclosure. A couple of intro words on the cadence of events over the year for Mirum. We're a commercial stage, rare disease-focused company that just kind of how these programs and readouts that we have tied together is pursuing opportunities in rare disease to bring forward medicines that are generally overlooked. Kind of the overall strategy is finding the small to mid-size medicines that fall off the radar for big pharma, and address real rare disease problems. Recognizing that there's only 5% of rare diseases actually have approved medicines for them. There's just a lot of runway for us to find medicines like that and bring them together in Mirum.

A lot of great ones that are making progress this year. On top of revenue of $680 million-$700 million expected this year, several really important readouts ahead of us. Later this month, actually, a phase III readout expected for the brelovitug HDV program. That's one of two phase III readouts. The second one reads out next quarter. AZURE-1 and 4 are those two studies. Together they'll constitute an expected BLA filing in the first half of next year. So, exciting moment for brelovitug and a new therapy for HDV patients as we get to that data readout. We also have later this month a PDUFA date for zilurgisertib and FOP. Zilurgisertib is an ALK2 inhibitor for FOP, and that submission is based on some really impressive phase II data that formed the submission program that we acquired from Incyte earlier this year.

We take over at the approval expected later this month. Into Q4, in addition to the brelovitug second phase III readout, we also have a phase III readout for LIVMARLI. So the EXPAND study, looking at a basket of cholestatic pruritus indications, kind of the third leg to LIVMARLI's growth profile, with that study reading out in the fourth quarter. Then into Q1 next year, we also have a second indication for volixibat reading out in PBC. I'm sure we're going to spend time talking about the PSC data and FDA conversation, but another data readout for that program Q1.

Right. Yeah. The brelovitug program, brelovitug is a HB surface antigen antibody. A really straightforward approach in this co-infection setting to knock down the surface antigen that hep delta relies on for replication and infection. And the phase II data, as you point out, are really clear and strong. Not only the phase IIb data from AZURE-1, which read out earlier this year, there's also a phase IIa study conducted previously by Bluejay Therapeutics, where this program originated, the clinical program originated. And consistent effects overall across the doses evaluated and from one study to the next, where you're seeing very high viral response rates. Most patients, most cohorts reaching 100% virologic response of 2 log or greater reduction, and impressive rates of ALT normalization over time.

There's a mix of different time points that have been looked at, week 24 and 48, but it's clear that by week 24, which is the phase III time point, you can get 100% or near 100% virologic response, and the majority of patients achieving or being near ALT normalization.

This is one of the key things that we were looking at when we were thinking about entering into HDV. It is still, I think, one of the debates that we hear brought to us as a question pretty commonly is on patient finding. It is something that the Mirum team, I think, has done really well in other settings. So, a really strong conviction in what we have seen to date and how we are approaching it. A couple of the observations and estimates we have, we think there is about 15,000 diagnosed insured patients in the U.S. So that is based on some claims data work. Where these patients are, I think, is important to spend a moment thinking about. Because when in interactions with KOLs, you might actually extrapolate to a lower number, because these patients are often more dispersed in the community.

In particular, in some of the major metro areas, there will be non-traditional for liver care points of care that are more primary care oriented or community clinics that would see most of these patients. A lot of the launch prep work we are doing is profiling who are the physicians that are seeing these patients that are already diagnosed, because that is going to be the first opportunity at launch. The second leg to this is thinking about diagnosis rates. Hepatitis delta, we think is very much underdiagnosed, and there is a story here on incorporating reflex testing for hepatitis delta based on hep B diagnoses. We have seen this play out in Europe over the past four or five years, where they have shifted from what is thought of as at-risk hepatitis delta testing, which ends up being very limited testing for hepatitis delta in hep B patients.

As Europe converted to their guidelines and their practices to be more automated tests for delta if you have a positive hep B result, the number diagnosed climbed rapidly. We are hoping that can be deployed against here in the U.S. as we have now already one approved and more coming new medicines for hepatitis delta expect to see a change in some of the practices on how it is tested for. Ultimately, we think there is probably at least 40,000 total patients in the U.S., so the majority of them being undiagnosed.

Exactly. Yeah. Okay. The estimates you see are in the 2%-5% range of HBV Okay would be HDV infected as well.