Mirum Pharmaceuticals, Inc. (NASDAQ:MIRM) Q1 2024 Earnings Call Transcript

Dae Gon Ha: Hey, good afternoon, guys. Thanks for taking my questions. Maybe a two-part question. On the PFIC side of the story, I was wondering if you can comment on your dialogue with the physicians given the label disparity between this and Bylvay the time being. And when you think about the reimbursement dialogue, will there need to be subsequent dialogues to be had once you get the label expansion done? And switching over to volixibat, bearing in mind the interim update in June for both VISTAS and VANTAGE, how are you guys thinking about sort of the Glaxo’s drug towards the back end of this year? And how might that impact your PBC strategy if both come out positive? Thanks so much.

Chris Peetz: Yeah. Thanks for the questions. Maybe I’ll just make a quick comment on the volixibat competition briefly and then pass over to Peter to talk about PFIC. And what we’re seeing and kind of how we’ve approached the dosing for volixibat, I think provides the potential for a real advantage in terms of activity level. It’s something we’ve learned across all of the IBAT programs, in particular, all the work we’ve done with LIVMARLI and volixibat on understanding where we’re at on the dose response curve, I think provides the potential to have really strong activity here. Of course, this is something we’ll see play out with the actual data sets as they come forward but excited about the dosing regimens that we’re evaluating in the VANTAGE study and what that can mean for patients. Maybe Peter can speak to the PFIC questions.

Peter Radovich: Sure. Yeah, thanks for the questions. Feedback on the LIVMARLI profile and PFIC has been very positive. I think, a lot of favorable feedback on the efficacy profile that was observed in the March study is reflected in the label as well as the broader genetic types of PFIC that are included in the labeling, which can sometimes make a difference in market access, depending on the payers’ policies. So, we really, really favorable feedback from clinicians and patients happy to have LIVMARLI available for those patients. And yes, payer conversations so far are going well. It’s kind of early days still, but have had really happy with the policies that have emerged. And then in terms of updated policies after, as you mentioned, a potential label update for younger than five years of age.

I’d expect that those — I mean, there’s a lot of payers in the U.S., it’s heterogeneous, but generally, those would occur pretty quickly. We saw that with Alagille when the initial label is one year of age and older and then lowered the age. Those subsequent follow-up conversations generally occur pretty quickly to update policies.

Dae Gon Ha: Great. Thanks for taking our questions.

Chris Peetz: Yeah, thanks for the questions.

Operator: The next question on the line comes from Steven Seedhouse of Raymond James. Please go ahead.

Steven Seedhouse: Hey, good afternoon. Thanks for taking the questions. Two separate questions. I’ll just ask them both now as they’re pretty straightforward. First, on the PBC readout, you mentioned price improvement, safety and serum bile acids would be the focus of that data release. And I’m just curious if you’ll also be sharing liver function tests, alphos, ALT, AST, bilirubin, just to get a sense of — even from a safety standpoint, what’s happening there? If there’s any impact of de novo bile acid synthesis on any of those parameters? And then the second one is just on business development. I would be curious your comments or thoughts on just the overall view of that or priorities for Mirum over the next, call it, 12 to 18 months, are you thinking about expanding the pipeline or focusing on volixibat primarily? Thank you.

Chris Peetz: Thanks, Steve, for the questions. I’ll speak to and comment on kind of our business development efforts and let Joanne come back on the PBC interims. And for our strategy and approach to business development remains consistent with what we’ve done over the course of Mirum. It’s very much in our DNA. It’s how the company came to be and started and its approach of being disciplined about making sure anything that we look to bring on is something that we can add value to that’s at terms and something that helps grow the company and really across a number of different rare disease settings is where we’re looking. I think we’re in a position where we’re quite lucky in that there’s a lot of growth in the commercial business, label expansion opportunities, the volixibat developments that there’s no urgency to do something so we can remain disciplined in looking at ways to grow the company. And then maybe Joanne can speak to the PBC question.

Joanne Quan: Yeah. Thanks, Chris, and thanks for the question. As I mentioned, this is an interim analysis. So it’s pretty limited in terms of scope. We’re mainly looking at it to ensure safety and to select the dose moving forward. So with that, we’ll look at pruritis, we’ll look at serum bile acids and safety, in particular. The data set is going to be pretty limited. So, we think it will be quite limited in terms of making any conclusions, certainly about any other parameters. I think we’d look to the final data set for that.

Steven Seedhouse: Thanks so much.

Chris Peetz: Thanks for the questions.

Operator: The next question on the line comes from Brian Skorney of Baird. Please go ahead. Your line is open.

Unidentified Analyst: Hi. This is Luke on for Brian. As we set expectations for VANTAGE in particular thinking about a comp to the seladelpar response study, do you think the subgroup in that study with baseline NRS greater than 4 is a reasonable comp for pruritus benefit? And then are you aware of the 11-point NRS scale they used in that study is the same as the itch reported outcome scale that you’re using?

Chris Peetz: Thanks, Luke, for the questions. Yes. I mean the scale used — it is similar. I mean there’s some very minor differences. But for adult pruritus measurements in registrational studies that kind of — this is all in line with FDA guidance. It uses 10 scale. That’s what we’re using in our study. So there is some — definitely some similarity there. And the treatment effect in that subset that they looked at, it’s not too far off with how we look at our change from placebo assumptions and powering, right, where we looked at the 1.75 point difference from placebo. So kind of looking at potentially a little bit more effect from an IBAT. But in general, it’s really not too far off if you’re thinking about study design assumptions. Of course, we’re quite excited about getting this data and seeing what that looks like. particular change from baseline, which is really what the patient experience is and what you’re doing to address the burden of disease.

Unidentified Analyst: Great. Thank you.

Chris Peetz: Thanks for the question.

Operator: The next question on the line comes from David Lebowitz of Citi. Please go ahead. Your line is open.