Mirum Pharmaceuticals, Inc. (NASDAQ:MIRM) Q1 2023 Earnings Call Transcript

Peter Radovich: Yes. And I think as you think about that piece there Mani, the Biliary Atresia is more common than Alagille and PFIC by a fair bit when you think about it from an incident perspective, probably on threefold more common on newborn incidents in Alagille. But because of the dynamics that Chris is describing, there’s much less of a prevalent pool there, because it’s generally pretty rapidly progressive and heads towards liver transplant. So we’d envision in the kind of early years after approval, the eligible patient population being kind of on the order of kids who are born within the last 12 to maybe 36 months. But as you — 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 better than the other two indications.

Mani Foroohar: That’s very helpful. And when we talk about what the drug hopes one can do. Obviously, it’s a little less certainty around the regulatory dynamic here, because it doesn’t internally ask . Can you give us a sense of how you think about target effects by, target product profile? And is there more certainty in your view on what need to show for clinical uptake? Or is that also a little bit up in the air as our regulatory questions?

Chris Peetz: Thanks for the question there. I mean there’s a couple of aspects to consider and thinking about the regulatory conversations that we’ll have after this data set is unblinded, regulators are data-driven. And they do have patient interest in mind. And so 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 will 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. So we have a close eye on that being able to down categorize patients on the bilirubin score. It’s above 6%, 2% to 6% and below 2% for bilirubin. Each step is a meaningful difference in risk of outcome. So we’ll look at those in a kind of responder or shift table format.

Mani Foroohar: All right. That’s very helpful. Thanks guys.

Chris Peetz: Thanks for the question.

Operator: Thank you. We have our next question comes from Steve Seedhouse from Raymond James. Steve your line is now open.

Ryan Deschner: Hi, two questions from me. This is Ryan Deschner on for Steve Seedhouse. The first — now that we’re more than a year into LIVMARLI launch, have you seen an appreciable step-up in sales due to the increases in average patient weight? And how often are treating physicians adjusting dose for growth in other reasons?

Chris Peetz: Thanks for the question. What we see there is I think about once a year, patients are weighed and they’re considered for dose increases. We do see dose increases in the real world setting is consistent with the prescribing information for LIVMARLI. Really, the majority of the growth we’re seeing is just de novo demand and new patient starts.

Ryan Deschner: Excellent. And then also, in what areas do you anticipate potentially being able to differentiate from competitor odevixibat in Biliary Atresia?