Mirum Pharmaceuticals (MIRM) Q2 FY26 earnings call: guidance and Q&A

What key topics will be addressed in future discussions with the FDA regarding the PSC NDA?

Management explained that the FDA team encountered during the pre-NDA meeting was new, and the discussions will focus on familiarizing them with the VISTAS study's design, its successful results, and the history of prior FDA alignment on its pivotal intent. The Breakthrough Therapy Designation, granted after the meeting, provides a good opportunity for further engagement.

“in the meeting, there was a new team from FDA. And so we think there's a lot of work to kind of get them up to speed on the backdrop here. So the history designing and conducting VISTAS and what this study means in a PSC setting.”

asked by Ryan Deschner · answered by Christopher Peetz

What was the new FDA team's specific rationale for recommending an additional Phase 3 study for volixibat in PSC (e.g., safety vs. efficacy)?

The FDA's comments on the Phase 3 recommendation were not specific, covering general efficacy and safety (IBD GI effects, liver safety). Management believes VISTAS addresses these, and the Breakthrough Therapy Designation (granted after the meeting) offers a chance to build familiarity with the data set.

“The comments about Phase 3 recommendation from them really were not specific. So we don't have great clarity on what specifically they're looking for. There were comments across the board on -- more general on efficacy... On the safety side, the discussion -- the couple of things that were brought up were IBD safety in the backdrop with IBAT GI effects and liver safety.”

asked by Gavin Clark-Gartner · answered by Christopher Peetz

Is there any read-through from the PSC regulatory discussions to the PBC VANTAGE study? And what is the status of commercial prep for zilurgisertib for FOP?

For PBC, management stated they received clear FDA feedback after Breakthrough Therapy Designation in 2024, addressing study size (over 330 patients) and analysis plan, confirming VANTAGE as pivotal. For FOP, commercial prep is going well, leveraging the rare genetics team, with typical pre-launch activities underway for a Q4 launch.

“in the correspondence after the breakthrough designation on VANTAGE, we actually received a pretty clear feedback from FDA on what we should do to consider VANTAGE a pivotal study. And we were able to address those. (Christopher Peetz) and we were able to drop that in the bags of our rare genetics team and had a couple of territories there. Lot of typical prelaunch activity and profiling accounts and understanding where the treaters are. (Peter Radovich)”

asked by Rohit Bhasin · answered by Christopher Peetz

Can management clarify the FDA review team for volixibat in PSC, specifically if leadership has changed or was involved? Also, provide an update on the zilurgisertib PDUFA late-cycle review meeting.

Management indicated that office leadership for the FDA review team might have changed and leadership was not present at the meeting. They believe the efficacy concerns can be addressed through iterative conversation. For zilurgisertib, the late-cycle meeting went very well, and the application is progressing as expected towards the PDUFA date.

“what I would say the office leadership, we think maybe has changed and leadership was not in the room in our review meeting. (Christopher Peetz) and Yes, we did have the late cycle meeting. Meeting went very well. So we feel the application is progressing quite well towards the PDUFA date. (Christopher Peetz)”

asked by Brian Skorney · answered by Christopher Peetz

Is a Phase 3 for volixibat in PSC still on the table, or is management confident it can be resolved through iterative dialogue? What informs the confidence for H1 2027 resubmission?

Management does not see what would be gained from another Phase 3 study given the robust VISTAS results, which is the largest ever conducted in PSC pruritus with clear definitive results and sufficient safety data. They are confident in resolving this through iterative dialogue, with H1 2027 timing allowing for one or two iterations with the FDA, based on prior experience with other applications.

“I mean VISTAS is the largest ever conducted in PSC pruritus clear definitive results. It's a big enough safety database for a setting like PSC. So we don't see what would be gained by going down that road and find that just the weight of evidence here is really convincing.”

asked by James Condulis · answered by Christopher Peetz