Mirum Initial Take On Volixibat Update 

Research evidence excerpt

J P M O R G A N

North America Equity Research

05 August 2026

Mirum

Initial Take On Volixibat Update

Overweight

MIRM, MIRM US

Price (05 Aug 26):$105.79

Biotechnology - Large Cap

MIRM reported a healthy topline beat and raised revenue guidance, but the

financial results were overshadowed by the news that the FDA has recommended

conducting a phase III study for volixibat in pruritis associated with PSC coming

out of a recent pre-NDA meeting. Interestingly, the FDA also granted volixibat

BTD in this setting after the meeting. (Volixibat already has BTD for pruritis

associated with PBC). The news comes as an abrupt surprise after the positive

VISTAS trial results earlier this year and in a worst-case scenario could represent

a meaningful delay to approval in this settting. MIRM mgmt does not see running

a phase III as the new base case, nor, in our catch up with mgmt, do they sound like

this is necessarily a realistic option (feasibility cited). MIRM intends to use

Breakthrough Designation to help educate the FDA team on the background

behind the trial with an aim to submit in 1H27, potentially supplementing the data

package, for example, with additional safety follow up. For a variety of reasons

mgmt walked through in our follow up, they expect to arrive at the desired outcome

(filing without another pre-approval trial) via dialogue. Stepping back, while the

news that MIRM and the FDA are not currently aligned on the NDA submission

package is clearly unwelcome and at a minimum likely introduces a potential

launch delay of ~6+ months, in addition to introducing the risk that the parties never

reach alignment, we do see a potential path forward through engaging with the

regulator and estimate even a 1 year delay as having a LSD % impact to our MIRM

valuation. In an extreme case, which does not look like the most likely scenario at

this point, removing this indication for volixibat could shave ~15% from our

valuation. Along these lines, even though the stock is entering a period of

uncertainty pending additional FDA dialogue, we maintain our Overweight rating.

Jessica Fye AC

(1-212) 622-4165

Abdul Tahlil

(1-212) 270-9644

Silvia Luo

(1-212) 622-0000

Jose Lora, Ph.D.

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