Mirum Pharmaceuticals: Phase 3 EXPAND shows maralixibat meets primary endpoint, plans 1H 2027 sNDA
Mirum Pharmaceuticals reported that its drug maralixibat met the primary endpoint in the Phase 3 EXPAND trial, showing significant improvement in cholestatic pruritus. All secondary endpoints were also met, including reductions in serum bile acids. The company plans to submit a U.S. supplemental NDA in the first half of 2027. According to the company, safety data were consistent with prior experience.
How this was made

The 30-second read
Why it matters
The data represent a pivotal step toward FDA approval, likely prompting analyst upgrades and increased trading volume.
Market read
First‑report of successful Phase 3 results is a high‑impact catalyst for the stock and may influence peer valuations.
What to watch
Potential competition from other pruritus treatments and the timeline to commercial launch.
Background
Mirum Pharmaceuticals (MIRM) is a U.S. biotech focused on rare liver diseases. The EXPAND trial evaluated marulixibat for cholestatic pruritus.
Ticker impact
Mirum Pharmaceuticals announced its Phase 3 EXPAND trial met the primary endpoint and plans a supplemental NDA in H1 2027.
likely upward pressure as market prices in the successful trial outcome
The trial met its primary and all secondary endpoints with strong statistical significance, a material catalyst for a biotech.
Market effects
Phase 3 success may boost sentiment for cholestatic pruritus therapeutics and related biotech peers.
U.S. biotech sector could see modest gains on the news.
Limited to investors tracking rare‑disease drug pipelines.
Counterpoint
If regulatory hurdles arise or market expectations were already priced in, the stock may see limited upside.
Key entities
- companyMirum Pharmaceuticals
U.S. biotech developing marulixibat.
- drugmarulixibat
Investigational therapy for cholestatic pruritus.
