---
schema_version: "secwatch.filing_event.v1"
accession: "0001759425-26-000051"
form_type: "8-K"
ticker: "MIRM"
cik: "0001759425"
company_name: "Mirum Pharmaceuticals, Inc."
filed_at: "2026-10-13T12:09:04+00:00"
generated_at: "2026-10-13T12:10:06.988985+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Mirum LIVMARLI Phase 3 EXPAND meets primary endpoint; itch score -0.98 vs placebo, sNDA set for H1 2027

## Summary
- Phase 3 EXPAND enrolled 52 patients (46 pediatric, 6 adult); ItchRO(Obs) improved 1.81 points vs 0.83 for placebo, a 0.98-point difference (p=0.0004).
- All five prespecified secondary endpoints met, including three in biliary atresia with native liver: itch -2.16 vs -1.01 (p=0.0002) and sBA -75.5% vs -9.0% (p<0.0001).
- Serum bile acids fell 70.1% from baseline vs 3.5% for placebo in the overall population, a 69.0% treatment effect (p<0.0001).
- Safety consistent with prior maralixibat experience; diarrhea in 64.0% of treated vs 11.1% placebo patients, no deaths and no new safety signals.
- Mirum plans a U.S. supplemental New Drug Application in H1 2027; sees ~2,000 addressable BA patients in U.S./Europe.

## SEC filing metadata
- accession: 0001759425-26-000051
- form_type: 8-K
- ticker: MIRM
- cik: 0001759425
- company_name: Mirum Pharmaceuticals, Inc.
- filed_at: 2026-10-13T12:09:04+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1759425/000175942526000051/0001759425-26-000051-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1759425/000175942526000051/mirm-20261012.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001759425-26-000051
- JSON: https://secwatch.observer/filing/0001759425-26-000051.json
- Plain text: https://secwatch.observer/filing/0001759425-26-000051.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.