---
schema_version: "secwatch.filing_event.v1"
accession: "0001759425-26-000049"
form_type: "8-K"
ticker: "MIRM"
cik: "0001759425"
company_name: "Mirum Pharmaceuticals, Inc."
filed_at: "2026-09-28T12:02:47+00:00"
generated_at: "2026-10-12T13:30:54.204088+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# FDA approves Mirum/Incyte's Atebrioz for FOP; brelovitug meets AZURE-1 Phase 3 primary endpoint

## Summary
- FDA approved Atebrioz (zilurgisertib) 100 mg once daily to reduce total new heterotopic ossification volume in FOP patients aged 12+; U.S. launch expected October 2026.
- In PROGRESS Cohort 1, Week 24 mean new HO lesion volume fell 3.2 cm3 with zilurgisertib vs increase of 24.6 cm3 on placebo; effects maintained through Week 48.
- Phase 3 AZURE-1: brelovitug met primary endpoint with 56% (300 mg QW) and 45% (900 mg Q4W) vs 0% delayed treatment (p<0.0001) in 153 treatment-naive chronic HDV patients.
- Brelovitug BLA submission expected H1 2027 and U.S. launch Q4 2027; AZURE-4 topline due Q4 2026. Mirum estimates >$1B annual revenue potential for brelovitug and >$200M for Atebrioz.
- Week 48 Phase 2b data showed deepening response: 300 mg QW primary endpoint rate rose from 45% to 55%, 900 mg Q4W from 35% to 55%; no new safety signals.

## SEC filing metadata
- accession: 0001759425-26-000049
- form_type: 8-K
- ticker: MIRM
- cik: 0001759425
- company_name: Mirum Pharmaceuticals, Inc.
- filed_at: 2026-09-28T12:02:47+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1759425/000175942526000049/0001759425-26-000049-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1759425/000175942526000049/mirm-20260925.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001759425-26-000049
- JSON: https://secwatch.observer/filing/0001759425-26-000049.json
- Plain text: https://secwatch.observer/filing/0001759425-26-000049.txt

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