JANUS HENDERSON GROUP PLC - 31 Dec 2025 SCHEDULE 13G/A Report for MIRUM PHARAMACEUTICALS, INC. Common Stock (MIRM)

Filing manager: JANUS HENDERSON GROUP PLC
Reporting owner: JANUS HENDERSON GROUP PLC
Security: MIRUM PHARAMACEUTICALS, INC. Common Stock
Beneficially owned shares: 6,065,308 shares
Large-stake signal: Form
SCHEDULE 13G/A
Passive or exempt beneficial ownership filing.
Ownership
12%
Beneficial ownership of this reported class.
Shares
6,065,308 shares
Shares beneficially owned as disclosed.
Event date
31 Dec 2025
Date tied to the ownership event or amendment.
Accepted by SEC
17 Feb 2026
EDGAR acceptance date.
How to read this large-stake filing
Schedule 13D/G filings focus on beneficial ownership stakes, not a full portfolio.
Compare this filing with the holder history and issuer page before treating the percentage as a current position.
Use amendments to understand whether the disclosed stake increased, decreased, or changed reporting status.
Class ownership: 12%
Symbol: MIRM
Shares outstanding: 51,400,915 shares
SEC form: SCHEDULE 13G/A
Accepted by SEC: 17 Feb 2026, 16:33:36 UTC
Event date: 31 Dec 2025
Prior SEC filing: 05 Dec 2025
Source filing: View source filing

Key filing fact

JANUS HENDERSON GROUP PLC disclosed 12% ownership in MIRUM PHARAMACEUTICALS, INC. Common Stock (MIRM) on 31 Dec 2025.

Key facts

JANUS HENDERSON GROUP PLC filed SCHEDULE 13G/A for MIRUM PHARAMACEUTICALS, INC. Common Stock (MIRM).
Disclosed ownership: 12%.
Date of event: 31 Dec 2025.

This page turns one Schedule 13D/G filing into a quick large-stake read before the raw reporting-person rows.
Use the linked SEC filing as the source of truth for ownership percentages, shares, and reporting-party details.

Backed by Schedule 13D/13G

Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.

Reporting persons

Names, ownership percentages, voting power, signatures, titles, and CIKs as disclosed in this Schedule 13D/G filing.

Name	Ownership	Shares owned	Sole voting power	Shared voting power	Signature	Title	CIK
JANUS HENDERSON GROUP PLC	12%	6,065,308	0	6,065,308	Kristin Mariani	Head of North America Compliance

CIK / CUSIP context first

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