Bain Capital Life Sciences Fund, L.P. - 09 Sep 2025 SCHEDULE 13G Report for X4 PHARMACEUTICALS, INC. Common Stock, par value $0.001 per share (XFOR)

Filing Manager
Bain Capital Life Sciences Fund, L.P.
Reporting Manager
Bain Capital Life Sciences Fund, L.P.
Security
X4 PHARMACEUTICALS, INC. Common Stock, par value $0.001 per share
Symbol
XFOR
Shares outstanding
24,390,270 shares
Disclosed Ownership
2,436,588 shares
Ownership
10%
Form type
SCHEDULE 13G
Filing time
15 Sep 2025, 16:30:02 UTC
Date of event
09 Sep 2025
Previous filing
13 Aug 2025
SEC
View on sec.gov

Reporting Managers (6)

Name Ownership Shares Owned sole voting power shared voting power Signature Title CIK
Bain Capital Life Sciences Fund, L.P. 10% 2,436,588 0 2,436,588 /s/ Andrew Hack Andrew Hack, Partner of Bain Capital Life Sciences Investors, LLC
Bain Capital Life Sciences Fund II, L.P. 10% 2,436,588 0 2,436,588 /s/ Andrew Hack Andrew Hack, Partner of Bain Capital Life Sciences Investors, LLC
BCIP Life Sciences Associates, LP 10% 2,436,588 0 2,436,588 /s/ Andrew Hack Andrew Hack, Authorized Signatory of Boylston Coinvestors, LLC
BCLS II Investco, LP 10% 2,436,588 0 2,436,588 /s/ Andrew Hack Andrew Hack, Partner of Bain Capital Life Sciences Investors, LLC
BCLS I Investco, LP 10% 2,436,588 0 2,436,588 /s/ Andrew Hack Andrew Hack, Partner of Bain Capital Life Sciences Investors, LLC
BCLS II Equity Opportunities, LP 10% 2,436,588 0 2,436,588 /s/ Andrew Hack Andrew Hack, Partner of Bain Capital Life Sciences Investors, LLC