Wellington Biomedical Innovation Master Investors (Cayman) II L.P. - 30 Sep 2025 SCHEDULE 13G/A Report for MBX Biosciences Common Stock (MBX)

Filing Manager: Wellington Biomedical Innovation Master Investors (Cayman) II L.P.
Reporting Manager: Wellington Biomedical Innovation Master Investors (Cayman) II, L.P.
Security: MBX Biosciences Common Stock
Symbol: MBX
Shares outstanding: 44.8M shares
Disclosed Ownership: 2.02M shares
Ownership: 4.5%
Form type: SCHEDULE 13G/A
Filing time: 12 Nov 2025, 18:44:54 UTC
Date of event: 30 Sep 2025
SEC: View on sec.gov

Reporting Managers (1)

Name	Ownership	Shares Owned	sole voting power	shared voting power	Signature	Title	CIK
Wellington Biomedical Innovation Master Investors (Cayman) II, L.P.	4.5%	2.02M	0	2.02M	Ihsan Speede	Authorized Person