Frazier Life Sciences Public Fund, L.P. - Sep 26, 2025 SCHEDULE 13D/A Report for MBX BIOSCIENCES, INC. Common Stock, $0.0001 par value per share (MBX)

Filing Manager
Frazier Life Sciences Public Fund, L.P.
Reporting Manager
Patrick J. Heron
Security
MBX BIOSCIENCES, INC. Common Stock, $0.0001 par value per share
Symbol
MBX
Shares outstanding
44.7M shares
Disclosed Ownership
5.22M shares
Ownership
11.7%
Form type
SCHEDULE 13D/A
Date filed
9/30/2025, 05:01 PM
Date of event
Sep 26, 2025
Previous filing
Aug 20, 2025
SEC
View on sec.gov

Reporting Managers (14)

Name Ownership Shares Owned sole voting power shared voting power Signature Title CIK
Frazier Life Sciences Public Fund, L.P. 2.5% 1.1M 0 1.1M /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLSP, L.L.C., GP of FHMLSP, L.P., GP of Frazier Life Sciences Public Fund, L.P. 0001863769
FHMLSP, L.P. 2.5% 1.1M 0 1.1M /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLSP, L.L.C., GP of FHMLSP, L.P. 0001879466
FHMLSP, L.L.C. 2.5% 1.1M 0 1.1M /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLSP, L.L.C. 0001879465
Frazier Life Sciences Public Overage Fund, L.P. 0.7% 326K 0 326K /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLSP Overage, L.L.C., GP of FHMLSP Overage, L.P., GP of Frazier Life Sciences Public Overage Fund, L.P. 0001913804
FHMLSP Overage, L.P. 0.7% 326K 0 326K /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLSP Overage, L.L.C., GP of FHMLSP Overage, L.P. 0001963247
FHMLSP Overage, L.L.C. 0.7% 326K 0 326K /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLSP Overage, L.L.C. 0001963248
Frazier Life Sciences X, L.P. 11.7% 5.22M 0 5.22M /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLS X, L.L.C., GP of FHMLS X, L.P., GP of Frazier Life Sciences X, L.P. 0001790879
FHMLS X, L.P. 11.7% 5.22M 0 5.22M /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLS X, L.L.C., GP of FHMLS X, L.P. 0001790880
FHMLS X, L.L.C. 11.7% 5.22M 0 5.22M /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLS X, L.L.C. 0001790811
Frazier Life Sciences XI, L.P. 0% 3K 0 3K /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLS XI, L.L.C., GP of FHMLS XI, L.P., GP of Frazier Life Sciences XI, L.P. 0001911592
FHMLS XI, L.P. 0% 3K 0 3K /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLS XI, L.L.C., GP of FHMLS XI, L.P. 0001911580
FHMLS XI, L.L.C. 0% 3K 0 3K /s/ Steve R. Bailey By Steve R. Bailey, CFO of FHMLS XI, L.L.C. 0001911623
James N. Topper 11.7% 5.22M 0 5.22M /s/ Steve R. Bailey By Steve R. Bailey, Attorney-in-Fact for James N. Topper, pursuant to a Power of Attorney, a copy of which was filed with the SEC on July 31, 2017 0001341382
Patrick J. Heron 11.7% 5.22M 4.66K 5.22M /s/ Steve R. Bailey By Steve R. Bailey, Attorney-in-Fact for Patrick J. Heron, pursuant to a Power of Attorney, a copy of which was filed with the SEC on July 31, 2017 0001365617