Population Health Partners GP, LLC - Nov 13, 2025 Form 4 Insider Report for Metsera, Inc. (MTSR)

Role
10%+ Owner
Signature
/s/ Christopher Cox, Member of Population Health Partners GP, LLC
Stock symbol
MTSR
Transactions as of
Nov 13, 2025
Transactions value $
$0
Form type
4
Date filed
11/13/2025, 09:15 PM

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Population Health Partners GP, LLC 10%+ Owner 1200 MORRIS TURNPIKE, SUITE 300, SHORT HILLS /s/ Christopher Cox, Member of Population Health Partners GP, LLC 2025-11-13 0002054502

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction MTSR Common Stock Disposed to Issuer -128K -100% 0 Nov 13, 2025 Direct F1, F2, F3
transaction MTSR Common Stock Disposed to Issuer -12.6M -100% 0 Nov 13, 2025 By Population Health Partners, L.P. F1, F2, F3
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Population Health Partners GP, LLC is no longer subject to Section 16 filing requirements. Form 4 or Form 5 obligations may continue.

Explanation of Responses:

Id Content
F1 Pursuant to the Agreement and Plan of Merger dated September 21, 2025, as amended on November 7, 2025 (the "Merger Agreement"), by and among Metsera, Inc. (the "Company"), Pfizer Inc., a Delaware corporation ("Parent"), and Mayfair Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of the Parent (the "Merger Sub"), the Merger Sub merged with and into the Company, with the Company continuing as the surviving corporation and a wholly owned subsidiary of the Parent (the "Merger"). At the Effective Time of the Merger (as defined in the Merger Agreement), each issued and outstanding share of common stock, par value $0.00001 per share of the Company (the "Common Stock") was converted automatically into the right to receive (i) cash in an amount equal to $65.60 per share without interest (the "Closing Amount"),
F2 (Continued from footnote 1) net of all applicable withholding taxes, plus (ii) one contractual contingent value right representing the right to receive contingent payments (a "CVR") in cash, without interest, upon the achievement of certain specified milestones, in accordance with the terms and conditions of the contingent value rights agreement entered into by the Parent and Equiniti Trust Company, LLC, dated November 13, 2025 (collectively, the "Merger Consideration").
F3 Population Health Partners, L.P. ("PHP LP") is the record owner of 12,639,787 shares of the Common Stock and Population Health Partners GP, LLC ("PHP GP LLC") is the record owner of 127,675 shares of the Common Stock. PHP GP LLC is the sole general partner of PHP LP and may be deemed to beneficially own the shares of the Common Stock held by PHP LP. Christopher Whitten Bernard, Christopher T. Cox and Clive A. Meanwell are members of PHP GP LLC and may be deemed to share the power to direct the disposition and vote of the shares of Common Stock held by PHP LP and PHP GP LLC. Each of PHP GP LLC, Christopher Whitten Bernard, Christopher T. Cox and Clive A. Meanwell disclaims beneficial ownership of the reported securities except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that it is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.