Pfizer Inc. (NYSE:PFE) agreed to acquire Metsera, Inc. (NasdaqGS:MTSR) from Arch Venture Partners, L.P., Population Health Partners, LLC and others for $5 billion on September 21, 2025. Under the terms of the agreement, Pfizer will acquire all outstanding shares of Metsera common stock for $47.50 per share in cash at closing. Additionally, the agreement includes a non-transferable contingent value right (CVR) entitling holders to potential additional payments of up to $22.50 per share in cash tied to three specific clinical and regulatory milestones: $5 per share following the Phase 3 clinical trial start of Metsera?s MET-097i+MET-233i combination, $7 per share following U.S. Food and Drug Administration (FDA) approval of Metsera?s monthly MET-097i monotherapy, and $10.50 per share following FDA approval of Metsera?s monthly MET-097i+MET-233i combination, if achieved. In case of termination of transaction, Arch Venture Partners, L.P. and Population Health Partners, LLC will pay a termination fee of $265 million.

As of November 7, 2025, Metsera entered into Amendment No. 1 to the Agreement and Plan of Merger with Pfizer. Under the terms of the Amendment, increase the upfront cash consideration to be paid from $47.50 to $65.60 in cash per share and decrease the maximum amount payable under the non-transferable contingent value right (?CVR?) from up to $22.50 to up to $20.65 per share.

The transaction is subject to approval of merger agreement by target board, approval of offer by acquirer board, approval by the shareholder of Metsera and subject to antitrust regulations. The deal has been unanimously approved by the Board of Directors of both Pfizer and Metsera. The expected completion of the transaction is fourth quarter of 2025. As on October 31, 2025, Pfizer Receives Early Clearance from U.S. Federal Trade Commission for Metsera Acquisition.

Citigroup Inc. acted as financial advisor and David K. Lam and Steven R. Green of Wachtell, Lipton, Rosen & Katz LLP acted as legal advisors to Pfizer Inc. The Goldman Sachs Group, Inc., Guggenheim Securities, LLC, BofA Securities, Inc. and Allen & Company LLC acted as financial advisors and Scott A. Barshay, Benjamin Goodchild, Andrew Krause, Patricia Vaz de Almeida, Matthew Friestedt, Cynthia Akard, Anne McGinnis, Brian Krause, Jonathan Ashtor, Jeffrey Osterman, Matthew Rosenberg, Scott Sher and Nicole Kar of Paul, Weiss, Rifkind, Wharton & Garrison LLP acted as legal advisors to Metsera, Inc. Innisfree M&A Incorporated acted as a information agent to Metsera. Equiniti Trust Company, LLC acted as a transfer agent to Metsera, Thomas W Greenberg of Skadden, Arps, Slate, Meagher & Flom LLP represented Goldman Sachs & Co. LLC and Guggenheim Securities as financial advisor to Metsera Inc.

Pfizer Inc. (NYSE:PFE) completed the acquisition of Metsera, Inc. (NasdaqGS:MTSR) from Arch Venture Partners, L.P., Population Health Partners, LLC and others on November 13, 2025. Metsera is now a wholly owned subsidiary of Pfizer. In connection with the acquisition, Metsera?s shares of common stock will cease trading on the NASDAQ Global Select Market following the close of market on November 13, 2025.