Pfizer Inc. today announced that it has filed a lawsuit against Metsera, Inc., its Board of Directors, and Novo Nordisk, S.A. in the Delaware Court of Chancery. The lawsuit asserts claims for breach of contract, breach of fiduciary duty, and tortious interference in contract arising from Metsera's breach of its obligations under the merger agreement between Pfizer and Metsera.

Pfizer alleges that the Novo Nordisk offer cannot qualify as a "Superior Company Proposal" under the terms of the merger agreement, including because, relative to the Pfizer deal, the Novo Nordisk transaction is not reasonably likely to be completed on the terms proposed in light of the significant regulatory risk of the proposal. By contrast, today the U.S. Federal Trade Commission granted early termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, with respect to Pfizer's pending acquisition of Metsera. All regulatory approvals in respect of Pfizer's acquisition of Metsera have been obtained, and Pfizer is ready to complete the transaction shortly following the Metsera stockholder meeting on November 13.

As set out in the lawsuit, the proposed Novo Nordisk transaction is an illegal attempt by a company with a dominant market position to suppress competition and uses an unprecedented structure designed to deliberately evade antitrust review. Metsera's Board previously determined that Novo Nordisk's prior proposal with an identical structure posed unacceptable regulatory risks, and these risks have not changed. The lawsuit also alleges that the proposed special dividend contemplated by Novo Nordisk's proposal is a violation of Delaware law and that the Metsera Directors have breached their fiduciary duties by, among other things, securing a self-interested indemnification provision from Novo Nordisk designed to cover their unlawful conduct.

Pfizer has filed a motion with the Court of Chancery requesting that it issue a temporary restraining order to block Metsera from terminating the merger agreement to allow Pfizer time to be heard on this important matter.

Pfizer said it "is taking this action to enforce and preserve its rights under the merger agreement. Metsera's and its Directors' actions, as well as those of Novo Nordisk, are in clear violation of their respective contractual and legal obligations. We are confident in the merits of our case and look forward to presenting it to the Court."

Pfizer seeks all appropriate remedies, including injunctive relief and damages, to address the harm caused by Metsera's and Novo Nordisk's conduct and to ensure that the terms of the merger agreement are fully enforced.

Disclosure Notice: The information contained in this release is as of October 31, 2025. This release contains forward-looking information about, among other topics, Pfizer's proposed acquisition of Metsera, a lawsuit filed by Pfizer against Metsera, Inc., its Board of Directors, and Novo Nordisk, S.A., that involves substantial risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. Risks and uncertainties include, among other things, uncertainties regarding the outcome of the lawsuit; risks and uncertainties related to the impact of Novo Nordisk's proposal on the proposed acquisition; risks related to the satisfaction or waiver of the conditions to closing the proposed acquisition (including the failure to obtain the requisite vote by Metsera stockholders) in the anticipated timeframe or at all, including the possibility that the proposed acquisition does not close; the possibility that competing offers may be made or accepted; the risk that the merger agreement may be terminated; risks related to the ability to realize the anticipated benefits of the proposed acquisition, including the possibility that the expected benefits from the acquisition will not be realized or will not be realized within the expected time period; the risk that the businesses will not be integrated successfully; disruption from the transaction making it more difficult to maintain business and operational relationships, including Metsera's ability to attract and retain highly qualified management and other clinical and scientific personals; negative effects of this announcement or the consummation of the proposed acquisition on the market price of Pfizer's or Metsera's common stock and/or operating results; significant transaction costs; unknown liabilities; the risk of litigation and/or regulatory actions related to the proposed acquisition or Metsera's business; other business effects and uncertainties, including the effects of industry, market, business, economic, political or regulatory conditions; future exchange and interest rates; risks and uncertainties related to issued or future executive orders or other new, or changes in, laws, regulations or policy; changes in tax and other laws, regulations, rates and policies; the uncertainties inherent in business and financial planning, including, without limitation, risks related to Pfizer's business and prospects, adverse developments in Pfizer's markets, or adverse developments in the U.S. or global capital markets, credit markets, regulatory environment, tariffs and other trade policies or economies generally; future business combinations or disposals; uncertainties regarding the commercial success of Metsera's pipeline products or Pfizer's commercialized and/or pipeline products; risks associated with Metsera conducting clinical trials and preclinical studies outside of the United States; Metsera's reliance on third parties to conduct clinical trials and preclinical studies and for the manufacture and shipping of its product candidates; the risk that Metsera's product candidates are associated with side effects, adverse events or other properties or safety risks; risks associated with Metsera's license and collaboration agreements and future strategic alliances; Metsera's ability to obtain, maintain, defend and enforce patent or other intellectual property protection for current or future product candidates or technology; the uncertainties inherent in research and development, including the ability to meet anticipated clinical endpoints, commencement and/or completion dates for clinical trials, regulatory submission dates, regulatory approval dates and/or launch dates, as well as the possibility of unfavorable new clinical data and further analyses of existing clinical data; risks associated with initial, preliminary or interim data; the risk that clinical trial data are subject to differing interpretations and assessments by regulatory authorities; whether regulatory authorities will be satisfied with the design of and results from the clinical studies; whether and when drug applications may be filed in any jurisdictions for Pfizer's or Metsera's pipeline products for any potential indications; whether and when any such applications may be approved by regulatory authorities, which will depend on myriad factors, including making a determination as to whether the product's benefits outweigh its known risks and determination of the product's efficacy and, if approved, whether any such products will be commercially successful; decisions by regulatory authorities impacting labeling, manufacturing processes, safety and/or other matters that could affect the availability or commercial potential of such products; uncertainties regarding the impact of COVID-19; and competitive developments.

You should carefully consider the foregoing factors and the other risks and uncertainties that affect Pfizer's business described in the "Risk Factors" and "Forward-Looking Information and Factors That May Affect Future Results" sections of Pfizer's Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and other documents filed from time to time with the U.S. Securities and Exchange Commission, all of which are available at www.sec.gov. These filings identify and address other important risks and uncertainties that could cause actual events and results to differ materially from those contained in the forward-looking statements. Forward-looking statements speak only as of the date they are made. Readers are cautioned not to put undue reliance on forward-looking statements, and Pfizer assumes no obligation to, and does not intend to, update or revise these forward-looking statements, whether as a result of new information, future events, or otherwise, unless required by law. Pfizer does not give any assurance that it will achieve its expectations.

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Media Contact: PfizerMediaRelations@Pfizer.com

Investor Contact: IR@Pfizer.com

Pfizer Files Lawsuit Against Metsera and its Directors and Novo Nordisk for Breach of Merger Agreement