As previously disclosed on December 13, 2021, Arena Pharmaceuticals, Inc., a Delaware corporation (the “Company” or “Arena”),
Pfizer Inc., a Delaware corporation (“Pfizer”), and Antioch Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Pfizer (“Merger Sub”), entered into an Agreement and Plan of Merger, dated as of December 12, 2021 (the “Merger
Agreement”), pursuant to which Merger Sub will merge with and into the Company, with the Company surviving the merger as a wholly owned subsidiary of Pfizer (the “Merger”).
The completion of the Merger is conditioned upon, among other things, the expiration or termination of the waiting period (and
any extension thereof) applicable to the Merger under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”). At 11:59 p.m., Eastern Time, on March 9, 2022, the waiting period applicable to the Merger under the HSR Act
expired. Accordingly, the portion of the conditions to the Merger relating to the expiration or termination of the waiting period under the HSR Act has been satisfied. The Merger continues to be subject to the remaining conditions set forth in the
Merger Agreement.
The Merger is currently expected to close on March 11, 2022, subject to the satisfaction or waiver of remaining conditions set forth in the Merger
Agreement.
Cautionary Statement Regarding Forward-Looking Statements
This communication and any documents referred to in this communication contain certain forward-looking statements within the meaning of the
federal securities laws with respect to the proposed transaction between Pfizer and Arena, including, but not limited to, statements regarding the expected benefits of the proposed transaction and the anticipated timing of the proposed transaction,
strategies, objectives and the products and markets of each company. These forward-looking statements generally are identified by the words “believe,” “predict,” “target,” “contemplate,” “potential,” “project,” “expect,” “anticipate,” “estimate,”
“intend,” “strategy,” “future,” “opportunity,” “plan,” “may,” “should,” “will,” “would,” “could,” “will be,” “will continue,” “will likely result,” and similar expressions. Forward-looking statements are predictions, projections and other
statements about future events that are based on current expectations and assumptions and, as a result, are subject to risks and uncertainties. Many factors could cause actual future events to differ materially from the forward-looking statements
in this communication, including but not limited to: (i) the risk that the proposed transaction may not be completed in a timely manner or at all, (ii) the failure to satisfy the conditions to the consummation of the proposed transaction, including
the receipt of certain governmental and regulatory approvals, (iii) the occurrence of any event, change or other circumstance that could give rise to the termination of the Merger Agreement, (iv) the effect of the announcement or pendency of the
proposed transaction on Arena’s business relationships, operating results, and business generally, (v) risks that the proposed transaction disrupts current plans and operations of Arena or Pfizer and potential difficulties in Arena employee
retention as a result of the proposed transaction, (vi) risks related to diverting management’s attention from Arena’s ongoing business operations, and (vii) the outcome of any legal proceedings that may be instituted against Pfizer or against
Arena related to the Merger Agreement or the proposed transaction. The risks and uncertainties may be amplified by the COVID-19 pandemic (and related variants), which has caused significant economic uncertainty. The extent to which the COVID-19
pandemic (and related variants) impacts Arena’s businesses, operations, and financial results, including the duration and magnitude of such effects, will depend on numerous factors, which are unpredictable, including, but not limited to, the
duration and spread of the outbreak, its severity, the actions to contain the virus or treat its impact, and how quickly and to what extent normal economic and operating conditions can resume. The foregoing list of factors is not exhaustive. You
should carefully consider the foregoing factors and the other risks and uncertainties that affect the businesses of Pfizer and Arena described in the “Risk Factors” section of Arena’s most recent Annual Report on Form 10-K, Quarterly Reports on
Form 10-Q and other documents filed by Arena from time to time with the SEC. 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 Arena 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. Arena gives no assurance that it will achieve its expectations.