SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of report: December 23, 2003 Date of earliest event reported: December 21, 2003 PFIZER INC. (Exact name of registrant as specified in its charter) Delaware 1-3619 13-5315170 (State or other (Commission File (I.R.S. Employer Jurisdiction of Number) Identification No.) incorporation) 235 East 42nd Street 10017 New York, New York (Zip Code) (Address of principal executive offices) Registrant's telephone number, including area code: (212) 573-2323 Item 5. Other Events and Regulation FD Disclosure On December 21, 2003, Pfizer Inc. announced that it had entered into an agreement (the "Agreement") to acquire Esperion Therapeutics, Inc., a biopharmaceutical company focused on the development of high density lipoprotein targeted therapies for the treatment of cardiovascular disease. Pursuant to this Agreement, Pfizer will commence a cash tender offer to acquire the shares of Esperion stock -more- -2- for $1.3 billion at a price of $35 per share, subject to certain conditions. Copies of Pfizer's press release and the Agreement are included as Exhibits 99.1 and 99.2, respectively, to this report and are incorporated herein by reference. Item 7(c). Exhibits Exhibit 99.1 -Press Release of Pfizer Inc. dated December 21, 2003 Exhibit 99.2 -Agreement between Pfizer Inc. and Esperion Therapeutics, Inc. dated December 19, 2003 SIGNATURE Under the requirements of the Securities Exchange Act of 1934, the registrant has caused this report to be signed on its behalf by the authorized undersigned. PFIZER INC. By: /s/Margaret M. Foran ---------------------------- Margaret M. Foran Title: Vice President-Corporate Governance and Secretary Dated: December 23, 2003 -more- -3- EXHIBIT INDEX Exhibit No. Description 99.1 Press Release of Pfizer Inc. dated December 21, 2003 99.2 Agreement between Pfizer Inc. and Esperion Therapeutics, Inc. dated December 19, 2003 -more-