$3,000,000,000 aggregate principal amount of 4.650% Notes due 2025

$3,000,000,000 aggregate principal amount of 4.450% Notes due 2026

$4,000,000,000 aggregate principal amount of 4.450% Notes due 2028

$3,000,000,000 aggregate principal amount of 4.650% Notes due 2030

$5,000,000,000 aggregate principal amount of 4.750% Notes due 2033

$3,000,000,000 aggregate principal amount of 5.110% Notes due 2043

$6,000,000,000 aggregate principal amount of 5.300% Notes due 2053

$4,000,000,000 aggregate principal amount of 5.340% Notes due 2063

The Notes will be issued by Pfizer’s wholly-owned subsidiary, Pfizer Investment Enterprises Pte. Ltd. (the “Issuer”), and will be fully and unconditionally guaranteed on a senior unsecured basis by Pfizer. Pfizer intends to use the net proceeds of the offering as part of the financing for Pfizer’s proposed acquisition of Seagen Inc. (the “Merger”). The Notes, other than any issuance of 10-year notes and 30-year notes, are expected to be subject to a special mandatory redemption (at a price equal to 101% of the aggregate principal amount of such series of notes) under certain circumstances if the Merger is terminated or does not close by an agreed upon date.

The closing of the offering is expected to occur on May 19, 2023, subject to satisfaction of customary closing conditions.

BofA Securities, Citigroup, Goldman Sachs and J.P. Morgan are acting as joint lead managers and joint book-running managers for the offering.

This offering is being made pursuant to an effective shelf registration statement and prospectus and a related preliminary prospectus supplement filed by the Issuer and Pfizer with the Securities and Exchange Commission (the “SEC”). Before investing, potential investors should read the prospectus and the related preliminary prospectus supplement, the shelf registration statement and other documents that Pfizer has filed with the SEC for more complete information about Pfizer and this offering.

Copies of the prospectus supplement and related prospectus for this offering can be obtained from BofA Securities toll-free at (800) 294-1322, from Citigroup toll-free at (800) 831-9146, from Goldman Sachs toll-free at (866) 471-2526 and from J.P. Morgan at (212) 834-4533.

This press release does not constitute an offer to sell or the solicitation of an offer to buy any securities, including the Notes. There shall not be any sale of the securities described herein in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or other jurisdiction.