PFIZER INC

For information about our effective tax rate and the events and circumstances contributing to the changes between periods, as well as details about discrete elements that impacted our tax provisions, see Note 5. See Note 5Ain our 2025 Form 10-K for information on our income taxes paid (net of refunds received).

Changes in Tax Laws––Many countries outside the U.S. have enacted legislation for global minimum taxation resulting from the Organization for Economic Co-operation and Development’s (OECD) Base Erosion and Profit Shifting “Pillar 2” project. The provisions are generally effective for Pfizer since 2024, though significant details and guidance around the provisions are still pending. Income tax expense could be impacted as the legislation becomes effective in countries in which we do business, and such impact could be material to our results of operations. We continue to monitor pending OECD guidance and legislation enactment and implementation by individual countries.

On July 4, 2025, the OBBBA was enacted into law in the U.S. The OBBBA includes significant tax provisions, such as the permanent extension of certain expiring provisions of the Tax Cuts and Jobs Act and modifications to the U.S. international tax framework. Among the favorable business provisions are the permanent expensing for domestic R&D costs, permanent bonus depreciation, full expensing of qualified production property, and the reduction of the tax rate applicable to foreign earnings as GILTI (now NCTI) effective in fiscal years 2026 and thereafter from 13.125% to 12.6%. The legislation includes various effective dates, with certain provisions effective in 2025 and the rest in 2026. We expect further guidance may be issued by the U.S. government with respect to certain OBBBA tax provisions.

See the Provision/(Benefit) for Taxes on Income section within the MD&A of our 2025 Form 10-K for more information.

PRODUCT DEVELOPMENTS

A comprehensive update of Pfizer’s development pipeline was published as of May 5, 2026 and is available atwww.pfizer.com/science/drug-product-pipeline. It includes an overview of our research and a list of compounds in development with targeted indication and phase of development, as well as mechanism of action for some candidates in Phase 1 and all candidates from Phase 2 through registration.

This section provides information as of the date of this report about significant marketing application-related regulatory actions by, and filings submitted to and accepted by the FDA and the EMA since the filing of our Annual Report on Form 10-K for the year ended December 31, 2025.

Approvals:

(a) Vepdegestrant is being developed in collaboration with Arvinas, Inc. In September 2025, Arvinas and Pfizer jointly agreed to out-license the commercialization rights to vepdegestrant to a third party. Together, the companies are on track to select a partner with the capabilities and expertise to maximize the commercial potential of vepdegestrant.

Regulatory Filings:

^ For the U.S., the filing date is the date on which the FDA accepted our submission. For the EU, the filing date is the date on which the EMA validated our submission.

(a) Padcev is being jointly developed and commercialized with Astellas in the U.S. Outside the U.S., we have commercialization rights in all countries in North and South America, and Astellas has commercialization rights in the rest of the world.

The following provides updates in new drug candidates in late-stage development since the filing of our Annual Report on Form 10-K for the year-ended December 31, 2025:

In December 2024, the FDA issued a partial clinical hold for osivelotor, which prohibited Pfizer from enrolling new participants into osivelotor clinical studies. In 2025, the FDA concluded that initiation of osivelotor studies and enrollment may proceed outside of sub-Saharan Africa and for participants who have not relocated from sub-Saharan Africa. Enrollment of new participants began in the first quarter of 2026.

For additional information about our R&D organization, see Note 13 and the Item 1. Business—Research and Development section of our 2025 Form 10-K. For additional information regarding certain collaboration arrangements, see the Item 1. Business—Collaboration and Co-Promotion Agreements section of our 2025 Form 10-K. For additional information about additional indications and new drug candidates in late-stage development and filings pending with certain regulatory authorities, see the Product Developments section within MD&A of our 2025 Form 10-K.