Item 1A. RISK FACTORS

We refer to the Overview of Our Performance, Operating Environment, Strategy and Outlook—Our Operating Environment and —The Global Economic Environment sections and the Forward-Looking Information and Factors That May Affect Future Results section within MD&A of this Form 10-Q and of our 2022 Form 10-K and to the Item 1A. Risk Factors section of our 2022 Form 10-K. We are including the following risk factors, which should be read in conjunction with the risk factors discussed in the Item 1A. Risk Factors section of our 2022 Form 10-K.

PROPOSED ACQUISITION OF SEAGEN

We may be unable to complete the acquisition of Seagen within the anticipated timeframe or at all, which could prevent us from receiving the anticipated benefits from the acquisition in the anticipated timeframe or at all.

On March 12, 2023, we entered into a merger agreement with Seagen. The transaction is expected to close in late 2023 or early 2024, and remains subject to customary closing conditions, including receipt of required regulatory approvals. As a result, there is no assurance that the acquisition will be consummated in the anticipated timeframe or at all. In addition, Pfizer may be required to pay Seagen a reverse termination fee of approximately $2.22 billion, subject to certain limitations set forth in the merger agreement, if the merger agreement is terminated by either party as a result of certain antitrust and/or foreign direct investment law-related conditions. Any failure to consummate the acquisition in the anticipated timeframe or at all could prevent Pfizer from receiving the expected benefits from the acquisition. See Note 1 and the Forward-Looking Information and Factors That May Affect Future Results section within MD&A.

We have expended and will continue to expend significant time and resources in connection with the acquisition of Seagen and have incurred substantial indebtedness to fund the acquisition.

Pfizer has expended and will continue to expend significant management time and resources and expenses related to the acquisition of Seagen, many of which must be paid regardless of whether the acquisition is consummated. For example, such time, resources and expenses are being and will continue to be incurred in connection with seeking regulatory approvals for the transaction. We intend to finance a portion of the transaction with the proceeds from the $31 billion of long-term debt issued in May 2023, plus additional short-term indebtedness to be issued prior to the acquisition, which indebtedness may limit our operating or financial flexibility relative to our current position.

We may not be successful in identifying and executing potential business development transactions, such as our acquisition of Seagen, or realizing the financial and strategic goals that were contemplated at the time of any historical or potential business development transaction, which could have an adverse impact on our ability to meet our growth objectives.

We have established significant growth goals, which we plan to achieve, in part, by accelerating revenue growth by not only advancing our own product pipelines and maximizing the value of our existing products, but also through various forms of business development activities, which can include alliances, licenses, JVs, collaborations, equity- or debt-based investments, dispositions, divestments, mergers and acquisitions. Our proposed acquisition of Seagen is part of that accelerated revenue growth plan. We view our business development activity as an enabler of our strategies and seek to generate growth by pursuing opportunities and transactions that have the potential to strengthen our business and our capabilities. The success of our business development activities is dependent on the availability and accurate evaluation of appropriate opportunities, competition from others that are seeking similar opportunities and our ability to successfully identify, structure and execute transactions, including the ability to satisfy or waive closing conditions in the anticipated timeframes, or at all, and our ability to successfully integrate acquired businesses and develop and commercialize acquired products. Pursuing, executing and consummating these transactions may require substantial investment, which may require us to obtain additional equity or debt

financing, which could result in increased leverage and/or a downgrade of our credit ratings or limit our operating or financial flexibility relative to our current position. The success of our business development transactions depends on our ability to realize the anticipated benefits of these transactions and is subject to numerous risks and uncertainties, many of which are outside of our control, including the possibility that the expected benefits from such transactions will not be realized or will not be realized within the expected time period. Unsuccessful clinical trials, regulatory hurdles and commercialization challenges may adversely impact revenue and income contribution from acquired products and businesses. We may fail to generate expected revenue growth for our existing products, product pipeline and acquired products or businesses or we may fail to achieve anticipated cost savings, such as those expected with respect to Seagen, within expected time frames or at all, which may impact our ability to meet our growth objectives. In certain transactions, we may agree to provide certain transition services for an extended period of time, which may divert our focus and resources that would otherwise be invested into maintaining or growing our business. Similarly, the accretive impact anticipated from transactions may not be realized or may be delayed. Integration of these products or businesses may result in the loss of key employees, the disruption of ongoing business, including third-party relationships, or inconsistencies in standards, controls, procedures and policies. Further, while we seek to mitigate risks and liabilities through, among other things, due diligence, we may be exposed to risks and liabilities as a result of business development transactions. There is no assurance that we will be able to acquire attractive businesses or enter into strategic business relationships on favorable terms ahead of our competitors, or that such acquisitions or strategic business development relationships will be accretive to earnings or improve our competitive position.

ITEM 2. UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS

The following summarizes purchases of our common stock during the third quarter of 2023:

(a)Represents (i) 98,065 shares of common stock surrendered to the Company to satisfy tax withholding obligations in connection with the vesting of awards under our long-term incentive programs and (ii) the open market purchase by the trustee of 2,445 shares of common stock in connection with the reinvestment of dividends paid on common stock held in trust for employees who deferred receipt of performance share awards.

(b)See the Analysis of Financial Condition, Liquidity, Capital Resources and Market Risk—Capital Allocation Framework section within MD&A of this Form 10-Q and Note 12 in our 2022 Form 10-K.