What changed in this filing

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Item 1A. Risk Factors

2026-04-29 compared with 2025-10-28 · 275 added, 241 removed, 758 unchanged (41% of the section changed)

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The risks described below include forward-looking statements, and actual events and our actual results may differ materially from these forward-looking statements.

References to past events are provided as examples only and are not intended to be a complete listing or representation as to whether or not such factors have occurred in the past or their likelihood of occurring in the future.

Additional risks and uncertainties not currently known to us or that we currently deem immaterial may also impair our business, prospects, operating results, and financial condition.

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Commercialization Risks

• We are substantially dependent on the success of EYLEA, EYLEA HD, and Dupixent.

• We are substantially dependent on revenues derived from net product sales of EYLEA HD, EYLEA, and Dupixent.

• Sales of our products are dependent on the availability and extent of coverage and reimbursement or copay assistance from third-party payors and other third parties, including private payors and government programs such as Medicare and Medicaid.

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Regulatory and Development Risks

• Drug development and obtaining and maintaining regulatory approval for drug products is costly, time-consuming, and highly uncertain.

• Drug development and obtaining and maintaining regulatory approval for drug and biological products is costly, time-consuming, and highly uncertain.

• Serious complications or side effects in connection with the use or development of our products or product candidates could cause our regulatory approvals to be revoked or limited or lead to delay or discontinuation of development of our product candidates or new indications for our marketed products.

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• We rely on limited internal and contracted manufacturing and supply chain capacity, which could adversely affect our ability to commercialize our products and to advance our clinical pipeline.

As we increase our production in response to higher product demand or in anticipation of a potential regulatory approval, our current manufacturing capacity will likely not be sufficient, and our dependence on our collaborators and/or contract manufacturers may increase, to produce adequate quantities of drug material for both commercial and clinical purposes.

As we increase our production in response to higher product demand or in anticipation of potential regulatory approvals, our current manufacturing capacity will likely not be sufficient, and our dependence on our collaborators and/or contract manufacturers may increase, to produce adequate quantities of drug material for both commercial and clinical purposes.

• Expanding our manufacturing capacity and establishing fill/finish capabilities has been and will continue to be costly and we may be unsuccessful in doing so in a timely manner, which could delay or prevent the launch and successful commercialization of our products approved for marketing and could jeopardize our clinical development programs.

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• If sales of our marketed products do not meet the levels currently expected, or if the launch of any of our product candidates is delayed or unsuccessful, we may face costs related to excess inventory or unused capacity at our manufacturing facilities and at the facilities of third parties or our collaborators.

• Third-party service or supply failures, failures at our manufacturing facilities in Rensselaer, New York and Limerick, Ireland, or failures at the facilities of any other party participating in the supply chain would adversely affect our ability to supply our products.

• Third-party service or supply failures, failures at our manufacturing facilities in Rensselaer, New York and Limerick, Ireland, or failures at the facilities of any other party participating in the supply chain could adversely affect our ability to supply our products.

• Our or our collaborators' or contract manufacturers' failure to meet the stringent requirements of governmental regulation in the manufacture of drug products or product candidates could result in incurring substantial remedial costs, delays in the development or approval of our product candidates or new indications for our marketed products and/or in their commercial launch if regulatory approval is obtained, and a reduction in sales.

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Other Risks Related to Our Business and Our Common Stock

• Our business is dependent on our key personnel and will be harmed if we cannot recruit and retain key members of our senior management team, including leaders in our research, development, manufacturing, and commercial organizations.

• Our business is dependent on our key personnel and will be harmed if we cannot recruit or retain key members of our senior management team, including leaders in our research, development, manufacturing, and commercial organizations.

• Significant disruptions of information technology systems or breaches of data security could adversely affect our business.

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Risks Related to Commercialization of Our Marketed Products, Product Candidates, and New Indications for Our Marketed Products

We are substantially dependent on the success of EYLEA, EYLEA HD, and Dupixent.

We are substantially dependent on the success of EYLEA and EYLEA HD.

EYLEA net product sales have historically represented a substantial portion of our revenues, and we expect that there will continue to be a concentration of our net sales from the net product sales of EYLEA HD and EYLEA.

For the nine months ended September 30, 2025 and 2024, our aggregate EYLEA HD and EYLEA net product sales in the United States represented 32% and 43% of our total revenues, respectively.

For the nine months ended September 30, 2025, EYLEA HD U.S.

We are substantially dependent on revenues derived from net product sales of EYLEA HD, EYLEA, and Dupixent.

We are substantially dependent on revenues derived from net product sales of EYLEA HD and EYLEA.

Net product sales of these products have historically represented a substantial portion of our revenues, and we expect net sales of these products to continue to be a significant contributor to our revenues and operating results, with an increasing dependence on EYLEA HD relative to our historical dependence on EYLEA.

For the three months ended March 31, 2026 and 2025, our aggregate EYLEA HD and EYLEA net product sales in the United States represented 26% and 34% of our total revenues, respectively.

For the three months ended March 31, 2026, EYLEA HD U.S.

net product sales represented 50% of our aggregate EYLEA HD and EYLEA U.S.

net product sales.

As we further commercialize EYLEA HD, we expect that our dependence on EYLEA HD will grow relative to our historical dependence on EYLEA.

If we experience difficulty with the commercialization of EYLEA HD or EYLEA in the United States or if Bayer experiences any difficulty with the commercialization of EYLEA HD or EYLEA outside the United States, if EYLEA net product sales experience a sustained decline in or outside the United States without an offset from EYLEA HD net product sales, or if we and Bayer are unable to maintain or obtain marketing approvals of these products (as applicable), we may experience a reduction in revenue and may not be able to stay profitable at the levels we previously achieved or at all, and our business, prospects, operating results, and financial condition may be materially harmed.

Commercialization of EYLEA and EYLEA HD in the United States and elsewhere is subject to significant competition (as described further below under " The commercial success of our products and product candidates is subject to significant competition "), which we expect to continue to increase in the future.

For the three and nine months ended September 30, 2025, EYLEA U.S.

net product sales declined by 41% and 39%, respectively, compared to the corresponding periods in 2024 as a result of competitive pressures and other factors described under Part I, Item 2.

If we experience difficulty with the commercialization of EYLEA HD or EYLEA in the United States or if Bayer experiences any difficulty with the commercialization of EYLEA HD or EYLEA outside the United States, if EYLEA HD net product sales do not sufficiently offset any sustained decline of EYLEA net product sales in or outside the United States, or if we and Bayer are unable to maintain or obtain marketing approvals of these products (as applicable), we may experience a reduction in revenue and may not be able to stay profitable at the levels we previously achieved or at all, and our business, prospects, operating results, and financial condition may be materially harmed.

Commercialization of EYLEA HD and EYLEA in the United States and elsewhere is subject to significant competition (as described further below under " The commercial success of our products and product candidates is subject to significant competition "), which we expect to continue to increase in the future.

For the three months ended March 31, 2026, EYLEA U.S.

net product sales declined by 36% compared to the corresponding period in 2025 as a result of competitive pressures and other factors described under Part I, Item 2.

"Management's Discussion and Analysis of Financial Condition and Results of Operations – Results of Operations." Following the expiration of the U.S.

regulatory exclusivity period for EYLEA (i.e., the period during which no biosimilar product can be approved by the FDA) in May 2024, several biosimilar versions of EYLEA have been approved by the FDA, and one such product has launched in the United States.

EYLEA and/or EYLEA HD net product sales recorded by us are likely to continue to be negatively impacted by biosimilar competition in the United States, which may have a material adverse impact on our results of operations.

In addition, we expect that competition for EYLEA outside the United States will continue to increase as biosimilar versions of EYLEA (including those already approved but not yet launched) are brought to market in additional countries, which may negatively

impact the amount of collaboration revenue we earn from Bayer.

While we expect certain regulatory decisions relevant to further commercialization of EYLEA HD as shown in the table under Part I, Item 2.

"Management's Discussion and Analysis of Financial Condition and Results of Operations - Overview - Programs in Clinical Development" and further discussed under Part I, Item 2.

"Management's Discussion and Analysis of Financial Condition and Results of Operations - Overview - Additional Information - Clinical Development Programs - EYLEA HD," there can be no assurance that any such milestones will be achieved in the currently anticipated time frame or at all and, if achieved, that they will help accelerate the ongoing launch and further commercialization of EYLEA HD.

regulatory exclusivity period for EYLEA in May 2024, several biosimilar versions of EYLEA have been approved by the FDA, and one such product has launched in the United States.

EYLEA and/or EYLEA HD net product sales recorded by us are likely to continue to be negatively impacted by biosimilar competition in the United States, including competition from additional biosimilar versions of EYLEA expected to launch in the United States in the second half of 2026, which may have a material adverse impact on our results of operations.

In addition, we expect that competition for EYLEA and/or EYLEA HD outside the United States will continue to increase as biosimilar versions of EYLEA (including those already approved but not yet launched) are brought to market in additional countries, which may negatively impact the amount of collaboration revenue we earn from Bayer.

While in the last six months the FDA approved EYLEA HD for the treatment of RVO and for additional dosing regimens and we continue to work toward FDA approval of the EYLEA HD pre-filled syringe as discussed under Part I, Item 1.

"Business - Programs in Clinical Development - Additional Information - Clinical Development Programs - EYLEA HD," there can be no assurance that these

enhancements (including potential FDA approval of the EYLEA HD pre-filled syringe) will help accelerate any potential future growth of EYLEA HD net product sales.

The degree to which EYLEA HD net product sales may offset further potential decreases in EYLEA net product sales, resulting from the factors discussed above or otherwise, is uncertain.

We also are substantially dependent on our share of profits from the commercialization of Dupixent under our Antibody Collaboration with Sanofi.

For the nine months ended September 30, 2025 and 2024, Sanofi collaboration revenue (most of which is attributable to our share of profits from the commercialization of Dupixent) represented 41% and 32% of our total revenues, respectively.

We also are substantially dependent on our share of profits from the commercialization of Dupixent under our collaboration with Sanofi (the "Antibody Collaboration").

For the three months ended March 31, 2026 and 2025, Sanofi collaboration revenue (most of which is attributable to our share of profits from the commercialization of Dupixent) represented 45% and 39% of our total revenues, respectively.

If we or Sanofi were to experience any difficulty with the commercialization of Dupixent or if we or Sanofi are unable to maintain current marketing approvals of Dupixent, we may experience a reduction in revenue and our business, prospects, operating results, and financial condition may be materially harmed.

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• our ability and our collaborators' ability to maintain sales of our marketed products in the face of competitive products and to differentiate our marketed products from competitive products, including as applicable product candidates currently in clinical development;

and, in the case of EYLEA and EYLEA HD, the existing and potential new branded and biosimilar competition (discussed further under " The commercial success of our products and product candidates is subject to significant competition - Marketed Products" below) and the willingness of retinal specialists and patients to start or continue treatment with such products or to switch from a competitive product to one of our products;

• the safety and efficacy of our marketed products (particularly those launched recently, such as EYLEA HD) seen in a broader patient group (i.e., real-world use);

• the effect of existing and new healthcare laws and regulations currently being considered or implemented in the United States and globally, including measures requiring the U.S.

and, in the case of EYLEA HD and EYLEA, the existing and potential new branded and biosimilar competition (discussed further under " The commercial success of our products and product candidates is subject to significant competition - Marketed Products" below) and the willingness of retinal specialists and patients to start or continue treatment with such products or to switch from a competitive product to one of our products;

• the safety and efficacy of our marketed products seen in a broader patient group (i.e., real-world use);

• the effect of existing and new healthcare laws and regulations, pricing mandates, and agreements with government entities (including the U.S.

Government Agreements) currently being considered or implemented in the United States and globally, including measures requiring the U.S.

government in the future to negotiate the prices of certain drugs and price reporting and other disclosure requirements and the potential impact of such requirements on physician prescribing practices and payor coverage;

• serious complications or side effects in connection with the use of our marketed products, as discussed under "Risks Related to Maintaining Approval of Our Marketed Products and the Development and Obtaining Approval of Our Product Candidates and New Indications for Our Marketed Products - Serious complications or side effects in connection with the use of our products and in clinical trials for our product candidates and new indications for our marketed products could cause our regulatory approvals to be revoked or limited or lead to delay or discontinuation of development of our product candidates or new indications for our marketed products, which could severely harm our business, prospects, operating results, and financial condition " below;

• maintaining and successfully monitoring commercial manufacturing arrangements for our marketed products with third parties who perform fill/finish and bulk product manufacturing or other steps in the manufacture of such products to ensure that they meet our standards and those of regulatory authorities, including the FDA, which extensively regulate and monitor pharmaceutical manufacturing facilities;

• serious complications or side effects in connection with the use of our marketed products, as discussed under "Risks Related to Maintaining Approval of Our Marketed Products and the Development and Obtaining Approval of Our Product Candidates and New Indications for Our Marketed Products - Serious complications or side effects in connection with the use or development of our products or product candidates could cause our regulatory approvals to be revoked or limited or lead to delay or discontinuation of development of our product candidates or new indications for our marketed products, which could severely harm our business, prospects, operating results, and financial condition " below;

• our ability to meet the demand for commercial supplies of our marketed products;

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We and our collaborators are subject to significant ongoing regulatory obligations and oversight with respect to the products we or they commercialize for the products' currently approved indications in the United States, EU, Japan, and other countries.

If we or our collaborators fail to maintain regulatory compliance or satisfy other obligations for such products' currently approved indications (including because the product does not meet the relevant endpoints of any required post-approval studies (such as those required under an accelerated approval by the FDA or other similar type of approval), or for any of the reasons discussed below under "Risks Related to Maintaining Approval of Our Marketed Products and the Development and Obtaining Approval of Our Product Candidates and New Indications for Our Marketed Products - Obtaining and maintaining regulatory approval for drug products is costly, time-consuming, and highly uncertain.

If we or our collaborators do not maintain regulatory approval for our marketed products, and obtain regulatory approval for our product candidates or new indications for our marketed products, we will not be able to market or sell them, which would materially and negatively impact our business, prospects, operating results, and financial condition.

If we or our collaborators fail to maintain regulatory compliance or satisfy other obligations for such products' currently approved indications (including because the product does not meet the relevant endpoints of any required post-approval studies (such as those required under an accelerated approval by the FDA or other similar type of approval), or for any of the reasons discussed below under "Risks Related to Maintaining Approval of Our Marketed Products and the Development and Obtaining Approval of Our Product Candidates and New Indications for Our Marketed Products - Obtaining and maintaining regulatory approval for drug and biological products is costly, time-consuming, and highly uncertain.

If we or our collaborators do not maintain regulatory approval for our marketed products, or obtain regulatory approval for our product candidates, we will not be able to market or sell them;

and if we do not obtain approvals for new indications for our marketed products, we may not be able to realize the full commercial potential of such products.

Any of the foregoing may materially and negatively impact our business, prospects, operating results, and financial condition.

"), the applicable marketing approval may be withdrawn, which would materially harm our business, prospects, operating results, and financial condition.

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Third-party payors may also require prior authorization for reimbursement, require failure on another type of treatment, or impose other utilization management restrictions before covering a particular drug, particularly with respect to higher-priced drugs.

Further, sales of our marketed products (such as EYLEA and EYLEA HD) in the United States may be adversely impacted by the lack of sufficient copay assistance from not-for-profit patient assistance funds.

Further, sales of our marketed products (such as EYLEA HD and EYLEA) in the United States may be adversely impacted by the lack of sufficient copay assistance from not-for-profit patient assistance funds.

For example, a loss in market share to compounded bevacizumab due to patient affordability constraints impacted U.S.

net product sales of EYLEA for the three and nine months ended September 30, 2025, as further described under Part I, Item 2.

"Management's

Discussion and Analysis of Financial Condition and Results of Operations – Results of Operations." If independent not-for-profit patient assistance funds that provide patient copay assistance are unable to support eligible patients, this will likely have a continued negative impact on patient affordability resulting in lower utilization of higher-cost anti-VEGF agents.

net product sales of EYLEA for the year ended December 31, 2025, as further described under Part II, Item 7.

"Management's Discussion and Analysis of Financial Condition and Results of Operations – Results of Operations" of our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 (filed February 4, 2026).

If independent not-for-profit patient assistance funds that provide patient copay assistance are unable to support eligible patients, this will likely have a continued negative impact on patient affordability resulting in lower utilization of higher-cost anti-VEGF agents.

As our currently marketed products and most of our product candidates are biologics, bringing them to market may cost more than bringing traditional, small-molecule drugs to market due to the complexity associated with the research, development, production, supply, and regulatory review of such products.

Given cost sensitivities in many healthcare systems, our currently marketed products and product candidates are likely to be subject to continued pricing pressures, which may have an adverse impact on our business, prospects, operating results, and financial condition.

In addition, in order for private insurance and governmental payors (such as Medicare and Medicaid in the United States) to reimburse the cost of our marketed products, we must maintain, among other things, our FDA registration and our National Drug Code, formulary approval by PBMs, and recognition by insurance companies and the Centers for Medicare & Medicaid Services ("CMS").

Given cost sensitivities in many healthcare systems, our currently

marketed products and product candidates are likely to be subject to continued pricing pressures, which may have an adverse impact on our business, prospects, operating results, and financial condition.

There is no certainty that we will be able to obtain or maintain the applicable requirements for reimbursement (including relevant formulary coverage, as discussed further below) of our current and future marketed products, which may have a material adverse effect on our business.

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For example, the EU provides options for its member states to restrict the range of medicinal products for which their national health insurance systems provide reimbursement and to control the prices of medicinal products for human use.

A member state may approve a specific price for the medicinal product or it may instead adopt a system of direct or indirect controls on the profitability of the company placing the medicinal product on the market.

A member state may approve a specific price for the medicinal product or it may instead adopt a system of direct or indirect limitations on the profitability of the medicinal product placed on the market.

In addition, in many countries outside the United States, we or our collaborators must participate in a tender process for public procurement of our products, and any failure to obtain acceptable pricing in the tender process could adversely affect our business.

Our results of operations may suffer if we or our collaborators are unable to market our products in countries outside the United States or if coverage and reimbursement for our marketed products in such countries is limited or delayed.

As discussed below under " If we are unable to establish sufficient commercial capabilities outside the United States for products we intend to commercialize or co-commercialize outside the United States, our business, prospects, operating results, and financial condition may be adversely affected, " we will need to manage these and other commercialization-related risks in order for us to successfully maintain and/or further develop sufficient commercial capabilities outside the United States (including those necessary for our successful commercialization and co-commercialization of Libtayo and Dupixent, respectively).

Product reimbursement and coverage policies and practices, pricing regulations and requirements, and our pricing strategy could change due to various factors beyond our control, which may adversely impact our business, prospects, operating results, and financial condition.

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The IRA implements changes to the Medicare Part D benefits to limit patient out-of-pocket drug costs and shift program liabilities from patients to other stakeholders, including health plans, manufacturers, and the government.

The full extent to which the policy changes described above will ultimately impact reimbursement levels of our marketed products, including those covered under Medicare Part B (such as EYLEA and EYLEA HD), or our product candidates that may be covered under Medicare Part B or Medicare Part D in the future, is currently unclear.

The full extent to which the policy changes described above will ultimately impact reimbursement levels of our marketed products, including those covered under Medicare Part B (such as EYLEA HD and EYLEA), or our product candidates that may be covered under Medicare Part B or Medicare Part D in the future, is currently unclear.

In addition, the current U.S.

administration is pursuing other measures to reduce the cost of drugs in the United States.

For example, a recent executive order directed the U.S.

Department of Health and Human Services ("HHS") and other federal agencies to take certain steps intended to, among other things, reduce the prices of drugs sold in the United States to match the lowest price available for the same drugs in comparably developed nations (commonly referred to as "most-favored-nation" ("MFN") pricing).

On July 31, 2025, as a follow-up to this executive order, President Trump sent a letter to several pharmaceutical companies (including Regeneron) requesting that within the next 60 days they, among other matters, provide their existing drugs at MFN rates to Medicaid patients, guarantee MFN pricing for newly launched drugs, and provide for direct-to-consumer and direct-to-business distribution models for high-volume, high-rebate prescription drugs.

In addition, a prior executive order directed the HHS to take appropriate steps to, among other things, modify certain provisions of the Medicare Drug Price Negotiation Program, develop and implement a payment model to reduce the price of high-cost prescription drugs and biological products covered by Medicare, accelerate approval of generic and biosimilar products, and facilitate the ability of states to import pharmaceuticals from other countries.

It is currently unclear how and to what extent these measures may be implemented and what impact any such implementation would have on our Company.

At the state level, legislatures are becoming increasingly aggressive in passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access, price and marketing cost disclosure and transparency measures, and measures that could impact the availability of the ceiling price under the federal government's 340B program (see also "Other Regulatory and Litigation Risks - If we fail to comply with our reporting and payment obligations under the Medicaid Drug Rebate program or other governmental pricing programs, we could be subject to additional reimbursement requirements, penalties, sanctions, and fines, which could have a material adverse effect on our business, financial condition, results of operations, and future prospects .").

For example, in May 2025, an executive order directed the U.S.

In addition, a prior executive order from April 2025 directed the HHS to take appropriate steps to, among other things, modify certain provisions of the Medicare Drug Price Negotiation Program, develop and implement a payment model to reduce the price of high-cost prescription drugs and biological products covered by Medicare, accelerate approval of generic and biosimilar products, and facilitate the ability of states to import pharmaceuticals from other countries.

In response to these executive orders, in December 2025, the Center for Medicare and Medicaid Innovation proposed two mandatory Medicare payment models that, if finalized, would apply to certain drugs covered under Medicare Parts B and D and test whether alternative methodologies for calculating inflationary rebates based on international reference pricing would reduce Medicare spending.

It is currently unclear how and to what extent the measures described in this paragraph may be implemented and what impact any such implementation would have on our Company.

In April 2026, in response to the May 2025 executive order described above and a related letter that we and certain other pharmaceutical companies received from President Trump, we entered into the U.S.

Government Agreements, pursuant to which we have agreed, among other matters, to provide certain of our products that we wholly own in the United States to the Medicaid program, and to price certain future medicines in the United States, at or below Most-Favored-Nation Pricing.

Government Agreements further provide that Regeneron's products will not face tariffs as a result of the investigation under Section 232 of the Trade Expansion Act of 1962, as amended ("Section 232"), through January 2029 so long as the Company continues its commitments to invest in manufacturing and research and development infrastructure in the United States.

Government Agreements will likely result, and any potential future agreements with government entities could also result, in reduced prices and reimbursement for certain of our current and future marketed products and may impact our results of operations.

See Part I, Item 2.

"Management's Discussion and Analysis of Financial Condition and Results of Operations – Overview – Recent Developments – Agreement with the U.S.

Government ." We also remain subject to any current or future pricing mandates implemented outside the United States, and it is possible that current or future pricing regulations may have a material impact on our business and results of operations.

At the state level, legislatures are becoming increasingly aggressive in passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access, price and marketing cost disclosure and transparency measures, and measures that could expand the applicability of the ceiling price under the federal government's 340B program (see also "Other Regulatory and Litigation Risks - If we fail to comply with our reporting and payment obligations under the Medicaid Drug Rebate program or other governmental pricing programs, we could be subject to additional reimbursement requirements, penalties, sanctions, and fines, which could have a material adverse effect on our business, financial condition, results of operations, and future prospects .").

In some cases, these measures are designed to encourage importation from other countries and bulk purchasing.

A reduction in the availability or extent of reimbursement from U.S.

government programs (including as a result of the legislation, proposals, initiatives, and developments described above) could have a material adverse effect on the sales of our marketed products.

government programs (including as a

result of the legislation, proposals, initiatives, and developments described above) could have a material adverse effect on the sales of our marketed products.

Economic pressure on state budgets may also have a similar impact.

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There is significant actual and potential future competition for each of our marketed products.

EYLEA and EYLEA HD.

EYLEA and EYLEA HD face significant competition in the marketplace.

For example, each of EYLEA and EYLEA HD competes in one or more of its approved indications with other VEGF inhibitors.

EYLEA HD and EYLEA.

EYLEA HD and EYLEA face significant competition in the marketplace.

For example, each of EYLEA HD and EYLEA competes in one or more of its approved indications with other VEGF inhibitors.

These include Genentech/Roche's Vabysmo ® (faricimab-svoa) and Susvimo ® (ranibizumab ocular implant);

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and a biosimilar version of Lucentis commercialized in the United States by Biogen Inc.

In addition, biosimilar versions of EYLEA have been approved and/or launched both in and outside the United States, including Amgen's Pavblu ™ (aflibercept-ayyh) (launched in the United States in the fourth quarter of 2024).

In addition, biosimilar versions of EYLEA have been approved and/or launched both in and outside the United States, including Amgen's Pavblu ™ (aflibercept-ayyh) in the United States.

We are aware of several other companies developing biosimilar versions of EYLEA, EYLEA HD, and/or other approved anti-VEGF treatments.

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"Business - Patents, Trademarks, and Trade Secrets" of our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 (filed February 4, 2026)).

Ophthalmologists are also using off-label, third-party repackaged versions of Genentech/Roche's approved VEGF antagonist, bevacizumab, for the treatment of certain of EYLEA's and EYLEA HD's respective indications, and we are aware of another company developing an ophthalmic formulation of such product that has been approved in the EU.

In DME (and, in the case of EYLEA, also RVO), EYLEA and EYLEA HD also compete with intravitreal implants of corticosteroids.

We are also aware of a number of companies working on the development of product candidates and extended delivery devices for the potential treatment of one or more of EYLEA's and EYLEA HD's respective indications, including those that act by blocking VEGF and VEGF receptors (including therapies designed to extend the treatment interval) and/or other targets.

Ophthalmologists are also using off-label, third-party repackaged versions of Genentech/Roche's approved VEGF antagonist, bevacizumab, for the treatment of certain of EYLEA HD's and EYLEA's respective indications, and we are aware of another company developing an ophthalmic formulation of such product that has been approved in the EU.

In DME and RVO, EYLEA HD and EYLEA also compete with intravitreal implants of corticosteroids.

We are also aware of a number of companies working on the development of product candidates and extended delivery devices for the potential treatment of one or more of EYLEA HD's and EYLEA's respective indications, including those that act by blocking VEGF and VEGF receptors (including therapies designed to extend the treatment interval) and/or other targets.

Other potentially competitive products in development include products for use in combination with EYLEA and/or other anti-VEGF treatments, small-molecule tyrosine kinase inhibitors, gene therapies, and other eye-drop formulations, devices, and oral therapies.

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We are aware of claims by third parties, including those based on published clinical data, alleging that ZALTRAP may be safely administered to the eye.

EYLEA HD was approved by the FDA in August 2023 for the treatment of wAMD, DME, and DR and entered the highly competitive environment described above.

Our success in commercializing EYLEA HD will continue to depend on a number of factors, including the degree of success and relative timing of our commercial launch and uptake efforts as compared to those of relevant competition, the extent to which we and our collaborators are able to differentiate EYLEA HD from competitive products (such as on the basis of dosing frequency, the method of administration, or the breadth of indications in which the product is approved), the safety and efficacy of EYLEA HD seen in a broader patient group (i.e., real-world use), the extent of payor coverage, reimbursement, and copay assistance, and the applicability of any restrictions imposed by payors, such as step therapy.

EYLEA HD was launched in 2023 and entered the highly competitive environment described above.

Our success in commercializing EYLEA HD will continue to depend on a number of factors, including the degree of success of our uptake efforts as compared to those of relevant competition, the extent to which we and our collaborators are able to differentiate EYLEA HD from competitive products (such as on the basis of dosing frequency, the method of administration, or the breadth of indications in which the product is approved), the safety and efficacy of EYLEA HD seen in a broader patient group (i.e., real-world use), the extent of payor coverage, reimbursement, and copay assistance, and the applicability of any restrictions imposed by payors, such as step therapy.

The market for Dupixent's current and potential future indications is also increasingly competitive.

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There is also an antibody against IL-31R approved for atopic dermatitis and prurigo nodularis.

In addition, a number of companies are

developing antibodies against other targets, including OX40(L), that may compete with Dupixent in atopic dermatitis and other indications (including asthma and/or prurigo nodularis).

In addition, a number of companies are developing antibodies against other targets, including OX40(L), that may compete with Dupixent in atopic dermatitis.

In asthma, competitors to Dupixent include antibodies against the IL-5 ligand or the IL-5 receptor, immunoglobulin E, or thymic stromal lymphopoietin ("TSLP");

and some of these antibodies are either approved or in development for indications that also compete or may compete in the future with Dupixent in CRSwNP, EoE, COPD, and CSU where approved.

There are several other potentially competitive products in development that may compete with Dupixent in asthma, COPD, and potential future indications, including antibodies against the IL-33 ligand or receptor.

Dupixent also faces competition from inhaled products in asthma, COPD, and potential future indications.

There are several other potentially competitive products in development that may compete with Dupixent in atopic dermatitis, asthma, COPD, and potential future indications, including STAT6 oral small molecules, and multispecific antibodies against IL-13 and TSLP, with and without IL-4.

Dupixent also faces competition from a Bruton tyrosine kinase inhibitor in CSU and may in the future face competition from inhaled products in asthma, COPD, and potential future indications.

Libtayo also faces significant competition.

There are several competitors that are marketing and/or developing antibodies against PD-1 and/or PDL-1 (some of which were approved in the relevant indications and commercialized before Libtayo), including Merck's Keytruda ® (pembrolizumab), Bristol-Myers Squibb's Opdivo ® (nivolumab), Roche's Tecentriq ® (atezolizumab), AstraZeneca's Imfinzi ® (durvalumab), and Sun Pharma's Unloxcyt ™ (cosibelimab).

There are several competitors that are marketing and/or developing antibodies against PD-1 and/or PDL-1 (some of which were approved in the relevant indications and commercialized before

Libtayo), including Merck's Keytruda ® (pembrolizumab), Bristol-Myers Squibb's Opdivo ® (nivolumab), Roche's Tecentriq ® (atezolizumab), AstraZeneca's Imfinzi ® (durvalumab), and Sun Pharma's Unloxcyt ™ (cosibelimab).

While Libtayo is currently approved for intravenous administration only, certain of these products are also approved or in development for subcutaneous use.

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Product Candidates

Our VelocImmune ® technology, other antibody generation technologies, and late-stage and earlier-stage clinical candidates face competition from many pharmaceutical and biotechnology companies using various technologies, including antibody generation technologies and other approaches such as RNAi, chimeric antigen receptor T cell (CAR-T cell), and gene therapy technologies.

For example, we are aware of other pharmaceutical and biotechnology companies actively engaged in the research and development of antibody-based and gene therapy-based products against targets that are also the targets of our early- and late-stage product candidates.

For example, we are aware of other pharmaceutical and biotechnology companies actively engaged in the research and development of antibody-based products (including bispecific antibodies, multispecific antibodies, and/or antibody-drug conjugates) and gene therapy-based products against targets that are also the targets of our early- and late-stage product candidates.

We are also aware of other companies developing or marketing small molecules or other treatments that may compete with our antibody-based product candidates in various indications, if such product candidates obtain regulatory approval in those indications.

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Accordingly, the relative speed with which we, or our collaborators, can develop our product candidates, complete the clinical trials and approval processes, and, if such product candidates are approved for marketing and sale, supply commercial quantities to the market is expected to continue to be an important competitive factor.

Due to the uncertainties associated with developing biopharmaceutical products, we may not be the first to obtain marketing approval for a product against any particular target, which may have a material adverse effect on our business or future prospects.

Due to the uncertainties associated with developing pharmaceutical products, we may not be the first to obtain marketing approval for a product against any particular target, which may have a material adverse effect on our business or future prospects.

While we evaluate market opportunities for our product candidates, there can be no assurance that our estimates will accurately reflect the market opportunity at the time of launch or that our product candidates will meet internal or external expectations and be successful commercially due to existing or potential future competition or otherwise.

We face increasing competition from Chinese biotechnology and pharmaceutical companies, including Chinese state-owned or state-backed enterprises, with respect to both our marketed products and product candidates.

China has become one of the world's leading developers of new drugs, and Chinese companies benefit from a regulatory regime that enables rapid, low-cost clinical trials that facilitate innovation.

Furthermore, we compete with other large pharmaceutical companies, many of which have invested significantly in China, in acquiring or licensing Chinese product candidates, and we may not be as successful as our competitors in identifying or accessing such assets.

We rely on our collaborations with Bayer and Sanofi for commercializing some of our marketed products.

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While we exercised our option under the Antibody Collaboration to co-commercialize Dupixent in certain jurisdictions outside the United States, we continue to rely in considerable part on Sanofi's sales and marketing organization in such jurisdictions.

As described in Note 12 to our Condensed Consolidated Financial Statements included in this report, we have sued Sanofi and certain of its affiliated entities (the "Antibody Collaboration Litigation") alleging that the defendants breached certain provisions of the agreement governing the Antibody Collaboration (the "Collaboration Agreement").

described in Note 12 to our Condensed Consolidated Financial Statements included in this report, we have sued Sanofi and certain of its affiliated entities (the "Antibody Collaboration Litigation") alleging that the defendants breached certain provisions of the agreement governing the Antibody Collaboration (the "Collaboration Agreement").

These provisions concern Sanofi's obligation to provide Regeneron with full access to material information relating to the commercialization of Dupixent or other products commercialized pursuant to the Collaboration Agreement and Regeneron's audit rights under the Collaboration Agreement.

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In the United States, prices for pharmaceuticals are generally higher than in the bordering nations of Canada and Mexico and sales of our marketed products in the United States may be reduced if the applicable product marketed in those bordering nations is imported into the United States.

In addition, there are proposals to legalize the import of pharmaceuticals from outside the United States into the United States and, as discussed above under " Product reimbursement and coverage policies and practices, pricing regulations and requirements, and our pricing strategy could change due to various factors beyond our control, which may adversely impact our business, prospects, operating results, and financial condition, " a recent executive order has directed the Secretary of the HHS to take appropriate steps to facilitate such importation at the state level.

In addition, there are proposals to legalize the import of pharmaceuticals from outside the United States into the United States and, as discussed above under " Product reimbursement and coverage policies and practices, pricing regulations and requirements, and our pricing strategy could change due to various factors beyond our control, which may adversely impact our business, prospects, operating results, and financial condition, " an executive order from April 2025 directed the Secretary of the HHS to take appropriate steps to facilitate such importation at the state level.

If such or other similar proposals were to be implemented, our future revenues derived from sales of our marketed products could be reduced.

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Establishing and maintaining sales, marketing, and distribution capabilities are expensive and time-consuming.

In addition, we may need to further develop or acquire these capabilities as we and/or our collaborators continue to pursue the development of drugs generated by means other than our established "Trap" or VelociSuite technologies, such as siRNA gene silencing, genome editing, and targeted viral-based gene delivery and expression.

Even if we obtain regulatory approval for our product candidates or new indications, if they are not successfully commercialized, we will not be able to recover the significant investment we have made in developing such products and our business, prospects, operating results, and financial condition would be severely harmed.

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We sell our marketed products for which we record net product sales in the United States to several distributors and specialty pharmacies, as applicable (collectively, "distributor customers"), which generally sell the product directly to healthcare providers or other pharmacies (as applicable).

For the nine months ended September 30, 2025 and 2024, our product sales to two distributor customers accounted on a combined basis for 77% and 75% of our total gross product revenue, respectively.

For the three months ended March 31, 2026 and 2025, our product sales to two distributor customers accounted on a combined basis for 75% and 76% of our total gross product revenue, respectively.

We expect significant distributor customer concentration to continue for the foreseeable future.

Our ability to generate and grow sales of these products will depend, in part, on the extent to which our distributor customers are able to provide adequate distribution of these products to healthcare providers.

Our ability to generate and grow sales of our products will depend, in part, on the extent to which our distributor customers are able to provide adequate distribution of our products to healthcare providers.

Although we believe we can find additional distributors, if necessary, our revenue during any period of disruption could suffer and we might incur additional costs.

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If we are unable to establish sufficient commercial capabilities outside the United States for products we intend to commercialize or co-commercialize outside the United States, our business, prospects, operating results, and financial condition may be adversely affected.

While we have made progress with establishing commercial capabilities in certain jurisdictions outside the United States in connection with our acquisition of the exclusive right to develop, commercialize, and manufacture Libtayo worldwide pursuant to the 2022 Amended and Restated Immuno-oncology License and Collaboration Agreement with Sanofi (the "A&R IO LCA") and the exercise of our option under the Antibody Collaboration to co-commercialize Dupixent in certain jurisdictions outside the United States, our commercial capabilities and experience with commercializing products outside the United States (as well as obtaining and/or maintaining regulatory approvals and securing pricing and reimbursement for our products outside the United States) are still somewhat limited.

There may be other circumstances in which we need to establish further commercial capabilities outside the United States, including because we decide to commercialize other products independently;

While we have made progress with establishing commercial capabilities in certain jurisdictions outside the United States in recent years (primarily in connection with our acquisition of the worldwide rights to Libtayo in 2022 and the exercise of our option under the Antibody Collaboration to co-commercialize Dupixent in certain jurisdictions outside the United States), our commercial capabilities and experience with commercializing products outside the United States (as well as obtaining and/or maintaining regulatory approvals and securing pricing and reimbursement for our products outside the United States) are still somewhat limited.

There may be other circumstances in which we need to establish further commercial capabilities outside the United States, including because we decide to commercialize other products independently (such as Lynozyfic and Ordspono, which we recently launched in the EU);

we are unable to find an appropriate collaborator;

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Risks Related to Maintaining Approval of Our Marketed Products and the Development and Obtaining Approval of Our Product Candidates and New Indications for Our Marketed Products

Obtaining and maintaining regulatory approval for drug products is costly, time-consuming, and highly uncertain.

Obtaining and maintaining regulatory approval for drug and biological products is costly, time-consuming, and highly uncertain.

If we or our collaborators do not maintain regulatory approval for our marketed products, or obtain regulatory approval for our product candidates, we will not be able to market or sell them;

and if we do not obtain approvals for new indications for our marketed products, we may not be able to realize the full commercial potential of such products.

Any of the foregoing may materially and negatively impact our business, prospects, operating results, and financial condition.

We cannot sell or market products without regulatory approval or other authorization.

If we or our collaborators do not maintain regulatory approval for our marketed products, and obtain regulatory approval for our product candidates or new indications of our marketed products (or are materially delayed in doing so), the value of our Company and our business, prospects, operating results, and financial condition may be materially harmed.

In the United States, we (which, for purposes of this risk factor, includes our collaborators, unless otherwise stated or required by the context) must obtain and maintain approval from the FDA for each drug we intend to sell.

We must obtain and maintain similar regulatory approvals from comparable foreign regulatory authorities in order to sell drugs outside the United States.

Obtaining FDA or comparable foreign regulatory authority approval for a new drug or indication is typically a lengthy and expensive process, and approval is highly uncertain.

If we or our collaborators do not maintain regulatory approval for our marketed products, or obtain regulatory approval for our product candidates or new indications of our marketed products (or are materially delayed in doing so), the value of our Company and our business, prospects, operating results, and financial condition may be materially harmed.

We must obtain and maintain similar regulatory approvals from comparable foreign regulatory authorities in order to sell drugs and biologics outside the United States.

Obtaining FDA or comparable foreign regulatory authority approval for a new drug or biologic or indication is typically a lengthy and expensive process, and approval is highly uncertain.

We cannot predict with certainty if or when we might submit for regulatory approval for our product candidates currently under development.

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Additionally, in the United States, the FDA may determine that a Risk Evaluation and Mitigation Strategy ("REMS") is necessary to ensure that the benefits of a new product outweigh its risks, and the product can therefore be approved.

A REMS may include various elements, ranging from a medication guide or patient package insert to limitations on who may prescribe or dispense the drug, depending on what the FDA considers necessary for the safe use of the drug.

A REMS may include various elements, ranging from a medication guide or patient package insert to limitations on who may prescribe or dispense the drug or biologic, depending on what the FDA considers necessary for the safe use of the drug or biologic.

The FDA has substantial discretion in the approval process (including with respect to setting specific conditions for submission) and may either refuse to accept an application for substantive review or may form the opinion after review of an application that the application is insufficient to allow approval of a product candidate.

If the FDA does not accept our application for review or approve our application, it may require that we conduct additional clinical, preclinical, or manufacturing validation studies or additional analyses of data from existing studies and submit the data before it will reconsider our application.

Depending on the extent of these or any other studies or analyses that might be required, approval of any applications that we submit may be delayed significantly, or we may be required to expend more resources.

It is also possible that any such additional studies or analyses, if performed and completed, may not be considered sufficient by the FDA to make our applications approvable.

If any of these outcomes occur, we may be forced to delay or abandon our applications for approval.

For example, in October 2023, the FDA issued a CRL for the sBLA for Dupixent in CSU stating that additional efficacy data are required to support an approval, which delayed by nearly 18 months the FDA's April 2025 approval of Dupixent in this indication.

In certain instances (such as when we use a biomarker-based test to identify and enroll specific patients in a clinical trial), regulatory approval of a companion diagnostic to our therapeutic product candidate may be required as a condition to regulatory approval of the therapeutic product candidate.

If the FDA does not accept from us an application for review or approve our application, it may require that we conduct additional clinical, preclinical, or manufacturing validation studies or additional analyses of data from existing studies and submit the data before it will reconsider our application.

Any such additional studies or analyses, if performed and completed, may not be considered sufficient by the FDA to make our applications approvable.

If any of these outcomes occur, we may be forced to delay or abandon applications for approval.

For example, in October 2023, the FDA issued a Complete Response Letter ("CRL") for the sBLA for Dupixent in CSU stating that additional efficacy data were required to support an approval, which delayed by nearly 18 months the FDA's April 2025 approval of Dupixent in this indication.

In certain instances (such as when we use a biomarker-based test to identify and enroll specific patients in a clinical trial), regulatory approval of a companion diagnostic to our therapeutic product candidate may be required as a condition for regulatory approval of the therapeutic product candidate.

We may need to rely on third parties to provide companion diagnostics for use with our product candidates.

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The FDA may also require us to conduct additional clinical trials after granting approval of a product.

The FDA has the explicit authority to require post-marketing studies (also referred to as post-approval or Phase 4 studies), labeling changes based on new safety information , and compliance with FDA-approved REMS.

Post-approval studies, whether conducted by us or by others and whether mandated by regulatory agencies or voluntary, and other data about our marketed products (or data about products similar to our marketed products that implicate an entire class of products or are perceived to do so) may result in changes in

product labeling, restrictions on use, product withdrawal or recall, loss of approval, or lower sales of our products.

Obligations equivalent in scope, but which can vary widely in application, apply in countries outside the United States.

According to the FDA policies under the Prescription Drug User Fee Act, the FDA system of review times for new drugs includes standard review and priority review.

While the FDA has performance goals that provide for action on BLA submissions by certain deadlines, the FDA's review goals are subject to change and the duration of the FDA's review depends on a number of factors, including the number and types of other applications that are submitted to the FDA around the same time period or are pending.

The FDA's review of our regulatory submissions has in the past been delayed, and may be delayed in the future, due to the FDA's request for additional information or for other reasons, including those beyond our control (such a s the recently announced and any future reductions of staffing or other resources at the FDA, as discussed further below).

The functioning of the FDA has been in the past and may in the future be affected by a variety of factors, such as shifting government priorities, budgets and funding levels, authorization and payment of user fees, the ability to hire and retain key personnel, as well as other statutory, regulatory, and policy changes impacting HHS, the FDA, or other HHS agencies.

The FDA has the explicit authority to require post-marketing studies (also referred to as post-approval studies), labeling changes based on new safety information , and compliance with FDA-approved REMS.

Post-approval studies, whether conducted by us or by others and whether mandated by regulatory agencies or voluntary, and other data about our marketed products (or data about products

similar to our marketed products that implicate an entire class of products or are perceived to do so) may result in changes in product labeling, restrictions on use, product withdrawal or recall, loss of approval, or lower sales of our products.

Obligations equivalent in scope, but which can vary widely in application, apply in jurisdictions outside the United States.

According to the FDA policies under the Prescription Drug User Fee Act, the FDA system of review times for new drugs and biologics includes standard review and priority review.

While the FDA has performance goals that provide for action on NDA and BLA submissions by certain deadlines, the FDA's review goals are subject to change and the duration of the FDA's review depends on a number of factors, including the number and types of other applications that are submitted to the FDA around the same time period or are pending.

The FDA's review of our regulatory submissions has in the past been delayed, and may be delayed in the future, due to the FDA's request for additional information or for other reasons, including those beyond our control (such a s the 2025 reduction and any future reductions of staffing or other resources at the FDA, as discussed further below).

The functioning of the FDA is affected by a variety of factors, such as shifting government priorities, budgets and funding levels, authorization and payment of user fees, the ability to hire and retain key personnel, as well as other statutory, regulatory, and policy changes impacting HHS, the FDA, or other HHS agencies.

policy changes have recently been implemented at a rapid pace, and additional changes may occur.

For example, recent efforts to reduce the size and budgets of U.S.

For example, efforts implemented or commenced in 2025 to reduce the size and budgets of U.S.

government agencies, downsize the federal workforce, and restructure parts of the executive branch of the federal government have directly or indirectly impacted agencies that support research and development activities or are otherwise important to our business, including the HHS and the FDA.

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These developments may also reduce the FDA's capacity to engage in pre-approval or guidance meetings or meetings to negotiate labeling or post-marketing commitments.

Furthermore, changes in FDA personnel and policy (such as the recent reductions in communication and policymaking roles) may negatively impact the transparency of agency actions, lead to modifications in FDA approval requirements, and alter the FDA's existing guidance pertinent to the development strategy for our products and product candidates.

Furthermore, changes in FDA personnel and policy (such as the 2025 reductions in communication and policymaking roles) may negatively impact the transparency of agency actions, lead to modifications in FDA approval requirements, and alter the FDA's existing guidance pertinent to the development strategy for our products and product candidates.

In addition, the U.S.

government has shut down multiple times in the past (including the shutdown that started on October 1, 2025 and continues as of the date of this report) and certain regulatory agencies, such as the FDA, had to furlough employees and stop some of their activities.

A prolonged government shutdown (including prolonged continuation of the current shutdown) or a widespread freeze on federal funding could significantly impact the ability of the FDA to timely review and process our regulatory submissions, or cause other agencies that support the FDA to slow their work.

government has shut down multiple times in the recent past and certain regulatory agencies, such as the FDA, have had to furlough employees and stop some of their activities.

A prolonged government shutdown or a widespread freeze on federal funding could significantly impact the ability of the FDA to timely review and process our regulatory submissions or cause other agencies that support the FDA to slow their work.

Any such factors could have a material adverse effect on our business.

If we believe we meet eligibility requirements, we may apply for various regulatory incentives in the United States, such as breakthrough therapy designation, fast track designation, accelerated approval, or priority review, where available, that serve to expedite drug development and/or review, and we may also seek similar designations elsewhere in the world.

Often, regulatory agencies have broad discretion in determining whether or not product candidates qualify for such regulatory incentives and benefits, and we cannot guarantee we would be successful in obtaining beneficial regulatory designations by the FDA or other regulatory agencies.

Even if obtained, such designations may not result in faster development processes, reviews, or approvals compared to drugs considered for approval under conventional FDA procedures.

If we believe we meet eligibility requirements, we may apply for various regulatory incentives in the United States, such as breakthrough therapy designation, fast track designation, accelerated approval, priority review, or the Commissioner's National Priority Voucher (CNPV) program, where potentially available, that serve to expedite drug development and/or review, and we may also seek similar designations elsewhere in the world.

Often, regulatory agencies have broad discretion in determining whether or not product candidates qualify for such regulatory incentives and benefits, and we may fail to obtain beneficial regulatory designations from the FDA or other regulatory agencies.

Even if obtained, such designations may not result in faster development processes, reviews, or approvals compared to drugs or biologics considered for approval under conventional FDA procedures.

In addition, the FDA may later decide that any of our development programs no longer meets the conditions for a beneficial regulatory designation (including due to factors beyond our control, such as intervening competitive developments) or decide that the time period for FDA review or approval will not be shortened.

FDA guidance relating to accelerated approval of oncology therapeutics indicates that a confirmatory trial for a particular oncology product candidate should be underway when the related BLA is submitted to the FDA and also states that the FDA may require that a confirmatory trial for a particular oncology product candidate be well underway, if not fully enrolled, by the time of the accelerated approval action.

FDA guidance relating to accelerated approval of oncology therapeutics indicates that a confirmatory trial for a particular oncology product candidate should be underway when the related marketing application is submitted to the FDA and also states that the FDA may require that a confirmatory trial for a particular oncology product candidate be well underway, if not fully enrolled, by the time of the accelerated approval action.

Application of this guidance and related rules to our product candidates may result in a delay of the FDA review and approval process despite any earlier beneficial regulatory designation such product candidates may have received.

For example, in March 2024, the FDA issued CRLs concerning our BLA for odronextamab for the treatment of relapsed/refractory FL and DLBCL due to the enrollment status of confirmatory Phase 3 trials, thus delaying any potential FDA approval.

See Part I, Item 2.

"Management's Discussion and Analysis of Financial Condition and Results of Operations - Overview - Additional Information - Clinical Development Programs - Ordspono (odronextamab)" regarding the current status of the FDA's review of this program.

The FDA and comparable foreign regulatory authorities enforce Good Clinical Practice requirements ("GCPs") and other regulations and legal requirements through periodic inspections of trial sponsors, clinical research organizations ("CROs"), principal investigators, and trial sites.

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This and similar instances of non-compliance with GCPs could result in non-approval of our product candidates by the FDA or foreign regulatory authorities such as the EC, or we or the FDA or such other regulatory authorities may decide to conduct additional inspections or require additional clinical studies, which would delay our development programs, require us to incur additional costs, and could substantially harm our business, prospects, operating results, and financial condition.

Before approving a new drug or biologic product, the FDA and such comparable foreign regulatory authorities require that the facilities at which the product will be manufactured or advanced through the supply chain be in compliance with current Good Manufacturing Practices, or cGMP, requirements and regulations governing the manufacture, shipment, and storage of the product.

Additionally, manufacturers of biological products and their facilities are subject to payment of substantial user fees and continual review and periodic inspections by the FDA and other regulatory authorities for compliance with cGMP regulations and adherence to any commitments made in the applicable BLA.

Before approving a new drug or biological product, the FDA and such comparable foreign regulatory authorities require that the facilities at which the product will be manufactured or advanced through the supply chain be in compliance with current Good Manufacturing Practices, or cGMP, requirements and regulations governing the manufacture, shipment, and storage of the product.

Additionally, manufacturers of drugs and biological products and their facilities are subject to payment of substantial user fees and continual review and periodic inspections by the FDA and other regulatory authorities for compliance with cGMP regulations and adherence to any commitments made in the applicable NDA or BLA.

These cGMP requirements and regulations are not prescriptive instructions on how to manufacture products, but rather a series of principles that must be observed during manufacturing;

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To be successful, our products must be manufactured in compliance with regulatory requirements, and at competitive costs.

If we or any of our third-party manufacturers, product packagers, labelers, or other parties performing steps in the supply chain are unable to maintain regulatory compliance with cGMP, the FDA and comparable foreign regulatory authorities can impose monetary penalties or other civil or criminal sanctions, including, among other things, refusal to approve a pending application for a new drug or biologic product, or revocation of a pre-existing approval.

If we or any of our third-party manufacturers, product packagers, labelers, or other parties performing steps in the supply chain are unable to maintain regulatory compliance with cGMP, the FDA and comparable foreign regulatory authorities can impose monetary penalties or other civil or criminal sanctions, including, among other things, refusal to approve a pending application for a new drug or biological product, or revocation of a pre-existing approval.

These include the July 2025 CRL concerning the BLA for odronextamab in relapsed/refractory FL, which has delayed further any potential FDA approval of odronextamab in this indication;

and the October 2025 CRL concerning the Company's regulatory application for the EYLEA HD pre-filled syringe (as described in Part I, Item 2.

"Management's Discussion and Analysis of Financial Condition and Results of Operations - Overview - Additional Information - Clinical Development Programs - EYLEA HD"), which has delayed further any potential FDA approval of the EYLEA HD pre-filled syringe.

and the October 2025 CRL concerning our regulatory application seeking approval of the EYLEA HD pre-filled syringe, which has delayed further any potential FDA approval of the EYLEA HD pre-filled syringe.

For additional information, see "Risks Related to Manufacturing and Supply - Our or our collaborators' or contract manufacturers' failure to meet the stringent requirements of governmental regulation in the manufacture of drug products or product candidates could result in incurring substantial remedial costs, delays in the development or approval of our product candidates or new indications for our marketed products and/or in their commercial launch if regulatory approval is obtained, and a reduction in sales.

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We are also subject to ongoing requirements imposed by the FDA and comparable foreign regulatory authorities governing the labeling, packaging, storage, distribution, safety surveillance, advertising, promotion, record-keeping, and reporting of safety and other post-marketing information.

The holder of an approved BLA or foreign equivalent is obligated to monitor and report adverse events and any failure of a product to meet the specifications in the BLA.

The holder of an approved BLA or foreign equivalent must also submit new or supplemental applications and obtain FDA or other regulatory approval for certain changes to the approved product, product labeling, or manufacturing process.

The holder of an approved NDA, BLA, or foreign equivalent is obligated to monitor and report adverse events and any failure of a product to meet the specifications in the application.

The holder of an approved NDA, BLA, or foreign equivalent must also submit new or supplemental applications and obtain FDA or other regulatory approval for certain changes to the approved product, product labeling, or manufacturing process.

Advertising and promotional materials must comply with FDA regulations and those of foreign regulatory authorities and may be subject to other potentially applicable federal and state laws.

The applicable regulations in countries outside the U.S.

The applicable regulations in jurisdictions outside the U.S.

grant similar powers to the competent authorities and impose similar obligations on companies.

In addition to the FDA and other regulatory agency regulations in the United States, we are subject to a variety of foreign regulatory requirements governing human clinical trials, manufacturing, marketing and approval of drugs, and commercial sale and distribution of drugs in countries outside the United States.

The foreign regulatory approval process is similarly a lengthy and expensive process, the result of which is highly uncertain, and foreign regulatory requirements include all of the risks associated with FDA approval as well as country specific regulations.

We and our collaborators must maintain regulatory compliance for the products we or they commercialize in countries outside the United States.

From time to time, we may hold a product's marketing approval in a jurisdiction outside the United States where we may have less experience and where our regulatory capabilities may be more limited;

for example, this is now the case for Libtayo in many jurisdictions outside the United States (including Europe and Japan) due to the transition under the A&R IO LCA discussed above.

In addition, actions by a regulatory agency in a country or region with respect to a product candidate may have an impact on the approval process

for that product candidate in another country or region.

Foreign regulatory authorities may ask for additional data in order to begin a clinical study, including Phase 3 clinical trials required to submit a Marketing Authorization Application ("MAA") in the EU.

In addition to the FDA and other regulatory agency regulations in the United States, we are subject to a variety of foreign regulatory requirements governing human clinical trials, manufacturing, marketing and approval, and commercial sale and distribution of drugs and biologics in jurisdictions outside the United States.

The foreign regulatory approval process is similarly a lengthy and expensive process, the result of which is highly uncertain, and foreign regulatory requirements generally include the risks associated with FDA approval as well as jurisdiction-specific regulations.

We and our collaborators must maintain regulatory compliance for the products we or they commercialize in jurisdictions outside the United States.

From time to time, we may hold a product's marketing approval in a jurisdiction outside the United States where we have less experience and where our regulatory capabilities are more limited;

for example, this is now the case for Libtayo in many jurisdictions outside the United States (including Europe and Japan) due to the transition under the Amended and Restated Immuno-oncology License and Collaboration Agreement with Sanofi.

In addition, actions by a regulatory agency in a country or region with respect to a product candidate may have an impact on the approval process for that product candidate in another country or

Foreign regulatory authorities may ask for additional data in order to begin a clinical study, including Phase 3 clinical trials required to submit an MAA in the EU.

In addition, such authorities often have the authority to require post-approval studies, such as a post-authorization safety study ("PASS") and/or a post-authorization efficacy study ("PAES"), which involve various risks similar to those described above.

Whether or not we obtain FDA approval for a product in the United States, we must obtain approval of the product by the comparable regulatory authorities in countries outside the United States before we can market that product or any other product in those countries.

Furthermore, we are subject to extensive pharmacovigilance reporting and other pharmacovigilance requirements, which may differ in the numerous countries in which we conduct clinical trials or commercialize a product.

Whether or not we obtain FDA approval for a product in the United States, we must obtain approval of the product by the comparable regulatory authorities in jurisdictions outside the United States before we can market that product or any other product in those jurisdictions.

Furthermore, we are subject to extensive pharmacovigilance reporting and other pharmacovigilance requirements, which may differ in the numerous jurisdictions in which we conduct clinical trials or commercialize a product.

Failure to comply with any such requirements may result in the premature closure of the clinical trials and other enforcement actions by the relevant regulatory authorities.

For example, if we do not manage to retain a Qualified Person Responsible for Pharmacovigilance ("QPPV"), to maintain a Pharmacovigilance System Master File ("PSMF"), or to comply with other pharmacovigilance obligations in the European Economic Area ("EEA"), we may be at risk of our clinical trials being closed prematurely, our marketing authorization being suspended, and we may be subject to other enforcement actions by the national competent authorities of the EEA or the EC.

For example, if we do not manage to retain a Qualified Person Responsible for Pharmacovigilance ("QPPV"), to maintain a Pharmacovigilance System Master File ("PSMF"), or to comply with other pharmacovigilance obligations in the European Economic Area ("EEA"), our clinical trials may be closed prematurely, our marketing authorization may be suspended, and we may be subject to other enforcement actions by the national competent authorities of the EEA or the EC.

Preclinical and clinical studies required for our product candidates and new indications of our marketed products are expensive and time-consuming, and their outcome is highly uncertain.

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difficulty in enrolling and maintaining subjects in a clinical trial;

clinical trial design that may not make it possible to enroll or retain a sufficient number of patients to achieve a statistically significant result or the desired level of statistical significance for the endpoint in question;

clinical trial design that may make it impossible to enroll or retain a sufficient number of patients to achieve a statistically significant result or the desired level of statistical significance for the endpoint in question;

lack of sufficient supplies of the product candidate or comparator drug;

and the failure of clinical investigators, trial monitors, contractors, consultants, or trial subjects to comply with the trial plan, protocol, or applicable regulations related to Good Laboratory Practice requirements ("GLPs") or GCPs.

Certain of these risks may be exacerbated as we pursue development of drugs generated by means other than our established "Trap" or VelociSuite technologies, such as siRNA gene silencing, genome editing, and targeted viral-based gene delivery and expression.

A clinical trial may also fail because the dose(s) of the investigational drug included in the trial were either too low or too high to determine the optimal effect of the investigational drug in the disease setting.

Additionally, conducting clinical trials in countries outside the United States presents additional risks, including political and economic risks that are not present in the United States, such as armed conflict and economic embargoes or boycotts.

Additionally, conducting clinical trials in countries outside the United States presents additional risks, including political and economic risks such as armed conflict and economic embargoes or boycotts.

For example, we and our collaborators are currently conducting and may in the future conduct or initiate clinical trials with sites in Russia, Ukraine, and/or Israel.

While we currently do not expect the Russia-Ukraine or Hamas-Israel armed conflict or related developments to have a significant impact on our ability to obtain results from clinical trials conducted by us or our collaborators, further escalation (whether in these countries or surrounding areas) may adversely affect our ability to adequately conduct certain clinical trials and maintain compliance with relevant protocols due to, among other reasons, the prioritization of hospital resources away from clinical trials, reallocation or evacuation of site staff and subjects, or as a result of government-imposed curfews, warfare, violence, or other governmental action or other events that restrict movement.

These developments may also result in our inability to access sites for monitoring or to obtain data from affected sites or patients going forward.

While we currently do not expect the Russia-Ukraine war, Israel's armed conflicts with Iran, Lebanon, or Hamas, or related developments to have a significant impact on our ability to obtain results from clinical trials conducted by us or our collaborators, further escalation (whether in these countries or surrounding areas) may adversely affect our ability to adequately conduct certain clinical trials and maintain compliance with relevant protocols due to, among other reasons, the prioritization of hospital resources away from clinical trials, reallocation or evacuation of site staff and subjects, or as a result of government-imposed curfews, warfare, violence, or other governmental action or other events that restrict movement.

These developments may also result in our inability to access sites for monitoring or to obtain data or samples from affected sites or patients going forward.

We could also experience disruptions in our supply chain or limits to our ability to provide sufficient investigational materials in such countries and surrounding regions.

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The failure of clinical trials to demonstrate the safety and effectiveness of our clinical candidates for the desired indication(s) would preclude the successful development of those candidates for such indication(s), in which event our business, prospects, operating results, and financial condition may be materially harmed.

Furthermore, some of our products and product candidates (such as Libtayo) are studied in combination with agents and treatments developed by us or our collaborators.

Furthermore, an increasing number of our products and product candidates (including Libtayo) are being studied in combination with agents and treatments developed by us or our collaborators.

There may be additional risks and unforeseen safety issues resulting from such combined administration, any of which may materially adversely impact clinical development of these product candidates and our ability to obtain regulatory approval.

In some jurisdictions such as the EU, initiating Phase 3 clinical trials and clinical trials in the pediatric population is subject to a requirement to obtain approval or a waiver from the competent authorities of the EU Member States and/or the EMA.

If we do not obtain such approval, our ability to conduct clinical trials and obtain marketing authorizations or approvals may be severely impaired and our business may be adversely impacted.

Certain of our research and development activities are conducted at our existing facilities primarily located in Tarrytown, New York.

As we continue to expand, we may lease, operate, purchase, or construct additional facilities to expand our research and development capabilities in the future.

Expanding our research and laboratory facilities may require significant time and resources.

Further, we may be unable to pursue our research and development efforts if the relevant facility were to cease operations due to fire, climate change, natural disasters, acts of war or terrorism, or other disruptions.

As we continue to expand, we may lease, operate, purchase, or construct additional facilities, which may require significant time and resources.

Further, we may be unable to pursue our research and development efforts if the relevant facility were to be impacted by fire, climate change, natural disasters, acts of war or terrorism, or other disruptions.

Any related delays may interfere with our research and development efforts and our business may be adversely impacted.

Successful development of our current and future product candidates is uncertain.

Only a small minority of all research and development programs ultimately result in commercially successful drugs.

Clinical trials may not demonstrate statistically sufficient effectiveness and safety to obtain the requisite regulatory approvals for these product candidates in these indications.

Only a small minority of all research and development programs ultimately result in commercially successful products.

Clinical trials may not demonstrate statistically sufficient effectiveness and safety to obtain the requisite regulatory approvals for particular product candidates in particular indications.

Many companies in the biopharmaceutical industry, including our Company, have suffered significant setbacks in clinical trials, even after promising results had been obtained in earlier trials.

For example, in May 2025, we and Sanofi announced that one of two Phase 3 trials evaluating itepekimab in adults who were former smokers with inadequately controlled COPD did not meet its primary endpoint, as further described under Part I, Item 2.

"Management's Discussion and Analysis of Financial Condition and Results of Operations - Overview - Additional Information - Clinical Development Programs." In a number of instances, we have terminated the development of product candidates due to a lack of or only modest effectiveness and/or safety concerns, and clinical trials evaluating our product candidates have failed to meet the relevant endpoints.

Moreover, even if we obtain positive results from preclinical testing or clinical trials, we may not achieve the same success in future trials, or the FDA and analogous foreign regulatory authorities may deem the results insufficient for an approval.

In a number of instances, we have terminated the development of product candidates due to a lack of or only modest effectiveness and/or safety concerns, and clinical trials evaluating our product candidates have failed to meet the relevant endpoints.

Moreover, even if we obtain positive results from preclinical testing or clinical trials, we may not achieve the same success in future trials, or the FDA and/or analogous foreign regulatory authorities may deem the results insufficient for an approval.

If concerns arise about the safety of a product candidate or non-compliance with the protocol or applicable regulatory requirements, the FDA or other regulatory authorities can delay or suspend a clinical trial by placing it on a full or partial "clinical hold" pending receipt of additional data or the satisfaction of other conditions.

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These product candidates may not demonstrate the requisite efficacy and/or safety profile to support continued development for some or all of the indications that are being, or are planned to be, studied, which would diminish our clinical "pipeline" and could negatively affect our future prospects and the value of our Company.

Serious complications or side effects in connection with the use of our products and in clinical trials for our product candidates and new indications for our marketed products could cause our regulatory approvals to be revoked or limited or lead to delay or discontinuation of development of our product candidates or new indications for our marketed products, which could severely harm our business, prospects, operating results, and financial condition.

Serious complications or side effects in connection with the use or development of our products or product candidates could cause our regulatory approvals to be revoked or limited or lead to delay or discontinuation of development of our product candidates or new indications for our marketed products, which could severely harm our business, prospects, operating results, and financial condition.

During the conduct of clinical trials, patients report changes in their health, including illnesses, injuries, and discomforts, to their study doctor.

Often, it is not possible to determine whether or not the drug candidate being studied caused these

Often, it is not possible to determine whether or not the drug candidate being studied caused these conditions.

Various illnesses, injuries, and discomforts have been reported from time-to-time during clinical trials of our product candidates and new indications for our marketed products.

It is possible that as we test our drug candidates or new indications in larger, longer, and more extensive or complex clinical programs (including those evaluating combination therapies), or as use of these drugs becomes more widespread if they receive regulatory approval, illnesses, injuries, and discomforts that were observed in earlier trials, as well as conditions that did not occur or went undetected in previous trials, will be reported by patients.

It is possible that as we test our drug candidates or new

indications in larger, longer, and more extensive or complex clinical programs (including those evaluating combination therapies), or as use of these drugs becomes more widespread if they receive regulatory approval, illnesses, injuries, and discomforts that were observed in earlier trials, as well as conditions that did not occur or went undetected in previous trials, will be reported by patients.

Many times, side effects are only detectable after investigational drugs are tested in large-scale, Phase 3 clinical trials or, in some cases, after they are made available to patients after approval.

If additional clinical experience indicates that any of our product candidates or new indications for our marketed products has many side effects or causes serious or life-threatening side effects, the development of the product candidate may be delayed or fail, or, if the product candidate has received regulatory approval, such approval may be revoked, which would severely harm our business, prospects, operating results, and financial condition.

With respect to EYLEA and EYLEA HD, there are many potential safety concerns associated with significant blockade of VEGF that may limit our ability to further successfully commercialize EYLEA and EYLEA HD.

These serious and potentially life-threatening risks, based on clinical and preclinical experience of VEGF inhibitors, include bleeding, intestinal perforation, hypertension, proteinuria, congestive heart failure, heart attack, and stroke.

Other VEGF blockers have reported side effects that became evident only after large-scale trials or after marketing approval when large numbers of patients were treated.

There are risks inherent in the intravitreal administration of drugs like aflibercept (such as intraocular inflammation, sterile and culture positive endophthalmitis, corneal decomposition, retinal detachment, retinal tear, and retinal vasculitis), which can cause injury to the eye and other complications.

The side effects previously reported for aflibercept include conjunctival hemorrhage, macular degeneration, eye pain, retinal hemorrhage, and vitreous floaters.

While the safety of EYLEA HD was similar to EYLEA in clinical trials, it is possible that the use of EYLEA HD outside the clinical trial setting may yield different outcomes or patient experiences.

In addition, commercialization of EYLEA and EYLEA HD or our other products and potential future commercialization of our product candidates may be impacted by actions of third parties on which we rely, such as manufacturers of syringes or other devices used in the administration of our products.

These and other complications or issues or side effects could harm further development and/or commercialization of EYLEA and EYLEA HD.

Dupixent and Libtayo are being studied in additional indications, as shown in the table under Part I, Item 2.

"Management's Discussion and Analysis of Financial Condition and Results of Operations - Overview - Programs in Clinical Development." There is no guarantee that the safety data from these trials will be consistent with the known Dupixent and Libtayo safety profiles (as applicable) or that regulatory approval of Dupixent or Libtayo (as applicable) in any of these indications will be successfully obtained.

The side effects previously reported for Dupixent include severe allergic reactions, eye problems (including eye pain or changes in vision), joint aches and pain, parasitic (helminth) infections, facial rash or redness, and inflammation of blood vessels in the skin;

and the side effects previously reported for Libtayo include certain immune-mediated adverse reactions that may occur in any organ system or tissue, including pneumonitis, colitis, hepatitis, endocrinopathies, nephritis, and dermatologic reactions, as well as infusion-related reactions, cellulitis, sepsis, pneumonia, urinary tract infection, fatigue, rash, and diarrhea.

These and other complications or side effects could harm further development and/or commercialization of Dupixent and Libtayo (as applicable).

There also are risks inherent in subcutaneous injections (which are used for administering most of our antibody-based products and product candidates), such as injection-site reactions (including redness, itching, swelling, pain, and tenderness) and other side effects.

In addition, there are risks inherent in intravenous administration (which are used for some of our antibody-based products and product candidates), such as infusion-related reactions (including nausea, pyrexia, rash, and dyspnea).

These and other complications or side effects could harm further development and/or commercialization of our antibody-based products and product candidates utilizing this method of administration.

For example, with respect to EYLEA HD and EYLEA, there are many potential safety concerns associated with significant blockade of VEGF, as well as risks inherent in their intravitreal administration.

While the safety of EYLEA HD was similar to EYLEA in clinical trials, it is possible that the use of EYLEA HD outside the clinical trial setting in a broader patient group (i.e., real-world use) may yield different outcomes or patient experiences.

In addition, there are risks inherent in subcutaneous injections (which are used for administering most of our antibody-based products and product candidates, such as Dupixent) and intravenous administration (which is used for some of our other antibody-based products and product candidates, such as Libtayo).

Some of our marketed products, such as Dupixent and Libtayo, are being studied in additional indications, as shown in the table under Part I, Item 2.

"Management's Discussion and Analysis of Financial Condition and Results of Operations - Overview - Programs in Clinical Development." There is no guarantee that the safety data from these trials will be consistent with the known safety profiles of these products or that regulatory approval of any of these additional indications will be successfully obtained.

Commercialization of our other products and potential future commercialization of our product candidates may also be impacted by actions of third parties on which we rely, such as manufacturers of syringes or other devices used in the administration of our products.

These and other complications or issues or side effects could harm further development and/or commercialization of our products and product candidates.

We may be unable to formulate or manufacture our product candidates in a way that is suitable for clinical or commercial use, which would delay or prevent continued development of such candidates and/or receipt of regulatory approval or commercial sale, which could materially harm our business, prospects, operating results, and financial condition.

If we are unable to continue to develop suitable product formulations or manufacturing processes to support large-scale clinical testing of our product candidates, including our antibody-based product candidates, we may be unable to supply necessary materials for our clinical trials, which would delay or prevent the development of our product candidates.

If we are unable to continue to develop suitable product formulations or manufacturing processes to support large-scale clinical testing of our product candidates, we may be unable to supply necessary materials for our clinical trials, which would delay or prevent the development of our product candidates.

Similarly, if we are unable, directly or through our collaborators or third parties, to supply sufficient quantities of our products or develop formulations of our product candidates suitable for commercial use, we will be unable to obtain regulatory approval for those product candidates.

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The FDA has substantial discretion in the approval process and may either refuse to accept an application for substantive review or may form the opinion after review of an application that the application is insufficient to allow approval of a drug-delivery device.

For example, in October 2025, the FDA issued a CRL for the EYLEA HD pre-filled syringe, which has delayed further any potential FDA approval of the EYLEA HD pre-filled syringe.

The timing of any potential resolution of the approvability issue cited in the CRL or any potential FDA approval of the EYLEA HD pre-filled syringe is uncertain.

For example, in October 2025, the FDA issued a CRL for the regulatory application seeking approval of the EYLEA HD pre-filled syringe, which has delayed further any potential FDA approval of the EYLEA HD pre-filled syringe.

There can be no assurance that FDA approval of the EYLEA HD pre-filled syringe will be obtained in the currently anticipated time frame or at all.

See Part I, Item 2.

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to conduct the studies and prepare related documentation required for approval or clearance by the applicable regulatory agencies;

and to continue to meet the applicable regulatory and other requirements to maintain approval or clearance once it has been received.

and to continue to meet the applicable regulatory and other requirements to maintain approval or

clearance once it has been received.

In addition, other parties may allege that our drug-delivery devices infringe patents or other intellectual property rights.

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Our patents may be challenged, invalidated, held to be unenforceable, or circumvented.

example, certain of our U.S.

patents (including those pertaining to our key products, such as EYLEA and EYLEA HD) have been and may in the future be challenged by parties who file a request for post-grant review or inter partes review under the America Invents Act of 2011 or ex parte reexamination (see Note 12 to our Condensed Consolidated Financial Statements included in this report for additional information).

Certain of our U.S.

patents (including those pertaining to our key products, such as EYLEA HD and EYLEA) have been and may in the future be challenged by parties who file a request for post-grant review or inter partes review under the America Invents Act of 2011 or ex parte reexamination.

For example, in March 2026, the Patent Trial and Appeal Board of the United States Patent and Trademark Office (the "USPTO") instituted a post-grant review of U.S.

12,168,036 relating to EYLEA HD.

Post-grant proceedings are increasingly common in the United States and are costly to defend.

In addition, patent applications filed outside the United States may be challenged by other parties, for example, by filing pre-grant third-party observations that argue against patentability or a post-grant opposition.

Such opposition proceedings are increasingly common in Europe and are costly to defend.

Similarly, such opposition proceedings are increasingly common in Europe and are costly to defend.

For example, certain of our European patents, including those pertaining to EYLEA and Dupixent, are subject to opposition proceedings before the European Patent Office (the "EPO") and/or patent offices of various European countries (see Note 12 to our Condensed Consolidated Financial Statements included in this report for additional information).

We have pending patent applications in the United States Patent and Trademark Office (the "USPTO"), the EPO, and the patent offices of other foreign jurisdictions, and it is likely that we will need to defend patents from challenges by others from time to time in the future.

We have pending patent applications in the USPTO, the EPO, and the patent offices of other foreign jurisdictions, and it is likely that we will need to defend patents from challenges by others from time to time in the future.

Our patent rights may not provide us with a proprietary position or competitive advantages against competitors.

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Additionally, the United States' and other government actions related to Russia's invasion of Ukraine may limit or prevent filing, prosecution, and maintenance of patent applications in Russia.

These actions could result in abandonment or lapse of our patents or patent applications, resulting in partial or complete loss of patent rights in Russia.

Further, a decree was adopted by the Russian government in March 2022, allowing Russian companies and individuals to exploit inventions owned by patent holders from the United States without consent or compensation.

These actions could result in abandonment or lapse of our

patents or patent applications, resulting in partial or complete loss of patent rights in Russia.

Further, a decree was adopted by the Russian government in 2022, allowing Russian companies and individuals to exploit inventions owned by patent holders from the United States without consent or compensation.

Consequently, we are not able to prevent third parties from practicing our inventions in Russia or from selling or importing products made using our inventions in and into Russia.

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For example, under the Orphan Drug Act in the United States, if a product candidate with an orphan drug designation subsequently receives FDA approval for indication(s) within the scope of such designation, the product will be entitled to orphan drug exclusivity for such indication(s), barring the FDA from approving for seven years in such approved indication(s) another sponsor's application for a product candidate considered under the FDA regulations to be the same drug as the previously-approved drug with orphan drug exclusivity.

This orphan drug exclusivity does not block approval of competing products intended for the orphan exclusivity-protected indication but containing a different active moiety or principal molecular structure, or containing the same active moiety or principal molecular structure but intended for a different indication.

but intended for a different indication.

Similarly, in the EU, a designated orphan drug is provided up to 10 years of market exclusivity in the orphan indication, during which time the EMA is generally precluded from accepting a MAA for a similar medicinal product.

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In the pharmaceutical and biotechnology industries, the majority of an innovative product's commercial value is usually realized during the period in which it has market exclusivity.

In the United States and some other countries, when market exclusivity expires and generic versions of a product are approved and marketed, there usually are very substantial and rapid declines in the product's sales.

In the United States and some other countries, when market exclusivity expires and generic or biosimilar versions of a product are approved and marketed, there usually are very substantial and rapid declines in the product's sales.

If our late-stage product candidates or other clinical candidates are approved for marketing in the United States or elsewhere, market exclusivity for those products will generally be based upon patent rights and/or certain regulatory forms of exclusivity.

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Absent patent protection or regulatory exclusivity for our products, it is possible, both in the United States and elsewhere, that generic, biosimilar, and/or interchangeable versions of those products may be approved and marketed, which would likely result in substantial and rapid reductions in revenues from sales of those products.

Under the federal Patient Protection and Affordable Care Act ("PPACA"), there is an abbreviated path in the United States for regulatory approval of products that are demonstrated to be "biosimilar" or "interchangeable" with an FDA-approved biological product.

The PPACA provides a regulatory mechanism that allows for FDA approval of biologic drugs that are similar to innovative drugs on the basis of less extensive data than is required by a full BLA.

Under the Patient Protection and Affordable Care Act ("PPACA"), there is an abbreviated path in the United States for regulatory approval of products that are demonstrated to be "biosimilar" or "interchangeable" with an FDA-approved biological product.

The PPACA provides a regulatory mechanism that allows for FDA approval of biologics that are similar to innovative biologics on the basis of less extensive data than is required by a full BLA.

Under this regulation, an application for approval of a biosimilar may be filed four years after approval of the innovator product.

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A number of jurisdictions outside the United States (such as the EU) have also established abbreviated pathways for regulatory approval of biological products that are biosimilar to earlier versions of biological products.

The increased likelihood of biosimilar competition has exacerbated the risk of loss of innovators' market exclusivity.

It is also not possible to predict changes in United States regulatory law that might reduce biological product regulatory exclusivity.

Due to this risk, and uncertainties regarding patent protection, it is not possible to predict the length of market exclusivity for any particular product we currently or may in the future commercialize with certainty based solely on the expiration of the relevant patent(s) or the current forms of regulatory exclusivity.

The increased likelihood of generic and biosimilar competition has exacerbated the risk of loss of innovators' market exclusivity.

It is also not possible to predict changes in United States regulatory law that might reduce drug or biological product regulatory exclusivity.

Due to this risk, and uncertainties regarding patent protection, the length of market exclusivity for any particular product we currently or may in the future commercialize is inherently uncertain.

Biosimilar versions of EYLEA have been recently approved and/or launched in the United States, EU, and other jurisdictions, with additional biosimilar versions of EYLEA and/or EYLEA HD in development, as discussed further under "Risks Related to Commercialization of Our Marketed Products, Product Candidates, and New Indications for Our Marketed Products - The commercial success of our products and product candidates is subject to significant competition - Marketed Products" above.

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As we increase our production in anticipation of potential regulatory approval for our product candidates, our current manufacturing capacity will likely not be sufficient, and our dependence on our collaborators and/or contract manufacturers may increase, to produce adequate quantities of drug material for both commercial and clinical purposes.

The COVID-19 pandemic has exacerbated, and this or other public health outbreaks, epidemics, or pandemics may in the future further exacerbate, certain of these risks.

For example, the impact of having to prioritize certain manufacturing-related resources for our COVID-19 monoclonal antibodies in recent years included, among other things, drawing down inventory safety stock levels for certain of our other products (including Dupixent and EYLEA).

The COVID-19 pandemic exacerbated, and this or other public health outbreaks, epidemics, or pandemics may in the future further exacerbate, certain of these risks.

For example, the impact of having to prioritize certain manufacturing-related resources for our COVID-19 monoclonal antibodies included, among other things, drawing down inventory safety stock levels for certain of our other products (including Dupixent and EYLEA).

Depending on the demand for our products and other relevant factors, we may not be able to replenish our inventory safety stock to the levels we deem prudent or supply our products and product candidates in sufficient quantities to satisfy our commercial and development needs.

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In addition to our existing manufacturing facilities in Rensselaer, New York and Limerick, Ireland, we may lease, operate, purchase, or construct additional facilities to conduct expanded manufacturing or other related activities in the future.

Expanding our manufacturing capacity to supply commercial quantities of the active pharmaceutical ingredients for our

marketed products and our product candidates if they are approved for marketing, and to supply clinical drug material to support the continued growth of our clinical programs, will require substantial additional expenditures, time, and various regulatory approvals and permits.

This also holds true for establishing fill/finish capabilities in the future, for which we have constructed a fill/finish facility in Rensselaer, New York that is currently undergoing process validation as required by regulatory authorities.

In addition, we may need to develop or acquire additional manufacturing capabilities to the extent we or our collaborators pursue the development of drugs generated by means other than our existing "Trap" or VelociSuite ® technologies, such as siRNA gene silencing, genome editing, and targeted viral-based gene delivery and expression.

Expanding our manufacturing capacity to supply commercial quantities of the active pharmaceutical ingredients for our marketed products and our product candidates if they are approved for marketing, and to supply clinical drug material to support the continued growth of our clinical programs, will require substantial additional expenditures, time, and various regulatory approvals and permits.

In addition, we may need to develop or acquire additional manufacturing capabilities as we and/or our collaborators continue to pursue the development of drugs generated by means other than our established "Trap" or VelociSuite technologies, such as siRNA gene silencing, genome editing, and targeted viral-based gene delivery and expression.

Further, we will need to hire and train significant numbers of employees and managerial personnel to staff our expanding manufacturing and supply chain operations, as well as any future fill/finish activities.

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The FDA and analogous foreign regulatory authorities must determine that any existing and expanded manufacturing facilities and any fill/finish activities conducted by us, our collaborators, or our contract manufacturers comply, or continue to comply, with cGMP requirements for both clinical and commercial production and license them, or continue to license them, accordingly, and such facilities must also comply with applicable environmental, safety, and other governmental permitting requirements.

We may not successfully expand or establish sufficient manufacturing or any future fill/finish capabilities or manufacture our products in a cost-effective manner or in compliance with cGMPs and other regulatory requirements, and we and our collaborators or contract manufacturers may not be able to build or procure additional capacity in the required timeframe to meet commercial demand for our products (or product candidates if they receive regulatory approval) and to continue to meet the requirements of our clinical programs.

our clinical programs.

This would interfere with our efforts to successfully commercialize our marketed products, and it could also delay or require us to discontinue one or more of our clinical development programs.

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For example, during each of the years ended December 31, 2022 and 2021, we recorded a substantial charge to write down inventory related to REGEN-COV ® .

Third-party service or supply failures, or other failures, business interruptions, or other disasters affecting our manufacturing facilities in Rensselaer, New York and Limerick, Ireland, the manufacturing facilities of our collaborators or contract manufacturers, or the facilities of any other party participating in the supply chain, would adversely affect our ability to supply our products.

Third-party service or supply failures, or other failures, business interruptions, or other disasters affecting our manufacturing facilities in Rensselaer, New York and Limerick, Ireland, the manufacturing facilities of our collaborators or contract manufacturers, or the facilities of any other party participating in the supply chain, could adversely affect our ability to supply our products.

Bulk drug materials are currently manufactured at our manufacturing facilities in Rensselaer, New York and Limerick, Ireland, as well as at our collaborators' and contract manufacturers' facilities.

We and our collaborators and contract manufacturers would be unable to manufacture these materials if the relevant facility were to cease production due to regulatory requirements or actions, business interruptions, labor shortages or disputes, supply chain interruptions or constraints (including with respect to natural gas and other raw materials), contaminations, fire, climate change, natural disasters, acts of war or terrorism, or other problems.

For example, during the first quarter of 2026, bulk manufacturing production at our facility in Limerick, Ireland was temporarily interrupted due to unanticipated facility repairs that commenced during the quarter.

See Part I, Item 2.

"Management's Discussion and Analysis of Financial Condition and Results of Operations – Results of Operations – Operating Expenses" for more information, including the interruption's impact on our reported and future financial results.

To date, this issue has not adversely impacted our product supply;

however, there can be no assurance that this issue will be remediated fully in the currently anticipated time frame or that it will not adversely affect the supply of our products in the future.

Many of our products and product candidates are very difficult to manufacture.

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For example, the pharmaceutical industry generally, and in some instances our Company or our collaborators or other third parties on which we rely, depend on China-based suppliers or service providers for certain raw materials, products and services, or other activities.

Our ability or the ability of our collaborators or such other third parties to continue to engage these China-based suppliers or service providers for certain preclinical research programs and clinical development programs could be restricted due to geopolitical developments between the United States and China, including as a result of the escalation of tariffs or other trade restrictions or if the previously proposed federal legislation known as the BIOSECURE Act or a similar law were to be enacted.

See also "Other Regulatory and Litigation Risks - We face risks associated with tariffs and other trade restrictions, which may have a material adverse impact on our results of operations and financial condition " below.

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Changes of suppliers or modifications of methods of manufacturing may require amending the relevant application(s) relating to our products or product candidates to the FDA or such comparable foreign agencies and acceptance of the change by the FDA or such comparable foreign agencies prior to release of product(s).

Because we produce multiple products and product

candidates at our facilities in Rensselaer, New York and Limerick, Ireland, there are increased risks associated with cGMP compliance.

Recently, the FDA issued CRLs to multiple companies (including us, as further discussed in this report or previously disclosed) citing unresolved inspection findings at third-party manufacturers, which prevented the timely approval of such companies' marketing applications.

Because we produce multiple products and product candidates at our facilities in Rensselaer, New York and Limerick, Ireland, there are increased risks associated with cGMP compliance.

In recent years, the FDA issued CRLs to multiple companies (including us, as further discussed in this report or previously disclosed) citing unresolved inspection findings at third-party manufacturers, which prevented the timely approval of such companies' marketing applications.

Our inability, or the inability of our collaborators, contract manufacturers, and third-party fill/finish or other service providers, to demonstrate ongoing cGMP compliance has in the past required us, and could in the future require us, to engage in lengthy and expensive remediation efforts, identify and onboard new service providers, withdraw or recall product, halt or interrupt clinical trials, and/or interrupt commercial supply of any marketed products, and could also delay or prevent our obtaining regulatory approval for our product candidates or new indications for our marketed products.

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Any finding of non-compliance could also increase our costs, cause us to delay the development of our product candidates, result in delay in our obtaining, or our not obtaining, regulatory approval of product candidates or new indications for our marketed products, and cause us to lose revenue from any marketed products, which could be seriously detrimental to our business, prospects, operating results, and financial condition.

We have recently received several CRLs from the FDA for regulatory submissions concerning our products or product candidates due to the FDA's findings from inspections at third-party manufacturers responsible for filling drug product, as discussed above under "Risks Related to Maintaining Approval of Our Marketed Products and the Development and Obtaining Approval of Our Product Candidates and New Indications for Our Marketed Products - Obtaining and maintaining regulatory approval for drug products is costly, time-consuming, and highly uncertain.

We recently received several CRLs from the FDA for regulatory submissions concerning our products or product candidates due to the FDA's findings from inspections at third-party manufacturers responsible for filling drug product, as discussed above under "Risks Related to Maintaining Approval of Our Marketed Products and the Development and Obtaining Approval of Our Product Candidates and New Indications for Our Marketed Products - Obtaining and maintaining regulatory approval for drug

and biological products is costly, time-consuming, and highly uncertain.

If we or our collaborators do not maintain regulatory approval for our marketed products, or obtain regulatory approval for our product candidates, we will not be able to market or sell them;

and if we do not obtain approvals for new indications for our marketed products, we may not be able to realize the full commercial potential of such products.

Any of the foregoing may materially and negatively impact our business, prospects, operating results, and financial condition.

" Significant noncompliance with the requirements discussed in this paragraph could also result in the imposition of monetary penalties or other civil or criminal sanctions and damage our reputation.

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From time to time, we are subject to claims by patients that they have been injured by a side effect associated (or alleged to be associated) with one of our products or product candidates.

For example, we are currently subject to product liability lawsuits relating to Dupixent, as described in Note 12 to our Condensed Consolidated Financial Statements included in this report.

Any such product liability claim, regardless of merit, may be costly and time consuming to investigate and defend and may have a negative impact on our reputation or business, including the degree to which we or our collaborators are able to successfully commercialize the applicable product or, if regulatory approval is obtained, product candidate.

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The current U.S.

administration, HHS, and FDA have recently announced an initiative intended to ensure transparency and accuracy in DTC prescription drug advertisements through a series of reforms that are expected to include FDA rulemaking, additional enforcement action, and expanded regulatory oversight of social media promotional activities.

Failure to comply with applicable FDA requirements and restrictions in the area of promotional activities (including those that currently apply or may apply in the future to DTC advertising) may subject a company to adverse enforcement action by the FDA, the Department of Justice, or the Office of the Inspector General of HHS, as well as state authorities.

This could subject a company to a range of penalties that could have a significant commercial

impact, including civil and criminal fines and agreements that materially restrict the manner in which a company promotes or distributes a drug.

administration, HHS, and FDA have recently announced an initiative intended to ensure transparency and accuracy in DTC prescription drug advertisements through a series of reforms that have included and are expected to continue to include FDA rulemaking, additional enforcement action, and expanded regulatory oversight of social media promotional activities.

Failure to comply with applicable FDA requirements for advertising and promotional activities (including those that currently apply or may apply in the future to DTC advertising) may subject a company to adverse enforcement action by the FDA, the Department of Justice, or the Office of the Inspector General of HHS, as well as state authorities.

This could subject a company to a range of penalties or other consequences that could have a significant commercial impact, including warning letters, civil and criminal fines, and agreements that materially restrict the manner in which a company promotes or distributes a drug.

Any such failures could also cause significant reputational harm.

The FDA may take enforcement action for promoting unapproved uses of a product or other violations of its advertising laws and regulations.

The applicable regulations in countries outside the U.S.

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Pharmaceutical companies have been investigated and/or prosecuted under these laws for a variety of alleged promotional and marketing activities, such as allegedly providing free product to customers with the expectation that the customers would bill federal programs for the product;

reporting to pricing services inflated average wholesale prices that were then used by federal programs to set reimbursement rates;

reporting to pricing services inflated average wholesale prices that were then used by federal

programs to set reimbursement rates;

engaging in promotion for uses that the FDA has not approved, known as off-label uses, that caused claims to be submitted to Medicaid for non-covered off-label uses;

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Any adverse decision, finding, allegation, or exercise of enforcement or regulatory discretion in any such proceedings or investigations could harm our business, prospects, operating results, and financial condition.

As part of the PPACA, the federal government requires that pharmaceutical manufacturers record any "transfers of value" made to U.S.

licensed physicians and teaching hospitals as well as ownership and investment interests held by physicians and their immediate family members.

Information provided by companies is aggregated and posted annually on an "Open Payments" website, which is managed by CMS, the agency responsible for implementing these disclosure requirements.

Applicable manufacturers also are required to report information regarding payments and transfers of value provided to physician assistants, nurse practitioners, clinical nurse specialists, certified nurse anesthetists, anesthesiologist assistants, and certified nurse-midwives.

We also have similar reporting obligations in other countries based on laws, regulations, and/or industry trade association requirements.

We continue to dedicate significant resources to comply with these requirements.

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We participate in the Medicaid Drug Rebate program, the Public Health Service's 340B program (which is administered by the Health Resources and Services Administration ("HRSA")), the U.S.

Department of Veterans Affairs ("VA") Federal Supply Schedule ("FSS") pricing program, the Tricare Retail Pharmacy Program, and other federal and state government pricing programs.

Department of Veteran Affairs ("VA") Federal Supply Schedule ("FSS") pricing program, the Tricare Retail Pharmacy Program, and other federal and state government pricing programs.

Such programs often require us to provide discounts and/or pay rebates to certain government payors and/or private purchasers.

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We are also required to report the 340B ceiling prices for our covered outpatient drugs to HRSA, which then publishes them to 340B covered entities.

There is ongoing litigation involving other parties that may restrict the number of third-party contract pharmacies that can dispense drugs that manufacturers sell to 340B covered entities.

There is ongoing litigation involving other parties that may change the number of third-party contract pharmacies that can dispense drugs that manufacturers sell to 340B covered entities.

The outcome of this litigation may change the scope of the 340B program in the coming years.

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We have obligations to report the average sales price for certain of our drugs to the Medicare program.

Statutory or regulatory changes or CMS guidance could affect the average sales price calculations for our products and the resulting Medicare payment rate, and could negatively impact our results of operations.

Statutory or regulatory changes or CMS guidance, including provisions included in the recent CMS calendar year 2026 Medicare Physician Fee Schedule final rule, could affect the average sales price calculations for our products and the resulting Medicare payment rate, and could negatively impact our results of operations.

Pursuant to applicable law, knowing provision of false information in connection with price reporting or contract‑based requirements under the VA FSS and/or Tricare programs can subject a manufacturer to civil monetary penalties.

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Failure to make necessary disclosures or to identify contract overcharges can result in allegations against us under the False Claims Act and other laws and regulations.

Unexpected refunds to the government, and/or response to a government

investigation or enforcement action, could be expensive and time-consuming, and could have a material adverse effect on our business, financial condition, results of operations, and future prospects.

Unexpected refunds to the government, and/or response to a government investigation or enforcement action, could be expensive and time-consuming, and could have a material adverse effect on our business, financial condition, results of operations, and future prospects.

Risks from the improper conduct of employees, agents, contractors, or collaborators could adversely affect our reputation and our business, prospects, operating results, and financial condition.

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There is no certainty that all of our employees, agents, contractors, or collaborators, or those of our affiliates, will comply with all applicable laws and regulations, particularly given the high level of complexity of these laws.

Violations of these laws and regulations could result in fines, criminal sanctions against us, our officers, or our employees, requirements to obtain export licenses, cessation of business activities in sanctioned countries, implementation of compliance programs, and prohibitions on the conduct of our business.

prohibitions on the conduct of our business.

Any such violations could include prohibitions on our ability to offer our products in one or more countries and could materially damage our reputation, our brand, our ability to expand internationally, our ability to attract and retain employees, and our business, prospects, operating results, and financial condition.

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As described above, the PPACA and potential regulations thereunder easing the entry of competing follow-on biologics into the marketplace, other new legislation or implementation of existing statutory provisions on importation of lower-cost competing drugs from other jurisdictions, and legislation on comparative effectiveness research are examples of previously enacted and possible future changes in laws that could adversely affect our business.

In addition, in April 2023, the European Commission published a proposal to replace the current pharmaceutical legislative framework in the EU.

In addition, in 2023, the European Commission published a proposal to replace the current pharmaceutical legislative framework in the EU.

While it is uncertain whether such proposal will be adopted in its current form, there may ultimately be a number of changes to the current regulatory framework in the EU, including a reduction of the data protection and market exclusivity periods provided thereby.

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government, including the FDA.

For example, a prolonged shutdown (including prolonged continuation of the current shutdown) may significantly delay the FDA's ability to timely review and process any submissions we have filed or may file or cause other regulatory delays, which could materially and adversely affect our business.

For example, a prolonged shutdown may significantly delay the FDA's ability to timely review and process any submissions we have filed or may file or cause other regulatory delays, which could materially and adversely affect our business.

The FDA's ability to timely review and process any submissions we have filed or may file in the future may also be affected by the recent efforts to reduce the size and budgets of U.S.

government agencies, downsize the federal workforce, and implement other U.S.

policy changes, as discussed above under "Risks Related to Maintaining Approval of Our Marketed Products and the Development and Obtaining Approval of Our Product Candidates and New Indications for Our Marketed Products - Obtaining and maintaining regulatory approval for drug products is costly, time-consuming, and highly uncertain.

policy changes, as discussed above under "Risks Related to Maintaining Approval of Our Marketed Products and the Development and Obtaining Approval of Our Product Candidates and New Indications for Our Marketed Products - Obtaining and maintaining regulatory approval for drug and biological products is costly, time-consuming, and highly uncertain.

If we or our collaborators do not maintain regulatory approval for our marketed products, or obtain regulatory approval for our product candidates, we will not be able to market or sell them;

and if we do not obtain approvals for new indications for our marketed products, we may not be able to realize the full commercial potential of such products.

Any of the foregoing may materially and negatively impact our business, prospects, operating results, and financial condition.

Risks associated with our operations outside the United States could adversely affect our business.

We have operations and conduct business in many countries outside the United States and have been significantly expanding the scope of these activities in existing and/or additional countries, including EU countries and Japan.

For example, as discussed above, we now have commercial presence in certain jurisdictions outside the United States in connection with our acquisition of the exclusive right to develop, commercialize, and manufacture Libtayo worldwide pursuant to the A&R IO LCA;

and we perform co-commercialization activities under the Antibody Collaboration related to Dupixent in certain jurisdictions outside the United States.

For example, as discussed above, we now have commercial presence in many jurisdictions outside the United States in connection with our commercialization of Libtayo and co-commercialization of Dupixent, and we expect this commercial presence to continue to increase as we expand our commercialization activities for other products outside the United States (including Lynozyfic and Ordspono, which recently launched in the EU).

Consequently, we are, and will continue to be, subject to risks related to operating in countries outside the United States, particularly those in which we have not previously established operations, and many of these risks will increase as we expand our activities in such jurisdictions.

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Bribery Act (discussed in greater detail above under " Risks from the improper conduct of employees, agents, contractors, or collaborators could adversely affect our reputation and our business, prospects, operating results, and financial condition "), as well as labor and employment laws and regulations;

• changes in the political or economic condition of a specific country or region, including as a result of the Russia-Ukraine or Hamas-Israel armed conflict;

• changes in the political or economic condition of a specific country or region, including as a result of the Russia-Ukraine war, or Israel's armed conflicts with Iran, Lebanon, or Hamas;

• fluctuations in the value of foreign currency versus the U.S.

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Department of the Treasury), other trade barriers (including further legislation or actions taken by the United States or other countries that restrict trade), and protectionist or retaliatory measures taken by the United States or other countries.

The United States has recently imposed significant tariffs on imports from other countries, including a baseline tariff of 10% on imports into the United States and higher tariffs on multiple designated countries, such as "reciprocal" tariffs at varying rates.

In 2025, the U.S.

administration imposed an array of tariffs under the International Emergency Economic Powers Act ("IEEPA").

In July 2025, the United States and the EU announced the framework of a trade agreement that generally imposes a 15% tariff on imports from the EU.

Under this agreement, pharmaceutical products would not be subject to any future duties under Section 232 in excess of this 15% rate.

Such tariffs have prompted retaliatory measures from several countries, which may further escalate.

Certain of these tariffs have been subsequently paused or modified, and the situation remains fluid.

While pharmaceutical products are currently excluded from the baseline and "reciprocal" tariffs imposed by the United States, such tariffs still apply to the raw materials and other products necessary for the manufacture and formulation of our marketed products and product candidates.

In addition, the U.S.

Department of Commerce has initiated an investigation under Section 232 of the Trade Expansion Act of 1962, as amended, to determine the effects of importing pharmaceuticals and pharmaceutical ingredients on national security.

This investigation may lead to the imposition of tariffs on pharmaceutical imports, consistent with the current U.S.

administration's stated policy objective of reshoring pharmaceutical manufacturing to the United States.

Further, the United States and the EU recently announced the framework of a trade agreement that is expected to impose a 15% tariff on most imports from the EU, including pharmaceutical products.

However, the details of this trade agreement remain uncertain, including whether and to what extent such agreement may be impacted by the results of the Section 232 investigation.

On February 20, 2026, the U.S.

Supreme Court ruled that IEEPA does not confer the authority to impose tariffs.

In response, the U.S.

administration ceased collecting these duties and, on February 24, 2026, imposed a 10% tariff on imports from all trading partners under Section 122 of the Trade Act of 1974 ("Section 122").

The United States has signaled an intention to raise the Section 122 tariff rate to the statutory maximum of 15%, but this has not materialized as of the date of this report.

Additionally, pharmaceuticals and pharmaceutical ingredients have thus far been exempted from these tariffs.

In addition, on April 2, 2026, the United States imposed new tariffs on imports of patented pharmaceuticals and associated pharmaceutical ingredients under Section 232, which are set to become effective on July 31, 2026.

The Section 232 tariffs create a tiered structure with multiple rates depending on the country of origin, the importing company's status concerning onshoring and pricing agreements, and the nature of the product.

The Section 232 tariffs implement all pharmaceutical-related

commitments in existing U.S.

As discussed under Part I, Item 2.

"Management's Discussion and Analysis of Financial Condition and Results of Operations – Recent Developments – U.S.

Government Agreements," we have entered into the U.S.

Government Agreements and thus have exemptions from the Section 232 tariffs through January 2029, subject to certain conditions.

The Office of the U.S.

Trade Representative ("USTR") has initiated two new investigations under Section 301 of the Trade Act of 1974 ("Section 301"), one focused on industrial overcapacity and another on forced labor in supply chains.

These investigations collectively target nearly eighty countries.

administration has signaled that duties imposed as a result of these investigations would replace the Section 122 tariffs when they expire in July 2026.

It remains unclear if exemptions and carve-outs from Section 122 duties that currently exist for products, including pharmaceutical products, will be replicated in their entirety with respect to any future set of Section 301 tariffs.

We face significant risks from the existing tariffs imposed by the United States (such as those discussed above) and potential new tariffs as well as their secondary effects, including other countries' imposition of retaliatory tariffs and non-tariff barriers.

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For example, the OECD Pillar Two framework has influenced tax laws in countries in which we operate, including the implementation of minimum taxes.

Changes to these or other laws and regulations or their interpretations, including those resulting from the recently approved OBBBA (as discussed further in Note 8 to our Condensed Consolidated Financial Statements included in this report), could materially adversely impact our effective tax rate or cash flows.

Changes to these or other laws and regulations or their interpretations, including those resulting from the "One Big Beautiful Bill Act" signed into law in July 2025 (as discussed further in Note 8 to our Condensed Consolidated Financial Statements included in this report), could materially adversely impact our effective tax rate or cash flows.

We face risks related to the personal data we collect, process, and share.

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The FTC also has the power to enforce the Health Breach Notification Rule, which imposes notification obligations on companies for breaches of certain health information contained in personal health records.

Enforcement by the FTC under the FTC Act and Health Breach Notification Rule can result in civil penalties or enforcement actions.

Enforcement by the

FTC under the FTC Act and Health Breach Notification Rule can result in civil penalties or enforcement actions.

In addition, at the state level, many state consumer privacy laws recently went into effect and many other consumer privacy laws are expected to go into effect in the near future.

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We also depend, or will depend, on some of these or other third parties in connection with the commercialization of our marketed products and our product candidates and new indications for our marketed products if they are approved for marketing.

If any of our existing

collaborators or service providers breaches or terminates its agreement with us or does not perform its development or manufacturing services under an agreement in a timely manner (including as a result of its inability to perform due to financial or other relevant constraints) or in compliance with applicable GMPs, GLPs, or GCP standards, we could experience additional costs, delays, and difficulties in the manufacture or development of, or in obtaining approval by regulatory authorities for, or successfully commercializing our product candidates.

If any of our existing collaborators or service providers breaches or terminates its agreement with us or does not perform its development or manufacturing services under an agreement in a timely manner (including as a result of its inability to perform due to financial or other relevant constraints) or in compliance with applicable GMPs, GLPs, or GCP standards, we could experience additional costs, delays, and difficulties in the manufacture or development of, or in obtaining approval by regulatory authorities for, or successfully commercializing our product candidates.

See also "Risks Related to Manufacturing and Supply - Our or our collaborators' or contract manufacturers' failure to meet the stringent requirements of governmental regulation in the manufacture of drug products or product candidates could result in incurring substantial remedial costs, delays in the development or approval of our product candidates or new indications for our marketed products and/or in their commercial launch if regulatory approval is obtained, and a reduction in sales.

We and our collaborators rely on third-party service providers to support the distribution of our marketed products and for many other related activities in connection with the commercialization of these marketed products.

Despite our or our collaborators' arrangements with them, these third parties may not perform adequately.

Despite our or our

collaborators' arrangements with them, these third parties may not perform adequately.

If these service providers do not perform their services adequately, sales of our marketed products will suffer.

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Other Risks Related to Our Business

We are dependent on our key personnel and if we cannot recruit and retain leaders in our research, development, manufacturing, and commercial organizations, our business will be harmed.

We are dependent on our key personnel and if we cannot recruit or retain leaders in our research, development, manufacturing, and commercial organizations, our business will be harmed.

We are highly dependent on certain of our executive officers and other key members of our senior management team.

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Such attacks are of ever-increasing levels of sophistication and are made by groups and individuals with a wide range of motives (including industrial espionage or extortion) and expertise, including by organized criminal groups, "hacktivists," nation states, and others.

Recent developments in the threat landscape, including the use of adversarial AI techniques and machine learning to rapidly identify vulnerabilities, amplify these risks.

As a company with an increasingly global presence, our systems are subject to frequent attacks and incidents.

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or globally), which could have a material adverse effect on our business, prospects, operating results, and financial condition.

The foregoing risks may be exacerbated as we periodically upgrade or enhance our information technology systems.

For example, we are in the early stages of a multi-year project to implement a new enterprise resource planning ("ERP") system.

Upgrading or implementing new business processes and information technology systems, including our new ERP system, requires the commitment of significant personnel, training, and financial resources, and includes risks to our business operations.

If we do not successfully implement our new ERP system or other information technology systems improvements, or if there are delays or difficulties in implementing these systems, we may not realize anticipated productivity improvements or cost efficiencies, and we may experience operational difficulties and challenges in effectively managing our business, any of which could have a material adverse effect on our business, prospects, operating results, and financial condition.

Public health outbreaks, epidemics, or pandemics have adversely affected and may in the future adversely affect our business.

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We have certain indebtedness and contingent liabilities, including milestone and royalty payment obligations.

As of September 30, 2025, we had an aggregate of $2.706 billion of outstanding indebtedness under our senior unsecured notes and the lease financing facility.

As of March 31, 2026, we had an aggregate of $2.706 billion of outstanding indebtedness under our senior unsecured notes and the lease financing facility.

We may also incur additional debt in the future.

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Therefore, significant changes in foreign exchange rates can impact our operating results and the financial condition of our Company.

For example, as previously reported, the amount of our share of profits we earned in connection with commercialization of antibodies outside the United States was adversely impacted in 2022 by the U.S.

dollar strengthening against foreign currencies, including the Japanese yen and the euro.

Our investments are subject to risks and other external factors that may result in losses or affect the liquidity of these investments.

As of September 30, 2025, we had $2.506 billion in cash and cash equivalents and $16.223 billion in marketable securities (including $700.8 million in equity securities).

As of March 31, 2026, we had $2.963 billion in cash and cash equivalents and $16.319 billion in marketable and other securities (including $790.2 million in equity securities).

Our investments consist primarily of debt securities, including investment-grade corporate bonds.

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• public concern as to the safety or effectiveness of any of our marketed products or product candidates or new indications for our marketed products;

• pricing or reimbursement actions, decisions, or recommendations by government authorities, insurers, or other organizations (such as health maintenance organizations and PBMs) affecting the coverage, reimbursement, copay assistance, or use of any of our marketed products or competitors' products;

• pricing or reimbursement actions, decisions, or recommendations by government authorities, insurers, or other organizations (such as health maintenance organizations and PBMs) and pricing agreements with government entities (including the U.S.

Government Agreements) affecting the coverage, reimbursement, copay assistance, or use of any of our marketed products or competitors' products;

• developments in our relationships with collaborators or key customers;

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Broad market fluctuations may also adversely affect the market price of our Common Stock.

Securities class action litigation is often initiated against companies following periods of volatility in their

Securities class action litigation is often initiated against companies following periods of volatility in their stock price.

For example, in January 2025, a putative class action civil complaint was filed against the Company and certain current and former executive officers of the Company asserting violations of federal securities laws, as further described in Note 12 to our Condensed Consolidated Financial Statements included in this report.

This type of litigation could result in substantial costs and divert our management's attention and resources, and could also require us to make substantial payments to satisfy judgments or to settle litigation, which may harm our business, prospects, operating results, and financial condition.

This type of litigation could result in

substantial costs and divert our management's attention and resources, and could also require us to make substantial payments to satisfy judgments or to settle litigation, which may harm our business, prospects, operating results, and financial condition.

Future sales of our Common Stock by our significant shareholders or us may depress our stock price and impair our ability to raise funds in new share offerings.

A small number of our shareholders beneficially own a substantial amount of our Common Stock.

As of September 30, 2025, our five largest shareholders plus Dr.

Schleifer, our Chief Executive Officer, beneficially owned approximately 31.9% of our outstanding shares of Common Stock, assuming, in the case of our Chief Executive Officer, the conversion of his Class A Stock into Common Stock and the exercise of all options held by him which are exercisable within 60 days of September 30, 2025.

As of April 14, 2026, our five largest shareholders plus Dr.

Schleifer, our Chief Executive Officer, beneficially owned approximately 32.0% of our outstanding shares of Common Stock, assuming, in the case of our Chief Executive Officer, the conversion of his Class A Stock into Common Stock and the exercise of all options held by him which are exercisable within 60 days of April 14, 2026.

If our significant shareholders or we sell substantial amounts of our Common Stock in the public market, or there is a perception that such sales may occur, the market price of our Common Stock could fall.

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There can be no assurance that we will continue to repurchase shares of our Common Stock or continue to declare cash dividends.

In February 2025, our board of directors authorized our most recent share repurchase program to repurchase up to $3.0 billion of our Common Stock (of which $2.156 billion remained available as of September 30, 2025).

In February 2025, our board of directors also initiated a quarterly cash dividend program.

In February 2025, our board of directors authorized a share repurchase program to repurchase up to $3.0 billion of our Common Stock (of which $688.2 million remained available as of March 31, 2026);

and, in April 2026, the board authorized an additional $3.0 billion for share repurchases.

In 2025, our board of directors also initiated a quarterly cash dividend program.

Any future share repurchases, share repurchase program authorizations, or dividend declarations will depend upon, among other factors, our cash balances and potential future capital requirements, our results of operations and financial condition, the price of our Common Stock on the NASDAQ Global Select Market, and other factors that we may deem relevant.

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Holders of Class A Stock, who are generally the shareholders who purchased their stock from us before our initial public offering, are entitled to ten votes per share, while holders of Common Stock are entitled to one vote per share.

As of September 30, 2025, holders of Class A Stock held 14.9% of the combined voting power of all shares of Common Stock and Class A Stock then outstanding.

As of April 14, 2026, holders of Class A Stock held 15.0% of the combined voting power of all shares of Common Stock and Class A Stock then outstanding.

These shareholders, if acting together, would be in a position to substantially influence the election of our directors and the vote on certain corporate transactions that require majority or supermajority approval of the combined classes, including mergers and other business combinations.

This may result in our taking corporate actions that other shareholders may not consider to be in their best interest and may affect the price of our Common Stock.

As of September 30, 2025:

• our current executive officers and directors beneficially owned 5.4% of our outstanding shares of Common Stock, assuming conversion of their Class A Stock into Common Stock and the exercise of all options and release of all restricted stock units held by such persons which are exercisable or releasable within 60 days of September 30, 2025, and 17.6% of the combined voting power of our outstanding shares of Common Stock and Class A Stock, assuming the exercise of all options and release of all restricted stock units held by such persons which are exercisable or releasable within 60 days of September 30, 2025;

As of April 14, 2026:

• our current executive officers and directors beneficially owned 5.2% of our outstanding shares of Common Stock, assuming conversion of their Class A Stock into Common Stock and the exercise of all options and release of all restricted stock units held by such persons which are exercisable or releasable within 60 days of April 14, 2026, and 17.5% of the combined voting power of our outstanding shares of Common Stock and Class A Stock, assuming the exercise of all options and release of all restricted stock units held by such persons which are exercisable or releasable within 60 days of April 14, 2026;

• our five largest shareholders plus Dr.

In addition, these five shareholders plus our Chief Executive Officer held approximately 40.3% of the combined voting power of our outstanding shares of Common Stock and Class A Stock, assuming the exercise of all options held by our Chief Executive Officer which are exercisable within 60 days of September 30, 2025.

In addition, these five shareholders plus our Chief Executive Officer held approximately 40.4% of the combined voting power of our outstanding shares of Common Stock and Class A Stock, assuming the exercise of all options held by our Chief Executive Officer which are exercisable within 60 days of April 14, 2026.

The anti-takeover effects of provisions of our charter, by-laws, and of New York corporate law, as well as the contractual provisions in our investor and collaboration agreements and certain provisions of our compensation plans and agreements, could deter, delay, or prevent an acquisition or other "change of control" of us and could adversely affect the price of our Common Stock.

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• authorization to issue "blank check" preferred stock, which is preferred stock that can be created and issued by the board of directors without prior shareholder approval, with rights senior to those of our Common Stock and Class A Stock;

• a staggered board of directors (which, pursuant to an amendment to our certificate of incorporation approved by shareholders in June 2025, will be phased out beginning in 2026 and result in the annual election of all of our directors commencing with the 2028 annual meeting of shareholders);

• a staggered board of directors (which, pursuant to an amendment to our certificate of incorporation approved by shareholders in 2025, will be phased out beginning in 2026 and result in the annual election of all of our directors commencing with the 2028 annual meeting of shareholders);

• a requirement that removal of directors may only be effected for cause and only upon the affirmative vote of at least eighty percent (80%) of the outstanding shares entitled to vote for directors, as well as a requirement that any vacancy on the board of directors may be filled only by the remaining directors;

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Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-Q

Item 1A. Risk Factors