UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)
☒	ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the fiscal year ended	December 31, 2019
	OR
☐	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the transition period from __________ to __________

Commission File Number: 0-19034

REGENERON PHARMACEUTICALS, INC.

(Exact name of registrant as specified in its charter)

New York	13-3444607
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)

777 Old Saw Mill River Road	Tarrytown,	New York	10591-6707
(Address of principal executive offices, including zip code)

(914) 847-7000

(Registrant's telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol	Name of each exchange on which registered
Common Stock - par value $.001 per share	REGN	NASDAQ Global Select Market

Securities registered pursuant to section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.	Yes	☒	No	☐
Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.	Yes	☐	No	☒
Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.	Yes	☒	No	☐
Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).	Yes	☒	No	☐
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

Large accelerated filer ☒ Accelerated filer ☐ Non-accelerated filer ☐ Smaller reporting company ☐ Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.		☐
Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).	Yes	☐	No	☒

The aggregate market value of the voting and non-voting common stock held by non-affiliates of the registrant was approximately $32,929,000,000, computed by reference to the closing sales price of the stock on NASDAQ on June 28, 2019, the last trading day of the registrant's most recently completed second fiscal quarter. For purposes of this calculation only, the registrant has assumed that all of its directors and executive officers, and no other persons, are its affiliates. This determination of affiliate status is not necessarily a determination for other purposes.

The number of shares outstanding of each of the registrant's classes of common stock as of January 31, 2020:

Class of Common Stock	Number of Shares
Class A Stock, $.001 par value	1,848,970
Common Stock, $.001 par value	108,170,839

DOCUMENTS INCORPORATED BY REFERENCE

Specified portions of the Registrant's definitive proxy statement to be filed in connection with solicitation of proxies for its 2020 Annual Meeting of Shareholders are incorporated by reference into Part III of this Form 10-K. Exhibit index is located on pages 76 to 81 of this filing.

REGENERON PHARMACEUTICALS, INC.

ANNUAL REPORT ON FORM 10-K

TABLE OF CONTENTS

		Page Numbers
PART I
Item 1.	Business	2
Item 1A.	Risk Factors	27
Item 1B.	Unresolved Staff Comments	55
Item 2.	Properties	55
Item 3.	Legal Proceedings	55
Item 4.	Mine Safety Disclosures	55
PART II
Item 5.	Market for Registrant's Common Equity, Related Stockholder Matters, and Issuer Purchases of Equity Securities	56
Item 6.	Selected Financial Data	59
Item 7.	Management's Discussion and Analysis of Financial Condition and Results of Operations	60
Item 7A.	Quantitative and Qualitative Disclosures About Market Risk	73
Item 8.	Financial Statements and Supplementary Data	74
Item 9.	Changes in and Disagreements with Accountants on Accounting and Financial Disclosure	74
Item 9A.	Controls and Procedures	75
Item 9B.	Other Information	75
PART III
Item 10.	Directors, Executive Officers and Corporate Governance	76
Item 11.	Executive Compensation	76
Item 12.	Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters	76
Item 13.	Certain Relationships and Related Transactions, and Director Independence	76
Item 14.	Principal Accounting Fees and Services	76
PART IV
Item 15.	Exhibits and Financial Statement Schedules	76
Item 16.	Form 10-K Summary	81
SIGNATURE PAGE		82

"ARCALYST^®", "EYLEA^®", "Libtayo^®" (in the United States), "Regeneron^®", "Regeneron Genetics Center^®", "Veloci-Bi^®", "VelociGene^®", "VelociMab^®", "VelocImmune^®", "VelociMouse^®", "VelociSuite^®", "VelociT™", and "ZALTRAP^®" are trademarks of Regeneron Pharmaceuticals, Inc. Trademarks and trade names of other companies appearing in this report are, to the knowledge of Regeneron Pharmaceuticals, Inc., the property of their respective owners.

PART I

ITEM 1. BUSINESS

This Annual Report on Form 10-K contains forward-looking statements that involve risks and uncertainties relating to future events and the future performance of Regeneron Pharmaceuticals, Inc. (where applicable, together with its subsidiaries, "Regeneron," "Company," "we," "us," and "our"), and actual events or results may differ materially from these forward-looking statements. Words such as "anticipate," "expect," "intend," "plan," "believe," "seek," "estimate," variations of such words, and similar expressions are intended to identify such forward-looking statements, although not all forward-looking statements contain these identifying words. These statements concern, and these risks and uncertainties include, among others, the nature, timing, and possible success and therapeutic applications of products marketed by us and/or our collaborators (collectively, "Regeneron's Products") and our product candidates and research and clinical programs now underway or planned, including without limitation EYLEA^® (aflibercept) Injection, Dupixent^® (dupilumab) Injection, Libtayo^® (cemiplimab) Injection, Praluent^® (alirocumab) Injection, Kevzara^® (sarilumab) Injection, fasinumab, evinacumab, REGN-EB3, garetosmab, pozelimab, and REGN1979; the likelihood and timing of achieving any of our anticipated clinical development milestones referenced in this report; unforeseen safety issues resulting from the administration of Regeneron's Products and product candidates in patients, including serious complications or side effects in connection with the use of Regeneron's Products and product candidates in clinical trials; the likelihood and timing of possible regulatory approval and commercial launch of our late-stage product candidates and new indications for Regeneron's Products, including without limitation EYLEA, Dupixent, Libtayo, Praluent, Kevzara, fasinumab, evinacumab, REGN-EB3, garetosmab, pozelimab, and REGN1979; the extent to which the results from the research and development programs conducted by us or our collaborators may be replicated in other studies and lead to therapeutic applications; ongoing regulatory obligations and oversight impacting Regeneron's Products (such as EYLEA, Dupixent, Libtayo, Praluent, and Kevzara), research and clinical programs, and business, including those relating to patient privacy; determinations by regulatory and administrative governmental authorities which may delay or restrict our ability to continue to develop or commercialize Regeneron's Products and product candidates; competing drugs and product candidates that may be superior to Regeneron's Products and product candidates; uncertainty of market acceptance and commercial success of Regeneron's Products and product candidates; our ability to manufacture and manage supply chains for multiple products and product candidates; the ability of our collaborators, suppliers, or other third parties (as applicable) to perform manufacturing, filling, finishing, packaging, labeling, distribution, and other steps related to Regeneron's Products and product candidates; coverage and reimbursement determinations by third-party payors, including Medicare and Medicaid; unanticipated expenses; the costs of developing, producing, and selling products; our ability to meet any of our financial projections or guidance, including without limitation capital expenditures, and changes to the assumptions underlying those projections or guidance; the potential for any license or collaboration agreement, including our agreements with Sanofi, Bayer, and Teva Pharmaceutical Industries Ltd. (or their respective affiliated companies, as applicable), to be cancelled or terminated without any further product success; and risks associated with intellectual property of other parties and pending or future litigation relating thereto (including without limitation the patent litigation and other related proceedings relating to Dupixent and Praluent described further in Note 16 to our Consolidated Financial Statements included in this report), other litigation and other proceedings and governmental investigations relating to the Company and/or its operations (including without limitation those described in Note 16 to our Consolidated Financial Statements included in this report), the ultimate outcome of any such proceedings and investigations, and the impact any of the foregoing may have on our business, prospects, operating results, and financial condition. These statements are made based on management's current beliefs and judgment, and the reader is cautioned not to rely on any such statements. In evaluating such statements, shareholders and potential investors should specifically consider the various factors identified under Part I, Item 1A. "Risk Factors," which could cause actual events and results to differ materially from those indicated by such forward-looking statements. We do not undertake any obligation to update publicly any forward-looking statement, whether as a result of new information, future events, or otherwise.

General

Regeneron Pharmaceuticals, Inc. is a fully integrated biotechnology company that discovers, invents, develops, manufactures, and commercializes medicines for the treatment of serious diseases. Our commercialized medicines and product candidates in development are designed to help patients with eye diseases, allergic and inflammatory diseases, cancer, cardiovascular and metabolic diseases, pain, infectious diseases, and rare diseases.

Our core business strategy is to maintain a strong foundation in basic scientific research and discovery-enabling technologies, and to build on that foundation with our clinical development, manufacturing, and commercial capabilities. Our objective is to continue to be an integrated, multi-product biotechnology company that provides patients and medical professionals with important options for preventing and treating human diseases.

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Selected financial information is summarized as follows:

	Year Ended December 31,
(In millions, except per share data)	2019		2018		2017
Revenues	$	7,863.4	$	6,710.8	$	5,872.2
Net income	$	2,115.8	$	2,444.4	$	1,198.5
Net income per share - diluted	$	18.46	$	21.29	$	10.34

In December 2019, we and Sanofi announced our intent to restructure the antibody collaboration for Kevzara and Praluent; completion of the proposed arrangement is expected to be finalized in the first quarter of 2020. Refer to "Collaboration Agreements - Collaborations with Sanofi - Antibody" section below for further details.

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Marketed Products

We currently have seven products that have received marketing approval, which are currently marketed by us, Bayer, and/or Sanofi:

Product		Disease Area(1)	Territory
			U.S.	EU	Japan	ROW(6)
EYLEA (aflibercept) Injection(2)	-	Neovascular age-related macular degeneration ("wet AMD")	a	a	a	a
	-	Diabetic macular edema ("DME")	a	a	a	a
	-	Macular edema following retinal vein occlusion ("RVO"), which includes macular edema following central retinal vein occlusion ("CRVO") and macular edema following branch retinal vein occlusion ("BRVO")	a	a	a	a
	-	Myopic choroidal neovascularization ("mCNV")		a	a	a
	-	Diabetic retinopathy	a
Dupixent (dupilumab) Injection(3)	-	Atopic dermatitis (in adults and adolescents)(7)	a	a	a	a
	-	Asthma (in adults and adolescents)	a	a	a	a
	-	Chronic rhinosinusitis with nasal polyposis ("CRSwNP")	a	a		a
Libtayo (cemiplimab) Injection(3)(4)	-	Metastatic or locally advanced cutaneous squamous cell carcinoma ("CSCC")	a	a		a
Praluent (alirocumab) Injection(3)	-	LDL-lowering in heterozygous familial hypercholesterolemia ("HeFH") or clinical atherosclerotic cardiovascular disease ("ASCVD") (in adults)	a	a	a	a
	-	Cardiovascular risk reduction in patients with established cardiovascular disease	a	a		a
Kevzara (sarilumab) Solution for Subcutaneous Injection(3)	-	Rheumatoid arthritis ("RA") (in adults)	a	a	a	a
ARCALYST® (rilonacept) Injection for Subcutaneous Use	-	Cryopyrin-Associated Periodic Syndromes ("CAPS"), including Familial Cold Auto-inflammatory Syndrome ("FCAS") and Muckle-Wells Syndrome ("MWS")	a
ZALTRAP® (ziv-aflibercept) Injection for Intravenous Infusion(5)	-	Metastatic colorectal cancer ("mCRC")	a	a	a	a
(1) Refer to label information in each territory for specific indication
(2) In collaboration with Bayer (outside the United States)
(3) In collaboration with Sanofi
(4) Marketed as Libtayo (cemiplimab-rwlc) Injection in the United States
(5) Pursuant to a 2015 amended and restated ZALTRAP agreement, Sanofi is solely responsible for the development and commercialization of ZALTRAP, and Sanofi pays us a percentage of aggregate net sales of ZALTRAP
(6) Rest of world. Checkmark in this column indicates that the product has received marketing approval in at least one country outside of the United States, European Union (EU), or Japan
(7) Approval in Japan is for adults and adolescents 15 years of age and older

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Net Product Sales of Regeneron-Discovered Products(1)	Year Ended December 31,
(In millions)	2019						2018						2017
	U.S.		ROW		Total		U.S.		ROW		Total		U.S.		ROW		Total
EYLEA(1)	$	4,644.2	$	2,897.4	$	7,541.6	$	4,076.7	$	2,668.9	$	6,745.6	$	3,701.9	$	2,226.9	$	5,928.8
Libtayo(1)	175.7		18.1		193.8		14.8		—		14.8		—		—		—
ARCALYST	14.5		—		14.5		14.7		—		14.7		16.6		—		16.6
Net product sales recorded by Regeneron	$	4,834.4					$	4,106.2					$	3,718.5
Net product sales recorded by Sanofi(1):
Dupixent	$	1,871.2	$	444.4	$	2,315.6	$	776.3	$	145.7	$	922.0	$	253.8	$	2.7	$	256.5
Praluent	$	126.0	$	162.7	$	288.7	$	181.3	$	125.5	$	306.8	$	131.4	$	63.3	$	194.7
Kevzara	$	129.0	$	77.7	$	206.7	$	74.7	$	21.9	$	96.6	$	11.6	$	1.7	$	13.3
ZALTRAP	$	7.3	$	101.1	$	108.4	$	9.0	$	98.8	$	107.8	$	10.7	$	73.1	$	83.8
(1) Bayer records net product sales of EYLEA outside the U.S., and Sanofi records net product sales of Libtayo outside the U.S. and global net product sales of Dupixent, Praluent, Kevzara, and ZALTRAP. Refer to "Collaboration Agreements" section below for further details.

Programs in Clinical Development

All 22 of our product candidates in clinical development, including the five U.S. Food and Drug Administration ("FDA") approved products which we are investigating in additional indications, were discovered in our research laboratories and are summarized in the table below. We believe that our ability to develop product candidates is enhanced by the application of our VelociSuite^® technology platforms (refer to "Research and Development Technologies - VelociSuite" section below). We continue to invest in the development of enabling technologies to assist in our efforts to identify, develop, manufacture, and commercialize new product candidates.

There are numerous uncertainties associated with drug development, including uncertainties related to safety and efficacy data from each phase of drug development (including any post-approval studies), uncertainties related to the enrollment and performance of clinical trials, changes in regulatory requirements, changes to drug pricing and reimbursement regulations and requirements, and changes in the competitive landscape affecting a product candidate. The planning, execution, and results of our clinical programs are significant factors that can affect our operating and financial results. Refer to Part I, Item 1A. "Risk Factors" for a description of these and other risks and uncertainties that may affect our clinical programs.

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Clinical Program	Phase 1		Phase 2		Phase 3		Regulatory Review(i)		2019 and 2020 Events to Date		Select Upcoming Milestones
Ophthalmology
EYLEA		-	High-dose formulation in wet AMD	-	Retinopathy of prematurity ("ROP")(c)			-	Approved by FDA for the treatment of diabetic retinopathy	-	Initiate Phase 3 studies of a high-dose formulation of aflibercept in wet AMD and DME (mid-2020)
								-	Pre-filled syringe approved by FDA
Immunology & Inflammatory Diseases
Dupixent (dupilumab)(a) Antibody to IL-4R alpha subunit		-	Grass allergy	-	Atopic dermatitis in pediatrics (6 months–5 years of age) (Phase 2/3)(d)	-	Atopic dermatitis in pediatrics (6–11 years of age) (U.S. and EU)(d)	-	Approved by FDA and European Commission ("EC") for expanded atopic dermatitis indication in adolescent patients (12–17 years of age)	-	FDA decision (target action date of May 26, 2020) on supplemental Biologics License Application ("sBLA") and EC decision (second half 2020) for expanded atopic dermatitis indication in pediatric patients (6–11 years of age)
		-	Peanut allergy
				-	Asthma in pediatrics (6–11 years of age)	-	CRSwNP (Japan)
				-	Eosinophilic esophagitis ("EOE")(c)	-	Auto-injector for 300 mg dose (U.S. and Japan)	-	Reported that Phase 3 study in pediatric patients (6–11 years of age) with severe atopic dermatitis met its primary and secondary endpoints
				-	Chronic obstructive pulmonary disease ("COPD")					-	Report results from Phase 3 study for atopic dermatitis in pediatric patients (6 months–5 years of age) (2022)
				-	Bullous pemphigoid (Phase 2/3)(c)			-	Approved by EC for treatment of asthma in adults and adolescents
				-	Chronic spontaneous urticaria					-	Report results from Phase 3 study for asthma in pediatric patients (6–11 years of age) (second half 2020)
				-	Prurigo nodularis			-	Approved by FDA and EC for CRSwNP
								-	EU approval for 200 mg and 300 mg auto-injector	-	Japan decision on application for CRSwNP (first half 2020)
								-	FDA issued Complete Response Letter ("CRL") on sBLA for 200 mg auto-injector	-	FDA decision on application for 300 mg auto-injector (target action date of March 20, 2020)
								-	Completed Phase 2a trial in grass allergy	-	Resubmit sBLA for 200 mg auto-injector (first half 2020)
										-	Present results from Phase 2a trial in grass allergy at medical meeting (first half 2020)

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Clinical Program (continued)		Phase 1		Phase 2		Phase 3	Regulatory Review(i)		2019 and 2020 Events to Date		Select Upcoming Milestones
										-	Report results from Phase 2 study in peanut allergy (first half 2021)
										-	Initiate Phase 3 study in pediatric patients with EOE (second half 2020)
										-	Report results from Phase 2 portion of Phase 2/3 study in EOE (mid-2020)
										-	Initiate Phase 3 studies in hand and foot atopic dermatitis and allergic bronchopulmonary aspergillosis ("ABPA") (first half 2020)
Kevzara (sarilumab)(a) Antibody to IL-6R			-	Polyarticular-course juvenile idiopathic arthritis ("pcJIA")	-	Polymyalgia rheumatica ("PMR")
			-	Systemic juvenile idiopathic arthritis ("sJIA")	-	Giant cell arteritis ("GCA")
REGN3500(a) Antibody to IL-33. Studied as monotherapy and in combination with Dupixent.			-	Asthma				-	Reported that Phase 2 study in asthma met its primary and key secondary endpoints	-	Report results from Phase 2 study in atopic dermatitis (second half 2020)
			-	COPD
			-	Atopic dermatitis				-	Sanofi reported that Phase 2 study in COPD demonstrated reduced exacerbations in the overall study population, but results were not statistically significant	-	Initiate Phase 2b study in asthma (second half 2020)
REGN1908-1909(f) Multi-antibody therapy to Feld1			-	Cat allergy						-	Report results from Phase 2 study in cat allergic asthmatics (first half 2020)
REGN5713-5714-5715 Antibody to Betv1	-	Birch allergy

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Clinical Program (continued)		Phase 1		Phase 2		Phase 3	Regulatory Review(i)		2019 and 2020 Events to Date		Select Upcoming Milestones
Oncology
Libtayo (cemiplimab)(a)(h) Antibody to PD-1	-	Solid tumors and advanced hematologic malignancies	-	Basal cell carcinoma ("BCC") (potentially pivotal study)	-	First-line non-small cell lung cancer ("NSCLC")		-	Conditionally approved by EC for treatment of advanced CSCC	-	Report results from potentially pivotal Phase 2 study in BCC (mid-2020)
			-	Metastatic or locally advanced CSCC(d)	-	Second-line cervical cancer(e)		-	Independent data monitoring committee conducted an interim analysis for overall survival in a Phase 3 NSCLC trial, and recommended trial continue as planned	-	Report results from Phase 3 study in cervical cancer (first half 2021)
			-	Neoadjuvant CSCC	-	Adjuvant CSCC
										-	Interim analysis of overall survival from Phase 3 NSCLC monotherapy study (2020)
REGN1979 Bispecific antibody targeting CD20 and CD3	-	Certain B-cell malignancies(c)	-	B-cell non-Hodgkin lymphoma ("B-NHL") (potentially pivotal study)				-	Reported updated results from Phase 1 trial in B-cell malignancies	-	Report updated results from initial study in certain B-cell malignancies (2020)
								-	Continued to expand potentially pivotal Phase 2 program with different subtypes of NHL	-	Continue to expand potentially pivotal Phase 2 study (2020)
REGN5458(a) Bispecific antibody targeting BCMA and CD3	-	Multiple myeloma						-	Reported positive preliminary results from Phase 1 trial in multiple myeloma	-	Report updated results from initial study in multiple myeloma (2020)
REGN5459(a) Bispecific antibody targeting BCMA and CD3	-	Multiple myeloma
REGN4018(a) Bispecific antibody targeting MUC16 and CD3	-	Platinum-resistant ovarian cancer
REGN5678 Bispecific antibody targeting PSMA and CD28	-	Prostate cancer
REGN5093 Bispecific antibody targeting two distinct MET epitopes	-	MET-altered advanced NSCLC
REGN3767(f) Antibody to LAG-3	-	Solid tumors and advanced hematologic malignancies

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Clinical Program (continued)	Phase 1		Phase 2		Phase 3	Regulatory Review(i)		2019 and 2020 Events to Date		Select Upcoming Milestones
Cardiovascular/Metabolic Diseases
Praluent (alirocumab)(a) Antibody to PCSK9				-	Homozygous familial hypercholesterolemia ("HoFH")(c) in adults and pediatrics		-	Approved by EC for a new indication to reduce cardiovascular risk in adults with established ASCVD	-	Report results from Phase 3 study in HoFH and submit sBLA (2020)
				-	HeFH in pediatrics		-	Approved by FDA for a new indication to reduce the risk of heart attack, stroke and unstable angina requiring hospitalization in adults with established CV disease
							-	Approved by FDA for treatment of adults with primary hyperlipidemia (including HeFH) to reduce low-density lipoprotein cholesterol ("LDL-C")
Evinacumab(f) (REGN1500) Antibody to ANGPTL3		-	Refractory hypercholesterolemia (both HeFH and non-FH)	-	HoFH(c)(d)		-	Reported positive top-line results from Phase 3 trial in HoFH	-	Submit BLA and Marketing Authorization Application ("MAA") for HoFH (2020)
		-	Severe hypertriglyceridemia
Pozelimab(f) (REGN3918) Antibody to C5		-	Paroxysmal nocturnal hemoglobinuria ("PNH")(c)				-	Reported positive top-line results from Phase 2 trial in PNH	-	Initiate combination program with Alnylam's cemdisiran (second half 2020)
									-	Initiate Phase 3 program in PNH (second half 2020)
Garetosmab(f) (REGN2477) Antibody to Activin A		-	Fibrodysplasia ossificans progressiva ("FOP")(c)(e) (potentially pivotal study)				-	Reported results from Phase 2 study in FOP	-	Discuss regulatory submission for FOP with regulatory authorities (first half 2020)
REGN4461(f) Agonist antibody to leptin receptor ("LEPR")		-	Generalized lipodystrophy(e)

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Clinical Program (continued)	Phase 1		Phase 2		Phase 3		Regulatory Review(i)		2019 and 2020 Events to Date		Select Upcoming Milestones
Pain
Fasinumab(b)(f) (REGN475) Antibody to NGF				-	Osteoarthritis pain of the knee or hip(e)					-	Report results from Phase 3 studies in osteoarthritis pain of the knee or hip (mid-2020)
REGN5069 Antibody to GFRα3		-	Osteoarthritis pain of the knee(e)							-	Report results from Phase 2 study in osteoarthritis pain of the knee (second half 2020)
Infectious Diseases
REGN-EB3(f)(g) (REGN3470-3471-3479) Multi-antibody therapy to Ebola virus infection ("Ebola")						-	Ebola (U.S.)(c)(d)(j)	-	Investigational trial in the Democratic Republic of Congo was stopped early based on data showing that REGN-EB3 was superior to ZMapp in preventing death	-	Complete rolling BLA submission for Ebola (first half 2020)

Note 1:  For purposes of the table above, a program is classified in Phase 1, 2, or 3 clinical development after recruiting for the corresponding study or studies has commenced

Note 2:  We have discontinued further clinical development of REGN4659, an antibody to CTLA4, which was previously being studied in advanced NSCLC

^(a) In collaboration with Sanofi

^(b) In collaboration with Teva and Mitsubishi Tanabe Pharma

^(c) FDA granted orphan drug designation

^(d) FDA granted Breakthrough Therapy designation

^(e) FDA granted Fast Track designation

^(f) Sanofi did not opt-in to or elected not to continue to co-develop the product candidate. Under the terms of our agreement, Sanofi is entitled to receive royalties on any future sales of the product candidate.

^(g) We and the Biomedical Advanced Research Development Authority ("BARDA") of the U.S. Department of Health and Human Services ("HHS") are parties to agreements whereby HHS provides certain funding to support research, development, and manufacturing of these antibodies.

^(h) Studied as monotherapy and in combination with other antibodies and treatments

⁽ⁱ⁾ Information in this column relates to U.S., EU, and Japan regulatory submissions only

^(j) Included as part of the Extension Phase of a trial coordinated by World Health Organization

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Additional Information - Marketed Products Studied in Additional Indications and Product Candidates in Late-Stage Clinical Development

EYLEA

EYLEA is a soluble fusion protein that acts as a vascular endothelial growth factor ("VEGF") inhibitor, formulated as an injection for the eye. It is designed to block the growth of new blood vessels and decrease the ability of fluid to pass through blood vessels (vascular permeability) in the eye by blocking VEGF-A and PLGF, two growth factors involved in angiogenesis.

Dupixent (dupilumab)

Dupixent is a fully-human monoclonal antibody that inhibits the signaling pathway of IL-4 and IL-13. Data from Dupixent clinical trials have shown that IL-4 and IL-13 are key drivers of the type 2 inflammation that plays a major role in atopic dermatitis, asthma, and CRSwNP, as well as other immunological and inflammatory diseases.

Kevzara (sarilumab)

Kevzara is a fully-human monoclonal antibody that binds specifically to the IL-6 receptor and inhibits IL-6-mediated signaling. IL-6 is a signaling protein produced in increased quantities in patients with RA and has been associated with disease activity, joint destruction, and other systemic problems.

Libtayo (cemiplimab) and REGN1979

Regeneron is developing a diverse and comprehensive oncology portfolio, including Libtayo, which is being studied as monotherapy and in combination with other anti-cancer agents in various indications.

Libtayo is a fully-human monoclonal antibody targeting the immune checkpoint receptor PD-1. The PD-1/PD-L1 immune checkpoint pathway has emerged as a major mechanism by which cancers evade immune destruction. Libtayo is also being studied by other companies in combination with their proprietary assets.

REGN1979 is an investigational bispecific monoclonal antibody designed to bridge T-cells and tumor cells. It is designed to trigger tumor killing by binding to both a protein expressed on B-cell cancers (CD20) and a component of the T-cell receptor ("TCR") complex (CD3). At the tumor site, it activates T-cells by engaging their CD3 molecules and promotes T-cell mediated killing of the cancer cells.

Praluent (alirocumab)

Praluent is a fully-human monoclonal antibody that inhibits the binding of PCSK9 to the LDL receptor. Through inhibiting PCSK9, Praluent increases the number of available LDL receptors on the surface of liver cells to clear LDL, which lowers LDL cholesterol levels in the blood.

Evinacumab

Evinacumab is an investigational, fully-human monoclonal antibody that specifically binds to and blocks ANGPTL3. ANGPTL3 plays a key role in regulating plasma lipid levels, including triglycerides, LDL cholesterol, and HDL cholesterol, through inhibition of lipase enzymes (lipoprotein lipase and endothelial lipase).

Pozelimab

Pozelimab is an investigational, fully-human monoclonal antibody designed to block complement factor C5 and prevent the destruction of red blood cells that cause the symptoms of PNH and other diseases mediated by abnormal complement pathway activity. PNH is an ultra-rare, chronic, life-threatening disease where genetic mutations cause hemolysis, resulting in a range of symptoms including fatigue, shortness of breath, and blood clots. Pozelimab binds with high affinity to wild-type and variant human C5 and blocks its activity.

Garetosmab

Garetosmab is an investigational, fully-human monoclonal antibody that binds and neutralizes Activin A, which is required for the development of additional bone outside the normal skeleton in patients with the ultra-rare genetic disorder, FOP. The abnormal bone formation in soft tissue outside of the normal skeleton, a process known as heterotopic ossification, leads to loss of mobility and premature death in FOP patients. Garetosmab reduces the formation of heterotopic bone lesions by neutralizing the Activin A protein.

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Fasinumab

Fasinumab is an investigational, fully-human monoclonal antibody that targets NGF, a protein that plays a central role in the regulation of pain signaling. NGF expression is elevated in many acute and chronic pain conditions and NGF blockade has demonstrated efficacy in clinical trials. Targeting NGF is a potential new way to manage pain without resorting to opioids.

REGN-EB3

REGN-EB3 is an investigational cocktail of three fully-human monoclonal antibodies that each bind to the Ebola virus at different points, which may serve to increase efficacy, reduce the development of viral sequences that lead to resistance, and potentially enable utility in future outbreaks as viruses continue to evolve. REGN-EB3 is being developed, tested, and manufactured through contracts awarded in 2015 and 2017 by BARDA, under the Assistant Secretary for Preparedness and Response within the U.S. Department of Health and Human Services.

Other Programs

Our preclinical research programs include the areas of oncology/immuno-oncology, angiogenesis, ophthalmology, metabolic and related diseases, muscle diseases and disorders, inflammation and immune diseases, bone and cartilage, pain and neurobiology, cardiovascular diseases, infectious diseases, and diseases related to aging.

Research and Development Technologies

Many proteins that play an important role in biology and disease are secreted by cells or located on the cell surface. Moreover, cells communicate through secreted factors and surface molecules. Our scientists have developed two different technologies to make protein therapeutics that potently and specifically block, activate, or inhibit the action of specific cell surface or secreted molecules. The first technology fuses receptor components to the constant region of an antibody molecule to make a class of drugs we call "Traps". EYLEA, ZALTRAP, and ARCALYST are drugs generated using our Trap technology. VelociSuite is our second technology platform, which is used for discovering, developing, and producing fully human antibodies that can address both secreted and cell-surface targets.

VelociSuite

VelociSuite consists of VelocImmune^®, VelociGene^®, VelociMouse^®, VelociMab^®, Veloci-Bi^®, VelociT™, and other related technologies. The VelocImmune mouse platform is utilized to produce fully human antibodies. VelocImmune was generated by leveraging our VelociGene technology (see below), in a process in which six megabases of mouse immune gene loci were replaced, or "humanized," with corresponding human immune gene loci. VelocImmune mice can be used efficiently to generate fully human antibodies to targets of therapeutic interest. VelocImmune and our entire VelociSuite offer the potential to increase the speed and efficiency through which human antibody therapeutics may be discovered and validated, thereby improving the overall efficiency of our early stage drug development activities. We are utilizing the VelocImmune technology to produce our next generation of drug candidates for preclinical and clinical development.

Our VelociGene platform allows custom and precise manipulation of very large sequences of DNA to produce highly customized alterations of a specified target gene, or genes, and accelerates the production of knock-out and transgenic expression models without using either positive/negative selection or isogenic DNA. In producing knock-out models, a color or fluorescent marker may be substituted in place of the actual gene sequence, allowing for high-resolution visualization of precisely where the gene is active in the body during normal body functioning as well as in disease processes. For the optimization of preclinical development and pharmacology programs, VelociGene offers the opportunity to humanize targets by replacing the mouse gene with the human homolog. Thus, VelociGene allows scientists to rapidly identify the physical and biological effects of deleting or over-expressing the target gene, as well as to characterize and test potential therapeutic molecules.

Our VelociMouse technology platform allows for the direct and immediate generation of genetically altered mice from embryonic stem cells ("ES cells"), thereby avoiding the lengthy process involved in generating and breeding knockout mice from chimeras. Mice generated through this method are normal and healthy and exhibit a 100% germ-line transmission. Furthermore, mice developed using our VelociMouse technology are suitable for direct phenotyping or other studies. We have also developed our VelociMab platform for the rapid screening of antibodies and rapid generation of expression cell lines for our Traps and our VelocImmune human antibodies.

We have utilized our VelociSuite technologies to develop a class of potential drug candidates, known as bi-specific antibodies. Veloci-Bi allows for the generation of full-length bi-specific antibodies similar to native antibodies that are amenable to production by standard antibody manufacturing techniques, and are likely to have favorable antibody-like pharmacokinetic properties. In the area of immunotherapies in oncology, we are exploring the use of bi-specific antibodies that target tumor antigens and the CD3 receptor on T-cells to harness the oncolytic properties of T-cells. Our first such CD3 bi-specific antibody, REGN1979, targets CD20. We are

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exploring additional indications and applications for our bi-specific technologies, such as other CD3 bi-specific antibodies to MUC16 (REGN4018) and BCMA (REGN5458 and REGN5459), as well as a new class of CD28 co-stimulatory bi-specifics, including an antibody that targets PSMA (REGN5678).

The VelociT mouse extends our research and drug discovery capabilities into cell-mediated immunity and therapeutic TCRs for oncology and other indications. VelociT was developed by using our VelociGene technology to humanize genes encoding TCRa and TCRb variable sequences, CD4 and CD8 co-receptors, β2m, and class-I and -II major histocompatibility complexes. As a result, VelociT mice generate fully human TCRs, providing for customized modeling of T-cell function in different diseases and a powerful platform for the discovery of unique TCR-based therapies.

Regeneron Genetics Center^®

Regeneron Genetics Center ("RGC"), a wholly owned subsidiary of Regeneron Pharmaceuticals, Inc., leverages de-identified clinical, genomic, and molecular data from human volunteers to identify medically relevant associations in a blinded fashion designed to preserve patients' privacy. The objective of RGC is to expand the use of human genetics for discovering and validating genetic factors that cause or influence a range of diseases where there are major unmet medical needs, with the prospect of improving the drug discovery and development process. RGC is undertaking multiple approaches, including large population-based efforts as well as family- and founder-based approaches. RGC utilizes laboratory automation and innovative approaches to cloud computing to achieve high-quality throughput.

Central to the work of RGC is a collaboration with the Geisinger Health System of Pennsylvania. Geisinger collects samples from consented patient volunteers, while RGC performs sequencing and genotyping to generate de-identified genomic data. In addition, RGC has expanded on its foundational population-based collaboration with Geisinger with a growing number of other organizations worldwide.

In addition, RGC has formed a consortium to fund the generation of genetic exome sequence data from 500,000 volunteer participants who make up the UK Biobank health resource. The current members of the consortium consist of AbbVie Inc., Alnylam Pharmaceuticals Inc., AstraZeneca PLC, Biogen Inc., Pfizer Inc., Millennium Pharmaceuticals, Inc. (a subsidiary of Takeda Pharmaceutical Company Unlimited), and Bristol-Myers Squibb. The consortium members have each committed up to $10.0 million in funding for Regeneron to sequence the UK Biobank's samples, which is performed at the RGC facility. Consortium members have a limited period of exclusive access to the sequencing data before the data are made available to other health researchers by UK Biobank.

Researchers from the RGC discovered a potential new therapeutic target to reduce the risk of chronic liver disease and progression to more advanced stages of disease, such as nonalcoholic steatohepatitis ("NASH"), by analyzing extensive genetic sequencing data linked with electronic health records. In 2018, we announced a publication describing this discovery in the New England Journal of Medicine, which identified for the first time a variant in the HSD17B13 gene that is associated with reduced risk of, or protection from, various chronic liver diseases for which there are currently no approved therapeutics. We are collaborating with Alnylam to discover RNA interference ("RNAi") therapeutics for NASH and potentially other related diseases.

Collaboration Agreements

Collaborations with Sanofi

Antibody

We are collaborating with Sanofi on the global development and commercialization of Dupixent, Praluent, Kevzara, and REGN3500 (the "Antibody Collaboration"). Under the terms of the Antibody License and Collaboration Agreement (the "LCA"), following receipt of the first positive Phase 3 trial results for a co-developed drug candidate, subsequent Phase 3 trial-related costs for that drug candidate are shared 80% by Sanofi and 20% by us. All other agreed-upon development costs incurred by both companies are funded 100% by Sanofi. We are obligated to reimburse Sanofi for 50% of worldwide development expenses that were fully funded by Sanofi and 30% of shared Phase 3 trial-related costs based on our share of collaboration profits from commercialization of collaboration products. However, we are only required to apply 10% of our share of the profits from the Antibody Collaboration in any calendar quarter to reimburse Sanofi for these development costs.

In January 2018, we and Sanofi entered into a letter agreement (the "Letter Agreement") amending the LCA in connection with, among other matters, the allocation of additional funds to certain proposed activities relating to dupilumab and REGN3500 (collectively, the "Dupilumab/REGN3500 Eligible Investments"). Pursuant to the Letter Agreement, we have agreed to allow Sanofi to satisfy in whole or in part its funding obligations with respect to the Dupilumab/REGN3500 Eligible Investments for the quarterly periods commencing on January 1, 2018 and ending on September 30, 2020 by selling up to an aggregate of 600,000 shares (of which 495,948 currently remains available) of our Common Stock directly or indirectly owned by Sanofi. Refer to the "Immuno-Oncology" section below for further details regarding the Letter Agreement.

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Under our collaboration agreement, Sanofi records product sales for commercialized products, and Regeneron has the right to co-commercialize such products on a country-by-country basis. We have exercised our option to co-commercialize Dupixent, Praluent, and Kevzara in the United States, and have exercised our option to co-commercialize Dupixent in certain countries outside the United States. We currently anticipate commencing co-commercialization of Dupixent outside the United States at the end of 2020. We supply certain commercial bulk product to Sanofi. We and Sanofi equally share profits and losses from sales within the United States. We and Sanofi share profits outside the United States on a sliding scale based on sales starting at 65% (Sanofi)/35% (us) and ending at 55% (Sanofi)/45% (us), and share losses outside the United States at 55% (Sanofi)/45% (us). In addition to profit and loss sharing, we are entitled to receive up to an aggregate of $250.0 million in milestone payments upon achievement of specified aggregate annual sales of antibodies (subject to this agreement) outside the United States on a rolling twelve-month basis. The Company will be entitled to receive the first sales milestone payment from Sanofi, in the amount of $50.0 million, when such sales outside the United States exceed $1.0 billion.

In December 2019, we and Sanofi announced our intent to restructure the Antibody Collaboration for Kevzara and Praluent and enter into a royalty-based arrangement. Under the proposed terms of the agreement, Sanofi is expected to gain sole global rights to Kevzara and sole rights to Praluent outside of the United States. Regeneron is expected to gain sole U.S. rights to Praluent. Under the proposed terms, each party will be solely responsible for funding development and commercialization expenses in their respective territories. In connection with the proposed agreement, the Company has eliminated certain commercialization activities and related headcount. The proposed agreement, which is expected to be finalized in the first quarter of 2020, will not impact the companies' existing collaboration relating to Dupixent and REGN3500.

Immuno-Oncology

We are collaborating with Sanofi on the development and commercialization of antibody-based cancer treatments in the field of immuno-oncology (the "IO Collaboration"). The IO Collaboration is governed by an Amended and Restated Immuno-oncology Discovery and Development Agreement (the "Amended IO Discovery Agreement"), and an Immuno-oncology License and Collaboration Agreement (the "IO License and Collaboration Agreement").

Effective December 31, 2018, the Company and Sanofi entered into the Amended IO Discovery Agreement, which narrowed the scope of the existing discovery and development activities conducted by the Company ("IO Development Activities") under the original 2015 Immuno-oncology Discovery and Development Agreement (the "2015 IO Discovery Agreement") to developing therapeutic bispecific antibodies targeting (i) BCMA and CD3 (the "BCMAxCD3 Program") and (ii) MUC16 and CD3 (the "MUC16xCD3 Program") through clinical proof-of-concept. The Amended IO Discovery Agreement provided for Sanofi's payment of $461.9 million to the Company as consideration for (x) the termination of the 2015 IO Discovery Agreement, (y) the prepayment for certain IO Development Activities regarding the BCMAxCD3 Program and the MUC16xCD3 Program, and (z) the reimbursement of costs incurred by the Company under the 2015 IO Discovery Agreement during the fourth quarter of 2018.

Under the terms of the Amended IO Discovery Agreement, the Company is required to conduct development activities with respect to (i) the BCMAxCD3 Program through the earlier of clinical proof-of-concept or the expenditure of $70.0 million (the "BCMAxCD3 Program Costs Cap") and (ii) the MUC16xCD3 Program through the earlier of clinical proof-of-concept or the expenditure of $50.0 million (the "MUC16xCD3 Program Costs Cap"); provided that under certain circumstances, Sanofi will have the option to increase the MUC16xCD3 Program Costs Cap to $70.0 million by making a payment to the Company in the amount of $20.0 million.

Pursuant to the Amended IO Discovery Agreement, we are primarily responsible for conducting the IO Development Activities (other than certain clinical trials that may be funded separately by Sanofi), including antibody development, preclinical activities, toxicology studies, manufacture of clinical supplies, filing of Investigational New Drug Applications ("INDs"), and clinical development through proof-of-concept. We are obligated to reimburse Sanofi for half of the development costs they funded that are attributable to clinical development of antibody product candidates under the Amended IO Discovery Agreement from our share of profits from commercialized IO Collaboration products.

With regard to the BCMAxCD3 Program and the MUC16xCD3 Program, when (i) clinical proof-of-concept is established, (ii) the applicable Program Costs Cap is reached, or (iii) in certain other limited circumstances, Sanofi will have the option to license rights to the product candidate and other antibodies targeting the same targets for, with regard to BCMAxCD3, immuno-oncology indications, and with regard to MUC16xCD3, all indications, pursuant to the IO License and Collaboration Agreement, as amended. If Sanofi does not exercise its option to license rights to a product candidate, we will retain the exclusive right to develop and commercialize such product candidate and Sanofi will receive a royalty on sales. Pursuant to the Amended IO Discovery Agreement, the parties agreed that (i) if Sanofi exercises its option with respect to a BCMAxCD3 Program antibody, Sanofi will lead the development and global commercialization of such BCMAxCD3 Program antibody; and (ii) if Sanofi exercises its option with respect to a MUC16xCD3 Program antibody, (x) we will lead the development of such MUC16xCD3 Program antibody and commercialization of such MUC16xCD3 Program antibody within the United States and (y) Sanofi will lead the commercialization of such MUC16xCD3 Program antibody outside of the United States.

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In connection with the IO License and Collaboration Agreement, Sanofi made a $375.0 million non-refundable up-front payment to us. If Sanofi exercises its option to license rights to a BCMAxCD3 Program antibody or MUC16xCD3 Program antibody thereunder, it will co-develop these drug candidates with us through product approval under the terms of the IO License and Collaboration Agreement. Sanofi will fund development costs up front for a BCMAxCD3 Program antibody and we will reimburse half of the total development costs for such antibody from our share of future IO Collaboration profits to the extent they are sufficient for this purpose. In addition, we and Sanofi will share equally, on an ongoing basis, the development costs for a MUC16xCD3 Program antibody. Each party will have the right to co-commercialize licensed products in countries where it is not the lead commercialization party. The parties will share equally in profits and losses in connection with the commercialization of collaboration products. We are obligated to use commercially reasonable efforts to supply clinical requirements of each drug candidate under the IO License and Collaboration Agreement until commercial supplies of that IO drug candidate are being manufactured.

Under the terms of the IO License and Collaboration Agreement, the parties are also co-developing and co-commercializing Libtayo (cemiplimab), an antibody targeting PD-1. We have principal control over the development of Libtayo, and the parties share equally, on an ongoing basis, development and commercialization expenses for Libtayo. Under the Letter Agreement, we have agreed to allow Sanofi to satisfy in whole or in part its funding obligation with respect to Libtayo development costs for the quarterly periods commencing on October 1, 2017 and ending on September 30, 2020 by selling up to an aggregate of 800,000 shares (of which 373,880 currently remains available) of our Common Stock directly or indirectly owned by Sanofi.

If Sanofi desires to sell shares of our Common Stock during the term of the Letter Agreement to satisfy a portion or all of its funding obligations for the Libtayo development and/or, as noted above, Dupilumab/REGN3500 Eligible Investments, we may elect to purchase, in whole or in part, such shares from Sanofi. If we do not elect to purchase such shares, Sanofi may sell the applicable number of shares (subject to certain daily and quarterly limits) in one or more open-market transactions. Refer to the "Antibody" section above for a description of share transactions related to Dupilumab/REGN3500 Eligible Investments.

With regard to Libtayo, we lead commercialization activities in the United States, while Sanofi leads commercialization activities outside of the United States and the parties equally share profits from worldwide sales. Sanofi has exercised its option to co-commercialize Libtayo in the United States. We will be entitled to a milestone payment of $375.0 million in the event that global sales of certain licensed products targeting PD-1 (including Libtayo), together with sales of any other products licensed under the IO License and Collaboration Agreement and sold for use in combination with any of such licensed products targeting PD-1, equal or exceed $2.0 billion in any consecutive twelve-month period.

Collaboration with Bayer

EYLEA outside the United States

Since 2006, we and Bayer have been parties to a license and collaboration agreement for the global development and commercialization outside the United States of EYLEA. Under the agreement, we and Bayer collaborate on, and share the costs of, the development of EYLEA. Bayer markets EYLEA outside the United States, where, for countries other than Japan, the companies share equally in profits and losses from sales of EYLEA. In Japan, we are entitled to receive a tiered percentage of between 33.5% and 40.0% of EYLEA net sales through 2021, and thereafter, the companies will share equally in profits and losses from the sales of EYLEA.

We are obligated to reimburse Bayer for 50% of the development costs that it has incurred under the agreement from our share of the collaboration profits (including payments to us based on sales in Japan). The reimbursement payment in any quarter will equal 5% of the then outstanding repayment obligation, but never more than our share of the collaboration profits in the quarter unless we elect to reimburse Bayer at a faster rate.

Within the United States, we retain exclusive commercialization rights to EYLEA and are entitled to all profits from such sales.

Collaboration with Teva

Fasinumab

In 2016, we entered into a collaboration agreement with Teva to develop and commercialize fasinumab globally, excluding certain Asian countries that are subject to our collaboration agreement with Mitsubishi Tanabe Pharma Corporation ("MTPC"). In connection with the agreement, Teva made a $250.0 million non-refundable up-front payment. We lead global development activities, and the parties will share equally, on an ongoing basis, development costs under a global development plan. As of December 31, 2019, we had earned an aggregate of $120.0 million of development milestones from Teva, and we are entitled to receive up to an aggregate of $340.0 million in additional development milestones and up to an aggregate of $1,890.0 million in contingent payments upon achievement of specified annual net sales amounts. We are responsible for the manufacture and supply of fasinumab globally.

Within the United States, we will lead commercialization activities, and the parties will share equally in any profits or losses in connection with commercialization of fasinumab. In the territory outside of the United States, Teva will lead commercialization

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activities and we will supply product to Teva at a tiered purchase price, which is calculated as a percentage of net sales of the product (subject to adjustment in certain circumstances).

Collaboration with Alnylam

In April 2019, we and Alnylam Pharmaceuticals, Inc. entered into a global, strategic collaboration to discover, develop, and commercialize RNAi therapeutics for a broad range of diseases by addressing therapeutic disease targets expressed in the eye and central nervous system ("CNS"), in addition to a select number of targets expressed in the liver. The collaboration is governed by a Master Collaboration Agreement (the "Master Agreement") (including the form of a License Agreement and a Co-Commercialization Collaboration Agreement). Under the terms of the Master Agreement, we made an up-front payment of $400.0 million to Alnylam. For each program, we will provide Alnylam with a specified amount of funding at program initiation and at lead candidate designation, and Alnylam is eligible to receive up to $200.0 million in clinical proof-of-principle milestones for eye or CNS programs.

Under the collaboration, the parties plan to perform discovery research until designation of lead candidates. Following designation of a lead candidate, the parties may further advance such lead candidate under either a License Agreement or a Co-Commercialization Collaboration Agreement structure. The initial target nomination and discovery period is five years (which may under certain situations automatically be extended for up to seven years in the aggregate) (the "Research Term"). In addition, we have an option to extend the Research Term for an additional five-year period for a research extension fee ranging from $200.0 million to $400.0 million; the actual amount of the fee will be determined based on the acceptance of one or more INDs (or their equivalent in certain other countries) for programs in the eye and CNS.

At the stage of designation of a lead candidate for CNS programs and liver programs, the parties have alternating rights to be a lead party for collaboration products. At the stage of designation of a lead candidate for eye programs, we have the sole right to take the product forward as a licensee. The lead party is required to take the program forward under the License Agreement structure unless the other party exercises its rights to opt-in to a Co-Commercialization Collaboration Agreement, in which case the lead party is required to take the program forward under the Co-Commercialization Collaboration Agreement structure. Alnylam does not have rights to opt-in to a Co-Commercialization Collaboration Agreement for eye programs.

Under a License Agreement, the lead party is designated as the licensee and has the right to develop and commercialize the collaboration product under such program. The licensee will be responsible for its own costs and expenses incurred in connection with the development and commercialization of the collaboration products under the License Agreement. The licensee will pay to the licensor certain development and/or commercialization milestone payments totaling up to $150.0 million for each collaboration product. In addition, following the first commercial sale of the applicable collaboration product under a License Agreement, the licensee is required to make certain tiered royalty payments, ranging from low double-digits up to 20%, to the licensor based on the aggregate annual net sales of the collaboration product, subject to customary reductions.

For CNS programs and liver programs, as soon as a party is designated as a lead party, the other company has rights to opt-in to a Co-Commercialization Collaboration Agreement as a participating party. Under a Co-Commercialization Collaboration Agreement, the party designated as the lead party has operational responsibility and final decision-making authority on development and commercialization of the program and the parties will split profits and share costs equally, subject to certain co-funding opt-outs at specified clinical trial phases or under other conditions. If a party exercises its co-funding opt-out right, the lead party will be required to make certain tiered royalty payments, ranging from low double-digits up to 20%, to the other party based on the aggregate annual net sales of the collaboration product and the timing of the exercise of the co-funding opt-out right, subject to customary reductions. If the non-lead party does not initially opt-in to a Co-Commercialization Collaboration Agreement, the lead party has the right to take the program forward under a License Agreement structure.

Under the collaboration, when we are the licensee under a License Agreement or the lead party under a Co-Commercialization Collaboration Agreement, Alnylam will be responsible for the manufacture and supply of the product to us for Phase 1 and Phase 2 clinical trials.

In connection with the collaboration, we and Alnylam also entered into a Stock Purchase Agreement. Pursuant to the terms of the Stock Purchase Agreement, we purchased 4,444,445 shares of Alnylam common stock for aggregate cash consideration of $400.0 million.

In August 2019, the parties entered into a Co-Commercialization Collaboration Agreement for a silencing RNA ("siRNA") therapeutic targeting the C5 component of the human complement pathway being developed by Alnylam, with Alnylam as the lead party, and a License Agreement for a combination product consisting of such siRNA therapeutic and a fully human monoclonal antibody targeting C5 being developed by us, with us as the licensee. The C5 siRNA Co-Commercialization Collaboration Agreement is consistent with the financial terms contained in the form of the existing Co-Commercialization Collaboration Agreement with Alnylam. The C5 siRNA License Agreement contains a flat low double-digit royalty payable to Alnylam on our potential future net sales of the combination product only subject to customary reductions, as well as up to $325.0 million in commercial milestones.

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Manufacturing

We currently manufacture bulk drug materials and products at our manufacturing facilities in Rensselaer, New York and Limerick, Ireland. These facilities consist of owned and leased research, manufacturing, office, laboratory, and warehouse space. In addition, during 2020, we expect to continue the construction of a fill/finish facility in Rensselaer, New York.

We currently have approximately 100,000 liters of cell culture capacity at our Rensselaer facility, and are approved by the FDA and other regulatory agencies to manufacture our bulk drug materials and products. In addition, we currently have approximately 130,000 liters of cell culture capacity at our Limerick facility which has received certain manufacturing approvals by regulatory agencies, including the FDA, and is in the process of further validation, as required by regulatory authorities, for the manufacture of our bulk drug materials and products.

Certain bulk drug materials and products are also manufactured by our collaborators, and certain raw materials or products necessary for the manufacture and formulation of our products and product candidates are provided by single-source unaffiliated third-party suppliers. In addition, we rely on our collaborators or third parties to perform packaging, filling, finishing, labeling, distribution, laboratory testing, and other services related to the manufacture of our products and product candidates, and to supply various raw materials and other products. See Part I, Item 1A. "Risk Factors - Risks Related to Manufacturing and Supply" for further information.

Among the conditions for regulatory marketing approval of a medicine is the requirement that the prospective manufacturer's quality control and manufacturing procedures conform to the good manufacturing practice ("GMP") regulations of the health authority. In complying with standards set forth in these regulations, manufacturers must continue to expend time, money, and effort in the areas of production and quality control to ensure full technical compliance. Manufacturing establishments, both foreign and domestic, are also subject to inspections by or under the authority of the FDA and by other national, federal, state, and local agencies.

Sales and Marketing

We have a New Products Marketing and Planning group, a Market Research group, and a Market Access group to evaluate commercial opportunities for our targets and drug candidates, assess the competitive environment, analyze the commercial potential of our product portfolio, and prepare for market launch of new products. These groups are fully functional to support our product and product candidates that we are independently developing and/or commercializing, and work closely with our collaborators for co-developed products to create marketing plans and forecasts and to establish and execute pre-launch market development programs.

We also have a full-service commercialization group to handle various aspects of our commercial programs. The group includes experienced professionals in the fields of marketing, communications, professional education, patient education and advocacy, reimbursement and market access, trade and distribution, commercial operations, commercial analytics, market research, and forecasting. Moreover, for our marketed products, we have hired, trained, and deployed a field-based organization including regional directors, medical specialists, and reimbursement managers, each typically with a number of years of experience in the biopharmaceutical industry in a variety of therapeutic areas including oncology, ophthalmology, inflammation, and cardiovascular. We have approximately 500 field-based employees in the United States.

Customers

We sell EYLEA and Libtayo in the United States to several distributors and specialty pharmacies. We sell ARCALYST in the United States to two specialty pharmacies. Under these distribution models, the distributors and specialty pharmacies generally take physical delivery of the product. For EYLEA and Libtayo, the distributors and specialty pharmacies generally sell the product directly to healthcare providers, whereas for ARCALYST, the specialty pharmacies sell the product directly to patients. We had sales to two customers (Besse Medical, a subsidiary of AmerisourceBergen Corporation, and McKesson Corporation) that each accounted for more than 10% of total gross product revenue for the year ended December 31, 2019. On a combined basis, our product sales to these customers accounted for approximately 90% of our gross product revenue for the year ended December 31, 2019. We are also a party to collaboration agreements with Bayer and Sanofi, whereby our collaborator is responsible for recording product sales of EYLEA outside the United States and global sales of Dupixent, Praluent, and Kevzara, respectively (refer to "Collaboration Agreements" section above for additional information).

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Competition

We face substantial competition from pharmaceutical, biotechnology, and chemical companies. Many of our competitors have substantially greater research, preclinical and clinical product development, manufacturing capabilities, and financial, marketing, and human resources than we do. Competition from smaller competitors may also be or become more significant if those competitors acquire or discover patentable inventions, form collaborative arrangements, or merge with large pharmaceutical or biotechnology companies. Even if we are able to commercialize additional product candidates, one or more of our competitors may have brought a competitive product to market earlier than us or may have patent protection that dominates or adversely affects our activities or products. Our ability to compete depends, to a great extent, on how fast we can develop safe and effective product candidates, complete clinical testing and approval processes, and supply commercial quantities of the product to the market. Competition among product candidates approved for sale is based on efficacy, safety, reliability, availability, price, patent position, and other factors.

Marketed Products

The table below provides an overview of the current competitive landscape for the key products marketed by us and/or our collaborators under our collaboration agreements with them in such products' currently approved indications. The table below is provided for illustrative purposes only and is not exhaustive. For additional information regarding the substantial competition these marketed products face, including potential future competition from product candidates in clinical development, see also Part I, Item 1A. "Risk Factors - 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."

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Marketed Product	Competitor Product	Competitor	Indication	Territory(1)
EYLEA	Lucentis® (ranibizumab)	Novartis AG and Genentech/Roche	Wet AMD, DME, macular edema following RVO (including CRVO and BRVO), diabetic retinopathy, mCNV, and ROP	Worldwide
	Avastin® (bevacizumab) (off-label and repackaged)	Genentech/Roche	Wet AMD, DME, and macular edema following RVO	Worldwide
	Beovu® (brolucizumab)	Novartis	Wet AMD	United States
	Ozurdex® (dexamethasone intravitreal implant)	Allergan, PLC	DME, RVO	Worldwide
	Iluvien® (fluocinolone acetonide intravitreal implant)	Alimera Sciences, Inc.	DME	Worldwide
	Conbercept	Chengdu Kanghong Pharmaceutical Group Co., Ltd.	Wet AMD, mCNV	China
Dupixent	Eucrisa® (crisaborole)	Pfizer	Mild-to-moderate atopic dermatitis	United States
	Xolair® (omalizumab)	Roche/Novartis	Asthma	Worldwide
	Nucala® (mepolizumab)	GlaxoSmithKline ("GSK")	Asthma	Worldwide
	Cinqair® (reslizumab)	Teva	Asthma	United States, EU
	Fasenra® (benralizumab)	AstraZeneca	Asthma	Worldwide
Libtayo	Keytruda® (pembrolizumab)	Merck & Co., Inc.	Various cancers	Worldwide
	Opdivo® (nivolumab)	Bristol-Myers Squibb	Various cancers	Worldwide
	Tecentriq® (atezolizumab)	Roche	Various cancers	Worldwide
	Imfinzi® (durvalumab)	AstraZeneca	Various cancers	Worldwide
	Bavencio® (avelumab)	Pfizer/Merck KGaA	Various cancers	Worldwide
Praluent	Repatha® (evolocumab)	Amgen	(1) Reduce the risk of myocardial infarction, stroke, and coronary revascularization in adults with established cardiovascular disease, (2) primary hyperlipidemia, and (3) HoFH	Worldwide
Kevzara	Actemra® (tocilizumab)	Genentech/Roche/ Chugai Pharmaceutical Co., Ltd.	Rheumatoid arthritis	Worldwide
	Orencia® (abatacept)	Bristol-Myers Squibb	Rheumatoid arthritis	Worldwide
	Xeljanz® (tofacitinib)	Pfizer	Rheumatoid arthritis	Worldwide
	Olumiant® (baricitinib)	Eli Lilly/Incyte	Rheumatoid arthritis	Worldwide
	Rinvoq® (upadacitinib)	AbbVie	Rheumatoid arthritis	Worldwide
(1) This table focuses primarily on the United States, EU, and Japan. "Worldwide" indicates that the relevant product is approved in at least the United States, EU, and Japan.

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Antibodies in Development

Our antibody-based clinical candidates in development are all fully-human antibodies which were generated using our VelocImmune technology. Our antibody generation technologies and clinical candidates face competition from many pharmaceutical and biotechnology companies using various technologies. Numerous other companies are developing therapeutic antibody products. Companies have generated therapeutic products that are currently in development or on the market that are derived from recombinant DNA that comprise human antibody sequences. We are also aware of several companies developing or marketing small molecules that may compete with our antibody product candidates in various indications, if such product candidates obtain regulatory approval in those indications.

For additional information regarding our antibody programs and the substantial competition they face, see also Part I, Item 1A. "Risk Factors - 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."

Other Areas

Many pharmaceutical and biotechnology companies are attempting to discover new therapeutics for indications in which we invest substantial time and resources. In these and related areas, intellectual property rights have been sought and certain rights have been granted to competitors and potential competitors of ours, and we may be at a substantial competitive disadvantage in such areas as a result of, among other things, our lack of experience, trained personnel, and expertise. A number of corporate and academic competitors are involved in the discovery and development of novel therapeutics that are the focus of other research or development programs we are now conducting. Some of these competitors are currently conducting advanced preclinical and clinical research programs in these areas. These and other competitors may have established substantial intellectual property and other competitive advantages.

If any of these or other competitors announces a successful clinical study involving a product that may be competitive with one of our product candidates or the grant of marketing approval by a regulatory agency for a competitive product, such developments may have an adverse effect on our business, operating results, financial condition, cash flows, or future prospects.

We also compete with academic institutions, governmental agencies, and other public or private research organizations, which conduct research, seek patent protection, and establish collaborative arrangements for the development and marketing of products that would provide royalties or other consideration for use of their technology. These institutions are becoming more active in seeking patent protection and licensing arrangements to collect royalties or other consideration for use of the technology they have developed. Products developed in this manner may compete directly with products we develop. We also compete with others in acquiring technology from these institutions, agencies, and organizations.

Patents, Trademarks, and Trade Secrets

We rely on a combination of intellectual property laws, including patent, trademark, copyright, trade secret, and domain name protection laws, as well as confidentiality and license agreements, to protect our intellectual property and proprietary rights.

Our success depends, in part, on our ability to obtain patents, maintain trade secret protection, and operate without infringing on the proprietary rights of third parties (see Part I, Item 1A. "Risk Factors - Risks Related to Intellectual Property and Market Exclusivity - We may be restricted in our development, manufacturing, and/or commercialization activities by patents or other proprietary rights of others, and could be subject to damage awards if we are found to have infringed such patents or rights"; and Note 16 to our Consolidated Financial Statements). Our policy is to file patent applications to protect technology, inventions, and improvements that we consider important to our business and operations. We hold an ownership interest in a number of issued patents in the United States and foreign countries with respect to our products and technologies. In addition, we hold an ownership interest in thousands of patent applications in the United States and foreign countries.

Our patent portfolio includes granted patents and pending patent applications covering our VelociSuite technologies, including our VelocImmune mouse platform which produces fully human antibodies. Our issued patents covering these technologies generally expire between 2020 and 2030. However, we continue to file patent applications directed to improvements to these technology platforms.

Our patent portfolio also includes issued patents and pending applications relating to commercialized products and our product candidates in clinical development. These patents cover the proteins and DNA encoding the proteins, manufacturing patents, method of use patents, and pharmaceutical compositions.

The following table describes our U.S. patents and European patents ("EP") that we currently consider of primary importance to our marketed products, including the territory, patent number, general subject matter class, and expected expiration dates. The noted expiration dates include any patent term adjustments. Certain of these patents may also be entitled to term extensions. We continue

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to pursue additional patents and patent term extensions in the United States and other jurisdictions covering various aspects of our products that may, if issued, extend exclusivity beyond the expiration of the patents listed in the table below. One or more patents with the same or earlier expiry date may fall under the same "general subject matter class" for certain products and are not separately listed.

Product	Molecule	Territory	Patent No.	General Subject Matter Class	Expiration
EYLEA	aflibercept	US	7,070,959	Composition of Matter	June 16, 2023*
		US	8,092,803	Formulation	June 21, 2027
		US	9,254,338	Methods of Treatment	May 22, 2032
		US	10,406,226	Method of Manufacturing	March 22, 2026
		EP	1183353	Composition of Matter	May 23, 2020**
		EP	1183353	Supplementary Protection Certificate	(May 23, 2025)**
		EP	2364691	Formulation	June 14, 2027
		EP	1544299	Methods of Treatment	May 23, 2020
Dupixent***	dupilumab	US	7,608,693	Composition of Matter	March 28, 2031****
		US	8,945,559	Formulation	October 17, 2032
		US	8,075,887	Methods of Treatment	April 17, 2028
		US	8,337,839	Methods of Treatment	October 2, 2027
		US	9,290,574	Methods of Treatment	July 10, 2034
		US	9,574,004	Methods of Treatment	December 22, 2033
		EP	2356151	Composition of Matter	October 27, 2029**
		EP	2356151	Supplementary Protection Certificate	(September 28, 2032)**
Libtayo	cemiplimab	US	9,987,500	Composition of Matter	September 18, 2035
Praluent***	alirocumab	US	8,062,640	Composition of Matter	December 15, 2029
		US	10,023,654	Composition of Matter	December 15, 2029
		US	10,472,425	Formulation	July 27, 2032
		US	8,357,371	Methods of Treatment	December 21, 2029
		US	9,550,837	Methods of Treatment	December 15, 2029
		US	9,724,411	Methods of Treatment	January 15, 2031
		EP	2358756	Composition of Matter	December 15, 2029**
		EP	2358756	Supplementary Protection Certificate	(September 25, 2030)**
Kevzara	sarilumab	US	7,582,298	Composition of Matter	January 4, 2028
		US	10,072,086	Formulation	September 19, 2031
		US	8,080,248	Methods of Treatment	June 1, 2027
		US	8,568,721	Methods of Treatment	June 1, 2027
		EP	2041177	Composition of Matter	June 1, 2027**
		EP	2041177	Supplementary Protection Certificate	(June 1, 2032)**
		EP	2766039	Methods of Treatment	October 10, 2032
* A patent term extension has been granted by the U.S. Patent and Trademark Office, extending the original patent term (May 23, 2020), insofar as it covers EYLEA, to June 16, 2023.
** Supplementary protection certificates ("SPCs") are pending and/or have been granted in various European countries, extending the original patent terms in those countries, where granted, to the applicable dates indicated in parentheses.
*** See Note 16 to our Consolidated Financial Statements for information regarding the patent infringement proceedings relating to Dupixent and Praluent.
**** A patent term extension has been granted by the U.S. Patent and Trademark Office, extending the original patent term (October 2, 2027), insofar as it covers Dupixent, to March 28, 2031.

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In addition, in the United States and certain other countries, our competitive position may be enhanced due to the availability of market exclusivity under relevant law (for additional information regarding market exclusivity, see Part I, Item 1A. "Risk Factors - Risks Related to Intellectual Property and Market Exclusivity - Loss or limitation of patent rights, and new regulatory pathways for biosimilar competition, could reduce the duration of market exclusivity for our products"). The effect of expiration of a patent relating to a particular product also depends upon other factors, such as the nature of the market and the position of the product in it, the growth of the market, the complexities and economics of the process for manufacture of the active ingredient of the product, and the requirements of new drug provisions of the Federal Food, Drug and Cosmetic Act or similar laws and regulations in other countries.

We also are the nonexclusive licensee of a number of additional patents and patent applications. These include a license agreement with Bristol-Myers Squibb, E. R. Squibb & Sons, L.L.C., and Ono Pharmaceutical Co., Ltd. to obtain a license under certain patents owned and/or exclusively licensed by one or more of these parties that includes the right to develop and sell Libtayo. Under the agreement, we and Sanofi pay royalties of 8.0% on worldwide sales of Libtayo through December 31, 2023, and royalties of 2.5% from January 1, 2024 through December 31, 2026. The royalties are shared equally by us and Sanofi.

Patent law relating to the patentability and scope of claims in the biotechnology field is evolving and our patent rights are subject to this additional uncertainty. The degree of patent protection that will be afforded to our products in the United States and other important commercial markets is uncertain and is dependent upon the scope of protection decided upon by the patent offices, courts, and governments in these countries. There is no certainty that our existing patents or others, if obtained, will provide us protection from competition or provide commercial benefit.

Others may independently develop similar products or processes to those developed by us, duplicate any of our products or processes or, if patents are issued to us, design around any products and processes covered by our patents. We expect to continue, when appropriate, to file product and process applications with respect to our inventions. However, we may not file any such applications or, if filed, the patents may not be issued. Patents issued to or licensed by us may be infringed by the products or processes of others.

We seek to file and maintain trademarks around the world based on commercial activities in most jurisdictions where we have, or desire to have, a business presence for a particular product or service. Trademark protection varies in accordance with local law, and continues in some countries as long as the trademark is used and in other countries as long as the trademark is registered. Trademark registrations generally are for fixed but renewable terms.

Defense and enforcement of our intellectual property rights is expensive and time consuming, even if the outcome is favorable to us. It is possible that patents issued or licensed to us will be successfully challenged, that a court may find that we are infringing validly issued patents of third parties, or that we may have to alter or discontinue the development of our products or pay licensing fees to take into account patent rights of third parties (see Part I, Item 1A. "Risk Factors - Risks Related to Intellectual Property and Market Exclusivity - We may be restricted in our development, manufacturing, and/or commercialization activities by patents or other proprietary rights of others, and could be subject to damage awards if we are found to have infringed such patents or rights"; and Note 16 to our Consolidated Financial Statements).

Government Regulation

Regulation by government authorities in the United States and foreign countries is a significant factor in the research, development, manufacture, and marketing of our products and our product candidates. A summary of the primary areas of government regulation that are relevant to our business is provided below. For a description of material regulatory risks we face, also refer to Part I, Item 1A. "Risk Factors."

Preclinical Requirements

The activities required before a product candidate may be marketed in the United States begin with preclinical tests. Preclinical tests include laboratory evaluations and animal studies to assess the potential safety and efficacy of the product candidate and its formulations. Certain preclinical trials must comply with the FDA's Good Laboratory Practice requirements ("GLPs") and the U.S. Department of Agriculture's Animal Welfare Act. The results of these studies must be submitted to the FDA as part of an IND, which must be reviewed by the FDA before proposed clinical testing can begin. In other countries, the data are reviewed by regulatory authorities as part of clinical trial applications. The FDA or other regulatory authorities may ask for additional data in order to begin a clinical study.

Product Approval

All of our product candidates require regulatory approval before they can be commercialized. In particular, human therapeutic products are subject to rigorous preclinical and clinical trials and other pre-market approval requirements by the FDA and foreign authorities. The structure and substance of the FDA and foreign pharmaceutical regulatory practices may evolve over time. The ultimate outcome and impact of such developments cannot be predicted.

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Typically, clinical testing involves a three-phase process. In Phase 1, trials are usually conducted with a small number of healthy volunteers to determine the early safety profile of the product candidate. In Phase 2, clinical trials are conducted with subjects afflicted with a specific disease or disorder to provide enough data to evaluate the preliminary safety, tolerability, and efficacy of different potential doses of the product candidate. In Phase 3, larger clinical trials are conducted with patients afflicted with the specific disease or disorder in order to provide enough data to understand the efficacy and safety profile of the product candidate, as required by the FDA. If concerns arise about the safety of the product candidate, the FDA or other regulatory authorities can stop clinical trials by placing them on a "clinical hold" pending receipt of additional data, which can result in a delay or termination of a clinical development program. The results of the preclinical and clinical testing of a biologic product candidate are then submitted to the FDA in the form of a BLA for evaluation to determine whether the product candidate may be approved for commercial sale under the Public Health Service Act. Under the Prescription Drug User Fee Act, we typically must pay fees to the FDA for review of any BLA, which can exceed $2 million per filing. In responding to a BLA, the FDA may grant marketing approval, request additional information, or deny the application. Before approving a new drug or biologic product, the FDA also requires 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, among other things, the manufacture, shipment, and storage of the product. The FDA also can audit the sponsor of the BLA to determine if the clinical studies were conducted in compliance with current Good Clinical Practice, or cGCP, requirements.

Any approval required by the FDA for any of our product candidates may not be obtained on a timely basis, or at all. The designation of a clinical trial as being of a particular phase is not necessarily indicative that such a trial will be sufficient to satisfy the parameters of a particular phase, and a clinical trial may contain elements of more than one phase notwithstanding the designation of the trial as being of a particular phase. The results of preclinical studies or early stage clinical trials may not predict long-term safety or efficacy of our compounds when they are tested or used more broadly in humans.

Approval of a product candidate by comparable regulatory authorities in foreign countries is generally required prior to commencement of marketing of the product in those countries. The approval procedure varies among countries and may involve different or additional testing, and the time required to obtain such approval may differ from that required for FDA approval. Approval by a regulatory authority in one jurisdiction does not guarantee approval by comparable regulatory authorities in other jurisdictions.

Various federal, state, and foreign statutes and regulations also govern or influence the research, manufacture, safety, labeling, storage, record keeping, marketing, transport, and other aspects of developing and commercializing pharmaceutical product candidates. The lengthy process of seeking these approvals and the compliance with applicable statutes and regulations require the expenditure of substantial resources. Any failure by us or our collaborators or licensees to obtain, or any delay in obtaining, regulatory approvals could adversely affect the manufacturing or marketing of our products and our ability to receive product or royalty revenue.

For additional information regarding U.S. and foreign regulatory approval processes and requirements, see Part I, Item 1A. "Risk Factors - 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."

Post-Approval Regulation

The FDA and comparable regulatory authorities in other jurisdictions may also require us to conduct additional clinical trials or to make certain changes related to a product after granting approval of the product. The FDA has the explicit authority to require postmarketing studies (also referred to as post-approval or Phase 4 studies), labeling changes based on new safety information, and compliance with FDA-approved risk evaluation and mitigation strategies.

Following approval, the FDA regulates the marketing and promotion of our products, which must comply with the Food, Drug, and Cosmetic Act and applicable FDA regulations and standards thereunder. The FDA's review of promotional activities includes, but is not limited to, healthcare provider-directed and direct-to-consumer advertising as well as sales representatives' communications. The FDA may take enforcement action for promoting unapproved uses of a product or other violations of its advertising and promotion laws and regulations. See Part I, Item 1A. "Risk Factors - Regulatory and Litigation Risks - If we market and sell approved products in a way that violates federal or state healthcare laws, we may be subject to civil or criminal penalties."

Adverse-event reporting and submission of periodic reports are required following marketing approval. The FDA requires BLA holders to employ a system for obtaining and reviewing safety information, adverse events, and product complaints associated with each drug and to submit safety reports to the FDA, with expedited reporting timelines in certain situations. Based on new safety information after approval, the FDA can, among other things, mandate product labeling changes, require new post-marketing studies, impose or modify a risk evaluation and mitigation strategy for the product, or suspend or withdraw approval of the product. We may be subject to audits by the FDA and other regulatory authorities to ensure that we are complying with the applicable requirements.

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In addition, we and our third-party suppliers are required to maintain compliance with cGMPs, and are subject to inspections by the FDA or comparable regulatory authorities in other jurisdictions to confirm such compliance. Changes of suppliers or modifications of methods of manufacturing may require amending our application(s) to the FDA or such comparable foreign regulatory authorities and acceptance of the change by the FDA or such comparable foreign regulatory authorities prior to release of product(s). FDA regulations also require investigation and correction of any deviations from cGMP and impose reporting and documentation requirements upon us and our third-party suppliers. Prescription drug manufacturers in the U.S. must comply with applicable provisions of the Drug Supply Chain Security Act and provide and receive product tracing information, maintain appropriate licenses, ensure they only work with other properly licensed entities, and have procedures in place to identify and properly handle suspect and illegitimate products. We may also be subject to state regulations related to the manufacturing and distribution of our products.

Failure to comply with these laws and regulations may lead the FDA and comparable regulatory authorities in other jurisdictions to take regulatory action, which could include ordering the suspension of manufacturing or withdrawing FDA approval of a product.

Pricing and Reimbursement

Sales in the United States of our marketed products are dependent, in large part, on the availability and extent of reimbursement from third-party payors, including private payor healthcare and insurance programs, health maintenance organizations, pharmacy benefit management companies, and government programs such as Medicare and Medicaid. Sales of our marketed products in other countries are dependent, in large part, on coverage and reimbursement mechanisms and programs administered by health authorities in those countries. See Part I, Item 1A. "Risk Factors - Risks Related to Commercialization of Our Marketed Products, Product Candidates, and New Indications for Our Marketed Products - Sales of our marketed products are dependent on the availability and extent of reimbursement from third-party payors, and changes to such reimbursement may materially harm our business, prospects, operating results, and financial condition."

We participate in, and have certain price reporting obligations to, the Medicaid Drug Rebate program, several state Medicaid supplemental rebate programs, and other governmental pricing programs. We also have obligations to report the average sales price for certain of our drugs to the Medicare program. Under the Medicaid Drug Rebate program, we are required to pay a rebate to each state Medicaid program for our covered outpatient drugs that are dispensed to Medicaid beneficiaries and paid for by a state Medicaid program as a condition of having federal funds being made available to the states for our drugs under Medicaid and Part B of the Medicare program.

Medicaid is a joint federal and state program that is administered by the states for low income and disabled beneficiaries. Medicaid rebates are based on pricing data reported by us on a monthly and quarterly basis to the Centers for Medicare & Medicaid Services ("CMS"), the federal agency that administers the Medicaid and Medicare programs. These data include the average manufacturer price and, in the case of innovator products, the best price for each drug which, in general, represents the lowest price available from the manufacturer to any entity in the U.S. in any pricing structure, calculated to include all sales and associated rebates, discounts, and other price concessions. The amount of the rebate is adjusted upward if average manufacture price increases more than inflation (measured by reference to the Consumer Price Index - Urban). If we become aware that our reporting for a prior quarter was incorrect, or has changed as a result of recalculation of the pricing data, we are obligated to resubmit the corrected data for up to three years after those data originally were due, which revisions could affect our rebate liability for prior quarters. The federal Patient Protection and Affordable Care Act (the "PPACA") made significant changes to the Medicaid Drug Rebate program, and CMS issued a final regulation, which became effective on April 1, 2016, to implement the changes to the Medicaid Drug Rebate program under the PPACA.

Medicare is a federal program that is administered by the federal government that covers individuals age 65 and over or that are disabled as well as those with certain health conditions. Medicare Part B generally covers drugs that must be administered by physicians or other health care practitioners; are provided in connection with certain durable medical equipment; or consist of certain oral anti-cancer drugs and certain oral immunosuppressive drugs. Medicare Part B pays for such drugs under a payment methodology based on the average sales price of the drugs. Manufacturers, including us, are required to report average sales price information to CMS on a quarterly basis. The manufacturer-submitted information is used by CMS to calculate Medicare payment rates.

Civil monetary penalties can be applied if we are found to have knowingly submitted any false pricing or other information to the government, if we are found to have made a misrepresentation in the reporting of our average sales price, or if we fail to submit the required data on a timely basis. Such conduct also could be grounds for CMS to terminate our Medicaid drug rebate agreement, in which case federal payments may not be available under Medicaid or Medicare Part B for our covered outpatient drugs.

Federal law requires that any company that participates in the Medicaid Drug Rebate program also participate in the Public Health Service's 340B drug pricing program (the "340B program") in order for federal funds to be available for the manufacturer's drugs under Medicaid and Medicare Part B. The 340B program, which is administered by the Health Resources and Services Administration, or HRSA, requires participating manufacturers to agree to charge statutorily defined covered entities no more than the 340B "ceiling price" for the manufacturer's covered outpatient drugs. Covered entities include hospitals that serve a disproportionate share of

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financially needy patients, community health clinics, and other entities that receive certain types of grants under the Public Health Service Act. The PPACA expanded the list of covered entities to include certain free-standing cancer hospitals, critical access hospitals, rural referral centers, and sole community hospitals, but exempts "orphan drugs" from the ceiling price requirements for these covered entities. The 340B ceiling price is calculated using a statutory formula, which is based on the average manufacturer price and Medicaid rebate amount for the covered outpatient drug as calculated under the Medicaid Drug Rebate program. In general, products subject to Medicaid price reporting and rebate liability are also subject to the 340B ceiling price calculation and discount requirement.

HRSA issued a final regulation regarding the calculation of the 340B ceiling price and the imposition of civil monetary penalties on manufacturers that knowingly and intentionally overcharge covered entities, which became effective on January 1, 2019. It is currently unclear how HRSA will apply its enforcement authority under the new regulation. Any charge by HRSA that we have violated the requirements of the regulation could result in civil monetary penalties. HRSA also implemented a new price reporting system during the first quarter of 2019, under which manufacturers are now required to report their 340B ceiling prices to HRSA on a quarterly basis. In addition, legislation may be introduced that, if passed, would further expand the 340B program to additional covered entities or would require participating manufacturers to agree to provide 340B discounted pricing on drugs used in an inpatient setting.

In order to be eligible to have our products paid for with federal funds under the Medicaid and Medicare Part B programs and purchased by certain federal agencies and grantees, we participate in the U.S. Department of Veterans Affairs ("VA") Federal Supply Schedule ("FSS") pricing program. FSS participation is required for our products to be purchased by the VA, Department of Defense ("DoD"), Coast Guard, and Public Health Service ("PHS"). Prices for innovator drugs purchased by the VA, DoD, Coast Guard, and PHS are subject to a cap (known as the "Federal Ceiling Price") equal to 76% of the annual non-federal average manufacturer price ("non-FAMP") minus, if applicable, an additional discount. The additional discount applies if non-FAMP increases more than inflation (measured by reference to the Consumer Price Index - Urban). We also participate in the Tricare Retail Pharmacy Program, under which we pay quarterly rebates to DoD for prescriptions of our innovator drugs dispensed to Tricare beneficiaries through Tricare Retail network pharmacies. The governing statute provides for civil monetary penalties for failure to provide information timely or for knowing submission of false information to the government.

Medicare Part D provides coverage to enrolled Medicare patients for self-administered drugs (i.e., drugs that are not administered by a physician). Medicare Part D is administered by private prescription drug plans approved by the U.S. government and, subject to detailed program rules and government oversight, each drug plan establishes its own Medicare Part D formulary for prescription drug coverage and pricing, which the drug plan may modify from time to time. The prescription drug plans negotiate pricing with manufacturers and pharmacies, and may condition formulary placement on the availability of manufacturer discounts. In addition, for 2020, manufacturers, including us, are required to provide to CMS a 70% discount on brand name prescription drugs utilized by Medicare Part D beneficiaries when those beneficiaries are in the coverage gap phase of the Part D benefit design.

Private payor healthcare and insurance providers, health maintenance organizations, and pharmacy benefit managers in the United States are adopting more aggressive utilization management techniques and are increasingly requiring significant discounts and rebates from manufacturers as a condition to including products on formulary with favorable coverage and copayment/coinsurance. As a consequence, these payors may not cover or adequately reimburse for use of our products or may do so at levels that disadvantage them relative to competitive products.

Outside the United States, within the EU, our products are paid for by a variety of payors, with governments being the primary source of payment. Government health authorities in the EU determine or influence reimbursement of products, and set prices or otherwise regulate pricing. Negotiating prices with governmental authorities can delay commercialization of our products. Governments may use a variety of cost-containment measures to control the cost of products, including price cuts, mandatory rebates, value-based pricing, and reference pricing (i.e., referencing prices in other countries or prices of competitive products and using those reference prices to set a price). Budgetary pressures in many EU countries are continuing to cause governments to consider or implement various cost-containment measures, such as price freezes, increased price cuts and rebates, and expanded generic substitution and patient cost-sharing.

Other Regulatory Requirements

We are subject to health care "fraud and abuse" laws, such as the federal False Claims Act, the anti-kickback provisions of the federal Social Security Act, and other state and federal laws and regulations. Federal and state anti-kickback laws prohibit, among other things, payments or other remuneration to induce or reward someone to purchase, prescribe, endorse, or recommend a product that is reimbursed under federal or state healthcare programs. Federal false claims laws prohibit any person from knowingly presenting, or causing to be presented, a false claim for payment to the federal government, or knowingly making, or causing to be made, a false statement to get a false claim paid. See Part I, Item 1A. "Risk Factors - Regulatory and Litigation Risks - If we market and sell approved products in a way that violates federal or state healthcare laws, we may be subject to civil or criminal penalties."

We are subject to the Foreign Corrupt Practices Act, or FCPA, and similar anti-bribery or anti-corruption laws, regulations or rules of other countries in which we operate, including the U.K. Bribery Act. See Part I, Item 1A. "Risk Factors - Regulatory and Litigation

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Risks - 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."

In the United States, there are federal and state privacy laws that regulate specific categories of personal data. The information privacy laws address state and federal health information, consumer protection, and children's personal data. There are also data protection laws that govern data breach notification and information security. Most health care providers, including research institutions from which we or our collaborators obtain patient health information, are subject to privacy and security regulations promulgated under the Health Insurance Portability and Accountability Act of 1996, or HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act. Although we are not directly subject to HIPAA other than with respect to providing certain employee benefits, we could potentially be subject to criminal penalties if we, our affiliates, or our agents knowingly obtain or disclose individually identifiable health information maintained by a HIPAA-covered entity in a manner that is not authorized or permitted by HIPAA. To the extent we collect California resident personal data for marketing activities, we are also subject to the California Consumer Privacy Act of 2018 (the "CCPA"). The CCPA became effective on January 1, 2020 and provides California residents with certain rights concerning the use of their personal data. The obligations to comply with the CCPA require us, among other things, to update our notices and develop new processes internally and with our partners. We may be subject to fines, penalties, or private actions in the event of non-compliance with the CCPA. Outside the United States, our clinical trial programs and research collaborations implicate international data protection laws, including the General Data Protection Regulation ("GDPR") in the EU. The GDPR became effective on May 25, 2018, increasing our responsibility and liability in relation to the processing of personal data of EU subjects. The GDPR, together with the national legislation of the EU member states governing the processing of personal data, impose strict obligations and restrictions on the ability to collect, analyze and transfer personal data, including health data and samples from clinical trials and adverse event reporting. In particular, these obligations and restrictions concern the consent of the individuals to whom the personal data relates, the information provided to the individuals, the transfer of personal data out of the EU, security breach notifications, security and confidentiality of the personal data and imposition of substantial potential fines for breaches of the data protection obligations. Data protection authorities from the different EU member states may promulgate national privacy laws that impose additional requirements, which add to the complexity of processing personal data in the EU. Guidance on implementation and compliance practices are often updated or otherwise revised. See Part I, Item 1A. "Risk Factors - Regulatory and Litigation Risks - We face potential liability related to the personal information we collect from individuals, data brokers, or research institutions or obtain from clinical trials sponsored by us or our collaborators."

In addition to the foregoing, our present business is, and our future business may be, subject to regulation under the United States Atomic Energy Act, the Clean Air Act, the Clean Water Act, the Comprehensive Environmental Response, Compensation and Liability Act, the National Environmental Policy Act, the Toxic Substances Control Act, the Resource Conservation and Recovery Act, national restrictions, and other current and potential future local, state, federal, and foreign regulations.

Business Segments

We manage our business as one segment which includes all activities related to the discovery, development, and commercialization of medicines for the treatment of serious diseases. For financial information related to our one segment, see Part II, Item 6. "Selected Financial Data" and our Consolidated Financial Statements and related notes.

Employees

As of December 31, 2019, we had approximately 8,100 full-time employees. We believe that we have been successful in attracting skilled and experienced personnel in a highly competitive environment; however, competition for these personnel is intense. Our management considers its relations with our employees to be good.

Corporate Information

We were incorporated in the State of New York in 1988 and publicly listed in 1991. Our principal executive offices are located at 777 Old Saw Mill River Road, Tarrytown, New York 10591, and our telephone number at that address is (914) 847-7000.

We make available free of charge on or through our Internet website (http://www.regeneron.com) our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and, if applicable, amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act, as soon as reasonably practicable after we electronically file such material with, or furnish it to, the Securities and Exchange Commission ("SEC").

Investors and other interested parties should note that we use our media and investor relations website (http://newsroom.regeneron.com) and our social media channels to publish important information about Regeneron, including information that may be deemed material to investors. We encourage investors and other interested parties to review the information we may publish through our media and investor relations website and the social media channels listed on our media and investor relations website, in addition to our SEC filings, press releases, conference calls, and webcasts.

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The information contained on our websites and social media channels is not included as a part of, or incorporated by reference into, this report.

ITEM 1A. RISK FACTORS

We operate in an environment that involves a number of significant risks and uncertainties. We caution you to read the following risk factors, which have affected, and/or in the future could affect, our business, prospects, operating results, and financial condition. The risks described below include forward-looking statements, and actual events and our actual results may differ materially from these forward-looking statements. 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. Furthermore, additional risks and uncertainties are described under other captions in this report and should also be considered by our investors. For purposes of this section, references to our products encompass products marketed by us and/or our collaborators under our collaboration agreements with them, unless otherwise stated or required by the context.

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 net sales represent a substantial portion of our revenues and this concentration of our net sales in a single product makes us substantially dependent on that product. For the years ended December 31, 2019 and 2018, EYLEA net sales in the United States represented 59% and 61% of our total revenues, respectively. If we were to experience difficulty with the commercialization of EYLEA in the United States, if Bayer were to experience any difficulty with the commercialization of EYLEA outside the United States, or if we and Bayer are unable to maintain current marketing approvals of EYLEA, we may experience a reduction in revenue and may not be able to sustain profitability, and our business, prospects, operating results, and financial condition would be materially harmed.

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If we or our collaborators are unable to continue to successfully commercialize our products, our business, prospects, operating results, and financial condition will be materially harmed.

We expect that the degree of commercial success of our marketed products will continue to depend on many factors, including the following (as applicable):

• effectiveness of the commercial strategy in and outside the United States for the marketing of our products, including pricing strategy;

• sufficient coverage of, and reimbursement for, our marketed products by third-party payors, including Medicare and Medicaid in the United States and other government and private payors in the United States and foreign jurisdictions, as well as U.S. and foreign payor restrictions on eligible patient populations and the reimbursement process (including drug price control measures that may be introduced in the United States by various federal and state authorities);

• 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, the existing and potential new competition for EYLEA (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 EYLEA or to switch from another product to EYLEA;

• 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 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;

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

• the outcome of the pending patent infringement proceedings relating to Dupixent and Praluent (described further in Note 16 to our Consolidated Financial Statements included in this report), as well as other risks relating to our marketed products associated with intellectual property of other parties and pending or future litigation relating thereto (as discussed under "Risks Related to Intellectual Property and Market Exclusivity" below);

• the outcome of the pending government investigations described in Note 16 to our Consolidated Financial Statements included in this report;

• the results of post-approval studies, whether conducted by us or by others and whether mandated by regulatory agencies or voluntary, and studies of other products that could implicate an entire class of products or are perceived to do so; and

• the effect of existing and new health care laws and regulations currently being considered or implemented in the United States, including price reporting and other disclosure requirements of such laws and regulations and the potential impact of such requirements on physician prescribing practices and payor coverage.

More detailed information about the risks related to the commercialization of our marketed products is provided in the risk factors below.

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We and our collaborators are subject to significant ongoing regulatory obligations and oversight with respect to the products we or our collaborators commercialize. If we or our collaborators fail to maintain regulatory compliance for any of such products, the applicable marketing approval may be withdrawn, which would materially harm our business, prospects, operating results, and financial condition.

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, and other countries where such products are approved. If we or our collaborators fail to maintain regulatory compliance for such products' currently approved indications (including because the product does not meet the relevant endpoints of any required post-approval studies, 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"), the applicable marketing approval may be withdrawn, which would materially harm our business, prospects, operating results, and financial condition. Failure to comply may also subject us to sanctions, product recalls, or withdrawals of previously approved marketing applications. See also "Risks Related to Manufacturing and Supply - Our or our collaborators' 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 they obtain regulatory approval, and a reduction in sales" below.

Sales of our marketed products are dependent on the availability and extent of reimbursement from third-party payors, and changes to such reimbursement may materially harm our business, prospects, operating results, and financial condition.

Sales of our marketed products in the United States are dependent, in large part, on the availability and extent of reimbursement from third-party payors, including private payor healthcare and insurance programs, health maintenance organizations, pharmacy benefit management companies, and government programs such as Medicare and Medicaid. Sales of our marketed products in other countries are dependent, in large part, on similar reimbursement mechanisms and programs in those countries.

Our future revenues and profitability will be adversely affected in a material manner if such third-party payors do not adequately defray or reimburse the cost of our marketed products to patients. If these entities do not provide coverage and reimbursement with respect to our marketed products or provide an insufficient level of coverage and reimbursement, such products may be too costly for many patients to afford them, and physicians may not prescribe them. Many third-party payors cover only selected drugs, or may prefer selected drugs, making drugs that are not covered or preferred by such payors more expensive for patients. Third-party payors may also require prior authorization for reimbursement, or require failure on another type of treatment before covering a particular drug, particularly with respect to higher-priced drugs. As our currently marketed products and 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 health care 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 pharmacy benefits managers, and recognition by insurance companies and the CMS. 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.

Government and other third-party payors (including pharmacy benefit management companies) are challenging the prices charged for healthcare products and increasingly limiting, and attempting to limit, both coverage and level of reimbursement for prescription drugs, such as by requiring outcomes-based or other pay-for-performance pricing arrangements. They are also imposing restrictions on eligible patient populations and the reimbursement process, including by means of required prior authorizations and utilization management criteria, such as step therapy (i.e., requiring the use of less costly medications before more costly medications are approved for coverage). Some states are also considering legislation that would control the prices and reimbursement of prescription drugs, and state Medicaid programs are increasingly requesting manufacturers to pay supplemental rebates and requiring prior authorization by the state program for use of any prescription drug for which supplemental rebates are not being paid. It is likely that federal and state legislatures and health agencies will continue to focus on additional health care reform measures in the future that will impose additional constraints on prices and reimbursements for our marketed products.

Further, there have been several recent U.S. Congressional inquiries and proposed federal and state legislation and policies designed to, among other things, bring more transparency to drug pricing, review the relationship between pricing and manufacturer patient programs, reduce the out-of-pocket cost of prescription drugs, and reform government program reimbursement methodologies for drugs. At the federal level, the current administration's prior budget proposals (including the proposal for fiscal year 2020) contained

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drug price control measures that may be subsequently rolled into the budget proposal for fiscal year 2021 and could be enacted during the 2021 budget process or in other future legislation, including, for example, measures to permit Medicare Part D plans to negotiate the price of certain drugs under Medicare Part B (such as EYLEA); to allow some states to negotiate drug prices under Medicaid; and to eliminate cost sharing for generic drugs for low-income patients. Additionally, on May 11, 2018, President Trump laid out his administration's "Blueprint to Lower Drug Prices and Reduce Out-of-Pocket Costs" to reduce the cost of prescription drugs while preserving innovation and cures. The Department of Health and Human Services has been soliciting feedback on some of these measures and may implement others impacting our business under its existing authority. CMS has also recently sought public comment on how best to leverage its authority provided under the Competitive Acquisition Program and introduce competition into Medicare Part B by allowing CMS to bring on vendors to negotiate payment amounts for Medicare Part B drugs. In addition, since January 1, 2019, CMS has allowed Medicare Advantage ("MA") plans to use step therapy for Part B drugs (such as EYLEA).  On October 25, 2018, President Trump announced that CMS was evaluating a program that proposes to set the Medicare payment amount for Part B single-source drugs and biologics to more closely align with international drug prices (also referred to as reference or international price index ("IPI") drug pricing) and pay physicians and hospitals participating in such program a set drug add-on payment for administered drugs. CMS also issued an advance notice of proposed rulemaking that requested public comment on the proposed program, which is contemplated to initially cover fifty percent of Medicare Part B spending on separately payable Part B drugs (such as EYLEA), with the IPI-based price for each such drug to be phased in over a period of five years; notice of proposed rulemaking on this program is pending review by the Office of Management and Budget. In addition, in July 2019, President Trump indicated that his administration was considering an executive order to establish a "most favored nation" pricing plan. While the scope and details of this contemplated executive action (including whether and how its mechanism may differ from that of the proposed IPI drug pricing program discussed above) are not clear, this seems to signal that the U.S. administration will continue to seek new measures to constrain drug costs and Medicare payments for drugs. Similarly, various members of the current U.S. Congress and potential 2020 presidential candidates have indicated that lowering drug prices continues to be a legislative and political priority, and some have introduced proposals aimed at drug pricing. 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, and price and marketing cost disclosure and transparency measures. 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 based on the proposals and initiatives described abov