Regeneron Pharmaceuticals (REGN) 10-Q2 May 242024 Q1 Quarterly reportFinancial data

Company Profile

Cover

Cover - shares	3 Months Ended
Cover - shares	Mar. 31, 2024	Apr. 16, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	000-19034
Entity Registrant Name	REGENERON PHARMACEUTICALS, INC.
Entity Incorporation, State or Country Code	NY
Entity Tax Identification Number	13-3444607
Entity Address, Address Line One	777 Old Saw Mill River Road
Entity Address, City or Town	Tarrytown
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10591-6707
City Area Code	914
Local Phone Number	847-7000
Title of 12(b) Security	Common Stock - par value $.001 per share
Trading Symbol	REGN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0000872589
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Amendment Flag	false
Class A Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		1,818,146
Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		108,367,357

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 2,602	$ 2,730
Marketable securities	7,917.5	8,114.8
Accounts receivable, net	5,222.2	5,667.3
Inventories	2,714.9	2,580.5
Prepaid expenses and other current assets	414.9	386.6
Total current assets	18,871.5	19,479.2
Marketable securities	6,978.8	5,396.5
Property, plant, and equipment, net	4,225.5	4,146.4
Intangible assets, net	1,058.7	1,038.6
Deferred tax assets	2,764.9	2,575.4
Other noncurrent assets	470.2	444.1
Total assets	34,369.6	33,080.2
Current liabilities:
Accounts payable	671.3	606.6
Accrued expenses and other current liabilities	2,392.9	2,357.9
Deferred revenue	516.7	458.9
Total current liabilities	3,580.9	3,423.4
Long-term debt	1,983.3	1,982.9
Finance lease liabilities	720	720
Deferred revenue	185.8	126.7
Other noncurrent liabilities	908.5	854.1
Total liabilities	7,378.5	7,107.1
Stockholders' equity:
Preferred Stock, par value $.01 per share; 30.0 shares authorized; shares issued and outstanding - none	0	0
Additional paid-in capital	11,942.6	11,354
Retained earnings	27,982.3	27,260.3
Accumulated other comprehensive loss	(77.2)	(80.9)
Treasury Stock, at cost; 25.8 shares in 2024 and 25.5 shares in 2023	(12,856.7)	(12,560.4)
Total stockholders' equity	26,991.1	25,973.1
Total liabilities and stockholders' equity	34,369.6	33,080.2
Class A Stock
Stockholders' equity:
Common stock	0	0
Common Stock
Stockholders' equity:
Common stock	$ 0.1	$ 0.1

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares shares in Millions	Mar. 31, 2024	Dec. 31, 2023
Stockholders' Equity Attributable to Parent [Abstract]
Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, shares authorized (in shares)	30	30
Preferred Stock, shares issued (in shares)	0	0
Preferred Stock, shares outstanding (in shares)	0	0
Treasury stock (in shares)	25.8	25.5
Class A Stock
Stockholders' Equity Attributable to Parent [Abstract]
Common Stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common Stock, shares authorized (in shares)	40	40
Common Stock, shares issued (in shares)	1.8	1.8
Common Stock, shares outstanding (in shares)	1.8	1.8
Common Stock
Stockholders' Equity Attributable to Parent [Abstract]
Common Stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common Stock, shares authorized (in shares)	320	320
Common Stock, shares issued (in shares)	134.2	133.1

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues:
Revenues	$ 3,145	$ 3,162.1
Expenses:
Research and development	1,248.4	1,101.2
Acquired in-process research and development	7.1	56.1
Selling, general, and administrative	689	601.1
Other operating expense (income), net	15.3	(0.5)
Total Expenses	2,393.6	2,215.4
Income from operations	751.4	946.7
Other income (expense):
Other (expense) income, net	(34.6)	(70.7)
Interest expense	(16.1)	(18)
Total other income (expense)	(50.7)	(88.7)
Income before income taxes	700.7	858
Income tax (benefit) expense	(21.3)	40.2
Net income	$ 722	$ 817.8
Net income per share - basic (in dollars per share)	$ 6.70	$ 7.64
Net income per share - diluted (in dollars per share)	$ 6.27	$ 7.17
Weighted average shares outstanding - basic (in shares)	107.8	107.1
Weighted average shares outstanding - diluted (in shares)	115.1	114
Statements of Comprehensive Income
Net income	$ 722	$ 817.8
Other comprehensive income (loss), net of tax:
Unrealized gain on debt securities	3.5	57.2
Gain on foreign currency translation	0.2	0
Comprehensive income	725.7	875
Net product sales
Revenues:
Revenues	1,761.3	1,668
Expenses:
Cost of goods, collaboration and contract manufacturing	240.4	208.4
Collaboration revenue
Revenues:
Revenues	1,266.8	1,378.1
Other revenue
Revenues:
Revenues	116.9	116
Cost of collaboration and contract manufacturing
Expenses:
Cost of goods, collaboration and contract manufacturing	$ 193.4	$ 249.1

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Class A Stock	Class A Stock Common Stock
Beginning Balance (in shares) at Dec. 31, 2022		130.4						1.8
Beginning Balance, treasury (in shares) at Dec. 31, 2022						(22.6)
Beginning Balance at Dec. 31, 2022	$ 22,664	$ 0.1	$ 9,949.3	$ 23,306.7	$ (238.8)	$ (10,353.3)		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock for equity awards granted under long-term incentive plans (in shares)		1.1
Issuance of Common Stock for equity awards granted under long-term incentive plans	491.3		491.3
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations (in shares)		(0.1)
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations	(99.2)		(99.2)
Issuance/distribution of Common Stock for 401(k) Savings Plan	20.6		18.9			$ 1.7
Repurchases of Common Stock (in shares)						(0.9)
Repurchases of Common Stock	(693.9)					$ (693.9)
Stock-based compensation charges	237.4		237.4
Net income	817.8			817.8
Other comprehensive income (loss), net of tax	57.2				57.2
Ending Balance (in shares) at Mar. 31, 2023		131.4						1.8
Ending Balance, treasury (in shares) at Mar. 31, 2023						(23.5)
Ending Balance at Mar. 31, 2023	$ 23,495.2	$ 0.1	10,597.7	24,124.5	(181.6)	$ (11,045.5)		$ 0
Beginning Balance (in shares) at Dec. 31, 2023		133.1					1.8	1.8
Beginning Balance, treasury (in shares) at Dec. 31, 2023	(25.5)					(25.5)
Beginning Balance at Dec. 31, 2023	$ 25,973.1	$ 0.1	11,354	27,260.3	(80.9)	$ (12,560.4)		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock for equity awards granted under long-term incentive plans (in shares)		1.5
Issuance of Common Stock for equity awards granted under long-term incentive plans	672.4		672.4
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations (in shares)		(0.4)
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations	(335.9)		(335.9)
Issuance/distribution of Common Stock for 401(k) Savings Plan	20.5		18.8			$ 1.7
Repurchases of Common Stock (in shares)						(0.3)
Repurchases of Common Stock	(298)					$ (298)
Stock-based compensation charges	233.3		233.3
Net income	722			722
Other comprehensive income (loss), net of tax	$ 3.7				3.7
Ending Balance (in shares) at Mar. 31, 2024		134.2					1.8	1.8
Ending Balance, treasury (in shares) at Mar. 31, 2024	(25.8)					(25.8)
Ending Balance at Mar. 31, 2024	$ 26,991.1	$ 0.1	$ 11,942.6	$ 27,982.3	$ (77.2)	$ (12,856.7)		$ 0

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net income	$ 722	$ 817.8
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	114.1	99.5
Stock-based compensation expense	230.1	238.7
Losses on marketable and other securities, net	196.1	166.6
Other non-cash items, net	0.1	20.6
Deferred income taxes	(190.4)	(216.5)
Changes in assets and liabilities:
Decrease in accounts receivable	446.8	210.1
Increase in inventories	(155.8)	(46.8)
Increase in prepaid expenses and other assets	(77.9)	(5.5)
Increase (decrease) in deferred revenue	116.9	(35.9)
Increase in accounts payable, accrued expenses, and other liabilities	110.5	119
Total adjustments	790.5	549.8
Net cash provided by operating activities	1,512.5	1,367.6
Cash flows from investing activities:
Purchases of marketable and other securities	(5,657.5)	(1,749.4)
Sales or maturities of marketable and other securities	4,132.2	1,792.8
Capital expenditures	(133.9)	(178.2)
Payments for Libtayo intangible asset	(27.9)	(100.9)
Net cash used in investing activities	(1,687.1)	(235.7)
Cash flows from financing activities:
Proceeds from issuance of Common Stock	682.1	485.2
Payments in connection with Common Stock tendered for employee tax obligations	(343.7)	(97)
Repurchases of Common Stock	(291.3)	(710.7)
Net cash provided by (used in) financing activities	47.1	(322.5)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(0.5)	0
Net (decrease) increase in cash, cash equivalents, and restricted cash	(128)	809.4
Cash, cash equivalents, and restricted cash at beginning of period	2,737.8	3,119.4
Cash, cash equivalents, and restricted cash at end of period	$ 2,609.8	$ 3,928.8

Interim Financial Statements

Interim Financial Statements	3 Months Ended
Interim Financial Statements	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interim Financial Statements	Interim Financial Statements Basis of Presentation The interim Condensed Consolidated Financial Statements of Regeneron Pharmaceuticals, Inc. and its subsidiaries ("Regeneron," "Company," "we," "us," and "our") have been prepared in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all information and disclosures necessary for a presentation of the Company's financial position, results of operations, and cash flows in conformity with accounting principles generally accepted in the United States of America. In the opinion of management, these financial statements reflect all normal recurring adjustments and accruals necessary for a fair statement of the Company's condensed consolidated financial statements for such periods. The results of operations for any interim period are not necessarily indicative of the results for the full year. The December 31, 2023 Condensed Consolidated Balance Sheet data were derived from audited financial statements, but do not include all disclosures required by accounting principles generally accepted in the United States of America. These financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. Recently Issued Accounting Standards In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update No. 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures . The amendments require disclosure of incremental segment information on an annual and interim basis. The amendments also require companies with a single reportable segment to provide all disclosures required by this amendment and all existing segment disclosures in Accounting Standards Codification 280, Segment Reporting . The amendments are effective for fiscal years beginning after December 15, 2023, and interim periods beginning after December 15, 2024. The Company does not expect the adoption of the amendments to have a significant impact on its financial statements. In December 2023, the FASB issued Accounting Standards Update No. 2023-09, Income Taxes - Improvements to Income Tax Disclosures . The amendments require (i) enhanced disclosures in connection with an entity's effective tax rate reconciliation and (ii) income taxes paid disaggregated by jurisdiction. The amendments are effective for annual periods beginning after December 15, 2024. The Company does not expect the adoption of the amendments to have a significant impact on its financial statements.

Product Sales

Product Sales	3 Months Ended
Product Sales	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
Product Sales	Product Sales Net product sales consist of the following: Three Months Ended (In millions) 2024 2023 EYLEA ® HD U.S. $ 200.0 $ — EYLEA ® U.S. 1,201.6 1,433.8 Total EYLEA HD and EYLEA U.S. 1,401.6 1,433.8 Libtayo ® U.S. 159.2 109.7 Libtayo ROW (a) 104.7 67.2 Total Libtayo Global 263.9 176.9 Praluent ® U.S. 70.0 40.2 Evkeeza ® U.S. 24.8 14.9 Inmazeb ® Global 1.0 2.2 $ 1,761.3 $ 1,668.0 (a) Rest of world ("ROW") As of March 31, 2024 and December 31, 2023, the Company had $3.739 billion and $3.888 billion, respectively, of trade accounts receivable that were recorded within Accounts receivable, net. The Company had product sales to certain customers that accounted for more than 10% of total gross product revenue for the three months ended March 31, 2024 and 2023. Sales to each of these customers as a percentage of the Company's total gross product revenue are as follows: Three Months Ended March 31, 2024 2023 Besse Medical, a subsidiary of Cencora, Inc. 51 % 52 % McKesson Corporation 24 % 25 %

Collaboration, License, and Oth

Collaboration, License, and Other Agreements	3 Months Ended
Collaboration, License, and Other Agreements	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
Collaboration, License, and Other Agreements	Collaboration, License, and Other Agreements a. Sanofi The Company is party to a global, strategic collaboration with Sanofi to research, develop, and commercialize fully human monoclonal antibodies, which currently consists of Dupixent ® (dupilumab), Kevzara ® (sarilumab), and itepekimab . Sanofi is generally responsible for funding 80% to 100% of agreed-upon development costs. The Company is obligated to reimburse Sanofi for 30% to 50% of worldwide development expenses that were funded by Sanofi (i.e., "development balance") based on the Company's share of collaboration profits; however, the Company is only required to apply 20% of its share of profits from the collaboration each calendar quarter to reimburse Sanofi for these development expenses. As of March 31, 2024, the Company's contingent reimbursement obligation to Sanofi under the collaboration was approximately $2.200 billion. Sanofi leads commercialization activities for products under the collaboration, subject to the Company's right to co-commercialize such products. Amounts recognized in the Company's Statements of Operations in connection with its Sanofi collaboration are as follows: Statement of Operations Classification Three Months Ended March 31, (In millions) 2024 2023 Regeneron's share of profits in connection with commercialization of antibodies Collaboration revenue $ 804.0 $ 636.5 Reimbursement for manufacturing of commercial supplies Collaboration revenue $ 105.8 $ 161.9 Regeneron's obligation for its share of Sanofi R&D expenses, net of reimbursement of R&D expenses (R&D expense) $ (18.6) $ (26.4) Reimbursement of commercialization-related expenses Reduction of SG&A expense $ 139.5 $ 117.6 The following table summarizes contract balances in connection with the Company's Sanofi collaboration: March 31, December 31, (In millions) 2024 2023 Accounts receivable, net $ 947.0 $ 1,029.1 Deferred revenue $ 532.2 $ 427.7 b. Bayer The Company is party to a license and collaboration agreement with Bayer for the global development and commercialization of EYLEA 8 mg (aflibercept 8 mg) and EYLEA (aflibercept) outside the United States. Agreed-upon development expenses incurred by the Company and Bayer are generally shared equally. Within the United States, the Company is responsible for commercialization and retains profits from such sales. Bayer is responsible for commercialization activities outside the United States, and the companies share equally in profits from such sales. Amounts recognized in the Company's Statements of Operations in connection with its Bayer collaboration are as follows: Statement of Operations Classification Three Months Ended March 31, (In millions) 2024 2023 Regeneron's share of profits in connection with commercialization of EYLEA 8 mg and EYLEA outside the United States Collaboration revenue $ 333.9 $ 331.6 Reimbursement for manufacturing of ex-U.S. commercial supplies Collaboration revenue $ 22.1 $ 25.3 Regeneron's obligation for its share of Bayer R&D expenses, net of reimbursement of R&D expenses (R&D expense) $ (8.7) $ (13.4) The following table summarizes contract balances in connection with the Company's Bayer collaboration: March 31, December 31, (In millions) 2024 2023 Accounts receivable, net $ 359.0 $ 381.7 Deferred revenue $ 151.1 $ 138.2 c. Alnylam The Company is party to a collaboration agreement with Alnylam Pharmaceuticals, Inc. to discover, develop, and commercialize RNA interference therapeutics for a broad range of diseases by addressing therapeutic disease targets expressed in the eye and central nervous system, in addition to a select number of targets expressed in the liver. For each program, the Company provides Alnylam with a specified amount of funding at program initiation and at lead candidate designation. Under the terms of the collaboration, the parties 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 co-development/co-commercialization collaboration agreement or license agreement. Amounts recognized in the Company's Statements of Operations in connection with its Alnylam collaboration are as follows: Statement of Operations Classification Three Months Ended (In millions) 2024 2023 Regeneron's obligation for its share of Alnylam R&D expenses, net of reimbursement of R&D expenses (R&D expense) $ (17.5) $ (21.3) The following table summarizes contract balances in connection with the Company's Alnylam collaboration: March 31, December 31, (In millions) 2024 2023 Accrued expenses and other current liabilities $ 18.9 $ 22.6 d. Roche The Company is a party to a collaboration agreement with Roche to develop, manufacture, and distribute the casirivimab and imdevimab antibody cocktail (known as REGEN-COV ® in the United States and Ronapreve ™ in other countries). Under the terms of the collaboration agreement, the parties jointly fund certain studies, and the Company has the right to distribute the product in the United States while Roche has the right to distribute the product outside the United States. The parties share gross profits from worldwide sales based on a pre-specified formula, depending on the amount of manufactured product supplied by each party to the market. Amounts recognized in the Company's Statements of Operations in connection with its Roche collaboration are as follows: Statement of Operations Classification Three Months Ended (In millions) 2024 2023 Global gross profit payment from Roche in connection with sales of Ronapreve Collaboration revenue $ 0.5 $ 222.2 Reimbursement of research and development expenses from Roche was not material for the three months ended March 31, 2024 and 2023. Contract balances in the Company's Balance Sheets in connection with the Roche collaboration were not material as of March 31, 2024 and December 31, 2023. e. Sonoma In March 2023, the Company and Sonoma Biotherapeutics, Inc. entered into a license and collaboration agreement to bring together the Company's VelociSuite ® technologies with Sonoma's technology platform for the discovery, development, and commercialization of novel regulatory T cell ("T reg ") therapies for autoimmune diseases. In connection with the agreement, the Company made a $45.0 million up-front payment (which was recorded to Acquired in-process research and development expense in the first quarter of 2023) and, in April 2023, the Company purchased an aggregate of $30.0 million of Sonoma preferred stock. Sonoma is also eligible to receive a $45.0 million development milestone payment. The parties co-fund research and development activities under the collaboration. Amounts recognized in the Company's Statements of Operations in connection with research and development activities co-funded under the Sonoma collaboration were not material for the three months ended March 31, 2024. In addition, contract balances in the Company's Balance Sheets in connection with the Sonoma collaboration were not material as of March 31, 2024 and December 31, 2023.

Net Income Per Share

Net Income Per Share	3 Months Ended
Net Income Per Share	Mar. 31, 2024
Earnings Per Share [Abstract]
Net Income Per Share	Net Income Per Share Basic net income per share is computed by dividing net income by the weighted average number of shares of Common Stock and Class A Stock outstanding. Net income per share is presented on a combined basis, inclusive of Common Stock and Class A Stock outstanding, as each class of stock has equivalent economic rights. Diluted net income per share includes the potential dilutive effect of other securities as if such securities were converted or exercised during the period, when the effect is dilutive. The calculations of basic and diluted net income per share are as follows: Three Months Ended March 31, (In millions, except per share data) 2024 2023 Net income - basic and diluted $ 722.0 $ 817.8 Weighted average shares - basic 107.8 107.1 Effect of dilutive securities: Stock options 5.3 5.0 Restricted stock awards and restricted stock units 2.0 1.9 Weighted average shares - diluted 115.1 114.0 Net income per share - basic $ 6.70 $ 7.64 Net income per share - diluted $ 6.27 $ 7.17 Shares which have been excluded from diluted per share amounts because their effect would have been antidilutive include the following: Three Months Ended March 31, (Shares in millions) 2024 2023 Stock options 1.5 1.7

Marketable Securities

Marketable Securities	3 Months Ended
Marketable Securities	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities Marketable securities as of March 31, 2024 and December 31, 2023 consist of both available-for-sale debt securities of investment grade issuers (see below and Note 6) as well as equity securities of publicly traded companies (see Note 6). The following tables summarize the Company's investments in available-for-sale debt securities: (In millions) Amortized Unrealized Fair As of March 31, 2024 Cost Basis Gains Losses Value Corporate bonds $ 7,478.9 $ 6.1 $ (83.9) $ 7,401.1 U.S. government and government agency obligations 5,291.2 0.4 (18.2) 5,273.4 Sovereign bonds 59.8 — (0.8) 59.0 Commercial paper 867.1 0.3 (0.5) 866.9 Certificates of deposit 389.7 0.2 — 389.9 Asset-backed securities 126.0 — (1.3) 124.7 $ 14,212.7 $ 7.0 $ (104.7) $ 14,115.0 As of December 31, 2023 Corporate bonds $ 6,492.5 $ 10.4 $ (104.9) $ 6,398.0 U.S. government and government agency obligations 4,839.6 2.4 (8.6) 4,833.4 Sovereign bonds 58.1 — (0.9) 57.2 Commercial paper 636.8 0.2 (0.2) 636.8 Certificates of deposit 520.8 0.6 — 521.4 Asset-backed securities 88.2 0.1 (1.2) 87.1 $ 12,636.0 $ 13.7 $ (115.8) $ 12,533.9 The Company classifies its investments in available-for-sale debt securities based on their contractual maturity dates. The available-for-sale debt securities as of March 31, 2024 mature at various dates through June 2029. The fair values of available-for-sale debt securities by contractual maturity consist of the following: March 31, December 31, (In millions) 2024 2023 Maturities within one year $ 7,917.5 $ 8,114.8 Maturities after one year through five years 6,184.1 4,414.5 Maturities after five years 13.4 4.6 $ 14,115.0 $ 12,533.9 The following table shows the fair value of the Company's available-for-sale debt securities that have unrealized losses, aggregated by investment category and length of time that the individual securities have been in a continuous loss position. Less than 12 Months 12 Months or Greater Total (In millions) As of March 31, 2024 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Corporate bonds $ 4,490.4 $ (10.7) $ 2,910.7 $ (73.2) $ 7,401.1 $ (83.9) U.S. government and government agency obligations 5,220.4 (15.9) 53.0 (2.3) 5,273.4 (18.2) Sovereign bonds 32.5 (0.2) 26.5 (0.6) 59.0 (0.8) Commercial paper 866.9 (0.5) — — 866.9 (0.5) Asset-backed securities 99.2 (0.6) 25.5 (0.7) 124.7 (1.3) $ 10,709.4 $ (27.9) $ 3,015.7 $ (76.8) $ 13,725.1 $ (104.7) As of December 31, 2023 Corporate bonds $ 2,363.3 $ (2.4) $ 4,034.7 $ (102.5) $ 6,398.0 $ (104.9) U.S. government and government agency obligations 4,780.6 (6.0) 52.7 (2.6) 4,833.3 (8.6) Sovereign bonds 12.4 (0.1) 44.8 (0.8) 57.2 (0.9) Commercial paper 636.8 (0.2) — — 636.8 (0.2) Asset-backed securities 61.8 (0.3) 25.3 (0.9) 87.1 (1.2) $ 7,854.9 $ (9.0) $ 4,157.5 $ (106.8) $ 12,012.4 $ (115.8) The unrealized losses on corporate bonds as of March 31, 2024 were primarily driven by increased interest rates. The Company has reviewed its portfolio of available-for-sale debt securities and determined that the decline in fair value below cost did not result from credit-related factors. In addition, the Company does not intend to sell, and it is not more likely than not that the Company will be required to sell, such securities before recovery of their amortized cost bases.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
Fair Value Measurements	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The table below summarizes the Company's assets and liabilities which are measured at fair value on a recurring basis. The following fair value hierarchy is used to classify assets and liabilities, based on inputs to valuation techniques utilized to measure fair value: • Level 1 - Quoted prices in active markets for identical assets or liabilities • Level 2 - Significant other observable inputs, such as quoted market prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, or model-based valuations in which significant inputs used are observable • Level 3 - Significant other unobservable inputs (In millions) Fair Value Measurements at Reporting Date As of March 31, 2024 Fair Value Level 1 Level 2 Level 3 Assets: Cash equivalents $ 1,056.4 $ 125.8 $ 930.6 $ — Available-for-sale debt securities: Corporate bonds 7,401.1 — 7,401.1 — U.S. government and government agency obligations 5,273.4 — 5,273.4 — Sovereign bonds 59.0 — 59.0 — Commercial paper 866.9 — 866.9 — Certificates of deposit 389.9 — 389.9 — Asset-backed securities 124.7 — 124.7 — Equity securities (unrestricted) 679.4 679.4 — — Equity securities (restricted) 101.9 101.9 — — Total assets $ 15,952.7 $ 907.1 $ 15,045.6 $ — Liabilities: Contingent consideration $ 59.0 $ — $ — $ 59.0 As of December 31, 2023 Assets: Cash equivalents $ 928.1 $ 6.4 $ 921.7 $ — Available-for-sale debt securities: Corporate bonds 6,398.0 — 6,398.0 — U.S. government and government agency obligations 4,833.4 — 4,833.4 — Sovereign bonds 57.2 — 57.2 — Commercial paper 636.8 — 636.8 — Certificates of deposit 521.4 — 521.4 — Asset-backed securities 87.1 — 87.1 — Equity securities (unrestricted) 864.5 864.5 — — Equity securities (restricted) 112.9 112.9 — — Total assets $ 14,439.4 $ 983.8 $ 13,455.6 $ — Liabilities: Contingent consideration $ 43.7 $ — $ — $ 43.7 As of March 31, 2024, the Company held restricted equity securities which are subject to transfer restrictions that expire in June 2024. During the three months ended March 31, 2024 and 2023, the Company recorded $196.2 million and $164.7 million, respectively, of net unrealized losses on equity securities in Other (expense) income, net. In addition to the investments summarized in the table above, as of March 31, 2024 and December 31, 2023, the Company had $73.7 million and $74.3 million, respectively, in equity investments that do not have a readily determinable fair value. These investments are recorded within Other noncurrent assets. As a result of the Company's acquisition of Decibel Therapeutics, Inc. in September 2023, the Company recorded a contingent consideration liability within other liabilities. The fair value of the liability is determined based on the probability of achieving certain clinical development and regulatory milestones and estimated discount rates, and is remeasured each reporting period until the contingencies are resolved. During the three months ended March 31, 2024, the Company recorded a $15.3 million charge related to the change in the estimated fair value of the contingent consideration liability within Other operating expense (income), net. The fair value of the Company's long-term debt, which was determined based on Level 2 inputs, was estimated to be $1.497 billion and $1.528 billion as of March 31, 2024 and December 31, 2023, respectively.

Inventories

Inventories	3 Months Ended
Inventories	Mar. 31, 2024
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consist of the following: March 31, December 31, (In millions) 2024 2023 Raw materials $ 814.8 $ 789.3 Work-in-process 1,108.1 1,121.8 Finished goods 180.5 147.3 Deferred costs 611.5 522.1 $ 2,714.9 $ 2,580.5 Deferred costs represent the costs of product manufactured and shipped to the Company's collaborators for which recognition of revenue has been deferred.

Income Taxes

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesThe Company is subject to U.S. federal, state, and foreign income taxes. The Company's effective tax rate was (3.0%) and 4.7% for the three months ended March 31, 2024 and 2023, respectively. The Company's effective tax rate for the three months ended March 31, 2024 and 2023 was positively impacted, compared to the U.S. federal statutory rate, primarily by stock-based compensation and income earned in foreign jurisdictions with tax rates lower than the U.S. federal statutory rate. The effective tax rate for the three months ended March 31, 2024 was positively impacted, compared to the same period in 2023, primarily by additional stock-based compensation.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
Stockholders' Equity	Mar. 31, 2024
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity In November 2021, the Company's board of directors authorized a share repurchase program to repurchase up to $3.0 billion of the Company's Common Stock. As of June 30, 2023, the Company had repurchased the entire $3.0 billion of its Common Stock that it was authorized to repurchase under the program. In January 2023, the Company's board of directors authorized an additional share repurchase program to repurchase up to $3.0 billion of the Company's Common Stock. The share repurchase program permits the Company to make repurchases through a variety of methods, including open-market transactions (including pursuant to a trading plan adopted in accordance with Rule 10b5-1 of the Exchange Act), privately negotiated transactions, accelerated share repurchases, block trades, and other transactions in compliance with Rule 10b-18 of the Exchange Act. Repurchases may be made from time to time at management's discretion, and the timing and amount of any such repurchases will be determined based on share price, market conditions, legal requirements, and other relevant factors. The program has no time limit and can be discontinued at any time. There can be no assurance as to the timing or number of shares of any repurchases in the future. As of March 31, 2024, $1.233 billion remained available for share repurchases under the program. The table below summarizes the shares of the Company's Common Stock the Company repurchased and the cost of the shares, which were recorded as Treasury Stock. Three Months Ended (In millions) 2024 2023 Number of shares 0.3 0.9 Total cost of shares $ 298.0 $ 693.9 In April 2024, the Company's board of directors authorized a new share repurchase program to repurchase up to an additional $3.0 billion of the Company's Common Stock. The share repurchase program was approved under terms substantially similar to the share repurchase programs described above.

Statement of Cash Flows

Statement of Cash Flows	3 Months Ended
Statement of Cash Flows	Mar. 31, 2024
Cash and Cash Equivalents [Abstract]
Statement of Cash Flows	Statement of Cash Flows The following provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Condensed Consolidated Balance Sheets to the total of the same such amounts shown in the Condensed Consolidated Statements of Cash Flows: March 31, (In millions) 2024 2023 Cash and cash equivalents $ 2,602.0 $ 3,916.3 Restricted cash included in Other noncurrent assets 7.8 12.5 Total cash, cash equivalents, and restricted cash shown in the Condensed Consolidated Statements of Cash Flows $ 2,609.8 $ 3,928.8 Restricted cash consists of amounts held by financial institutions pursuant to contractual arrangements. Supplemental disclosure of non-cash investing and financing activities March 31, December 31, March 31, December 31, (In millions) 2024 2023 2023 2022 Accrued capital expenditures $ 108.0 $ 75.4 $ 90.3 $ 70.8 Accrued contingent consideration in connection with acquisitions $ 88.8 $ 71.6 $ 55.2 $ 135.5

Legal Matters

Legal Matters	3 Months Ended
Legal Matters	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Legal Matters	Legal Matters From time to time, the Company is a party to legal proceedings in the course of the Company's business. The outcome of any such proceedings, regardless of the merits, is inherently uncertain. If the Company were unable to prevail in any such proceedings, its consolidated financial position, results of operations, and future cash flows may be materially impacted. Costs associated with the Company's involvement in legal proceedings are expensed as incurred. The Company recognizes accruals for loss contingencies associated with such proceedings when it is probable that a liability will be incurred and the amount of loss can be reasonably estimated. As of March 31, 2024 and December 31, 2023, the Company's accruals for loss contingencies were not material. There are certain loss contingencies that the Company deems reasonably possible for which the possible loss or range of possible loss is not estimable at this time. Proceedings Relating to Praluent (alirocumab) Injection United States On May 27, 2022, the Company filed a lawsuit against Amgen Inc. in the United States District Court for the District of Delaware, alleging that, beginning in 2020, Amgen engaged in an anticompetitive bundling scheme which was designed to exclude Praluent from the market in violation of federal and state laws. The lawsuit seeks damages for harm caused by the alleged scheme, as well as injunctive relief restraining Amgen from continuing its alleged anticompetitive conduct. On August 1 and 11, 2022, Amgen filed a motion to dismiss the complaint and a motion to stay these proceedings, respectively. On February 10, 2023, the court denied Amgen's motion to stay; and on March 21, 2023, the court denied Amgen's motion to dismiss. On August 28, 2023, the Company filed an amended complaint in this matter; and, as part of its response, on September 20, 2023, Amgen filed a counterclaim alleging that the Company engaged in unfair business practices in violation of state law. A trial has been scheduled to begin in November 2024. Europe On June 1, 2023, Amgen filed a lawsuit against the Company and certain of Sanofi's affiliated entities in the Munich Local Division of the Unified Patent Court (the "UPC") alleging infringement of Amgen's European Patent No. 3,666,797 (the "'797 Patent"). The lawsuit seeks, among other things, a permanent injunction in several countries in Europe and monetary damages. The '797 Patent is a divisional patent of European Patent No. 2,215,124 (the "'124 Patent") (i.e., a patent that shares the same priority date, disclosure, and patent term of the parent '124 Patent), which was previously invalidated by Technical Board of Appeal (the "TBA") of the European Patent Office (the "EPO"). A trial has been scheduled for October 16–17, 2024. Also on June 1, 2023, Sanofi filed an action in the Munich Central Division of the UPC seeking revocation of the '797 Patent. A trial has been scheduled for June 4–5, 2024. Proceedings Relating to EYLEA (aflibercept) Injection Certain of the Company's patents pertaining to EYLEA are subject to post-grant proceedings before the United States Patent and Trademark Office ("USPTO"), EPO, or other comparable foreign authorities, including those described in greater detail below. In addition, the Company has filed patent infringement lawsuits in several jurisdictions alleging infringement of certain Company patents pertaining to EYLEA, including those described in greater detail below. United States Post-Grant Proceedings Before USPTO Company Patent(s) Challenger(s) Type of Challenge Date of Challenge Latest Events/Current Status U.S. Patent Nos. 9,254,338 (the "'338 Patent") and 9,669,069 (the "'069 Patent") Mylan Pharmaceuticals Inc., joined by Apotex Inc. and Celltrion IPR petitions seeking declarations of invalidity May 5, 2021 On November 9, 2022, the USPTO issued final written decisions finding that the challenged claims of the '338 and '069 Patents are unpatentable and, therefore, invalid. On January 10, 2023, the Company filed notices of appeal of these decisions to the United States Court of Appeals for the Federal Circuit (the "Federal Circuit"). U.S. Patent Nos. 10,130,681 (the "'681 Patent") and 10,888,601 (the "'601 Patent") Mylan, joined by Celltrion ('601 and '681 Patents) and Samsung Bioepis Co., Ltd. ('601 Patent) IPR petitions seeking declarations of invalidity July 1, 2022 On January 9, 2024, the USPTO issued final written decisions finding that that the challenged claims of the '681 and '601 Patents are unpatentable and, therefore, invalid. On March 12, 2024, the Company filed notices of appeal of these decisions to the Federal Circuit. Samsung Bioepis, joined by Biocon Biologics Inc. ('601 Patent) IPR petitions seeking declarations of invalidity January 6, 2023 ('681 Patent) March 26, 2023 ('601 Patent) On July 19, 2023 and October 20, 2023, the USPTO instituted IPR proceedings concerning the '681 Patent and the '601 Patent, respectively. U.S. Patent No. 11,253,572 (the "'572 Patent") Samsung Bioepis IPR petition seeking declaration of invalidity April 27, 2023 On November 17, 2023, the USPTO instituted IPR proceedings concerning the '572 Patent. U.S. Patent Litigation On August 2, 2022, the Company filed a patent infringement lawsuit against Mylan, a wholly-owned subsidiary of Viatris Inc., in the United States District Court for the Northern District of West Virginia alleging that Mylan's filing for FDA approval of an aflibercept 2 mg biosimilar infringes certain Company patents. On April 20, 2023, Mylan filed a motion for summary judgment or partial summary judgment concerning four of the asserted patents. On April 26, 2023, the Company filed a stipulation accepting summary judgment of noninfringement of all asserted claims of the Company's U.S. Patent No. 11,104,715. On June 5, 2023, Biocon, as successor-in-interest to the aflibercept 2 mg biosimilar, was joined as a defendant to the lawsuit. A trial was held from June 12, 2023 through June 23, 2023 concerning certain claims of the '601 Patent, the '572 Patent, and the Company's U.S. Patent No. 11,084,865 (the "'865 Patent"). On December 27, 2023, the court issued a decision finding that (i) the asserted claims of the '865 Patent were valid and infringed by Mylan and (ii) the asserted claims of the '601 and '572 Patents were infringed by Mylan but were invalid as obvious. A scheduling conference has been set for May 17, 2024. On November 8, November 22, and November 29, 2023, respectively, the Company filed patent infringement lawsuits against Celltrion, Samsung Bioepis, and Formycon AG in the United States District Court for the Northern District of West Virginia following service on Regeneron of each company's notice of commercial marketing. The lawsuits allege that each company has infringed certain Company patents, including based on each company's filing for FDA approval of an aflibercept 2 mg biosimilar. On December 27, 2023, the Company filed a second patent infringement lawsuit against Samsung Bioepis in the United States District Court for the Northern District of West Virginia alleging that Samsung's filing for FDA approval of an aflibercept 2 mg biosimilar infringes certain Company patents. A scheduling conference has been set for May 17, 2024. On January 10, 2024, the Company filed a patent infringement lawsuit against Amgen in the United States District Court for the Central District of California alleging that Amgen's filing for FDA approval of an aflibercept 2 mg biosimilar infringes certain Company patents. On January 11, 2024, the Company filed a motion with the United States Judicial Panel on Multidistrict Litigation seeking to transfer this lawsuit to the United States District Court for the Northern District of West Virginia for coordinated pretrial proceedings with the lawsuits described in the preceding paragraph. On April 11, 2024, the United States Judicial Panel on Multidistrict Litigation granted the Company's motion to transfer this lawsuit to the United States District Court for the Northern District of West Virginia for coordinated and consolidated pretrial proceedings with the lawsuits described in the preceding paragraph. A scheduling conference before the United States District Court for the Northern District of West Virginia has been set for May 17, 2024. Europe Post-Grant Proceedings Authority/Court Company Patent(s) Challenger(s) Type of Challenge Date of Challenge Latest Events/Current Status EPO European Patent No. 2,944,306 (the "'306 Patent") Anonymous parties Opposition proceedings October 26 and October 27, 2021 Oral hearing scheduled for November 2024. EPO European Patent No. 3,716,992 (the "EP '992 Patent") Amgen and three anonymous parties Opposition proceedings May 5-10, 2023 Oral hearing to be scheduled. EPO European Patent No. 3,384,049 (the "'049 Patent") Amgen and anonymous parties Opposition proceedings April 22-30, 2024 Oral hearing to be scheduled. German Federal Patent Court German designation of European Patent No. 2,364,691 (the "'691 Patent") Samsung Bioepis NL B.V. Invalidation proceedings June 22, 2023 Trial has been scheduled to begin in June 2025. High Court of Justice of England and Wales United Kingdom designations of the '691 Patent and '306 Patent Formycon AG and Klinge Biopharma GmbH Invalidation proceedings and declaration of non-infringement by challengers' aflibercept 2 mg biosimilar April 18, 2024 Trial to be scheduled. Canada Proceedings against Viatris Canada and BCIL In 2022, the Company and Bayer Inc. filed patent infringement lawsuits against BGP Pharma ULC d.b.a Viatris Canada ("Viatris Canada") in the Federal Court of Canada seeking a declaration that the making, constructing, using, or selling of an aflibercept 2 mg biosimilar would directly or indirectly infringe one or more claims of the Company's Canadian Patent Nos. 2,654,510 (the "'510 Patent") and 3,007,276 (the "'276 Patent") (in the lawsuit filed on June 15, 2022); the Company's Canadian Patent No. 2,965,495 (the "'495 Patent") (in the lawsuit filed on July 15, 2022); the Company's Canadian Patent No. 2,906,768 (the "'768 Patent") (in the lawsuit filed on August 30, 2022, which has been joined with the lawsuit filed on July 15, 2022); and the Company's Canadian Patent No. 3,129,193 (the "'193 Patent") (in the lawsuit filed on October 4, 2022). On June 5, 2023, following the transfer of Viatris Canada's New Drug Submission of its aflibercept 2 mg biosimilar to Biosimilar Collaborations Ireland Limited ("BCIL"), BCIL was added as a defendant in the lawsuit concerning the '510 Patent and the '276 Patent. On March 23, 2023 and June 14, 2023, the Company and Bayer Inc. filed patent infringement lawsuits against BCIL in the Federal Court of Canada seeking a declaration that the making, constructing, using, or selling of an aflibercept 2 mg biosimilar would directly or indirectly infringe one or more claims of the Company's '510 and '276 Patents. On September 14, 2023, the Company, Bayer Inc., and Bayer Healthcare LLC filed patent infringement lawsuits against Viatris Canada and BCIL in the Federal Court of Canada seeking a declaration that the making, constructing, using, or selling of an aflibercept 2 mg biosimilar would directly or indirectly infringe one or more claims of Bayer Healthcare LLC's Canadian Patent No. 2,970,315 (the "'315 Patent"). On March 1, 2024, the Company, Bayer Inc., Bayer Healthcare LLC, Viatris Canada, BCIL, and Biocon Biologics Limited entered into a settlement agreement concerning the lawsuits described in the preceding two paragraphs. Pursuant to the settlement agreement, each of such lawsuits has been dismissed and BCIL is generally precluded from launching its aflibercept 2 mg biosimilar product in Canada until July 1, 2025. Proceedings against Amgen Canada On May 9, 2023, Amgen Canada Inc. ("Amgen Canada") filed invalidation proceedings against the Company in the Federal Court of Canada seeking revocation of the '510 Patent and the '276 Patent. On September 14, 2023, the Company, Bayer Inc., and Bayer Healthcare LLC filed patent infringement lawsuits against Amgen Canada in the Federal Court of Canada seeking a declaration that the making, constructing, using, or selling of an aflibercept 2 mg biosimilar would directly or indirectly infringe one or more claims of the '315 Patent. On September 14, 2023, the Company and Bayer Inc. filed three separate patent infringement lawsuits against Amgen Canada in the Federal Court of Canada seeking a declaration that the making, constructing, using, or selling of an aflibercept 2 mg biosimilar would directly or indirectly infringe one or more claims of the Company's '193 Patent, '495 Patent, and '768 Patent, respectively. On October 11, 2023, the Company, Bayer Inc., and Bayer Healthcare LLC filed two separate patent infringement lawsuits against Amgen Canada in the Federal Court of Canada seeking a declaration that the making, constructing, using, or selling of an aflibercept 2 mg biosimilar would directly or indirectly infringe one or more claims of the Company's '510 Patent and '276 Patent, respectively. A trial for the lawsuits concerning the '510 Patent and the '276 Patent has been scheduled for May 2025. Proceedings against Celltrion On January 15, 2024, the Company and Bayer Inc. filed patent infringement lawsuits against Celltrion, Inc., Celltrion Healthcare Co, Ltd., Celltrion Pharma Inc., and Celltrion Healthcare Canada Ltd. in the Federal Court of Canada seeking a declaration that the making, constructing, using, or selling of an aflibercept 2 mg biosimilar would directly or indirectly infringe one or more claims of the '510 Patent, the '276 Patent, the '495 Patent, the '768 Patent, the '193 Patent, and the '315 Patent. Proceedings against Apotex On March 6, 2024, the Company, Bayer Inc., and Bayer Healthcare LLC filed patent infringement lawsuits against Apotex Inc. in the Federal Court of Canada seeking a declaration that the making, constructing, using, or selling of an aflibercept 2 mg biosimilar would directly or indirectly infringe one or more claims of the '510 Patent, the '276 Patent, the '495 Patent, the '768 Patent, the '193 Patent, and the '315 Patent. An oral hearing for certain motions concerning the '276 Patent, the '315 Patent, and the '510 Patent has been scheduled for July 8-9, 2024. South Korea On October 31, 2022 and December 13, 2022, Samsung Bioepis Co., Ltd. initiated invalidation proceedings before the Intellectual Property Trial and Appeal Board of the Korean Intellectual Property Office against the Company's Korean Patent Nos. 1131429 and 1406811, respectively, seeking revocation of each of such patents in its entirety. On January 16, 2023, the Company filed patent infringement lawsuits against Samsung Bioepis Co., Ltd. and its parent company Samsung Biologics Co., Ltd. before the Seoul Central District Court seeking a declaration that the making, constructing, using, or selling of an aflibercept 2 mg biosimilar would infringe one or more claims of the Company's Korean Patent No. 659477 (the "'477 Patent"). On July 20, 2023, the Company filed a preliminary injunction petition against Samsung Bioepis Co., Ltd. and its parent company Samsung Biologics Co., Ltd. before the Seoul Central District Court seeking a court order enjoining the manufacture, use, and assignment of an aflibercept 2 mg biosimilar that infringes one or more claims of the '477 Patent; and on December 20, 2023, the Seoul Central District Court granted a preliminary injunction. On January 10, 2024, the injunction was lifted against the Samsung entities following the expiration of the '477 Patent. On March 2, 2023, the Company filed an affirmative scope confirmation action against Samsung Bioepis Co., Ltd. before the Intellectual Property Tribunal and Appeal Board of the Korean Intellectual Property Office seeking a ruling that Samsung Bioepis's aflibercept 2 mg biosimilar is covered by the claims of the '477 Patent. In March 2024, these proceedings were terminated as a result of the expiration of the '477 Patent. Proceedings Relating to EYLEA (aflibercept) Injection Pre-filled Syringe On June 19, 2020, Novartis Pharma AG, Novartis Pharmaceuticals Corporation, and Novartis Technology LLC (collectively, "Novartis") filed a patent infringement lawsuit (as amended on August 2, 2021) in the U.S. District Court for the Northern District of New York asserting claims of Novartis's U.S. Patent No. 9,220,631 (the "'631 Patent") and seeking preliminary and permanent injunctions to prevent the Company from continuing to infringe the '631 Patent. Novartis also seeks a judgment of patent infringement of the '631 Patent, monetary damages (together with interest), an order of willful infringement of the '631 Patent (which would allow the court in its discretion to award damages up to three times the amount assessed), costs and expenses of the lawsuits, and attorneys' fees. On November 7, 2022, the Company and Novartis entered into a stipulation staying the lawsuit in light of the decision in the IPR proceeding discussed below. On July 16, 2020, the Company initiated two IPR petitions in the USPTO seeking a declaration of invalidity of the '631 Patent on two separate grounds. On October 26, 2021, the USPTO issued a decision instituting the IPR proceeding. An oral hearing was held on July 21, 2022. On October 25, 2022, the Patent Trial and Appeal Board ("PTAB") of the USPTO issued a final written decision invalidating all claims of the '631 Patent. On December 23, 2022, Novartis filed a notice of appeal of the PTAB's decision to the Federal Circuit. On July 17, 2020, the Company filed an antitrust lawsuit against Novartis and Vetter Pharma International Gmbh ("Vetter") in the United States District Court for the Southern District of New York seeking a declaration that the '631 Patent is unenforceable and a judgment that the defendants' conduct violates Sections 1 and 2 of the Sherman Antitrust Act of 1890, as amended (the "Sherman Antitrust Act"). The Company is also seeking injunctive relief and treble damages. On September 4, 2020, Novartis filed, and Vetter moved to join, a motion to dismiss the complaint, to transfer the lawsuit to the Northern District of New York, or to stay the suit; and on October 19, 2020, Novartis filed, and Vetter moved to join, a second motion to dismiss the complaint on different grounds. On January 25, 2021, the Company filed an amended complaint seeking a judgment that Novartis's conduct violates Section 2 of the Sherman Antitrust Act based on additional grounds, as well as a judgment of tortious interference with contract. On February 22, 2021, Novartis filed, and Vetter moved to join, a motion to dismiss the amended complaint. On September 21, 2021, the court granted Novartis and Vetter's motion to transfer this lawsuit to the Northern District of New York. As a result, this lawsuit was transferred to the same judge that had been assigned to the patent infringement lawsuit discussed above. On January 31, 2022, the court granted Novartis and Vetter's motion to dismiss the amended complaint. On June 10, 2022, the Company filed an appeal of the District Court's decision to dismiss the amended complaint with the U.S. Court of Appeals for the Second Circuit (the "Second Circuit"). On March 18, 2024, the Second Circuit reversed the District Court's decision to dismiss the amended complaint and remanded the lawsuit to the District Court for further proceedings consistent with the Second Circuit's opinion. Proceedings Relating to REGEN-COV (casirivimab and imdevimab) On October 5, 2020, Allele Biotechnology and Pharmaceuticals, Inc. ("Allele") filed a lawsuit (as amended on April 8, 2021 and December 12, 2022) against the Company in the United States District Court for the Southern District of New York, asserting infringement of U.S. Patent No. 10,221,221 (the "'221 Patent"). Allele seeks a judgment of patent infringement of the '221 Patent, an award of monetary damages (together with interest), an order of willful infringement of the '221 Patent (which would allow the court in its discretion to award damages up to three times the amount assessed), costs and expenses of the lawsuit, and attorneys' fees. On July 16, 2021, the Company filed a motion to dismiss the complaint, which motion was denied on March 2, 2022. On September 18, 2023, the parties entered into a stipulation that narrowed the case to (i) whether any safe harbor defense under federal law applies to Regeneron's use of the invention covered, based on the court's claim construction, by the '221 Patent; (ii) damages for any use by Regeneron found to not be covered by such safe harbor defense; and (iii) whether any use referred to in clause (ii) above was willful. Department of Justice Matters In January 2017, the Company received a subpoena from the U.S. Attorney's Office for the District of Massachusetts requesting documents relating to its support of 501(c)(3) organizations that provide financial assistance to patients; documents concerning its provision of financial assistance to patients with respect to products sold or developed by Regeneron (including EYLEA, Praluent, ARCALYST ® , and ZALTRAP ® ); and certain other related documents and communications. On June 24, 2020, the U.S. Attorney's Office for the District of Massachusetts filed a civil complaint in the U.S. District Court for the District of Massachusetts alleging violations of the federal Anti-Kickback Statute, and asserting causes of action under the federal False Claims Act and state law (the "June 2020 Civil Complaint"). On August 24, 2020, the Company filed a motion to dismiss the June 2020 Civil Complaint in its entirety. On December 4, 2020, the court denied the motion to dismiss. On December 28, 2022, the U.S. Attorney's Office for the District of Massachusetts filed a motion for partial summary judgment. On January 31, 2023, the Company filed a motion for summary judgment. An oral hearing on the parties' respective motions for summary judgment was held on July 21, 2023. On September 27, 2023, the court (i) denied in part and granted in part the Company's motion for summary judgment and (ii) denied in its entirety the motion for partial summary judgment filed by the U.S. Attorney's Office for the District of Massachusetts. On October 25, 2023, the court certified for interlocutory appeal a portion of the court's September 27, 2023 order that addressed the causation standard applicable to the alleged violations of the federal Anti-Kickback Statute and federal False Claims Act; and on December 11, 2023, the U.S. Court of Appeals for the First Circuit certified for appeal (i.e., accepted for review) the court's September 27, 2023 order. In September 2019, the Company and Regeneron Healthcare Solutions, Inc., a wholly-owned subsidiary of the Company, each received a civil investigative demand ("CID") from the U.S. Department of Justice pursuant to the federal False Claims Act relating to remuneration paid to physicians in the form of consulting fees, advisory boards, speaker fees, and payment or reimbursement for travel and entertainment allegedly in violation of the federal Anti-Kickback Statute. The CIDs relate to EYLEA, Praluent, Dupixent, ZALTRAP, ARCALYST, and Kevzara and cover the period from January 2015 to the present. On June 3, 2021, the United States District Court for the Central District of California unsealed a qui tam complaint filed against the Company, Regeneron Healthcare Solutions, Inc., and Sanofi-Aventis U.S. LLC by two qui tam plaintiffs (known as relators) purportedly on behalf of the United States and various states (the "State Plaintiffs"), asserting causes of action under the federal False Claims Act and state law. Also on June 3, 2021, the United States and the State Plaintiffs notified the court of their decision to decline to intervene in the case. On October 29, 2021, the qui tam plaintiffs filed an amended complaint in this matter. On January 14, 2022, the Company filed a motion to dismiss the amended complaint in its entirety. On July 25, 2023, the court in part granted and in part denied the Company's motion to dismiss. On September 1, 2023, the Company filed a second motion to dismiss the amended complaint or, in the alternative, a motion for judgment on the pleadings. A trial has been scheduled for April 2025. In June 2021, the Company received a CID from the U.S. Department of Justice pursuant to the federal False Claims Act. The CID states that the investigation concerns allegations that the Company (i) violated the False Claims Act by paying kickbacks to distributors and ophthalmology practices to induce purchase of EYLEA, including through discounts, rebates, credit card fees, free units of EYLEA, and inventory management systems; and (ii) inflated reimbursement rates for EYLEA by excluding applicable discounts, rebates, and benefits from the average sales price reported to the Centers for Medicare & Medicaid Services. The CID covers the period from January 2011 through June 2021. On November 29, 2023, the U.S. Department of Justice informed the Company that it had filed a notice of partial intervention in this matter. On March 28, 2024, the Department of Justice and the U.S. Attorney's Office for the District of Massachusetts filed a civil complaint intervention in the U.S. District Court for the District of Massachusetts asserting causes of action under the federal False Claims Act and a claim for unjust enrichment. Also on March 28, 2024, the U.S. District Court of the District of Massachusetts unsealed a qui tam complaint against the Company, AmerisourceBergen, and Besse Medical by two qui tam plaintiffs (known as relators) purportedly on behalf of the United States and various states and municipalities, asserting causes of action under the federal False Claims Act and state and local laws, and alleging violations of the federal Anti-Kickback statute. California Department of Insurance Subpoena In September 2022, the Company received a subpoena from the Insurance Commissioner for the State of California pursuant to the California Insurance Code. The subpoena seeks information relating to the marketing, sale, and distribution of EYLEA, including (i) discounts, rebates, credit card fees, and inventory management systems; (ii) Regeneron's relationships with distributors; (iii) price reporting; (iv) speaker programs; and (v) patient support programs. The subpoena covers the period from January 1, 2014 through August 1, 2021. The Company is cooperating with this investigation. Proceedings Initiated by Other Payors Relating to Patient Assistance Organization Support The Company is party to several lawsuits relating to the conduct alleged in the June 2020 Civil Complaint discussed under "Department of Justice Matters" above. These lawsuits were filed by UnitedHealthcare Insurance Company and United Healthcare Services, Inc. (collectively, "UHC") and Humana Inc. ("Humana") in the United States District Court for the Southern District of New York on December 17, 2020 and July 22, 2021, respectively; and by Blue Cross and Blue Shield of Massachusetts, Inc. and Blue Cross and Blue Shield of Massachusetts HMO Blue, Inc. (collectively, "BCBS"), Medical Mutual of Ohio ("MMO"), Horizon Healthcare Services, Inc. d/b/a Horizon Blue Cross Blue Shield of New Jersey ("Horizon"), and Local 464A United Food and Commercial Workers Union Welfare Service Benefit Fund ("Local 464A") in the U.S. District Court for the District of Massachusetts on December 20, 2021, February 23, 2022, April 4, 2022, and June 17, 2022, respectively. These lawsuits allege causes of action under state law and the federal Racketeer Influenced and Corrupt Organizations Act and seek monetary damages and equitable relief. The MMO and Local 464A lawsuits are putative class action lawsuits. On December 29, 2021, the lawsuits filed by UHC and Humana were stayed by the United States District Court for the Southern District of New York pending resolution of the proceedings before the U.S. District Court for the District of Massachusetts concerning the allegations in the June 2020 Civil Complaint. On September 27, 2022, the lawsuits filed by BCBS, MMO, and Horizon were stayed by the U.S. District Court for the District of Massachusetts pending resolution of the proceedings before the same court concerning the allegations in the June 2020 Civil Complaint; and, in light of these stays, the parties to the Local 464A action have also agreed to stay that matter. Proceedings Relating to Shareholder Derivative Complaint

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Millions	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net income	$ 722	$ 817.8

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2024 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	As disclosed in the table below, during the three months ended March 31, 2024, certain of our directors and/or executive officers adopted plans for trading arrangements intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) of the Exchange Act. Name Position Date of Plan Adoption Scheduled End Date of Trading Arrangement (a) Total Number of Securities to Be Sold Under the Plan Bonnie L. Bassler, Ph.D. Director 2/27/2024 4/30/2025 3,851 Michael S. Brown, M.D. Director 2/26/2024 8/31/2024 2,707 Joseph J. LaRosa Executive Vice President, General Counsel and Secretary 2/16/2024 2/10/2025 5,191 Marion McCourt Executive Vice President, Commercial 2/13/2024 5/31/2025 8,122 Leonard S. Schleifer, M.D., Ph.D. Board co-Chair, President and Chief Executive Officer 2/5/2024 8/5/2025 229,204 George D. Yancopoulos, M.D., Ph.D. Board co-Chair, President and Chief Scientific Officer 2/14/2024 2/10/2025 100,000 (a) In each case, the trading arrangement may expire on an earlier date if and when all transactions under the arrangement are completed.
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Bonnie L. Bassler, Ph.D. [Member]
Trading Arrangements, by Individual
Name	Bonnie L. Bassler, Ph.D.
Title	Director
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	2/27/2024
Arrangement Duration	428 days
Aggregate Available	3,851
Michael S. Brown, M.D. [Member]
Trading Arrangements, by Individual
Name	Michael S. Brown, M.D.
Title	Director
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	2/26/2024
Arrangement Duration	187 days
Aggregate Available	2,707
Joseph J. LaRosa [Member]
Trading Arrangements, by Individual
Name	Joseph J. LaRosa
Title	Executive Vice President, General Counsel and Secretary
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	2/16/2024
Arrangement Duration	360 days
Aggregate Available	5,191
Marion McCourt [Member]
Trading Arrangements, by Individual
Name	Marion McCourt
Title	Executive Vice President, Commercial
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	2/13/2024
Arrangement Duration	473 days
Aggregate Available	8,122
Leonard S. Schleifer, M.D., Ph.D. [Member]
Trading Arrangements, by Individual
Name	Leonard S. Schleifer, M.D., Ph.D.
Title	Board co-Chair, President and Chief Executive Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	2/5/2024
Arrangement Duration	547 days
Aggregate Available	229,204
George D. Yancopoulos, M.D., Ph.D. [Member]
Trading Arrangements, by Individual
Name	George D. Yancopoulos, M.D., Ph.D.
Title	Board co-Chair, President and Chief Scientific Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	2/14/2024
Arrangement Duration	362 days
Aggregate Available	100,000

Interim Financial Statements (P

Interim Financial Statements (Policies)	3 Months Ended
Interim Financial Statements (Policies)	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Recently Issued Accounting Standards	Recently Issued Accounting Standards In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update No. 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures . The amendments require disclosure of incremental segment information on an annual and interim basis. The amendments also require companies with a single reportable segment to provide all disclosures required by this amendment and all existing segment disclosures in Accounting Standards Codification 280, Segment Reporting . The amendments are effective for fiscal years beginning after December 15, 2023, and interim periods beginning after December 15, 2024. The Company does not expect the adoption of the amendments to have a significant impact on its financial statements. In December 2023, the FASB issued Accounting Standards Update No. 2023-09, Income Taxes - Improvements to Income Tax Disclosures . The amendments require (i) enhanced disclosures in connection with an entity's effective tax rate reconciliation and (ii) income taxes paid disaggregated by jurisdiction. The amendments are effective for annual periods beginning after December 15, 2024. The Company does not expect the adoption of the amendments to have a significant impact on its financial statements.
Basis of Presentation	The interim Condensed Consolidated Financial Statements of Regeneron Pharmaceuticals, Inc. and its subsidiaries ("Regeneron," "Company," "we," "us," and "our") have been prepared in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all information and disclosures necessary for a presentation of the Company's financial position, results of operations, and cash flows in conformity with accounting principles generally accepted in the United States of America. In the opinion of management, these financial statements reflect all normal recurring adjustments and accruals necessary for a fair statement of the Company's condensed consolidated financial statements for such periods. The results of operations for any interim period are not necessarily indicative of the results for the full year. The December 31, 2023 Condensed Consolidated Balance Sheet data were derived from audited financial statements, but do not include all disclosures required by accounting principles generally accepted in the United States of America. These financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023.
Legal Matters	Costs associated with the Company's involvement in legal proceedings are expensed as incurred.

Product Sales (Tables)

Product Sales (Tables)	3 Months Ended
Product Sales (Tables)	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Product Sales	Net product sales consist of the following: Three Months Ended (In millions) 2024 2023 EYLEA ® HD U.S. $ 200.0 $ — EYLEA ® U.S. 1,201.6 1,433.8 Total EYLEA HD and EYLEA U.S. 1,401.6 1,433.8 Libtayo ® U.S. 159.2 109.7 Libtayo ROW (a) 104.7 67.2 Total Libtayo Global 263.9 176.9 Praluent ® U.S. 70.0 40.2 Evkeeza ® U.S. 24.8 14.9 Inmazeb ® Global 1.0 2.2 $ 1,761.3 $ 1,668.0 (a) Rest of world ("ROW") Amounts recognized in the Company's Statements of Operations in connection with its Sanofi collaboration are as follows: Statement of Operations Classification Three Months Ended March 31, (In millions) 2024 2023 Regeneron's share of profits in connection with commercialization of antibodies Collaboration revenue $ 804.0 $ 636.5 Reimbursement for manufacturing of commercial supplies Collaboration revenue $ 105.8 $ 161.9 Regeneron's obligation for its share of Sanofi R&D expenses, net of reimbursement of R&D expenses (R&D expense) $ (18.6) $ (26.4) Reimbursement of commercialization-related expenses Reduction of SG&A expense $ 139.5 $ 117.6 Amounts recognized in the Company's Statements of Operations in connection with its Bayer collaboration are as follows: Statement of Operations Classification Three Months Ended March 31, (In millions) 2024 2023 Regeneron's share of profits in connection with commercialization of EYLEA 8 mg and EYLEA outside the United States Collaboration revenue $ 333.9 $ 331.6 Reimbursement for manufacturing of ex-U.S. commercial supplies Collaboration revenue $ 22.1 $ 25.3 Regeneron's obligation for its share of Bayer R&D expenses, net of reimbursement of R&D expenses (R&D expense) $ (8.7) $ (13.4) Amounts recognized in the Company's Statements of Operations in connection with its Roche collaboration are as follows: Statement of Operations Classification Three Months Ended (In millions) 2024 2023 Global gross profit payment from Roche in connection with sales of Ronapreve Collaboration revenue $ 0.5 $ 222.2
Schedules of Sales to Customers as Percentage of Total Gross Product Revenue	Sales to each of these customers as a percentage of the Company's total gross product revenue are as follows: Three Months Ended March 31, 2024 2023 Besse Medical, a subsidiary of Cencora, Inc. 51 % 52 % McKesson Corporation 24 % 25 %

Collaboration, License, and O_2

Collaboration, License, and Other Agreements (Tables)	3 Months Ended
Collaboration, License, and Other Agreements (Tables)	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Collaborative Revenue	Net product sales consist of the following: Three Months Ended (In millions) 2024 2023 EYLEA ® HD U.S. $ 200.0 $ — EYLEA ® U.S. 1,201.6 1,433.8 Total EYLEA HD and EYLEA U.S. 1,401.6 1,433.8 Libtayo ® U.S. 159.2 109.7 Libtayo ROW (a) 104.7 67.2 Total Libtayo Global 263.9 176.9 Praluent ® U.S. 70.0 40.2 Evkeeza ® U.S. 24.8 14.9 Inmazeb ® Global 1.0 2.2 $ 1,761.3 $ 1,668.0 (a) Rest of world ("ROW") Amounts recognized in the Company's Statements of Operations in connection with its Sanofi collaboration are as follows: Statement of Operations Classification Three Months Ended March 31, (In millions) 2024 2023 Regeneron's share of profits in connection with commercialization of antibodies Collaboration revenue $ 804.0 $ 636.5 Reimbursement for manufacturing of commercial supplies Collaboration revenue $ 105.8 $ 161.9 Regeneron's obligation for its share of Sanofi R&D expenses, net of reimbursement of R&D expenses (R&D expense) $ (18.6) $ (26.4) Reimbursement of commercialization-related expenses Reduction of SG&A expense $ 139.5 $ 117.6 Amounts recognized in the Company's Statements of Operations in connection with its Bayer collaboration are as follows: Statement of Operations Classification Three Months Ended March 31, (In millions) 2024 2023 Regeneron's share of profits in connection with commercialization of EYLEA 8 mg and EYLEA outside the United States Collaboration revenue $ 333.9 $ 331.6 Reimbursement for manufacturing of ex-U.S. commercial supplies Collaboration revenue $ 22.1 $ 25.3 Regeneron's obligation for its share of Bayer R&D expenses, net of reimbursement of R&D expenses (R&D expense) $ (8.7) $ (13.4) Amounts recognized in the Company's Statements of Operations in connection with its Roche collaboration are as follows: Statement of Operations Classification Three Months Ended (In millions) 2024 2023 Global gross profit payment from Roche in connection with sales of Ronapreve Collaboration revenue $ 0.5 $ 222.2
Schedule of Accounts Receivable and Deferred Revenue Information	The following table summarizes contract balances in connection with the Company's Sanofi collaboration: March 31, December 31, (In millions) 2024 2023 Accounts receivable, net $ 947.0 $ 1,029.1 Deferred revenue $ 532.2 $ 427.7 The following table summarizes contract balances in connection with the Company's Bayer collaboration: March 31, December 31, (In millions) 2024 2023 Accounts receivable, net $ 359.0 $ 381.7 Deferred revenue $ 151.1 $ 138.2 The following table summarizes contract balances in connection with the Company's Alnylam collaboration: March 31, December 31, (In millions) 2024 2023 Accrued expenses and other current liabilities $ 18.9 $ 22.6
Schedule of Collaboration Expenses	Amounts recognized in the Company's Statements of Operations in connection with its Alnylam collaboration are as follows: Statement of Operations Classification Three Months Ended (In millions) 2024 2023 Regeneron's obligation for its share of Alnylam R&D expenses, net of reimbursement of R&D expenses (R&D expense) $ (17.5) $ (21.3)

Net Income Per Share (Tables)

Net Income Per Share (Tables)	3 Months Ended
Net Income Per Share (Tables)	Mar. 31, 2024
Earnings Per Share [Abstract]
Basic and Diluted Net Income (Loss) Per Share	The calculations of basic and diluted net income per share are as follows: Three Months Ended March 31, (In millions, except per share data) 2024 2023 Net income - basic and diluted $ 722.0 $ 817.8 Weighted average shares - basic 107.8 107.1 Effect of dilutive securities: Stock options 5.3 5.0 Restricted stock awards and restricted stock units 2.0 1.9 Weighted average shares - diluted 115.1 114.0 Net income per share - basic $ 6.70 $ 7.64 Net income per share - diluted $ 6.27 $ 7.17
Antidilutive Securities	Shares which have been excluded from diluted per share amounts because their effect would have been antidilutive include the following: Three Months Ended March 31, (Shares in millions) 2024 2023 Stock options 1.5 1.7

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
Marketable Securities (Tables)	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Debt Securities	The following tables summarize the Company's investments in available-for-sale debt securities: (In millions) Amortized Unrealized Fair As of March 31, 2024 Cost Basis Gains Losses Value Corporate bonds $ 7,478.9 $ 6.1 $ (83.9) $ 7,401.1 U.S. government and government agency obligations 5,291.2 0.4 (18.2) 5,273.4 Sovereign bonds 59.8 — (0.8) 59.0 Commercial paper 867.1 0.3 (0.5) 866.9 Certificates of deposit 389.7 0.2 — 389.9 Asset-backed securities 126.0 — (1.3) 124.7 $ 14,212.7 $ 7.0 $ (104.7) $ 14,115.0 As of December 31, 2023 Corporate bonds $ 6,492.5 $ 10.4 $ (104.9) $ 6,398.0 U.S. government and government agency obligations 4,839.6 2.4 (8.6) 4,833.4 Sovereign bonds 58.1 — (0.9) 57.2 Commercial paper 636.8 0.2 (0.2) 636.8 Certificates of deposit 520.8 0.6 — 521.4 Asset-backed securities 88.2 0.1 (1.2) 87.1 $ 12,636.0 $ 13.7 $ (115.8) $ 12,533.9
Marketable Securities, Based on Contractual Maturity Dates	The fair values of available-for-sale debt securities by contractual maturity consist of the following: March 31, December 31, (In millions) 2024 2023 Maturities within one year $ 7,917.5 $ 8,114.8 Maturities after one year through five years 6,184.1 4,414.5 Maturities after five years 13.4 4.6 $ 14,115.0 $ 12,533.9
Fair Value and Unrealized Losses of Marketable Securities	The following table shows the fair value of the Company's available-for-sale debt securities that have unrealized losses, aggregated by investment category and length of time that the individual securities have been in a continuous loss position. Less than 12 Months 12 Months or Greater Total (In millions) As of March 31, 2024 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Corporate bonds $ 4,490.4 $ (10.7) $ 2,910.7 $ (73.2) $ 7,401.1 $ (83.9) U.S. government and government agency obligations 5,220.4 (15.9) 53.0 (2.3) 5,273.4 (18.2) Sovereign bonds 32.5 (0.2) 26.5 (0.6) 59.0 (0.8) Commercial paper 866.9 (0.5) — — 866.9 (0.5) Asset-backed securities 99.2 (0.6) 25.5 (0.7) 124.7 (1.3) $ 10,709.4 $ (27.9) $ 3,015.7 $ (76.8) $ 13,725.1 $ (104.7) As of December 31, 2023 Corporate bonds $ 2,363.3 $ (2.4) $ 4,034.7 $ (102.5) $ 6,398.0 $ (104.9) U.S. government and government agency obligations 4,780.6 (6.0) 52.7 (2.6) 4,833.3 (8.6) Sovereign bonds 12.4 (0.1) 44.8 (0.8) 57.2 (0.9) Commercial paper 636.8 (0.2) — — 636.8 (0.2) Asset-backed securities 61.8 (0.3) 25.3 (0.9) 87.1 (1.2) $ 7,854.9 $ (9.0) $ 4,157.5 $ (106.8) $ 12,012.4 $ (115.8)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
Fair Value Measurements (Tables)	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Schedule of Assets Measured at Fair Value On a Recurring Basis	The table below summarizes the Company's assets and liabilities which are measured at fair value on a recurring basis. The following fair value hierarchy is used to classify assets and liabilities, based on inputs to valuation techniques utilized to measure fair value: • Level 1 - Quoted prices in active markets for identical assets or liabilities • Level 2 - Significant other observable inputs, such as quoted market prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, or model-based valuations in which significant inputs used are observable • Level 3 - Significant other unobservable inputs (In millions) Fair Value Measurements at Reporting Date As of March 31, 2024 Fair Value Level 1 Level 2 Level 3 Assets: Cash equivalents $ 1,056.4 $ 125.8 $ 930.6 $ — Available-for-sale debt securities: Corporate bonds 7,401.1 — 7,401.1 — U.S. government and government agency obligations 5,273.4 — 5,273.4 — Sovereign bonds 59.0 — 59.0 — Commercial paper 866.9 — 866.9 — Certificates of deposit 389.9 — 389.9 — Asset-backed securities 124.7 — 124.7 — Equity securities (unrestricted) 679.4 679.4 — — Equity securities (restricted) 101.9 101.9 — — Total assets $ 15,952.7 $ 907.1 $ 15,045.6 $ — Liabilities: Contingent consideration $ 59.0 $ — $ — $ 59.0 As of December 31, 2023 Assets: Cash equivalents $ 928.1 $ 6.4 $ 921.7 $ — Available-for-sale debt securities: Corporate bonds 6,398.0 — 6,398.0 — U.S. government and government agency obligations 4,833.4 — 4,833.4 — Sovereign bonds 57.2 — 57.2 — Commercial paper 636.8 — 636.8 — Certificates of deposit 521.4 — 521.4 — Asset-backed securities 87.1 — 87.1 — Equity securities (unrestricted) 864.5 864.5 — — Equity securities (restricted) 112.9 112.9 — — Total assets $ 14,439.4 $ 983.8 $ 13,455.6 $ — Liabilities: Contingent consideration $ 43.7 $ — $ — $ 43.7

Inventories (Tables)

Inventories (Tables)	3 Months Ended
Inventories (Tables)	Mar. 31, 2024
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventories consist of the following: March 31, December 31, (In millions) 2024 2023 Raw materials $ 814.8 $ 789.3 Work-in-process 1,108.1 1,121.8 Finished goods 180.5 147.3 Deferred costs 611.5 522.1 $ 2,714.9 $ 2,580.5

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
Stockholders' Equity (Tables)	Mar. 31, 2024
Equity [Abstract]
Schedule of Shares Repurchased	The table below summarizes the shares of the Company's Common Stock the Company repurchased and the cost of the shares, which were recorded as Treasury Stock. Three Months Ended (In millions) 2024 2023 Number of shares 0.3 0.9 Total cost of shares $ 298.0 $ 693.9

Statement of Cash Flows (Tables

Statement of Cash Flows (Tables)	3 Months Ended
Statement of Cash Flows (Tables)	Mar. 31, 2024
Cash and Cash Equivalents [Abstract]
Schedule of Cash and Cash Equivalents	The following provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Condensed Consolidated Balance Sheets to the total of the same such amounts shown in the Condensed Consolidated Statements of Cash Flows: March 31, (In millions) 2024 2023 Cash and cash equivalents $ 2,602.0 $ 3,916.3 Restricted cash included in Other noncurrent assets 7.8 12.5 Total cash, cash equivalents, and restricted cash shown in the Condensed Consolidated Statements of Cash Flows $ 2,609.8 $ 3,928.8
Restrictions on Cash and Cash Equivalents	The following provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Condensed Consolidated Balance Sheets to the total of the same such amounts shown in the Condensed Consolidated Statements of Cash Flows: March 31, (In millions) 2024 2023 Cash and cash equivalents $ 2,602.0 $ 3,916.3 Restricted cash included in Other noncurrent assets 7.8 12.5 Total cash, cash equivalents, and restricted cash shown in the Condensed Consolidated Statements of Cash Flows $ 2,609.8 $ 3,928.8
Summary of Non-Cash Investing and Financing Activities	March 31, December 31, March 31, December 31, (In millions) 2024 2023 2023 2022 Accrued capital expenditures $ 108.0 $ 75.4 $ 90.3 $ 70.8 Accrued contingent consideration in connection with acquisitions $ 88.8 $ 71.6 $ 55.2 $ 135.5

Legal Matters (Tables)

Legal Matters (Tables)	3 Months Ended
Legal Matters (Tables)	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Schedule of Loss Contingencies by Contingency	Post-Grant Proceedings Before USPTO Company Patent(s) Challenger(s) Type of Challenge Date of Challenge Latest Events/Current Status U.S. Patent Nos. 9,254,338 (the "'338 Patent") and 9,669,069 (the "'069 Patent") Mylan Pharmaceuticals Inc., joined by Apotex Inc. and Celltrion IPR petitions seeking declarations of invalidity May 5, 2021 On November 9, 2022, the USPTO issued final written decisions finding that the challenged claims of the '338 and '069 Patents are unpatentable and, therefore, invalid. On January 10, 2023, the Company filed notices of appeal of these decisions to the United States Court of Appeals for the Federal Circuit (the "Federal Circuit"). U.S. Patent Nos. 10,130,681 (the "'681 Patent") and 10,888,601 (the "'601 Patent") Mylan, joined by Celltrion ('601 and '681 Patents) and Samsung Bioepis Co., Ltd. ('601 Patent) IPR petitions seeking declarations of invalidity July 1, 2022 On January 9, 2024, the USPTO issued final written decisions finding that that the challenged claims of the '681 and '601 Patents are unpatentable and, therefore, invalid. On March 12, 2024, the Company filed notices of appeal of these decisions to the Federal Circuit. Samsung Bioepis, joined by Biocon Biologics Inc. ('601 Patent) IPR petitions seeking declarations of invalidity January 6, 2023 ('681 Patent) March 26, 2023 ('601 Patent) On July 19, 2023 and October 20, 2023, the USPTO instituted IPR proceedings concerning the '681 Patent and the '601 Patent, respectively. U.S. Patent No. 11,253,572 (the "'572 Patent") Samsung Bioepis IPR petition seeking declaration of invalidity April 27, 2023 On November 17, 2023, the USPTO instituted IPR proceedings concerning the '572 Patent. Post-Grant Proceedings Authority/Court Company Patent(s) Challenger(s) Type of Challenge Date of Challenge Latest Events/Current Status EPO European Patent No. 2,944,306 (the "'306 Patent") Anonymous parties Opposition proceedings October 26 and October 27, 2021 Oral hearing scheduled for November 2024. EPO European Patent No. 3,716,992 (the "EP '992 Patent") Amgen and three anonymous parties Opposition proceedings May 5-10, 2023 Oral hearing to be scheduled. EPO European Patent No. 3,384,049 (the "'049 Patent") Amgen and anonymous parties Opposition proceedings April 22-30, 2024 Oral hearing to be scheduled. German Federal Patent Court German designation of European Patent No. 2,364,691 (the "'691 Patent") Samsung Bioepis NL B.V. Invalidation proceedings June 22, 2023 Trial has been scheduled to begin in June 2025. High Court of Justice of England and Wales United Kingdom designations of the '691 Patent and '306 Patent Formycon AG and Klinge Biopharma GmbH Invalidation proceedings and declaration of non-infringement by challengers' aflibercept 2 mg biosimilar April 18, 2024 Trial to be scheduled.

Product Sales - Schedule of Net

Product Sales - Schedule of Net Product Sales (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 3,145	$ 3,162.1
Net product sales
Disaggregation of Revenue [Line Items]
Revenues	1,761.3	1,668
Libtayo
Disaggregation of Revenue [Line Items]
Revenues	263.9	176.9
Inmazeb
Disaggregation of Revenue [Line Items]
Revenues	1	2.2
U.S. \| ELYEA HD And EYLEA
Disaggregation of Revenue [Line Items]
Revenues	1,401.6	1,433.8
U.S. \| ELYEA HD
Disaggregation of Revenue [Line Items]
Revenues	200	0
U.S. \| EYLEA
Disaggregation of Revenue [Line Items]
Revenues	1,201.6	1,433.8
U.S. \| Libtayo
Disaggregation of Revenue [Line Items]
Revenues	159.2	109.7
U.S. \| Praluent
Disaggregation of Revenue [Line Items]
Revenues	70	40.2
U.S. \| Evkeeza
Disaggregation of Revenue [Line Items]
Revenues	24.8	14.9
Rest Of World \| Libtayo
Disaggregation of Revenue [Line Items]
Revenues	$ 104.7	$ 67.2

Product Sales - Narrative (Deta

Product Sales - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	$ 5,222.2	$ 5,667.3
Trade accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	$ 3,739	$ 3,888

Product Sales - Schedule of Con

Product Sales - Schedule of Concentration of Risk, by Risk Factor (Details) - Gross product revenue - Customer concentration risk	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Besse Medical, a subsidiary of Cencora, Inc.
Concentration Risk [Line Items]
Concentration risk, percentage	51%	52%
McKesson Corporation
Concentration Risk [Line Items]
Concentration risk, percentage	24%	25%

Collaboration, License, and O_3

Collaboration, License, and Other Agreements - Sanofi, Antibody Narrative (Details) - Sanofi Collaboration Agreement, Antibody $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)
Disaggregation of Revenue [Line Items]
Percentage share of profits to reimburse collaborating party	20%
Contingent reimbursement obligation	$ 2,200
Minimum
Disaggregation of Revenue [Line Items]
Percentage of trial costs required to be funded by collaborating party	80%
Percentage share of profits to reimburse collaborating party	30%
Maximum
Disaggregation of Revenue [Line Items]
Percentage of trial costs required to be funded by collaborating party	100%
Percentage share of profits to reimburse collaborating party	50%

Collaboration, License, and O_4

Collaboration, License, and Other Agreements - Amounts Recognized In Statement of Operations with Sanofi (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 3,145	$ 3,162.1
Sanofi Collaboration Agreement, Antibody \| Collaboration revenue \| Regeneron's share of profits in connection with commercialization
Disaggregation of Revenue [Line Items]
Revenues	804	636.5
Sanofi Collaboration Agreement, Antibody \| Collaboration revenue \| Reimbursement for manufacturing of commercial supplies
Disaggregation of Revenue [Line Items]
Revenues	105.8	161.9
Sanofi Collaboration Agreement, Antibody \| (R&D expense) \| Regeneron's obligation for its share of Sanofi R&D expenses, net of reimbursement of R&D expenses
Disaggregation of Revenue [Line Items]
Revenues	(18.6)	(26.4)
Sanofi Collaboration Agreement, Antibody \| Reduction of SG&A expense \| Reimbursement of commercialization-related expenses
Disaggregation of Revenue [Line Items]
Revenues	$ 139.5	$ 117.6

Collaboration, License, and O_5

Collaboration, License, and Other Agreements - Schedule of Contract Balances, Antibody Collaboration (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 5,222.2	$ 5,667.3
Sanofi Collaboration Agreement, Antibody
Disaggregation of Revenue [Line Items]
Accounts receivable, net	947	1,029.1
Deferred revenue	$ 532.2	$ 427.7

Collaboration, License, and O_6

Collaboration, License, and Other Agreements - Amounts Recognized in Statement of Operations with Bayer (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 3,145	$ 3,162.1
Bayer \| Rest Of World \| Collaboration revenue \| Regeneron's share of profits in connection with commercialization of EYLEA 8 mg and EYLEA outside the United States
Disaggregation of Revenue [Line Items]
Revenues	333.9	331.6
Bayer \| Rest Of World \| Collaboration revenue \| Reimbursement for manufacturing of ex-U.S. commercial supplies
Disaggregation of Revenue [Line Items]
Revenues	22.1	25.3
Bayer \| Rest Of World \| (R&D expense) \| Regeneron's obligation for its share of Bayer R&D expenses, net of reimbursement of R&D expenses
Disaggregation of Revenue [Line Items]
Revenues	$ (8.7)	$ (13.4)

Collaboration, License, and O_7

Collaboration, License, and Other Agreements - Schedule of Contract Balances, Bayer Collaboration (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 5,222.2	$ 5,667.3
Bayer
Disaggregation of Revenue [Line Items]
Accounts receivable, net	359	381.7
Deferred revenue	$ 151.1	$ 138.2

Collaboration, License, and O_8

Collaboration, License, and Other Agreements - Amounts Recognized in Statement of Operations with Alnylam (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Research and development expenses	$ (1,248.4)	$ (1,101.2)
Alnylam Pharmaceuticals, Inc. Collaboration Agreement \| (R&D expense)
Disaggregation of Revenue [Line Items]
Research and development expenses	$ (17.5)	$ (21.3)

Collaboration, License, and O_9

Collaboration, License, and Other Agreements - Schedule of Contract Balances, Alnylam Collaboration (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Accrued expenses and other current liabilities	$ 2,392.9	$ 2,357.9
Alnylam Pharmaceuticals, Inc. Collaboration Agreement
Disaggregation of Revenue [Line Items]
Accrued expenses and other current liabilities	$ 18.9	$ 22.6

Collaboration, License, and _10

Collaboration, License, and Other Agreements - Amounts Recognized in Statement of Operations with Roche (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 3,145	$ 3,162.1
Ronapreve \| Roche Collaboration Agreement \| Collaboration revenue
Disaggregation of Revenue [Line Items]
Revenues	$ 0.5	$ 222.2

Collaboration, License, and _11

Collaboration, License, and Other Agreements - Sonoma Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Apr. 30, 2023	Mar. 31, 2024	Mar. 31, 2023
Sonoma Biotherapeutics, Inc. Collaboration Agreement
Disaggregation of Revenue [Line Items]
Purchase of preferred stock	$ 30
Revenue		$ 45
Sonoma Biotherapeutics, Inc.
Disaggregation of Revenue [Line Items]
Up-front payment to collaborating party			$ 45

Net Income Per Share - Schedule

Net Income Per Share - Schedule of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income - basic and diluted	$ 722	$ 817.8
Weighted average shares - basic (in shares)	107.8	107.1
Weighted average shares - diluted (in shares)	115.1	114
Net income per share - basic (in dollars per share)	$ 6.70	$ 7.64
Net income per share - diluted (in dollars per share)	$ 6.27	$ 7.17
Stock options
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive securities (in shares)	5.3	5
Restricted stock awards and restricted stock units
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive securities (in shares)	2	1.9

Net Income Per Share - Schedu_2

Net Income Per Share - Schedule of Antidilutive Securities Excluded From Computation (Details) - shares shares in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options (in shares)	1.5	1.7

Marketable Securities - Schedul

Marketable Securities - Schedule of Investments in Available For Sale Debt Securities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	$ 14,212.7	$ 12,636
Unrealized Gains	7	13.7
Unrealized Losses	(104.7)	(115.8)
Fair Value	14,115	12,533.9
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	7,478.9	6,492.5
Unrealized Gains	6.1	10.4
Unrealized Losses	(83.9)	(104.9)
Fair Value	7,401.1	6,398
U.S. government and government agency obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	5,291.2	4,839.6
Unrealized Gains	0.4	2.4
Unrealized Losses	(18.2)	(8.6)
Fair Value	5,273.4	4,833.4
Sovereign bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	59.8	58.1
Unrealized Gains	0	0
Unrealized Losses	(0.8)	(0.9)
Fair Value	59	57.2
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	867.1	636.8
Unrealized Gains	0.3	0.2
Unrealized Losses	(0.5)	(0.2)
Fair Value	866.9	636.8
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	389.7	520.8
Unrealized Gains	0.2	0.6
Unrealized Losses	0	0
Fair Value	389.9	521.4
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	126	88.2
Unrealized Gains	0	0.1
Unrealized Losses	(1.3)	(1.2)
Fair Value	$ 124.7	$ 87.1

Marketable Securities - Sched_2

Marketable Securities - Schedule of Debt Securities Based on Contractual Maturity Dates (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Maturities within one year	$ 7,917.5	$ 8,114.8
Maturities after one year through five years	6,184.1	4,414.5
Maturities after five years	13.4	4.6
Total	$ 14,115	$ 12,533.9

Marketable Securities - Sched_3

Marketable Securities - Schedule of Fair Value and Unrealized Losses of Debt Securities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Fair Value
Less than 12 Months	$ 10,709.4	$ 7,854.9
12 Months or Greater	3,015.7	4,157.5
Total	13,725.1	12,012.4
Unrealized Loss
Less than 12 Months	(27.9)	(9)
12 Months or Greater	(76.8)	(106.8)
Total	(104.7)	(115.8)
Corporate bonds
Fair Value
Less than 12 Months	4,490.4	2,363.3
12 Months or Greater	2,910.7	4,034.7
Total	7,401.1	6,398
Unrealized Loss
Less than 12 Months	(10.7)	(2.4)
12 Months or Greater	(73.2)	(102.5)
Total	(83.9)	(104.9)
U.S. government and government agency obligations
Fair Value
Less than 12 Months	5,220.4	4,780.6
12 Months or Greater	53	52.7
Total	5,273.4	4,833.3
Unrealized Loss
Less than 12 Months	(15.9)	(6)
12 Months or Greater	(2.3)	(2.6)
Total	(18.2)	(8.6)
Sovereign bonds
Fair Value
Less than 12 Months	32.5	12.4
12 Months or Greater	26.5	44.8
Total	59	57.2
Unrealized Loss
Less than 12 Months	(0.2)	(0.1)
12 Months or Greater	(0.6)	(0.8)
Total	(0.8)	(0.9)
Commercial paper
Fair Value
Less than 12 Months	866.9	636.8
12 Months or Greater	0	0
Total	866.9	636.8
Unrealized Loss
Less than 12 Months	(0.5)	(0.2)
12 Months or Greater	0	0
Total	(0.5)	(0.2)
Asset-backed securities
Fair Value
Less than 12 Months	99.2	61.8
12 Months or Greater	25.5	25.3
Total	124.7	87.1
Unrealized Loss
Less than 12 Months	(0.6)	(0.3)
12 Months or Greater	(0.7)	(0.9)
Total	$ (1.3)	$ (1.2)

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	$ 14,115	$ 12,533.9
Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	7,401.1	6,398
U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	5,273.4	4,833.4
Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	59	57.2
Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	866.9	636.8
Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	389.9	521.4
Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	124.7	87.1
Measured on a recurring basis
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	1,056.4	928.1
Total assets	15,952.7	14,439.4
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration	59	43.7
Measured on a recurring basis \| Unrestricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	679.4	864.5
Measured on a recurring basis \| Restricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	101.9	112.9
Measured on a recurring basis \| Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	7,401.1	6,398
Measured on a recurring basis \| U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	5,273.4	4,833.4
Measured on a recurring basis \| Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	59	57.2
Measured on a recurring basis \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	866.9	636.8
Measured on a recurring basis \| Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	389.9	521.4
Measured on a recurring basis \| Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	124.7	87.1
Measured on a recurring basis \| Level 1
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	125.8	6.4
Total assets	907.1	983.8
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration	0	0
Measured on a recurring basis \| Level 1 \| Unrestricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	679.4	864.5
Measured on a recurring basis \| Level 1 \| Restricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	101.9	112.9
Measured on a recurring basis \| Level 1 \| Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0	0
Measured on a recurring basis \| Level 1 \| U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0	0
Measured on a recurring basis \| Level 1 \| Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0	0
Measured on a recurring basis \| Level 1 \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0	0
Measured on a recurring basis \| Level 1 \| Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0	0
Measured on a recurring basis \| Level 1 \| Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0	0
Measured on a recurring basis \| Level 2
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	930.6	921.7
Total assets	15,045.6	13,455.6
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration	0	0
Measured on a recurring basis \| Level 2 \| Unrestricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	0	0
Measured on a recurring basis \| Level 2 \| Restricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	0	0
Measured on a recurring basis \| Level 2 \| Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	7,401.1	6,398
Measured on a recurring basis \| Level 2 \| U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	5,273.4	4,833.4
Measured on a recurring basis \| Level 2 \| Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	59	57.2
Measured on a recurring basis \| Level 2 \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	866.9	636.8
Measured on a recurring basis \| Level 2 \| Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	389.9	521.4
Measured on a recurring basis \| Level 2 \| Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	124.7	87.1
Measured on a recurring basis \| Level 3
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	0	0
Total assets	0	0
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration	59	43.7
Measured on a recurring basis \| Level 3 \| Unrestricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	0	0
Measured on a recurring basis \| Level 3 \| Restricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	0	0
Measured on a recurring basis \| Level 3 \| Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0	0
Measured on a recurring basis \| Level 3 \| U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0	0
Measured on a recurring basis \| Level 3 \| Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0	0
Measured on a recurring basis \| Level 3 \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0	0
Measured on a recurring basis \| Level 3 \| Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0	0
Measured on a recurring basis \| Level 3 \| Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	$ 0	$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net unrealized gains (losses)	$ (196.2)	$ (164.7)
Securities owned not readily marketable	73.7		$ 74.3
Gain (loss) related to change in the estimated fair value of contingent consideration liability	(15.3)
Level 2 \| Measured on a recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	$ 1,497		$ 1,528

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Raw materials	$ 814.8	$ 789.3
Work-in-process	1,108.1	1,121.8
Finished goods	180.5	147.3
Deferred costs	611.5	522.1
Total Inventories	$ 2,714.9	$ 2,580.5

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended
Income Taxes (Details)	Mar. 31, 2024	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Effective income tax rate	(3.00%)	4.70%

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($)	3 Months Ended		20 Months Ended
Stockholders' Equity - Narrative (Details) - USD ($)	Mar. 31, 2024	Mar. 31, 2023	Jun. 30, 2023	Apr. 30, 2024	Jan. 31, 2023	Nov. 30, 2021
Class of Stock [Line Items]
Total cost of shares	$ 298,000,000	$ 693,900,000
Remaining authorized repurchase amount	$ 1,233,000,000
November 2021 Share Repurchase Program
Class of Stock [Line Items]
Share repurchase program, authorized amount						$ 3,000,000,000
Total cost of shares			$ 3,000,000,000
Share Repurchase Program, January 2023
Class of Stock [Line Items]
Share repurchase program, authorized amount					$ 3,000,000,000
Share Repurchase Program, April 2024 \| Subsequent Event
Class of Stock [Line Items]
Share repurchase program, authorized amount				$ 3,000,000,000

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Share Repurchases (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Equity [Abstract]
Number of shares (in shares)	0.3	0.9
Total cost of shares	$ 298	$ 693.9

Statement of Cash Flows - Sched

Statement of Cash Flows - Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 2,602	$ 2,730	$ 3,916.3
Restricted cash included in Other noncurrent assets	7.8		12.5
Total cash, cash equivalents, and restricted cash shown in the Condensed Consolidated Statements of Cash Flows	$ 2,609.8	$ 2,737.8	$ 3,928.8	$ 3,119.4

Statement of Cash Flows - Summa

Statement of Cash Flows - Summary of Non-cash Investing and Financing Activities (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Abstract]
Accrued capital expenditures	$ 108	$ 90.3	$ 75.4	$ 70.8
Accrued contingent consideration in connection with acquisitions	$ 88.8	$ 55.2	$ 71.6	$ 135.5

Legal Matters (Details)

Legal Matters (Details)	Jul. 16, 2020 claim
'631 Patent
Loss Contingencies [Line Items]
Number of IPR filed	2