Regeneron Pharmaceuticals (REGN) 10-Q 2 Nov 23 2023 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2023	Oct. 26, 2023
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
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	2023
Document Fiscal Period Focus	Q3
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		107,128,838

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 2,152.3	$ 3,105.9
Marketable securities	7,761.3	4,636.4
Accounts receivable, net	5,584.5	5,328.7
Inventories	2,562	2,401.9
Prepaid expenses and other current assets	574.7	411.2
Total current assets	18,634.8	15,884.1
Marketable securities	5,778.5	6,591.8
Property, plant, and equipment, net	4,006.1	3,763
Intangible assets, net	1,017.2	915.5
Deferred tax assets	2,316.8	1,723.7
Other noncurrent assets	409.9	336.4
Total assets	32,163.3	29,214.5
Current liabilities:
Accounts payable	536.6	589.2
Accrued expenses and other current liabilities	2,644.7	2,074.2
Deferred revenue	417.3	477.9
Total current liabilities	3,598.6	3,141.3
Long-term debt	1,982.6	1,981.4
Finance lease liabilities	720	720
Deferred revenue	125.3	69.8
Other noncurrent liabilities	832.4	638
Total liabilities	7,258.9	6,550.5
Stockholders' equity:
Preferred Stock, par value $.01 per share; 30.0 shares authorized; issued and outstanding - none	0	0
Additional paid-in capital	11,251.5	9,949.3
Retained earnings	26,100.7	23,306.7
Accumulated other comprehensive loss	(176.8)	(238.8)
Treasury Stock, at cost; 25.1 shares in 2023 and 22.6 shares in 2022	(12,271.1)	(10,353.3)
Total stockholders' equity	24,904.4	22,664
Total liabilities and stockholders' equity	32,163.3	29,214.5
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	Sep. 30, 2023	Dec. 31, 2022
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)	25.1	22.6
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)	132.1	130.4

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenues:
Revenues	$ 3,362.7	$ 2,936.2	$ 9,682.9	$ 8,758.5
Expenses:
Research and development	1,075.3	911.3	3,261.8	2,549.4
Acquired in-process research and development	100	0	156.1	225.1
Selling, general, and administrative	640.5	529.1	1,893.6	1,455.4
Other operating (income) expense, net	(0.5)	(45.7)	(1.6)	(83.3)
Total Expenses	2,251.7	1,712.5	6,608.7	5,166.4
Income from operations	1,111	1,223.7	3,074.2	3,592.1
Other income (expense):
Other income (expense), net	17.6	301.4	32.2	(16)
Interest expense	(17.8)	(15.3)	(54.7)	(42)
Total other income (expense)	(0.2)	286.1	(22.5)	(58)
Income before income taxes	1,110.8	1,509.8	3,051.7	3,534.1
Income tax expense	103	194.1	257.7	392.8
Net income	$ 1,007.8	$ 1,315.7	$ 2,794	$ 3,141.3
Net income per share - basic (in dollars per share)	$ 9.48	$ 12.31	$ 26.16	$ 29.30
Net income per share - diluted (in dollars per share)	$ 8.89	$ 11.66	$ 24.57	$ 27.73
Weighted average shares outstanding - basic (in shares)	106.3	106.9	106.8	107.2
Weighted average shares outstanding - diluted (in shares)	113.4	112.8	113.7	113.3
Statements of Comprehensive Income
Net income	$ 1,007.8	$ 1,315.7	$ 2,794	$ 3,141.3
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on debt securities	21.3	(51.3)	62.8	(249.9)
Loss on foreign currency translation	(0.4)	0	(0.8)	0
Unrealized gain on cash flow hedges	0	0	0	1
Comprehensive income	1,028.7	1,264.4	2,856	2,892.4
Net product sales
Revenues:
Revenues	1,786.1	1,801.4	5,226.2	5,194.4
Expenses:
Cost of goods, collaboration and contract manufacturing	224.5	141.3	625.3	497.8
Collaboration revenue
Revenues:
Revenues	1,438.3	1,050.6	4,133.1	3,326.7
Other revenue
Revenues:
Revenues	138.3	84.2	323.6	237.4
Cost of collaboration and contract manufacturing
Expenses:
Cost of goods, collaboration and contract manufacturing	$ 211.9	$ 176.5	$ 673.5	$ 522

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, 2021		126.2						1.8
Beginning Balance, treasury (in shares) at Dec. 31, 2021						(19.4)
Beginning Balance at Dec. 31, 2021	$ 18,768.8	$ 0.1	$ 8,087.5	$ 18,968.3	$ (26.2)	$ (8,260.9)		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock for equity awards granted under long-term incentive plans (in shares)		1.6
Issuance of Common Stock for equity awards granted under long-term incentive plans	593.7		593.7
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations (in shares)		(0.2)
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations	(105.8)		(105.8)
Issuance/distribution of Common Stock for 401(k) Savings Plan	14.5		12.8			$ 1.7
Repurchases of Common Stock (in shares)						(0.5)
Repurchases of Common Stock	(352)					$ (352)
Stock-based compensation charges	165.9		165.9
Net income	973.5			973.5
Other comprehensive income (loss), net of tax	(143.9)				(143.9)
Ending Balance (in shares) at Mar. 31, 2022		127.6						1.8
Ending Balance, treasury (in shares) at Mar. 31, 2022						(19.9)
Ending Balance at Mar. 31, 2022	19,914.7	$ 0.1	8,754.1	19,941.8	(170.1)	$ (8,611.2)		$ 0
Beginning Balance (in shares) at Dec. 31, 2021		126.2						1.8
Beginning Balance, treasury (in shares) at Dec. 31, 2021						(19.4)
Beginning Balance at Dec. 31, 2021	18,768.8	$ 0.1	8,087.5	18,968.3	(26.2)	$ (8,260.9)		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,141.3
Ending Balance (in shares) at Sep. 30, 2022		129						1.8
Ending Balance, treasury (in shares) at Sep. 30, 2022						(22)
Ending Balance at Sep. 30, 2022	21,438.8	$ 0.1	9,518.2	22,109.6	(275.1)	$ (9,914)		$ 0
Beginning Balance (in shares) at Mar. 31, 2022		127.6						1.8
Beginning Balance, treasury (in shares) at Mar. 31, 2022						(19.9)
Beginning Balance at Mar. 31, 2022	19,914.7	$ 0.1	8,754.1	19,941.8	(170.1)	$ (8,611.2)		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock for equity awards granted under long-term incentive plans (in shares)		0.8
Issuance of Common Stock for equity awards granted under long-term incentive plans	228		228
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	(41.9)		(41.9)
Issuance/distribution of Common Stock for 401(k) Savings Plan	16.2		14			$ 2.2
Repurchases of Common Stock (in shares)						(0.7)
Repurchases of Common Stock	(393.6)					$ (393.6)
Stock-based compensation charges	166		166
Net income	852.1			852.1
Other comprehensive income (loss), net of tax	(53.7)				(53.7)
Ending Balance (in shares) at Jun. 30, 2022		128.3						1.8
Ending Balance, treasury (in shares) at Jun. 30, 2022						(20.6)
Ending Balance at Jun. 30, 2022	20,687.8	$ 0.1	9,120.2	20,793.9	(223.8)	$ (9,002.6)		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock for equity awards granted under long-term incentive plans (in shares)		0.9
Issuance of Common Stock for equity awards granted under long-term incentive plans	322.9		322.9
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations (in shares)		(0.2)
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations	(108.9)		(108.9)
Issuance/distribution of Common Stock for 401(k) Savings Plan	14.5		12.9			$ 1.6
Repurchases of Common Stock (in shares)						(1.4)
Repurchases of Common Stock	(913)					$ (913)
Stock-based compensation charges	171.1		171.1
Net income	1,315.7			1,315.7
Other comprehensive income (loss), net of tax	(51.3)				(51.3)
Ending Balance (in shares) at Sep. 30, 2022		129						1.8
Ending Balance, treasury (in shares) at Sep. 30, 2022						(22)
Ending Balance at Sep. 30, 2022	$ 21,438.8	$ 0.1	9,518.2	22,109.6	(275.1)	$ (9,914)		$ 0
Beginning Balance (in shares) at Dec. 31, 2022		130.4					1.8	1.8
Beginning Balance, treasury (in shares) at Dec. 31, 2022	(22.6)					(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, 2022		130.4					1.8	1.8
Beginning Balance, treasury (in shares) at Dec. 31, 2022	(22.6)					(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]
Net income	$ 2,794
Ending Balance (in shares) at Sep. 30, 2023		132.1					1.8	1.8
Ending Balance, treasury (in shares) at Sep. 30, 2023	(25.1)					(25.1)
Ending Balance at Sep. 30, 2023	$ 24,904.4	$ 0.1	11,251.5	26,100.7	(176.8)	$ (12,271.1)		$ 0
Beginning Balance (in shares) at Mar. 31, 2023		131.4						1.8
Beginning Balance, treasury (in shares) at Mar. 31, 2023						(23.5)
Beginning Balance at Mar. 31, 2023	23,495.2	$ 0.1	10,597.7	24,124.5	(181.6)	$ (11,045.5)		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock for equity awards granted under long-term incentive plans (in shares)		0.2
Issuance of Common Stock for equity awards granted under long-term incentive plans	80.7		80.7
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations	(14)		(14)
Issuance/distribution of Common Stock for 401(k) Savings Plan	18.5		16.1			$ 2.4
Repurchases of Common Stock (in shares)						(1)
Repurchases of Common Stock	(722.8)					$ (722.8)
Stock-based compensation charges	208		208
Net income	968.4			968.4
Other comprehensive income (loss), net of tax	(16.1)				(16.1)
Ending Balance (in shares) at Jun. 30, 2023		131.6						1.8
Ending Balance, treasury (in shares) at Jun. 30, 2023						(24.5)
Ending Balance at Jun. 30, 2023	24,017.9	$ 0.1	10,888.5	25,092.9	(197.7)	$ (11,765.9)		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock for equity awards granted under long-term incentive plans (in shares)		0.7
Issuance of Common Stock for equity awards granted under long-term incentive plans	268.9		268.9
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations (in shares)		(0.2)
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations	(129.4)		(129.4)
Issuance/distribution of Common Stock for 401(k) Savings Plan	18		16.1			$ 1.9
Repurchases of Common Stock (in shares)						(0.6)
Repurchases of Common Stock	(507.1)					$ (507.1)
Stock-based compensation charges	207.4		207.4
Net income	1,007.8			1,007.8
Other comprehensive income (loss), net of tax	$ 20.9				20.9
Ending Balance (in shares) at Sep. 30, 2023		132.1					1.8	1.8
Ending Balance, treasury (in shares) at Sep. 30, 2023	(25.1)					(25.1)
Ending Balance at Sep. 30, 2023	$ 24,904.4	$ 0.1	$ 11,251.5	$ 26,100.7	$ (176.8)	$ (12,271.1)		$ 0

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net income	$ 2,794	$ 3,141.3
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	308	241.3
Stock-based compensation expense	644.6	493
Losses on marketable and other securities, net	324.5	117.4
Other non-cash items, net	17.4	199
Deferred income taxes	(551.5)	(466.7)
Acquired in-process research and development in connection with asset acquisition	0	195
Changes in assets and liabilities:
(Increase) decrease in accounts receivable	(256.1)	488.2
Increase in inventories	(224.4)	(552.2)
Increase in prepaid expenses and other assets	(284.4)	(167.3)
(Decrease) increase in deferred revenue	(5.1)	92
Increase (decrease) in accounts payable, accrued expenses, and other liabilities	737.3	(486)
Total adjustments	710.3	153.7
Net cash provided by operating activities	3,504.3	3,295
Cash flows from investing activities:
Purchases of marketable and other securities	(9,514.2)	(4,345)
Sales or maturities of marketable and other securities	7,059.3	4,013.1
Capital expenditures	(467.2)	(437.9)
Payments for Libtayo intangible asset	(145.7)	(926.8)
Acquisitions, net of cash acquired	(51.1)	(230.3)
Net cash used in investing activities	(3,118.9)	(1,926.9)
Cash flows from financing activities:
Proceeds from issuance of Common Stock	844.5	1,146.9
Payments in connection with Common Stock tendered for employee tax obligations	(242.5)	(256.6)
Repurchases of Common Stock	(1,946)	(1,651.7)
Net cash used in financing activities	(1,344)	(761.4)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(0.6)	0
Net (decrease) increase in cash, cash equivalents, and restricted cash	(959.2)	606.7
Cash, cash equivalents, and restricted cash at beginning of period	3,119.4	2,898.1
Cash, cash equivalents, and restricted cash at end of period	$ 2,160.2	$ 3,504.8

Interim Financial Statements

Interim Financial Statements	9 Months Ended
	Sep. 30, 2023
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, 2022 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, 2022. Certain reclassifications have been made to prior period amounts to conform with the current period's presentation.

Product Sales

Product Sales	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Product Sales	Product Sales Net product sales consist of the following: Three Months Ended Nine Months Ended (In millions) 2023 2022 2023 2022 EYLEA ® U.S. $ 1,448.2 $ 1,629.4 $ 4,382.1 $ 4,768.2 EYLEA HD U.S. 42.7 — 42.7 — Libtayo ®(a) U.S. 144.1 94.7 384.0 264.5 Libtayo (a) ROW (b) 88.3 31.0 235.3 31.0 Praluent ® U.S. 40.4 29.7 121.1 94.5 Evkeeza ® U.S. 19.1 13.6 53.3 33.2 Inmazeb ® U.S. 3.3 3.0 7.7 3.0 $ 1,786.1 $ 1,801.4 $ 5,226.2 $ 5,194.4 (a) Prior to July 1, 2022, Regeneron recorded net product sales of Libtayo in the United States and Sanofi recorded net product sales of Libtayo outside the United States. Effective July 1, 2022, the Company records global net product sales of Libtayo. See Note 3 for further details. (b) Rest of world ("ROW") As of September 30, 2023 and December 31, 2022, the Company had $3.792 billion and $3.586 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 and nine months ended September 30, 2023 and 2022. Sales to each of these customers as a percentage of the Company's total gross product revenue are as follows: Three Months Ended Nine Months Ended 2023 2022 2023 2022 Besse Medical, a subsidiary of Cencora, Inc. 53 % 56 % 52 % 56 % McKesson Corporation 24 % 28 % 25 % 29 %

Collaboration, License, and Oth

Collaboration, License, and Other Agreements	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Collaboration, License, and Other Agreements	Collaboration, License, and Other Agreements a. Sanofi Amounts recognized in our Statements of Operations in connection with our collaborations with Sanofi are detailed below: Statement of Operations Classification Three Months Ended Nine Months Ended (In millions) 2023 2022 2023 2022 Antibody: Regeneron's share of profits in connection with commercialization of antibodies Collaboration revenue $ 863.0 $ 551.1 * $ 2,250.6 $ 1,463.0 * Sales-based milestones earned Collaboration revenue $ 50.0 $ — $ 50.0 $ 50.0 Reimbursement for manufacturing of commercial supplies Collaboration revenue $ 151.5 $ 160.5 $ 506.0 $ 466.8 Other Collaboration revenue $ — $ (0.2) $ — $ 28.7 Regeneron's obligation for its share of Sanofi R&D expenses, net of reimbursement of R&D expenses (R&D expense)/Reduction of R&D expense $ (25.8) $ (4.3) $ (66.7) $ 59.6 Reimbursement of commercialization-related expenses Reduction of SG&A expense $ 135.5 $ 108.6 $ 384.0 $ 311.1 Immuno-oncology (a) : Regeneron's share of profits in connection with commercialization of Libtayo outside the United States Collaboration revenue $ — $ — $ — $ 6.7 Reimbursement for manufacturing of ex-U.S. commercial supplies Collaboration revenue $ — $ — $ — $ 4.6 Reimbursement of R&D expenses Reduction of R&D expense $ — $ — $ — $ 42.7 Reimbursement of commercialization-related expenses Reduction of SG&A expense $ — $ — $ — $ 41.4 Regeneron's obligation for its share of Sanofi commercial expenses SG&A expense $ — $ — $ — $ (19.9) Regeneron's obligation for Sanofi's share of Libtayo U.S. gross profits Cost of goods sold $ — $ — $ — $ (70.1) Amounts recognized in connection with up-front payments received Other operating income $ — $ — $ — $ 35.1 * Net of one-time payment of $56.9 million to Sanofi in connection with the amendment to the Antibody License and Collaboration Agreement described below (a) As described within the " Immuno-Oncology " section below, effective July 1, 2022, the Company obtained the exclusive right to develop, commercialize, and manufacture Libtayo worldwide. Antibody The Company is party to a global, strategic collaboration with Sanofi to research, develop, and commercialize fully human monoclonal antibodies (the "Antibody Collaboration"), which currently consists of Dupixent ® (dupilumab), Kevzara ® (sarilumab), and itepekimab . Under the terms of the Antibody License and Collaboration Agreement (the "LCA"), 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 based on the Company's share of collaboration profits from commercialization of collaboration products. Under the terms of the LCA, the Company was required to apply 10% of its share of the profits from the Antibody Collaboration in any calendar quarter to reimburse Sanofi for these development costs. On July 1, 2022, an amendment to the LCA became effective, pursuant to which the percentage of the Company's share of profits used to reimburse Sanofi for such development costs increased from 10% to 20%. A portion of the value associated with the increase in reimbursement percentage was deemed to be contingent consideration attributable to the Company's acquisition of the Libtayo (cemiplimab) rights described within the " Immuno-Oncology " section below; this portion will be recorded as an increase to the Libtayo intangible asset over time as the Company repays such development costs to Sanofi. Sanofi leads commercialization activities for products under the Antibody Collaboration, subject to the Company's right to co-commercialize such products. In addition to profit and loss sharing, the Company was entitled to receive sales milestone payments from Sanofi. During the three months ended September 30, 2023, the Company earned the final $50.0 million sales-based milestone from Sanofi, upon aggregate annual sales of antibodies outside the United States (including Praluent) exceeding $3.0 billion on a rolling twelve-month basis. During the three months ended March 31, 2022, the Company earned a $50.0 million sales-based milestone from Sanofi, upon aggregate annual sales of antibodies outside the United States (including Praluent) exceeding $2.0 billion on a rolling twelve-month basis. The following table summarizes contract balances in connection with the Company's Antibody Collaboration with Sanofi: September 30, December 31, (In millions) 2023 2022 Accounts receivable, net $ 1,128.2 $ 692.3 Deferred revenue $ 417.3 $ 415.8 Immuno-Oncology The Company was previously a party to a collaboration with Sanofi for antibody-based cancer treatments in the field of immuno-oncology (the "IO Collaboration"). Under the terms of the Immuno-oncology License and Collaboration Agreement, the parties were co-developing and co-commercializing Libtayo. The parties shared equally, on an ongoing basis, development and commercialization expenses for Libtayo. The Company had principal control over the development of Libtayo and led commercialization activities in the United States, while Sanofi led commercialization activities outside of the United States. The parties shared equally in profits and losses in connection with the commercialization of Libtayo. Effective July 1, 2022, the Company obtained the exclusive right to develop, commercialize, and manufacture Libtayo worldwide under an Amended and Restated Immuno-oncology License and Collaboration Agreement with Sanofi (the "A&R IO LCA"). In connection with the A&R IO LCA, in 2022, the Company made a $900.0 million up-front payment to Sanofi, as well as a $100.0 million regulatory milestone payment. In addition, Sanofi was eligible to earn an aggregate of $100.0 million in Libtayo sales-based milestones under the terms of the A&R IO LCA, of which they earned $65.0 million in 2022 and $35.0 million in 2023. The Company also pays Sanofi an 11% royalty on net product sales of Libtayo through March 31, 2034. The transaction was accounted for as an asset acquisition and amounts paid to Sanofi in connection with obtaining the worldwide rights to Libtayo, including the up-front payment and any contingent consideration, are recorded as an intangible asset. b. Bayer The Company is party to a license and collaboration agreement with Bayer for the global development and commercialization of EYLEA (aflibercept) and aflibercept 8 mg outside the United States. Agreed-upon development expenses incurred by the Company and Bayer are generally shared equally. Bayer is responsible for commercialization activities outside the United States, and the companies share equally in profits and losses 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 Nine Months Ended (In millions) 2023 2022 2023 2022 Regeneron's share of profits in connection with commercialization of EYLEA outside the United States Collaboration revenue $ 349.9 $ 315.3 $ 1,031.0 $ 993.4 Reimbursement for manufacturing of ex-U.S. commercial supplies Collaboration revenue $ 27.2 $ 17.5 $ 79.7 $ 60.3 One-time payment in connection with change in Japan arrangement Collaboration revenue $ — $ — $ — $ 21.9 Regeneron's obligation for its share of Bayer R&D expenses, net of reimbursement of R&D expenses (R&D expense)/Reduction of R&D expense $ (9.7) $ 7.1 $ (35.1) $ 10.3 The following table summarizes contract balances in connection with the Company's Bayer collaboration: September 30, December 31, (In millions) 2023 2022 Accounts receivable, net $ 361.7 $ 348.2 Deferred revenue $ 125.3 $ 131.9 c. 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 of 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 Nine Months Ended (In millions) 2023 2022 2023 2022 Global gross profit payment from Roche in connection with sales of Ronapreve Collaboration revenue $ — $ 6.4 $ 222.2 $ 230.9 Other Collaboration revenue $ (5.7) $ — $ (9.5) $ — Reimbursement of research and development expenses from Roche was not material for the three and nine months ended September 30, 2023 and 2022. The following table summarizes contract balances in connection with the Company's Roche collaboration: September 30, December 31, (In millions) 2023 2022 Accounts receivable, net $ — $ 396.6 d. Alnylam In 2019, the Company and Alnylam Pharmaceuticals, Inc. entered into a global, strategic collaboration to discover, develop, and commercialize RNA interference ("RNAi") therapeutics for a broad range of diseases by addressing therapeutic disease targets expressed in the eye and central nervous system ("CNS"), in addition to a select number of targets expressed in the liver. In connection with entering into the collaboration, the Company made an up-front payment of $400.0 million to Alnylam, and also purchased shares of Alnylam common stock for $400.0 million. 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 ("Co-Co Collaboration Agreement") (under which the parties are advancing ALN-APP and ALN-PNP, which are currently in clinical development) or license agreement. During the three months ended September 30, 2023, the Company became obligated to pay Alnylam a $100.0 million development milestone, which was recorded to Acquired in-process research and development expense, upon the achievement of specified proof-of-principle criteria for the ALN-APP program. Alnylam is eligible to receive an additional $100.0 million clinical proof-of-principle milestone in connection with an eye program. 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 Nine Months Ended (In millions) 2023 2022 2023 2022 Regeneron's obligation for its share of Alnylam R&D expenses, net of reimbursement of R&D expenses (R&D expense) $ (13.5) $ (10.6) $ (52.1) $ (36.1) Development milestone Acquired in-process research and development $ (100.0) $ — $ (100.0) $ — The following table summarizes contract balances in connection with the Company's Alnylam collaboration: September 30, December 31, (In millions) 2023 2022 Accrued expenses and other current liabilities $ 111.5 $ 7.4 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 Company and Sonoma will co-fund research and development activities and share equally any future commercial expenses and profits. The Company will have the option to lead late-stage development and commercialization on all products globally, with Sonoma retaining rights to co-promote all such products in the United States. f. Biomedical Advanced Research and Development Authority ("BARDA") In August 2023, the Company expanded its Other Transaction Agreement ("OTA") with BARDA, pursuant to which the U.S. Department of Health and Human Services ("HHS") is obligated to fund up to 70% of the Company's costs incurred for certain development activities related to a next-generation COVID-19 monoclonal antibody therapy for the prevention of SARS-CoV-2 infection. The agreement could result in payments to the Company of up to approximately $326 million in the aggregate to support clinical development, clinical manufacturing, and the regulatory licensure process. Amounts recognized within Other revenue in the Company's Statements of Operations in connection with this BARDA agreement were $34.2 million for the three months ended September 30, 2023. The following table summarizes the Company's contract balances in connection with this BARDA agreement: September 30, (In millions) 2023 Accounts receivable, net $ 34.2 g. Decibel In 2017, the Company entered into an agreement with Decibel Therapeutics, Inc. to discover and develop new potential therapeutics to protect, repair and restore hearing (including DB-OTO, which is currently in clinical development, and preclinical programs for GJB2-related and stereocilin-related hearing loss). In connection with the agreement, the Company also purchased shares of Decibel stock. In August 2023, the Company entered into an Agreement and Plan of Merger to acquire Decibel, and in September 2023, the Company completed its acquisition of Decibel. The Company paid $101.3 million in cash (or $4.00 per share of Decibel common stock), of which $6.6 million was attributed to post-combination services to be rendered by Decibel equity award holders, and as a result, was excluded from the amount of consideration transferred for purchase accounting. In addition, Decibel shareholders received one non-tradeable contingent value right ("CVR") per share of Decibel common stock, which entitles the holder to receive up to $3.50 per share in cash upon achievement of certain clinical development and regulatory milestones for DB-OTO within specified time periods. At closing, the Company recorded a liability related to the fair value of the CVRs of $43.7 million (see Note 6). The maximum aggregate amount that holders of the CVRs may be entitled to receive if all the milestones contemplated by the CVRs are achieved is approximately $97 million. The fair value of the Company's investment in Decibel stock immediately before the acquisition date was $10.3 million. The Decibel acquisition was accounted for as a business combination. In a business combination, the acquisition method of accounting generally requires that the assets acquired and liabilities assumed be recorded as of the date of the acquisition at their respective fair values. Amounts allocated to acquired in-process research and development are capitalized and accounted for as indefinite-lived intangible assets, subject to impairment testing until completion or abandonment of the associated research and development efforts. Any excess of the purchase price (consideration transferred) over the fair values of net assets acquired is recorded as goodwill. Transaction costs in connection with a business combination are expensed as incurred. The following table summarizes the amounts recognized for assets acquired and liabilities assumed based on their estimated fair values as of the acquisition date: September 25, (In millions) 2023 Cash and cash equivalents $ 42.2 Marketable securities 12.1 Deferred tax assets, net 58.1 Indefinite-lived intangible asset related to in-process research and development 42.5 Goodwill 5.2 Other assets and liabilities, net (11.4) $ 148.7 The final determination of fair values of assets acquired, liabilities assumed, and tax-related items will be completed no later than one year from the acquisition date. h. Checkmate In May 2022, the Company completed its acquisition of Checkmate Pharmaceuticals, Inc. for a total equity value of approximately $250 million. As a result of the transaction, which was accounted for as an asset acquisition, the Company recorded, during the three months ended June 30, 2022, (i) a charge of $195.0 million to Acquired in-process research and development and (ii) net assets of $61.7 million, including $26.4 million of cash and cash equivalents acquired, related to the assets acquired (including deferred tax assets and investments) and liabilities assumed.

Net Income Per Share

Net Income Per Share	9 Months Ended
	Sep. 30, 2023
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 Nine Months Ended (In millions, except per share data) 2023 2022 2023 2022 Net income - basic and diluted $ 1,007.8 $ 1,315.7 $ 2,794.0 $ 3,141.3 Weighted average shares - basic 106.3 106.9 106.8 107.2 Effect of dilutive securities: Stock options 4.8 4.3 4.9 4.7 Restricted stock awards and restricted stock units 2.3 1.6 2.0 1.4 Weighted average shares - diluted 113.4 112.8 113.7 113.3 Net income per share - basic $ 9.48 $ 12.31 $ 26.16 $ 29.30 Net income per share - diluted $ 8.89 $ 11.66 $ 24.57 $ 27.73 Shares which have been excluded from diluted per share amounts because their effect would have been antidilutive include the following: Three Months Ended Nine Months Ended (Shares in millions) 2023 2022 2023 2022 Stock options 1.7 2.4 1.7 2.3

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities Marketable securities as of September 30, 2023 and December 31, 2022 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 September 30, 2023 Cost Basis Gains Losses Value Corporate bonds $ 6,726.3 $ 0.4 $ (189.1) $ 6,537.6 U.S. government and government agency obligations 5,112.6 0.2 (30.5) 5,082.3 Sovereign bonds 67.3 — (1.7) 65.6 Commercial paper 505.1 0.2 (0.2) 505.1 Certificates of deposit 342.6 0.1 (0.1) 342.6 Asset-backed securities 89.6 — (2.4) 87.2 $ 12,843.5 $ 0.9 $ (224.0) $ 12,620.4 As of December 31, 2022 Corporate bonds $ 6,975.5 $ — $ (291.1) $ 6,684.4 U.S. government and government agency obligations 2,945.4 0.9 (6.9) 2,939.4 Sovereign bonds 67.1 — (3.0) 64.1 Commercial paper 121.1 — — 121.1 Certificates of deposit 182.1 — (0.1) 182.0 Asset-backed securities 28.9 — (1.7) 27.2 $ 10,320.1 $ 0.9 $ (302.8) $ 10,018.2 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 September 30, 2023 mature at various dates through April 2029. The fair values of available-for-sale debt securities by contractual maturity consist of the following: September 30, December 31, (In millions) 2023 2022 Maturities within one year $ 7,786.0 $ 4,636.4 Maturities after one year through five years 4,830.0 5,381.4 Maturities after five years 4.4 0.4 $ 12,620.4 $ 10,018.2 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 September 30, 2023 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Corporate bonds $ 1,976.1 $ (23.8) $ 4,387.1 $ (165.3) $ 6,363.2 $ (189.1) U.S. government and government agency obligations 2,794.8 (26.8) 51.7 (3.7) 2,846.5 (30.5) Sovereign bonds 12.2 (0.2) 53.3 (1.5) 65.5 (1.7) Commercial paper 431.8 (0.2) — — 431.8 (0.2) Certificates of deposit 136.3 (0.1) — — 136.3 (0.1) Asset-backed securities 62.3 (1.1) 24.9 (1.3) 87.2 (2.4) $ 5,413.5 $ (52.2) $ 4,517.0 $ (171.8) $ 9,930.5 $ (224.0) As of December 31, 2022 Corporate bonds $ 2,445.4 $ (73.1) $ 4,200.4 $ (218.0) $ 6,645.8 $ (291.1) U.S. government and government agency obligations 785.2 (2.0) 71.0 (4.9) 856.2 (6.9) Sovereign bonds 18.6 (1.1) 45.6 (1.9) 64.2 (3.0) Certificates of deposit 40.2 (0.1) — — 40.2 (0.1) Asset-backed securities 11.5 (0.6) 15.2 (1.1) 26.7 (1.7) $ 3,300.9 $ (76.9) $ 4,332.2 $ (225.9) $ 7,633.1 $ (302.8) The unrealized losses on corporate bonds as of September 30, 2023 were primarily driven by increases in 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. With respect to marketable securities, for the three and nine months ended September 30, 2023 and 2022, amounts reclassified from Accumulated other comprehensive loss into Other income (expense), net were related to realized gains/losses on sales of available-for-sale debt securities. For the three months ended September 30, 2023, realized gains on sales of marketable securities were not material and there were no realized losses. For the nine months ended September 30, 2023, and for the three and nine months ended September 30, 2022, realized gains and losses on sales of marketable securities were not material.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
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 September 30, 2023 Fair Value Level 1 Level 2 Level 3 Assets: Cash equivalents $ 1,018.5 $ 119.9 $ 898.6 $ — Available-for-sale debt securities: Corporate bonds 6,537.6 — 6,537.6 — U.S. government and government agency obligations 5,082.3 — 5,082.3 — Sovereign bonds 65.6 — 65.6 — Commercial paper 505.1 — 505.1 — Certificates of deposit 342.6 — 342.6 — Asset-backed securities 87.2 — 87.2 — Equity securities (unrestricted) 802.3 802.3 — — Equity securities (restricted) 117.1 117.1 — — Total assets $ 14,558.3 $ 1,039.3 $ 13,519.0 $ — Liabilities: Contingent consideration - CVRs $ 43.7 $ — $ — $ 43.7 As of December 31, 2022 Assets: Cash equivalents $ 1,662.8 $ 88.3 $ 1,574.5 $ — Available-for-sale debt securities: Corporate bonds 6,684.4 — 6,684.4 — U.S. government and government agency obligations 2,939.4 — 2,939.4 — Sovereign bonds 64.1 — 64.1 — Commercial paper 121.1 — 121.1 — Certificates of deposit 182.0 — 182.0 — Asset-backed securities 27.2 — 27.2 — Equity securities (unrestricted) 24.6 24.6 — — Equity securities (restricted) 1,185.4 1,185.4 — — Total assets $ 12,891.0 $ 1,298.3 $ 11,592.7 $ — The Company held certain restricted equity securities as of September 30, 2023 which are subject to transfer restrictions that expire at various dates through 2024. During the three and nine months ended September 30, 2023, the Company recorded $100.3 million and $295.9 million of net unrealized losses, respectively, on equity securities in Other income (expense), net. In addition, during the three months ended September 30, 2023, the Company recorded a write-down of $29.0 million in Other income (expense), net related to the Company's investments in private companies. During the three and nine months ended September 30, 2022, the Company recorded $254.3 million of net unrealized gains and $120.6 million of net unrealized losses, respectively, on equity securities in Other income (expense), net. In addition to the investments summarized in the table above, as of September 30, 2023 and December 31, 2022, the Company had $60.8 million and $48.3 million, respectively, in equity investments that do not have a readily determinable fair value. These investments are recorded within Other noncurrent assets. As described in Note 3, in September 2023, the Company acquired Decibel and recorded a liability for the CVRs within other liabilities. The fair value of the CVR liability is determined based on the probability of achieving certain clinical development and regulatory milestones and estimated discount rates. The fair value of the CVR liability is remeasured each reporting period until the contingencies are resolved, with any changes in fair value recorded in Other operating (income) expense, net. The fair value of the Company's long-term debt, which was determined based on Level 2 inputs, was estimated to be $1.395 billion and $1.443 billion as of September 30, 2023 and December 31, 2022, respectively.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2023
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consist of the following: September 30, December 31, (In millions) 2023 2022 Raw materials $ 787.3 $ 818.4 Work-in-process 1,123.9 963.1 Finished goods 114.2 98.6 Deferred costs 536.6 521.8 $ 2,562.0 $ 2,401.9 Inventory balances in the table above are net of reserves of $726.2 million and $720.7 million as of September 30, 2023 and December 31, 2022, respectively. 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	9 Months Ended
	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company is subject to U.S. federal, state, and foreign income taxes. The Company's effective tax rate was 9.3% and 12.9% for the three months ended September 30, 2023 and 2022, respectively, and 8.4% and 11.1% for the nine months ended September 30, 2023 and 2022, respectively. The Company's effective tax rate for the three and nine months ended September 30, 2023 and September 30, 2022 was positively impacted, compared to the U.S. federal statutory rate, primarily by income earned in foreign jurisdictions with tax rates lower than the U.S. federal statutory rate and, to a lesser extent, stock-based compensation and federal tax credits for research activities. In August 2022, the Inflation Reduction Act of 2022 ("IRA") was signed into law in the United States. The IRA created a new corporate alternative minimum tax of 15% on adjusted financial statement income and an excise tax of 1% of the value of certain stock repurchases. The provisions of the IRA became effective for periods beginning after December 31, 2022. The IRA did not have a material impact on the Company's financial statements for the three and nine months ended September 30, 2023.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity In November 2021, our board of directors authorized a share repurchase program to repurchase up to $3.0 billion of our 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, our board of directors authorized an additional share repurchase program to repurchase up to $3.0 billion of our 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 September 30, 2023, $1.826 billion remained available for share repurchases under the January 2023 program. The table below summarizes the shares of our Common Stock the Company repurchased and the cost of the shares, which were recorded as Treasury Stock. As described in Note 8, effective January 1, 2023 share repurchases, net of issuances, are subject to a 1% excise tax; such amount, if applicable, is recognized as an additional cost of the shares acquired. Three Months Ended Nine Months Ended (In millions) 2023 2022 2023 2022 Number of shares 0.7 1.5 2.6 2.7 Total cost of shares $ 507.1 $ 913.0 $ 1,923.8 $ 1,658.6

Statement of Cash Flows

Statement of Cash Flows	9 Months Ended
	Sep. 30, 2023
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 Sheet to the total of the same such amounts shown in the Condensed Consolidated Statement of Cash Flows: September 30, (In millions) 2023 2022 Cash and cash equivalents $ 2,152.3 $ 3,491.3 Restricted cash included in Other noncurrent assets 7.9 13.5 Total cash, cash equivalents, and restricted cash shown in the Condensed Consolidated Statement of Cash Flows $ 2,160.2 $ 3,504.8 Restricted cash consists of amounts held by financial institutions pursuant to contractual arrangements. Supplemental disclosure of non-cash investing and financing activities September 30, December 31, September 30, December 31, (In millions) 2023 2022 2022 2021 Accrued capital expenditures $ 98.9 $ 70.8 $ 83.1 $ 74.8 Accrued contingent consideration for Libtayo intangible asset $ 62.8 $ 135.5 $ 116.0 $ — Accrued contingent consideration in connection with acquisitions $ 43.7 $ — $ — $ —

Legal Matters

Legal Matters	9 Months Ended
	Sep. 30, 2023
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 September 30, 2023 and December 31, 2022, 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 As described below, the Company is currently a party to patent infringement actions initiated by Amgen Inc. (and/or its affiliated entities) against the Company and/or Sanofi (and/or the Company's and Sanofi's respective affiliated entities) in a number of jurisdictions relating to Praluent. In addition, as described below, the Company filed a lawsuit against Amgen alleging that Amgen engaged in an anticompetitive bundling scheme which was designed to exclude Praluent from the market in violation of U.S. federal and state laws. United States In the United States, Amgen asserted claims of U.S. Patent Nos. 8,829,165 (the "'165 Patent") and 8,859,741 (the "'741 Patent"), and sought a permanent injunction to prevent the Company and the Sanofi defendants from commercial manufacturing, using, offering to sell, or selling within the United States (as well as importing into the United States) (collectively, "Commercializing") Praluent. Amgen also sought a judgment of patent infringement of the asserted patents, monetary damages (together with interest), costs and expenses of the lawsuits, and attorneys' fees. As previously reported, on February 11, 2021, the United States Court of Appeals for the Federal Circuit (the "Federal Circuit") affirmed the lower court's decision that certain of Amgen's asserted patent claims are invalid based on lack of enablement. On April 14, 2021, Amgen filed a petition for a rehearing en banc with the Federal Circuit, which was denied on June 21, 2021. On November 4, 2022, the United States Supreme Court granted Amgen's petition for writ of certiorari. An oral hearing was held on March 27, 2023. On May 28, 2023, the United States Supreme Court affirmed the Federal Circuit's decision that certain of Amgen's asserted patent claims are invalid based on lack of enablement. On May 27, 2022, the Company filed a lawsuit against Amgen 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, 2022, Amgen filed a motion to dismiss the complaint. On August 11, 2022, Amgen filed a motion to stay these proceedings pending resolution of the patent litigation described in the preceding paragraph. An oral hearing on Amgen's motion to dismiss and motion to stay was held on January 6, 2023. 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 Amgen has asserted European Patent No. 2,215,124 (the "'124 Patent"), which pertains to PCSK9 monoclonal antibodies, in certain countries in Europe. In October 2020, the '124 Patent claims directed to compositions of matter and medical use relevant to Praluent were ruled invalid based on a lack of inventive step by the Technical Board of Appeal (the "TBA") of the European Patent Office (the "EPO"). Following the EPO's decision, each of the '124 Patent infringement proceedings initiated by Amgen against the Company and certain of Sanofi's affiliated entities in these countries was dismissed, including in Germany. The dismissal in Germany followed an earlier finding of infringement and granting of an injunction, both of which were subsequently overturned. As a result of the overturned injunction in Germany, the Company and/or certain of Sanofi's affiliated entities are seeking damages caused by Amgen's enforcement of the injunction. As part of its opposition to these damages claims, on March 23, 2022, Amgen filed a counterclaim that asserted the German designation of European Patent No. 2,641,917 (the "'917 Patent") and seeks, among other things, a judgment of patent infringement, injunctive relief, and monetary damages. The '917 Patent is a divisional patent of the '124 Patent discussed above (i.e., a patent that shares the same priority date, disclosure, and patent term of the parent '124 Patent but contains claims to a different invention). The '917 Patent is also subject to opposition proceedings in the EPO, which were initiated by Sanofi on May 5, 2021. An oral hearing before the EPO was held on February 21, 2023, at which the '917 Patent was revoked. Amgen filed a notice to appeal to the TBA of the EPO on February 27, 2023. 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 the '124 Patent discussed above. Also on June 1, 2023, Sanofi filed an action in the Munich Central Division of the UPC seeking revocation of the '797 Patent. 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. 10,406,226 (the "'226 Patent") and 10,464,992 (the "'992 Patent") Anonymous parties Ex parte reexamination February 11, 2020 On September 11, 2023, the USPTO dismissed the '226 Patent reexamination proceedings following the Company’s filing of a Notice of Disclaimer, disclaiming all claims of the '226 Patent. On September 8, 2023, the '992 Patent reexamination proceedings were stayed by the USPTO pending resolution of the inter partes review ("IPR") of the '992 Patent initiated by Celltrion, Inc., as discussed further below. U.S. Patent Nos. 9,254,338 (the "'338 Patent") and 9,669,069 (the "'069 Patent") Mylan Pharmaceuticals Inc., Apotex Inc., and Celltrion, Inc. IPR petitions seeking declarations of invalidity May 5, 2021 On November 9, 2022, the USPTO issued final written decisions finding that the claims of the '338 and '069 Patents are unpatentable and, therefore, invalid. On January 10, 2023, the Company filed notices of appeal of the USPTO written decisions concerning the '338 and '069 Patents with the Federal Circuit. U.S. Patent Nos. 10,130,681 (the "'681 Patent"), 10,888,601 (the "'601 Patent"), and 10,857,205 (the "'205 Patent") Mylan IPR petitions seeking declarations of invalidity July 1, 2022 ('681 Patent and '601 Patent) October 28, 2022 ('205 Patent) IPR proceedings concerning the '681 Patent and the '601 Patent instituted on January 11, 2023; oral hearing held on October 25, 2023. On March 1, 2023, the USPTO denied institution of Mylan's IPR petition against the '205 Patent following the Company's filing of a Notice of Disclaimer with the USPTO, disclaiming all claims of the '205 Patent. '681 Patent and '601 Patent Samsung Bioepis Co., Ltd. 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") Apotex IPR petitions seeking declaration of invalidity September 9, 2022 On March 10, 2023, the USPTO declined to institute an IPR proceeding. Samsung Bioepis Co., Ltd. IPR petition seeking declaration of invalidity April 27, 2023 Decision whether to institute pending. '992 Patent and '226 Patent Celltrion IPR petitions seeking declarations of invalidity January 17, 2023 ('992 Patent) February 28, 2023 ('226 Patent) On July 20, 2023, the USPTO instituted an IPR proceeding concerning the '992 Patent. On September 1, 2023, the USPTO denied institution of Celltrion's IPR petition against the '226 Patent following the Company’s filing of a Notice of Disclaimer with the USPTO, disclaiming all claims of the '226 Patent. Patent Litigation On August 2, 2022, the Company filed a patent infringement lawsuit against Mylan in the United States District Court for the Northern District of West Virginia alleging that Mylan's filing for a U.S. Food and Drug Administration approval of an aflibercept 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. 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. Closing arguments were presented on August 3, 2023. 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 to be scheduled. 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. 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 Oral hearing to be scheduled. Canada On June 15, July 15, August 30, and October 4, 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 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). A trial for the lawsuit concerning the '510 Patent and the '276 Patent (the "Viatris Canada 510/276 Lawsuit") has been scheduled for March 2024; a trial for the lawsuit concerning the '193 Patent has been scheduled for May 2024; and a trial for the lawsuit concerning the '495 Patent and the '768 Patent has been scheduled for November/December 2024. The filing of the Viatris Canada 510/276 Lawsuit resulted in a statutory 24-month stay of regulatory approval of Viatris Canada's aflibercept biosimilar in Canada unless the lawsuit is resolved earlier. On March 27, 2023, in light of the transfer of Viatris Canada's New Drug Submission ("NDS") of its aflibercept biosimilar to Biosimilar Collaborations Ireland Limited ("BCIL"), the Company filed a motion in the Federal Court of Canada seeking termination of the Viatris Canada 510/276 Lawsuit. On June 5, 2023, BCIL was added as a defendant in the Viatris Canada 510/276 Lawsuit. 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 biosimilar would directly or indirectly infringe one or more claims of the Company's '510 and '276 Patents. The June 14, 2023 lawsuit was filed after BCIL served Bayer Inc. with a statutory notification in relation to the NDS on May 23, 2023. 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 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 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 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 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 biosimilar would directly or indirectly infringe one or more claims of the Company's '510 Patent and '276 Patent, respectively. 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 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 biosimilar that infringes one or more claims 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 biosimilar is covered by the claims of the '477 Patent. On March 7, 2023, the action was designated for expedited proceedings. 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 November 5, 2021, the Company filed a motion to stay these proceedings in light of the pending IPR proceeding discussed above. On January 31, 2022, the court denied the Company's motion to stay these proceedings and 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. An oral hearing before the U.S. Court of Appeals for the Second Circuit was held on October 11, 2023. 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. On August 24, 2020, the Company filed a motion to dismiss the 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. 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. The Company is cooperating with this investigation. 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 civil complaint filed by the U.S. Attorney's Office for the District of Massachusetts 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 discussed under "Department of Justice Matters" above. 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 discussed under "Department of Justice Matters" above; 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						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Pay vs Performance Disclosure
Net income	$ 1,007.8	$ 968.4	$ 817.8	$ 1,315.7	$ 852.1	$ 973.5	$ 2,794	$ 3,141.3

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	9 Months Ended
	Sep. 30, 2023 shares	Sep. 30, 2023 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		As disclosed in the table below, during the three months ended September 30, 2023, 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 Michael S. Brown, M.D. Director 8/24/2023 5/24/2024 2,049 Christopher Fenimore Senior Vice President, Controller 8/25/2023 2/15/2024 8,940 Joseph L. Goldstein, M.D. Director 8/24/2023 5/24/2024 3,537 Arthur F. Ryan Director 8/7/2023 11/29/2024 1,200 (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
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	8/24/2023
Arrangement Duration	274 days
Aggregate Available	2,049	2,049
Christopher R. Fenimore [Member]
Trading Arrangements, by Individual
Name	Christopher Fenimore
Title	Senior Vice President, Controller
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	8/25/2023
Arrangement Duration	174 days
Aggregate Available	8,940	8,940
Joseph L. Goldstein, M.D. [Member]
Trading Arrangements, by Individual
Name	Joseph L. Goldstein, M.D.
Title	Director
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	8/24/2023
Arrangement Duration	274 days
Aggregate Available	3,537	3,537
Arthur F. Ryan [Member]
Trading Arrangements, by Individual
Name	Arthur F. Ryan
Title	Director
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	8/7/2023
Arrangement Duration	480 days
Aggregate Available	1,200	1,200

Interim Financial Statements (P

Interim Financial Statements (Policies)	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
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, 2022 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, 2022.
Legal Matters	Costs associated with the Company's involvement in legal proceedings are expensed as incurred.

Product Sales (Tables)

Product Sales (Tables)	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Schedule of Product Sales	Net product sales consist of the following: Three Months Ended Nine Months Ended (In millions) 2023 2022 2023 2022 EYLEA ® U.S. $ 1,448.2 $ 1,629.4 $ 4,382.1 $ 4,768.2 EYLEA HD U.S. 42.7 — 42.7 — Libtayo ®(a) U.S. 144.1 94.7 384.0 264.5 Libtayo (a) ROW (b) 88.3 31.0 235.3 31.0 Praluent ® U.S. 40.4 29.7 121.1 94.5 Evkeeza ® U.S. 19.1 13.6 53.3 33.2 Inmazeb ® U.S. 3.3 3.0 7.7 3.0 $ 1,786.1 $ 1,801.4 $ 5,226.2 $ 5,194.4 (a) Prior to July 1, 2022, Regeneron recorded net product sales of Libtayo in the United States and Sanofi recorded net product sales of Libtayo outside the United States. Effective July 1, 2022, the Company records global net product sales of Libtayo. See Note 3 for further details. (b) Rest of world ("ROW") Amounts recognized in our Statements of Operations in connection with our collaborations with Sanofi are detailed below: Statement of Operations Classification Three Months Ended Nine Months Ended (In millions) 2023 2022 2023 2022 Antibody: Regeneron's share of profits in connection with commercialization of antibodies Collaboration revenue $ 863.0 $ 551.1 * $ 2,250.6 $ 1,463.0 * Sales-based milestones earned Collaboration revenue $ 50.0 $ — $ 50.0 $ 50.0 Reimbursement for manufacturing of commercial supplies Collaboration revenue $ 151.5 $ 160.5 $ 506.0 $ 466.8 Other Collaboration revenue $ — $ (0.2) $ — $ 28.7 Regeneron's obligation for its share of Sanofi R&D expenses, net of reimbursement of R&D expenses (R&D expense)/Reduction of R&D expense $ (25.8) $ (4.3) $ (66.7) $ 59.6 Reimbursement of commercialization-related expenses Reduction of SG&A expense $ 135.5 $ 108.6 $ 384.0 $ 311.1 Immuno-oncology (a) : Regeneron's share of profits in connection with commercialization of Libtayo outside the United States Collaboration revenue $ — $ — $ — $ 6.7 Reimbursement for manufacturing of ex-U.S. commercial supplies Collaboration revenue $ — $ — $ — $ 4.6 Reimbursement of R&D expenses Reduction of R&D expense $ — $ — $ — $ 42.7 Reimbursement of commercialization-related expenses Reduction of SG&A expense $ — $ — $ — $ 41.4 Regeneron's obligation for its share of Sanofi commercial expenses SG&A expense $ — $ — $ — $ (19.9) Regeneron's obligation for Sanofi's share of Libtayo U.S. gross profits Cost of goods sold $ — $ — $ — $ (70.1) Amounts recognized in connection with up-front payments received Other operating income $ — $ — $ — $ 35.1 * Net of one-time payment of $56.9 million to Sanofi in connection with the amendment to the Antibody License and Collaboration Agreement described below (a) As described within the " Immuno-Oncology " section below, effective July 1, 2022, the Company obtained the exclusive right to develop, commercialize, and manufacture Libtayo worldwide. 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 Nine Months Ended (In millions) 2023 2022 2023 2022 Regeneron's share of profits in connection with commercialization of EYLEA outside the United States Collaboration revenue $ 349.9 $ 315.3 $ 1,031.0 $ 993.4 Reimbursement for manufacturing of ex-U.S. commercial supplies Collaboration revenue $ 27.2 $ 17.5 $ 79.7 $ 60.3 One-time payment in connection with change in Japan arrangement Collaboration revenue $ — $ — $ — $ 21.9 Regeneron's obligation for its share of Bayer R&D expenses, net of reimbursement of R&D expenses (R&D expense)/Reduction of R&D expense $ (9.7) $ 7.1 $ (35.1) $ 10.3 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 Nine Months Ended (In millions) 2023 2022 2023 2022 Global gross profit payment from Roche in connection with sales of Ronapreve Collaboration revenue $ — $ 6.4 $ 222.2 $ 230.9 Other Collaboration revenue $ (5.7) $ — $ (9.5) $ —
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 Nine Months Ended 2023 2022 2023 2022 Besse Medical, a subsidiary of Cencora, Inc. 53 % 56 % 52 % 56 % McKesson Corporation 24 % 28 % 25 % 29 %

Collaboration, License, and O_2

Collaboration, License, and Other Agreements (Tables)	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Schedule of Collaborative Revenue	Net product sales consist of the following: Three Months Ended Nine Months Ended (In millions) 2023 2022 2023 2022 EYLEA ® U.S. $ 1,448.2 $ 1,629.4 $ 4,382.1 $ 4,768.2 EYLEA HD U.S. 42.7 — 42.7 — Libtayo ®(a) U.S. 144.1 94.7 384.0 264.5 Libtayo (a) ROW (b) 88.3 31.0 235.3 31.0 Praluent ® U.S. 40.4 29.7 121.1 94.5 Evkeeza ® U.S. 19.1 13.6 53.3 33.2 Inmazeb ® U.S. 3.3 3.0 7.7 3.0 $ 1,786.1 $ 1,801.4 $ 5,226.2 $ 5,194.4 (a) Prior to July 1, 2022, Regeneron recorded net product sales of Libtayo in the United States and Sanofi recorded net product sales of Libtayo outside the United States. Effective July 1, 2022, the Company records global net product sales of Libtayo. See Note 3 for further details. (b) Rest of world ("ROW") Amounts recognized in our Statements of Operations in connection with our collaborations with Sanofi are detailed below: Statement of Operations Classification Three Months Ended Nine Months Ended (In millions) 2023 2022 2023 2022 Antibody: Regeneron's share of profits in connection with commercialization of antibodies Collaboration revenue $ 863.0 $ 551.1 * $ 2,250.6 $ 1,463.0 * Sales-based milestones earned Collaboration revenue $ 50.0 $ — $ 50.0 $ 50.0 Reimbursement for manufacturing of commercial supplies Collaboration revenue $ 151.5 $ 160.5 $ 506.0 $ 466.8 Other Collaboration revenue $ — $ (0.2) $ — $ 28.7 Regeneron's obligation for its share of Sanofi R&D expenses, net of reimbursement of R&D expenses (R&D expense)/Reduction of R&D expense $ (25.8) $ (4.3) $ (66.7) $ 59.6 Reimbursement of commercialization-related expenses Reduction of SG&A expense $ 135.5 $ 108.6 $ 384.0 $ 311.1 Immuno-oncology (a) : Regeneron's share of profits in connection with commercialization of Libtayo outside the United States Collaboration revenue $ — $ — $ — $ 6.7 Reimbursement for manufacturing of ex-U.S. commercial supplies Collaboration revenue $ — $ — $ — $ 4.6 Reimbursement of R&D expenses Reduction of R&D expense $ — $ — $ — $ 42.7 Reimbursement of commercialization-related expenses Reduction of SG&A expense $ — $ — $ — $ 41.4 Regeneron's obligation for its share of Sanofi commercial expenses SG&A expense $ — $ — $ — $ (19.9) Regeneron's obligation for Sanofi's share of Libtayo U.S. gross profits Cost of goods sold $ — $ — $ — $ (70.1) Amounts recognized in connection with up-front payments received Other operating income $ — $ — $ — $ 35.1 * Net of one-time payment of $56.9 million to Sanofi in connection with the amendment to the Antibody License and Collaboration Agreement described below (a) As described within the " Immuno-Oncology " section below, effective July 1, 2022, the Company obtained the exclusive right to develop, commercialize, and manufacture Libtayo worldwide. 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 Nine Months Ended (In millions) 2023 2022 2023 2022 Regeneron's share of profits in connection with commercialization of EYLEA outside the United States Collaboration revenue $ 349.9 $ 315.3 $ 1,031.0 $ 993.4 Reimbursement for manufacturing of ex-U.S. commercial supplies Collaboration revenue $ 27.2 $ 17.5 $ 79.7 $ 60.3 One-time payment in connection with change in Japan arrangement Collaboration revenue $ — $ — $ — $ 21.9 Regeneron's obligation for its share of Bayer R&D expenses, net of reimbursement of R&D expenses (R&D expense)/Reduction of R&D expense $ (9.7) $ 7.1 $ (35.1) $ 10.3 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 Nine Months Ended (In millions) 2023 2022 2023 2022 Global gross profit payment from Roche in connection with sales of Ronapreve Collaboration revenue $ — $ 6.4 $ 222.2 $ 230.9 Other Collaboration revenue $ (5.7) $ — $ (9.5) $ —
Schedule of Accounts Receivable and Deferred Revenue Information	The following table summarizes contract balances in connection with the Company's Antibody Collaboration with Sanofi: September 30, December 31, (In millions) 2023 2022 Accounts receivable, net $ 1,128.2 $ 692.3 Deferred revenue $ 417.3 $ 415.8 The following table summarizes contract balances in connection with the Company's Bayer collaboration: September 30, December 31, (In millions) 2023 2022 Accounts receivable, net $ 361.7 $ 348.2 Deferred revenue $ 125.3 $ 131.9 The following table summarizes contract balances in connection with the Company's Roche collaboration: September 30, December 31, (In millions) 2023 2022 Accounts receivable, net $ — $ 396.6 The following table summarizes contract balances in connection with the Company's Alnylam collaboration: September 30, December 31, (In millions) 2023 2022 Accrued expenses and other current liabilities $ 111.5 $ 7.4 The following table summarizes the Company's contract balances in connection with this BARDA agreement: September 30, (In millions) 2023 Accounts receivable, net $ 34.2
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 Nine Months Ended (In millions) 2023 2022 2023 2022 Regeneron's obligation for its share of Alnylam R&D expenses, net of reimbursement of R&D expenses (R&D expense) $ (13.5) $ (10.6) $ (52.1) $ (36.1) Development milestone Acquired in-process research and development $ (100.0) $ — $ (100.0) $ —
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table summarizes the amounts recognized for assets acquired and liabilities assumed based on their estimated fair values as of the acquisition date: September 25, (In millions) 2023 Cash and cash equivalents $ 42.2 Marketable securities 12.1 Deferred tax assets, net 58.1 Indefinite-lived intangible asset related to in-process research and development 42.5 Goodwill 5.2 Other assets and liabilities, net (11.4) $ 148.7

Net Income Per Share (Tables)

Net Income Per Share (Tables)	9 Months Ended
	Sep. 30, 2023
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 Nine Months Ended (In millions, except per share data) 2023 2022 2023 2022 Net income - basic and diluted $ 1,007.8 $ 1,315.7 $ 2,794.0 $ 3,141.3 Weighted average shares - basic 106.3 106.9 106.8 107.2 Effect of dilutive securities: Stock options 4.8 4.3 4.9 4.7 Restricted stock awards and restricted stock units 2.3 1.6 2.0 1.4 Weighted average shares - diluted 113.4 112.8 113.7 113.3 Net income per share - basic $ 9.48 $ 12.31 $ 26.16 $ 29.30 Net income per share - diluted $ 8.89 $ 11.66 $ 24.57 $ 27.73
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 Nine Months Ended (Shares in millions) 2023 2022 2023 2022 Stock options 1.7 2.4 1.7 2.3

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2023
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 September 30, 2023 Cost Basis Gains Losses Value Corporate bonds $ 6,726.3 $ 0.4 $ (189.1) $ 6,537.6 U.S. government and government agency obligations 5,112.6 0.2 (30.5) 5,082.3 Sovereign bonds 67.3 — (1.7) 65.6 Commercial paper 505.1 0.2 (0.2) 505.1 Certificates of deposit 342.6 0.1 (0.1) 342.6 Asset-backed securities 89.6 — (2.4) 87.2 $ 12,843.5 $ 0.9 $ (224.0) $ 12,620.4 As of December 31, 2022 Corporate bonds $ 6,975.5 $ — $ (291.1) $ 6,684.4 U.S. government and government agency obligations 2,945.4 0.9 (6.9) 2,939.4 Sovereign bonds 67.1 — (3.0) 64.1 Commercial paper 121.1 — — 121.1 Certificates of deposit 182.1 — (0.1) 182.0 Asset-backed securities 28.9 — (1.7) 27.2 $ 10,320.1 $ 0.9 $ (302.8) $ 10,018.2
Marketable Securities, Based on Contractual Maturity Dates	The fair values of available-for-sale debt securities by contractual maturity consist of the following: September 30, December 31, (In millions) 2023 2022 Maturities within one year $ 7,786.0 $ 4,636.4 Maturities after one year through five years 4,830.0 5,381.4 Maturities after five years 4.4 0.4 $ 12,620.4 $ 10,018.2
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 September 30, 2023 Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Corporate bonds $ 1,976.1 $ (23.8) $ 4,387.1 $ (165.3) $ 6,363.2 $ (189.1) U.S. government and government agency obligations 2,794.8 (26.8) 51.7 (3.7) 2,846.5 (30.5) Sovereign bonds 12.2 (0.2) 53.3 (1.5) 65.5 (1.7) Commercial paper 431.8 (0.2) — — 431.8 (0.2) Certificates of deposit 136.3 (0.1) — — 136.3 (0.1) Asset-backed securities 62.3 (1.1) 24.9 (1.3) 87.2 (2.4) $ 5,413.5 $ (52.2) $ 4,517.0 $ (171.8) $ 9,930.5 $ (224.0) As of December 31, 2022 Corporate bonds $ 2,445.4 $ (73.1) $ 4,200.4 $ (218.0) $ 6,645.8 $ (291.1) U.S. government and government agency obligations 785.2 (2.0) 71.0 (4.9) 856.2 (6.9) Sovereign bonds 18.6 (1.1) 45.6 (1.9) 64.2 (3.0) Certificates of deposit 40.2 (0.1) — — 40.2 (0.1) Asset-backed securities 11.5 (0.6) 15.2 (1.1) 26.7 (1.7) $ 3,300.9 $ (76.9) $ 4,332.2 $ (225.9) $ 7,633.1 $ (302.8)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
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 September 30, 2023 Fair Value Level 1 Level 2 Level 3 Assets: Cash equivalents $ 1,018.5 $ 119.9 $ 898.6 $ — Available-for-sale debt securities: Corporate bonds 6,537.6 — 6,537.6 — U.S. government and government agency obligations 5,082.3 — 5,082.3 — Sovereign bonds 65.6 — 65.6 — Commercial paper 505.1 — 505.1 — Certificates of deposit 342.6 — 342.6 — Asset-backed securities 87.2 — 87.2 — Equity securities (unrestricted) 802.3 802.3 — — Equity securities (restricted) 117.1 117.1 — — Total assets $ 14,558.3 $ 1,039.3 $ 13,519.0 $ — Liabilities: Contingent consideration - CVRs $ 43.7 $ — $ — $ 43.7 As of December 31, 2022 Assets: Cash equivalents $ 1,662.8 $ 88.3 $ 1,574.5 $ — Available-for-sale debt securities: Corporate bonds 6,684.4 — 6,684.4 — U.S. government and government agency obligations 2,939.4 — 2,939.4 — Sovereign bonds 64.1 — 64.1 — Commercial paper 121.1 — 121.1 — Certificates of deposit 182.0 — 182.0 — Asset-backed securities 27.2 — 27.2 — Equity securities (unrestricted) 24.6 24.6 — — Equity securities (restricted) 1,185.4 1,185.4 — — Total assets $ 12,891.0 $ 1,298.3 $ 11,592.7 $ —

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2023
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventories consist of the following: September 30, December 31, (In millions) 2023 2022 Raw materials $ 787.3 $ 818.4 Work-in-process 1,123.9 963.1 Finished goods 114.2 98.6 Deferred costs 536.6 521.8 $ 2,562.0 $ 2,401.9

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Schedule of Shares Repurchased	The table below summarizes the shares of our Common Stock the Company repurchased and the cost of the shares, which were recorded as Treasury Stock. As described in Note 8, effective January 1, 2023 share repurchases, net of issuances, are subject to a 1% excise tax; such amount, if applicable, is recognized as an additional cost of the shares acquired. Three Months Ended Nine Months Ended (In millions) 2023 2022 2023 2022 Number of shares 0.7 1.5 2.6 2.7 Total cost of shares $ 507.1 $ 913.0 $ 1,923.8 $ 1,658.6

Statement of Cash Flows (Tables

Statement of Cash Flows (Tables)	9 Months Ended
	Sep. 30, 2023
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 Sheet to the total of the same such amounts shown in the Condensed Consolidated Statement of Cash Flows: September 30, (In millions) 2023 2022 Cash and cash equivalents $ 2,152.3 $ 3,491.3 Restricted cash included in Other noncurrent assets 7.9 13.5 Total cash, cash equivalents, and restricted cash shown in the Condensed Consolidated Statement of Cash Flows $ 2,160.2 $ 3,504.8
Restrictions on Cash and Cash Equivalents	The following provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Condensed Consolidated Balance Sheet to the total of the same such amounts shown in the Condensed Consolidated Statement of Cash Flows: September 30, (In millions) 2023 2022 Cash and cash equivalents $ 2,152.3 $ 3,491.3 Restricted cash included in Other noncurrent assets 7.9 13.5 Total cash, cash equivalents, and restricted cash shown in the Condensed Consolidated Statement of Cash Flows $ 2,160.2 $ 3,504.8
Summary of Non-Cash Investing and Financing Activities	September 30, December 31, September 30, December 31, (In millions) 2023 2022 2022 2021 Accrued capital expenditures $ 98.9 $ 70.8 $ 83.1 $ 74.8 Accrued contingent consideration for Libtayo intangible asset $ 62.8 $ 135.5 $ 116.0 $ — Accrued contingent consideration in connection with acquisitions $ 43.7 $ — $ — $ —

Legal Matters (Tables)

Legal Matters (Tables)	9 Months Ended
	Sep. 30, 2023
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. 10,406,226 (the "'226 Patent") and 10,464,992 (the "'992 Patent") Anonymous parties Ex parte reexamination February 11, 2020 On September 11, 2023, the USPTO dismissed the '226 Patent reexamination proceedings following the Company’s filing of a Notice of Disclaimer, disclaiming all claims of the '226 Patent. On September 8, 2023, the '992 Patent reexamination proceedings were stayed by the USPTO pending resolution of the inter partes review ("IPR") of the '992 Patent initiated by Celltrion, Inc., as discussed further below. U.S. Patent Nos. 9,254,338 (the "'338 Patent") and 9,669,069 (the "'069 Patent") Mylan Pharmaceuticals Inc., Apotex Inc., and Celltrion, Inc. IPR petitions seeking declarations of invalidity May 5, 2021 On November 9, 2022, the USPTO issued final written decisions finding that the claims of the '338 and '069 Patents are unpatentable and, therefore, invalid. On January 10, 2023, the Company filed notices of appeal of the USPTO written decisions concerning the '338 and '069 Patents with the Federal Circuit. U.S. Patent Nos. 10,130,681 (the "'681 Patent"), 10,888,601 (the "'601 Patent"), and 10,857,205 (the "'205 Patent") Mylan IPR petitions seeking declarations of invalidity July 1, 2022 ('681 Patent and '601 Patent) October 28, 2022 ('205 Patent) IPR proceedings concerning the '681 Patent and the '601 Patent instituted on January 11, 2023; oral hearing held on October 25, 2023. On March 1, 2023, the USPTO denied institution of Mylan's IPR petition against the '205 Patent following the Company's filing of a Notice of Disclaimer with the USPTO, disclaiming all claims of the '205 Patent. '681 Patent and '601 Patent Samsung Bioepis Co., Ltd. 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") Apotex IPR petitions seeking declaration of invalidity September 9, 2022 On March 10, 2023, the USPTO declined to institute an IPR proceeding. Samsung Bioepis Co., Ltd. IPR petition seeking declaration of invalidity April 27, 2023 Decision whether to institute pending. '992 Patent and '226 Patent Celltrion IPR petitions seeking declarations of invalidity January 17, 2023 ('992 Patent) February 28, 2023 ('226 Patent) On July 20, 2023, the USPTO instituted an IPR proceeding concerning the '992 Patent. On September 1, 2023, the USPTO denied institution of Celltrion's IPR petition against the '226 Patent following the Company’s filing of a Notice of Disclaimer with the USPTO, disclaiming all claims of the '226 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 to be scheduled. 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. 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 Oral hearing to be scheduled.

Product Sales - Schedule of Net

Product Sales - Schedule of Net Product Sales (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 3,362.7	$ 2,936.2	$ 9,682.9	$ 8,758.5
Net product sales
Disaggregation of Revenue [Line Items]
Revenues	1,786.1	1,801.4	5,226.2	5,194.4
U.S. | EYLEA
Disaggregation of Revenue [Line Items]
Revenues	1,448.2	1,629.4	4,382.1	4,768.2
U.S. | EYLEA HD
Disaggregation of Revenue [Line Items]
Revenues	42.7	0	42.7	0
U.S. | Libtayo
Disaggregation of Revenue [Line Items]
Revenues	144.1	94.7	384	264.5
U.S. | Praluent
Disaggregation of Revenue [Line Items]
Revenues	40.4	29.7	121.1	94.5
U.S. | Evkeeza
Disaggregation of Revenue [Line Items]
Revenues	19.1	13.6	53.3	33.2
U.S. | Inmazeb
Disaggregation of Revenue [Line Items]
Revenues	3.3	3	7.7	3
ROW | Libtayo
Disaggregation of Revenue [Line Items]
Revenues	$ 88.3	$ 31	$ 235.3	$ 31

Product Sales - Narrative (Deta

Product Sales - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	$ 5,584.5	$ 5,328.7
Trade accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	$ 3,792	$ 3,586

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		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Besse Medical, a subsidiary of Cencora, Inc.
Concentration Risk [Line Items]
Concentration risk, percentage	53%	56%	52%	56%
McKesson Corporation
Concentration Risk [Line Items]
Concentration risk, percentage	24%	28%	25%	29%

Collaboration, License, and O_3

Collaboration, License, and Other Agreements - Amounts Recognized In Statement of Operations with Sanofi (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 3,362.7	$ 2,936.2	$ 9,682.9	$ 8,758.5
One-time payment		(56.9)		(56.9)
Sanofi Collaboration Agreement, Antibody | Collaboration revenue | Regeneron's share of profits in connection with commercialization
Disaggregation of Revenue [Line Items]
Revenues	863	551.1	2,250.6	1,463
Sanofi Collaboration Agreement, Antibody | Collaboration revenue | Sales-based milestones earned
Disaggregation of Revenue [Line Items]
Revenues	50	0	50	50
Sanofi Collaboration Agreement, Antibody | Collaboration revenue | Reimbursement for manufacturing of commercial supplies
Disaggregation of Revenue [Line Items]
Revenues	151.5	160.5	506	466.8
Sanofi Collaboration Agreement, Antibody | Collaboration revenue | Other
Disaggregation of Revenue [Line Items]
Revenues	0	(0.2)	0	28.7
Sanofi Collaboration Agreement, Antibody | (R&D expense)/Reduction of 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	(25.8)	(4.3)	(66.7)	59.6
Sanofi Collaboration Agreement, Antibody | SG&A expense | Reimbursement of commercialization-related expenses
Disaggregation of Revenue [Line Items]
Revenues	135.5	108.6	384	311.1
Sanofi Collaboration Agreement, Immuno-oncology | Collaboration revenue | Regeneron's share of profits in connection with commercialization | Outside United States
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	6.7
Sanofi Collaboration Agreement, Immuno-oncology | Collaboration revenue | Reimbursement for manufacturing of ex-U.S. commercial supplies
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	4.6
Sanofi Collaboration Agreement, Immuno-oncology | (R&D expense)/Reduction of R&D expense | Reimbursement of R&D expenses
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	42.7
Sanofi Collaboration Agreement, Immuno-oncology | SG&A expense | Reimbursement of commercialization-related expenses
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	41.4
Sanofi Collaboration Agreement, Immuno-oncology | SG&A expense | Regeneron's obligation for its share of Sanofi commercial expenses
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	(19.9)
Sanofi Collaboration Agreement, Immuno-oncology | Cost of goods sold | Regeneron's obligation for Sanofi's share of Libtayo U.S. gross profits
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	(70.1)
Sanofi Collaboration Agreement, Immuno-oncology | Other operating income | Amounts recognized in connection with up-front payments received
Disaggregation of Revenue [Line Items]
Revenues	$ 0	$ 0	$ 0	$ 35.1

Collaboration, License, and O_4

Collaboration, License, and Other Agreements - Sanofi, Antibody Narrative (Details) - USD ($) $ in Millions			3 Months Ended			9 Months Ended
	Jul. 01, 2022	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues			$ 3,362.7	$ 2,936.2		$ 9,682.9	$ 8,758.5
Sanofi Collaboration Agreement, Antibody
Disaggregation of Revenue [Line Items]
Percentage share of profits to reimburse collaborating party						10%
Percentage of share of profits used to reimburse collaborating party for trial costs	20%	10%
Sanofi Collaboration Agreement, Antibody | Sales Milestone Three
Disaggregation of Revenue [Line Items]
Levels of twelve-month sales at which sales milestone payments would be received					$ 2,000
Period for achieving sales target for milestone payment, rolling basis					12 months
Revenues					$ 50
Sanofi Collaboration Agreement, Antibody | Sales Milestone Five
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation, variable consideration amount			50			$ 50
Levels of twelve-month sales at which sales milestone payments would be received			$ 3,000
Period for achieving sales target for milestone payment, rolling basis			12 months
Sanofi Collaboration Agreement, Antibody | 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%
Sanofi Collaboration Agreement, Antibody | 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_5

Collaboration, License, and Other Agreements - Schedule of Contract Balances, Antibody Collaboration (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 5,584.5	$ 5,328.7
Sanofi Collaboration Agreement, Antibody
Disaggregation of Revenue [Line Items]
Accounts receivable, net	1,128.2	692.3
Deferred revenue	$ 417.3	$ 415.8

Collaboration, License, and O_6

Collaboration, License, and Other Agreements - Sanofi, Immuno-Oncology Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Up-front payment to be made to collaborator	$ 3,362.7	$ 2,936.2		$ 9,682.9	$ 8,758.5
Sanofi
Disaggregation of Revenue [Line Items]
Up-front payment to collaborating party			$ 900
Sanofi Collaboration Agreement, Immuno-oncology
Disaggregation of Revenue [Line Items]
Royalty payment to collaborating party, percentage of net product sales				11%
Sanofi Collaboration Agreement, Immuno-oncology | Regulatory Milestone | Sanofi
Disaggregation of Revenue [Line Items]
Up-front payment to collaborating party			100
Sanofi Collaboration Agreement, Immuno-oncology | Sales-Based Milestones | Sanofi
Disaggregation of Revenue [Line Items]
Up-front payment to be made to collaborator			100
Sanofi Collaboration Agreement, Immuno-oncology | Sales-Based Milestone One | Sanofi
Disaggregation of Revenue [Line Items]
Up-front payment to be made to collaborator			$ 65
Sanofi Collaboration Agreement, Immuno-oncology | Sales-Based Milestone Two | Sanofi
Disaggregation of Revenue [Line Items]
Up-front payment to be made to collaborator				$ 35

Collaboration, License, and O_7

Collaboration, License, and Other Agreements - Amounts Recognized in Statement of Operations with Bayer (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 3,362.7	$ 2,936.2	$ 9,682.9	$ 8,758.5
Bayer | Outside United States | Collaboration revenue | Regeneron's share of profits in connection with commercialization of EYLEA outside the United States
Disaggregation of Revenue [Line Items]
Revenues	349.9	315.3	1,031	993.4
Bayer | Outside United States | Collaboration revenue | Reimbursement for manufacturing of ex-U.S. commercial supplies
Disaggregation of Revenue [Line Items]
Revenues	27.2	17.5	79.7	60.3
Bayer | Outside United States | Collaboration revenue | One-time payment in connection with change in Japan arrangement
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	21.9
Bayer | Outside United States | (R&D expense)/Reduction of 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	$ (9.7)	$ 7.1	$ (35.1)	$ 10.3

Collaboration, License, and O_8

Collaboration, License, and Other Agreements - Schedule of Contract Balances, Bayer Collaboration (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 5,584.5	$ 5,328.7
Bayer
Disaggregation of Revenue [Line Items]
Accounts receivable, net	361.7	348.2
Deferred revenue	$ 125.3	$ 131.9

Collaboration, License, and O_9

Collaboration, License, and Other Agreements - Amounts Recognized in Statement of Operations with Roche (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 3,362.7	$ 2,936.2	$ 9,682.9	$ 8,758.5
Ronapreve | Roche Collaboration Agreement | Collaboration revenue
Disaggregation of Revenue [Line Items]
Revenues	0	6.4	222.2	230.9
Other | Roche Collaboration Agreement | Collaboration revenue
Disaggregation of Revenue [Line Items]
Revenues	$ (5.7)	$ 0	$ (9.5)	$ 0

Collaboration, License, and _10

Collaboration, License, and Other Agreements - Schedule of Contract Balances - Roche (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 5,584.5	$ 5,328.7
Roche Collaboration Agreement
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 0	$ 396.6

Collaboration, License, and _11

Collaboration, License, and Other Agreements - Alnylam Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenues	$ 3,362.7	$ 2,936.2	$ 9,682.9	$ 8,758.5
Alnylam Pharmaceuticals, Inc. Collaboration Agreement
Disaggregation of Revenue [Line Items]
Upfront payment made					$ 400
Collaborative arrangement additional payment eligible			$ 100
Alnylam Pharmaceuticals, Inc. Collaboration Agreement | Clinical Proof-of-Principle Milestone | Alnylam
Disaggregation of Revenue [Line Items]
Revenues	$ 100
Alnylam Pharmaceuticals, Inc. Collaboration Agreement | Alnylam Pharmaceuticals, Inc. Stock Purchase Agreement
Disaggregation of Revenue [Line Items]
Cash consideration for Stock Purchase Agreement					$ 400

Collaboration, License, and _12

Collaboration, License, and Other Agreements - Amounts Recognized in Statement of Operations with Alnylam (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Research and development expenses	$ (1,075.3)	$ (911.3)	$ (3,261.8)	$ (2,549.4)
Alnylam Pharmaceuticals, Inc. Collaboration Agreement | (R&D expense)
Disaggregation of Revenue [Line Items]
Research and development expenses	(13.5)	(10.6)	(52.1)	(36.1)
Alnylam Pharmaceuticals, Inc. Collaboration Agreement | Acquired in-process research and development
Disaggregation of Revenue [Line Items]
Research and development expenses	$ (100)	$ 0	$ (100)	$ 0

Collaboration, License, and _13

Collaboration, License, and Other Agreements - Schedule of Contract Balances, Alnylam Collaboration (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Accrued expenses and other current liabilities	$ 2,644.7	$ 2,074.2
Alnylam Pharmaceuticals, Inc. Collaboration Agreement
Disaggregation of Revenue [Line Items]
Accrued expenses and other current liabilities	$ 111.5	$ 7.4

Collaboration, License, and _14

Collaboration, License, and Other Agreements - Sonoma Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Apr. 30, 2023	Mar. 31, 2023	Sep. 30, 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

Collaboration, License, and _15

Collaboration, License, and Other Agreements - BARDA, Other Transaction Agreement Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues		$ 3,362.7	$ 2,936.2	$ 9,682.9	$ 8,758.5
BARDA, Other Transaction Agreement
Disaggregation of Revenue [Line Items]
Percentage of costs required to be funded by collaborating party	70%
"Next Generation" Covid Antibodies | BARDA, Other Transaction Agreement | Collaboration revenue
Disaggregation of Revenue [Line Items]
Revenues		$ 34.2
US Government | "Next Generation" Covid Antibodies
Disaggregation of Revenue [Line Items]
Maximum transaction agreement payments				$ 326

Collaboration, License, and _16

Collaboration, License, and Other Agreements - Schedule of Contract Balances, BARDA (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 5,584.5	$ 5,328.7
BARDA, Other Transaction Agreement
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 34.2

Collaboration, License, and _17

Collaboration, License, and Other Agreements - Decibel Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Sep. 30, 2023	Aug. 31, 2023
Disaggregation of Revenue [Line Items]
Business combination, amount excluded from consideration transferred	$ 6.6
Decibel Therapeutics, Inc.
Disaggregation of Revenue [Line Items]
Payment to acquire business, cash paid	$ 101.3
Business combination, share price (in dollars per share)	$ 4
Business combination, fair value of equity interest		$ 10.3
Class of warrant or right, exercise price (in dollars per share)	$ 3.50
Business combination, fair value of CVRs	$ 43.7
Business combination, contingent consideration arrangements	$ 97

Collaboration, License, and _18

Collaboration, License, and Other Agreements - Summary of Assets Acquired and Liabilities Assumed, Decibel (Details) - Decibel Therapeutics, Inc. $ in Millions	Sep. 25, 2023 USD ($)
Business Acquisition [Line Items]
Cash and cash equivalents	$ 42.2
Marketable securities	12.1
Deferred tax assets, net	58.1
Indefinite-lived intangible asset related to in-process research and development	42.5
Goodwill	5.2
Other assets and liabilities, net	(11.4)
Total	$ 148.7

Collaboration, License, and _19

Collaboration, License, and Other Agreements - Checkmate Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	May 31, 2022	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Acquired in-process research and development in connection with asset acquisition			$ 0	$ 195
Asset acquisition, cash and cash equivalents acquired		$ 26.4
Checkmate Pharmaceuticals, Inc.
Disaggregation of Revenue [Line Items]
Asset acquisition, consideration transferred	$ 250
Acquired in-process research and development in connection with asset acquisition		195
Asset acquisition, assets acquired and liabilities assumed, net		$ 61.7

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						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income - basic and diluted	$ 1,007.8	$ 968.4	$ 817.8	$ 1,315.7	$ 852.1	$ 973.5	$ 2,794	$ 3,141.3
Weighted average shares - basic (in shares)	106.3			106.9			106.8	107.2
Weighted average shares - diluted (in shares)	113.4			112.8			113.7	113.3
Net income per share - basic (in dollars per share)	$ 9.48			$ 12.31			$ 26.16	$ 29.30
Net income per share - diluted (in dollars per share)	$ 8.89			$ 11.66			$ 24.57	$ 27.73
Stock options
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive securities (in shares)	4.8			4.3			4.9	4.7
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)	2.3			1.6			2	1.4

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		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options (in shares)	1.7	2.4	1.7	2.3

Marketable Securities - Schedul

Marketable Securities - Schedule of Investments in Available For Sale Debt Securities (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	$ 12,843.5	$ 10,320.1
Unrealized Gains	0.9	0.9
Unrealized Losses	(224)	(302.8)
Fair Value	12,620.4	10,018.2
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	6,726.3	6,975.5
Unrealized Gains	0.4	0
Unrealized Losses	(189.1)	(291.1)
Fair Value	6,537.6	6,684.4
U.S. government and government agency obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	5,112.6	2,945.4
Unrealized Gains	0.2	0.9
Unrealized Losses	(30.5)	(6.9)
Fair Value	5,082.3	2,939.4
Sovereign bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	67.3	67.1
Unrealized Gains	0	0
Unrealized Losses	(1.7)	(3)
Fair Value	65.6	64.1
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	505.1	121.1
Unrealized Gains	0.2	0
Unrealized Losses	(0.2)	0
Fair Value	505.1	121.1
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	342.6	182.1
Unrealized Gains	0.1	0
Unrealized Losses	(0.1)	(0.1)
Fair Value	342.6	182
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost Basis	89.6	28.9
Unrealized Gains	0	0
Unrealized Losses	(2.4)	(1.7)
Fair Value	$ 87.2	$ 27.2

Marketable Securities - Sched_2

Marketable Securities - Schedule of Debt Securities Based on Contractual Maturity Dates (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Maturities within one year	$ 7,786	$ 4,636.4
Maturities after one year through five years	4,830	5,381.4
Maturities after five years	4.4	0.4
Total	$ 12,620.4	$ 10,018.2

Marketable Securities - Sched_3

Marketable Securities - Schedule of Fair Value and Unrealized Losses of Debt Securities (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	$ 5,413.5	$ 3,300.9
Unrealized Loss - Less than 12 months	(52.2)	(76.9)
Fair Value - 12 Months or Greater	4,517	4,332.2
Unrealized Loss - 12 Months or Greater	(171.8)	(225.9)
Fair Value - Total	9,930.5	7,633.1
Unrealized Loss - Total	(224)	(302.8)
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	1,976.1	2,445.4
Unrealized Loss - Less than 12 months	(23.8)	(73.1)
Fair Value - 12 Months or Greater	4,387.1	4,200.4
Unrealized Loss - 12 Months or Greater	(165.3)	(218)
Fair Value - Total	6,363.2	6,645.8
Unrealized Loss - Total	(189.1)	(291.1)
U.S. government and government agency obligations
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	2,794.8	785.2
Unrealized Loss - Less than 12 months	(26.8)	(2)
Fair Value - 12 Months or Greater	51.7	71
Unrealized Loss - 12 Months or Greater	(3.7)	(4.9)
Fair Value - Total	2,846.5	856.2
Unrealized Loss - Total	(30.5)	(6.9)
Sovereign bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	12.2	18.6
Unrealized Loss - Less than 12 months	(0.2)	(1.1)
Fair Value - 12 Months or Greater	53.3	45.6
Unrealized Loss - 12 Months or Greater	(1.5)	(1.9)
Fair Value - Total	65.5	64.2
Unrealized Loss - Total	(1.7)	(3)
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	431.8
Unrealized Loss - Less than 12 months	(0.2)
Fair Value - 12 Months or Greater	0
Unrealized Loss - 12 Months or Greater	0
Fair Value - Total	431.8
Unrealized Loss - Total	(0.2)
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	136.3	40.2
Unrealized Loss - Less than 12 months	(0.1)	(0.1)
Fair Value - 12 Months or Greater	0	0
Unrealized Loss - 12 Months or Greater	0	0
Fair Value - Total	136.3	40.2
Unrealized Loss - Total	(0.1)	(0.1)
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Fair Value - Less than 12 Months	62.3	11.5
Unrealized Loss - Less than 12 months	(1.1)	(0.6)
Fair Value - 12 Months or Greater	24.9	15.2
Unrealized Loss - 12 Months or Greater	(1.3)	(1.1)
Fair Value - Total	87.2	26.7
Unrealized Loss - Total	$ (2.4)	$ (1.7)

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	$ 12,620.4	$ 10,018.2
Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	6,537.6	6,684.4
U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	5,082.3	2,939.4
Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	65.6	64.1
Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	505.1	121.1
Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	342.6	182
Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	87.2	27.2
Measured on a recurring basis
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	1,018.5	1,662.8
Total assets	14,558.3	12,891
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration - CVRs	43.7
Measured on a recurring basis | Unrestricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	802.3	24.6
Measured on a recurring basis | Restricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	117.1	1,185.4
Measured on a recurring basis | Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	6,537.6	6,684.4
Measured on a recurring basis | U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	5,082.3	2,939.4
Measured on a recurring basis | Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	65.6	64.1
Measured on a recurring basis | Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	505.1	121.1
Measured on a recurring basis | Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	342.6	182
Measured on a recurring basis | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	87.2	27.2
Measured on a recurring basis | Level 1
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	119.9	88.3
Total assets	1,039.3	1,298.3
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration - CVRs	0
Measured on a recurring basis | Level 1 | Unrestricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	802.3	24.6
Measured on a recurring basis | Level 1 | Restricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	117.1	1,185.4
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	898.6	1,574.5
Total assets	13,519	11,592.7
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration - CVRs	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	6,537.6	6,684.4
Measured on a recurring basis | Level 2 | U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	5,082.3	2,939.4
Measured on a recurring basis | Level 2 | Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	65.6	64.1
Measured on a recurring basis | Level 2 | Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	505.1	121.1
Measured on a recurring basis | Level 2 | Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	342.6	182
Measured on a recurring basis | Level 2 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	87.2	27.2
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 - CVRs	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		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net unrealized gains (losses)	$ (100.3)	$ 254.3	$ (295.9)	$ (120.6)
Write-down in other income (expense)	29
Securities owned not readily marketable	60.8		60.8		$ 48.3
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	$ 1,395		$ 1,395		$ 1,443

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Raw materials	$ 787.3	$ 818.4
Work-in-process	1,123.9	963.1
Finished goods	114.2	98.6
Deferred costs	536.6	521.8
Total Inventories	$ 2,562	$ 2,401.9

Inventories - Narrative (Detail

Inventories - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Inventory valuation reserves	$ 726.2	$ 720.7

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Effective income tax rate	9.30%	12.90%	8.40%	11.10%

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended		20 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Jan. 31, 2023	Nov. 30, 2021
Class of Stock [Line Items]
Total cost of shares	$ 507,100,000	$ 913,000,000	$ 1,923,800,000	$ 1,658,600,000
Remaining authorized repurchase amount	$ 1,826,000,000		$ 1,826,000,000
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

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Share Repurchases (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Equity [Abstract]
Number of shares (in shares)	0.7	1.5	2.6	2.7
Total cost of shares	$ 507.1	$ 913	$ 1,923.8	$ 1,658.6

Statement of Cash Flows - Sched

Statement of Cash Flows - Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 2,152.3	$ 3,105.9	$ 3,491.3
Restricted cash included in Other noncurrent assets	7.9		13.5
Total cash, cash equivalents, and restricted cash shown in the Condensed Consolidated Statement of Cash Flows	$ 2,160.2	$ 3,119.4	$ 3,504.8	$ 2,898.1

Statement of Cash Flows - Summa

Statement of Cash Flows - Summary of Non-cash Investing and Financing Activities (Details) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Abstract]
Accrued capital expenditures	$ 98.9	$ 83.1	$ 70.8	$ 74.8
Accrued contingent consideration for Libtayo intangible asset	62.8	116	135.5	0
Accrued contingent consideration in connection with acquisitions	$ 43.7	$ 0	$ 0	$ 0

Legal Matters (Details)

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