
	Statement of Operations Classification	Year Ended December 31,
		2020		2019		2018
Antibody:
Regeneron's share of profits (losses) in connection with commercialization of antibodies	Sanofi collaboration revenue	$	785.2	$	209.3	$	(227.0)
Sales-based milestone earned	Sanofi collaboration revenue	$	50.0	—		—
Reimbursement for manufacturing of commercial supplies	Sanofi collaboration revenue	$	368.0	$	216.0	$	113.7
Reimbursement of research and development expenses	Reduction of Research and development expense	$	226.7	$	277.7	$	265.3
Regeneron's obligation for its share of Sanofi research and development expenses	Research and development expense	$	(77.6)	$	(46.0)	$	(47.7)
Reimbursement of commercialization-related expenses	Reduction of Selling, general, and administrative expense	$	359.4	$	479.9	$	417.2
Regeneron's obligation for its share of Sanofi other expenses	Cost of collaboration and contract manufacturing	$	(21.5)	$	(12.8)	$	(16.1)

Immuno-oncology:
Regeneron's share of losses in connection with commercialization of Libtayo outside the United States	Sanofi collaboration revenue	$	(25.7)	$	(21.7)	$	(12.4)
Reimbursement for manufacturing of commercial supplies	Sanofi collaboration revenue	$	8.9	—		—
Reimbursement of research and development expenses	Reduction of Research and development expense	$	166.2	$	163.0	$	311.8
Reimbursement of commercialization-related expenses	Reduction of Selling, general, and administrative expense	$	64.7	$	10.3	$	8.9
Regeneron's obligation for Sanofi's share of Libtayo U.S. gross profits	Cost of goods sold	$	(119.1)	$	(78.2)	$	(6.8)
Amounts recognized in connection with up-front payments received	Other operating income	$	210.6	$	92.7	$	243.8

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, Kevzara, and itepekimab. Under the terms of the Antibody License and Collaboration Agreement ("LCA"), Sanofi is generally responsible for funding 80%–100% of agreed-upon development costs. We are obligated to reimburse Sanofi for 30%–50% of worldwide development expenses that were funded by Sanofi (collectively, the "development balance") based on our share of collaboration profits from commercialization of collaboration products. However, we are only required to apply 10% of our share of the profits from the Antibody Collaboration in any calendar quarter to reimburse Sanofi for these development costs. The Company's contingent reimbursement obligation to Sanofi under the Antibody Collaboration was approximately $3.103 billion as of December 31, 2020.

Regeneron is obligated to use commercially reasonable efforts to supply clinical requirements of each drug candidate under the Antibody Collaboration until commercial supplies of that drug candidate are being manufactured. Sanofi leads commercialization activities for products under the Antibody Collaboration, subject to the Company's right to co-commercialize such products. The Company co-commercializes Dupixent in the United States and exercised its option to co-commercialize Dupixent in certain countries outside the United States. We currently anticipate commencing co-commercialization of Dupixent in such countries outside the United States in 2021. The parties equally share profits and losses from sales within the United States. The parties share profits outside the United States on a sliding scale based on sales starting at 65% (Sanofi)/35% (Regeneron) and ending at 55% (Sanofi)/45% (Regeneron), and losses outside the United States at 55% (Sanofi)/45% (Regeneron).

In addition to profit and loss sharing, we are entitled to receive sales milestone payments from Sanofi. In the third quarter of 2020, the Company earned, and recognized as revenue, the first $50.0 million sales-based milestone from Sanofi, upon aggregate annual sales of Dupixent, Kevzara, and Praluent outside the United States exceeding $1.0 billion on a rolling twelve-month basis. We are entitled to receive up to an aggregate of $200.0 million in additional milestone payments from Sanofi, including the second sales milestone in the amount of $50.0 million, when such sales outside the United States exceed $1.5 billion on a rolling twelve-month basis.

In April 2020, the Company and Sanofi entered into an amendment to the LCA in connection with, among other things, the removal of Praluent from the LCA such that (i) effective April 1, 2020, the LCA no longer governs the development, manufacture, or commercialization of Praluent and (ii) the quarterly period ended March 31, 2020 was the last quarter for which Sanofi and the Company shared profits and losses for Praluent under the LCA. The parties also entered into a Praluent Cross License & Commercialization Agreement (the "Praluent Agreement") pursuant to which, effective April 1, 2020, the Company, at its sole cost, is solely responsible for the development and commercialization of Praluent in the United States, and Sanofi, at its sole cost, is solely responsible for the development and commercialization of Praluent outside of the United States. Under the Praluent Agreement, Sanofi will pay the Company a 5% royalty on Sanofi’s net product sales of Praluent outside the United States until March 31, 2032. The Company will not owe Sanofi royalties on the Company’s net product sales of Praluent in the United States. Although each party will be responsible for manufacturing Praluent for its respective territory, the parties have entered into definitive supply agreements under which, for a certain transitional period, the Company will continue to supply drug substance to Sanofi and Sanofi will continue to supply finished product to Regeneron. With respect to any intellectual property or product liability litigation relating to Praluent, the parties have agreed that, effective April 1, 2020, Regeneron and Sanofi each will be solely responsible for any such litigation (including damages and other costs and expenses thereof) in the United States and outside the United States, respectively, arising out of Praluent sales or other activities on or after April 1, 2020 (subject to Sanofi's right to set off a portion of any third-party royalty payments resulting from certain patent litigation proceedings against up to 50% of any Praluent royalty payment owed to Regeneron). The parties will each bear 50% of any damages arising out of Praluent sales or other activities prior to April 1, 2020. See Note 15 for discussion of legal proceedings related to Praluent.

The Company's significant promised goods and services in connection with the Antibody Collaboration consist of providing research and development services, including the manufacturing of clinical supplies, and providing commercial-related services, including the manufacturing of commercial supplies. We recognize amounts in connection with the Antibody Collaboration based on the amount we have the right to invoice and such amount corresponds directly with our performance to date; therefore, we do not disclose the value of the transaction price (i.e., the amount of consideration we expect to be entitled to) allocated to our remaining unsatisfied obligations.

The Company is party to a collaboration with Sanofi to research, develop, and commercialize antibody-based cancer treatments in the field of immuno-oncology (the "IO Collaboration"). The IO Collaboration is governed by an Amended and Restated Immuno-oncology Discovery and Development Agreement ("Amended IO Discovery Agreement"), and an Immuno-oncology License and Collaboration Agreement ("IO License and Collaboration Agreement"). In connection with the execution of the original Immuno-oncology Discovery and Development Agreement in 2015 ("2015 IO Discovery Agreement"), which has been replaced by the Amended IO Discovery Agreement (as discussed below), Sanofi made a $265.0 million non-refundable up-front payment to the Company. Pursuant to the 2015 IO Discovery Agreement, the Company was to spend up to $1.090 billion to identify and validate potential immuno-oncology targets and develop therapeutic antibodies against such targets through clinical proof-of-concept, and Sanofi was to reimburse the Company for up to $825.0 million of these costs, subject to certain annual limits.

We are obligated to reimburse Sanofi for half of the development costs they funded that are attributable to clinical development of antibody product candidates from our share of future profits from commercialized IO Collaboration products. However, the Company is only required to apply 10% of its share of the profits from IO Collaboration products in any calendar quarter towards reimbursing Sanofi for these development costs. The Company's contingent reimbursement obligation to Sanofi under the IO Collaboration was approximately $107 million as of December 31, 2020.

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

With regard to the BCMAxCD3 Program and the MUC16xCD3 Program, when (i) clinical proof-of-concept is established, (ii) the applicable Program Costs Cap is reached, or (iii) in certain other limited circumstances, Sanofi will have the option to license rights to the product candidate and other antibodies targeting the same targets for, with regard to BCMAxCD3, immuno-oncology indications, and with regard to MUC16xCD3, all indications, pursuant to the IO License and Collaboration Agreement, as amended. Given the applicable Program Costs Cap for the BCMAxCD3 Program and MUC16xCD3 Program has been reached, we expect Sanofi to provide its decision on whether it will exercise its option to license rights to these product candidates in early 2021. If Sanofi does not exercise its option to license rights to a product candidate, we will retain the exclusive right to develop and commercialize such product candidate and Sanofi will receive a royalty on sales. Pursuant to the Amended IO Discovery Agreement, the parties agreed that (i) if Sanofi exercises its option with respect to a BCMAxCD3 Program antibody, Sanofi will lead the development and global commercialization of such BCMAxCD3 Program antibody; and (ii) if Sanofi exercises its option with respect to a MUC16xCD3 Program antibody, (x) we will lead the development of such MUC16xCD3 Program antibody and commercialization of such MUC16xCD3 Program antibody within the United States and (y) Sanofi will lead the commercialization of such MUC16xCD3 Program antibody outside of the United States.

If Sanofi exercises its option to license rights to a BCMAxCD3 Program antibody or MUC16xCD3 Program antibody thereunder, it will co-develop these drug candidates with the Company through product approval. Sanofi will fund development costs up front for a BCMAxCD3 Program antibody and we will reimburse half of the total development costs for such antibody from our share of future IO Collaboration profits to the extent they are sufficient for this purpose, subject to the same 10% reimbursement provision described above. In addition, we and Sanofi will share equally, on an ongoing basis, the development costs for a MUC16xCD3 Program antibody.

In connection with the execution of the IO License and Collaboration Agreement in 2015, Sanofi made a $375.0 million non-refundable up-front payment to the Company. Under the terms of the IO License and Collaboration Agreement, the parties are co-developing and co-commercializing Libtayo (cemiplimab), an antibody targeting the receptor known as programmed cell death protein 1 (PD-1). The parties share equally, on an ongoing basis, agreed-upon development and commercialization

expenses for Libtayo. Pursuant to the Letter Agreement, the Libtayo development budget was increased and the Company allowed Sanofi to satisfy in whole or in part its funding obligations with respect to the Libtayo development and Dupilumab/Itepekimab Eligible Investments incurred in periods through September 30, 2020 by selling certain shares of our Common Stock directly or indirectly owned by Sanofi; if Sanofi desired to sell such shares, we were able to elect to purchase, in whole or in part, such shares from Sanofi. See Note 11 for additional information regarding shares purchased by us from Sanofi.

In August 2018, we and Sanofi entered into a license agreement with Bristol-Myers Squibb Company, E. R. Squibb & Sons, L.L.C., and Ono Pharmaceutical Co., Ltd. to obtain a license under certain patents owned and/or exclusively licensed by one or more of those parties that includes the right to develop and sell Libtayo. Under the agreement, we and Sanofi made an up-front payment of $20.0 million and are obligated to pay royalties of 8.0% on worldwide sales of Libtayo through December 31, 2023, and royalties of 2.5% from January 1, 2024 through December 31, 2026. The up-front payment was shared, and the royalties are shared, equally by us and Sanofi.

Each party will have the right to co-commercialize licensed products in countries where it is not the lead commercialization party. The parties share equally in profits and losses in connection with the commercialization of collaboration products. The Company is obligated to use commercially reasonable efforts to supply clinical requirements of each drug candidate under the IO License and Collaboration Agreement until commercial supplies of that IO drug candidate are being manufactured.

At the inception of the IO Collaboration, the Company's significant promised goods and services consisted of a license to certain rights and intellectual property and providing research and development services, including the manufacturing of clinical supplies. The Company concluded that the license was not distinct, primarily as a result of (i) Sanofi being unable to benefit on its own or together with other resources that are readily available as the license provides access to Regeneron's complex and specialized know-how and (ii) the research and development services, including manufacturing in support of such services, were expected to significantly modify the initial license. Therefore, the promised goods and services were considered a combined unit of account. Consequently, the $640.0 million in aggregate up-front payments made by Sanofi during 2015 in connection with the execution of the IO Collaboration was recorded within other liabilities and has been included in the transaction price.

During 2020, we updated our estimate of the total research and development costs expected to be incurred (which resulted in a change to the estimate of the stage of completion) in connection with the Sanofi IO Collaboration, and, as a result, recorded a cumulative catch-up adjustment of $135.4 million to other operating income. During 2018, we updated our estimate of the total research and development costs expected to be incurred for this arrangement, including in connection with the termination of the 2015 IO Discovery Agreement, and, as result, a cumulative catch-up adjustment of $135.0 million was recorded to other operating income.


	Statement of Operations Classification	Year Ended December 31,
		2020		2019		2018
Regeneron's net profit in connection with commercialization of EYLEA outside the United States	Bayer collaboration revenue	$	1,107.9	$	1,091.4	$	992.3
Reimbursement for manufacturing of commercial supplies	Bayer collaboration revenue	$	78.2	$	54.2	$	43.8
Reimbursement of development expenses	Reduction of Research and development expense	$	46.7	$	23.0	$	11.2
Regeneron's obligation for its share of Bayer research and development expenses	Research and development expense	$	(35.8)	$	(20.1)	$	(0.5)
Reimbursement of other expenses	Cost of collaboration and contract manufacturing	$	7.4	$	19.0	$	28.9

Bayer markets EYLEA outside the United States, where, for countries other than Japan, the companies share equally in profits and losses from sales of EYLEA. In Japan, the Company is currently entitled to receive a tiered percentage of between 33.5% and 40.0% of EYLEA net product sales through 2021, and thereafter, the companies will share equally in profits and losses from the sales of EYLEA. Within the United States, the Company is responsible for commercialization of EYLEA and retains exclusive rights to all profits from such commercialization in the United States. The Company is obligated to reimburse Bayer out of its share of the collaboration profits (including the Company's percentage of sales of EYLEA in Japan) for 50% of the agreed-upon development expenses that Bayer has incurred in accordance with a formula based on the amount of development expenses that Bayer has incurred and the Company's share of the collaboration profits, or at a faster rate at the Company's option. The Company's contingent reimbursement obligation to Bayer was approximately $276 million as of December 31, 2020.

The Company and Teva are parties to a collaboration agreement (the "Teva Collaboration Agreement") to develop and commercialize fasinumab globally, excluding certain Asian countries that are subject to our collaboration agreement with Mitsubishi Tanabe Pharma Corporation. In connection with the Teva Collaboration Agreement, Teva made a $250.0 million non-refundable up-front payment. The Company leads global development activities, and the parties share development costs equally, on an ongoing basis, under a global development plan. The Company is also responsible for the manufacture and supply of fasinumab globally.

Within the United States, the Company will lead commercialization activities, and the parties will share equally in any profits and losses in connection with commercialization of fasinumab. In the territory outside the United States, Teva will lead commercialization activities and the Company will supply product to Teva at a tiered purchase price, which is calculated as a percentage of net sales of the product (subject to adjustment in certain circumstances).

At the inception of the Teva Collaboration Agreement, the Company's significant promised goods and services consisted of a license to certain rights and intellectual property and providing research and development services, including the manufacturing of clinical supplies. The Company concluded that the license was not distinct, primarily as a result of (i) Teva being unable to benefit from the license on its own or together with other resources that are readily available as the license provides access to Regeneron's complex and specialized know-how and (ii) the research and development services, including manufacturing in support of such services, were expected to significantly modify the initial license. Therefore, the promised goods and services were considered a combined unit of account. Consequently, the $250.0 million up-front payment and development milestones received from Teva, as described above, have been recorded within other liabilities and included in the transaction price.

In May 2020, we expanded our existing collaboration with Intellia to provide us with rights to develop products for additional in vivo CRISPR/Cas9-based therapeutic targets and for the parties to jointly develop potential products for the treatment of hemophilia A and B. In addition, we also received non-exclusive rights to independently develop and commercialize ex vivo gene edited products. In connection with the agreement, we made a $70.0 million up-front payment, which was recorded to Research and development expense in 2020, and purchased 925,218 shares of Intellia common stock for an aggregate purchase price of $30.0 million. The amount paid in excess of the fair market value of the shares purchased, or $15.0 million, was also recorded to Research and development expense in 2020.

In the first quarter of 2020, we announced an expansion of our Other Transaction Agreement ("OTA") with the Biomedical Advanced Research Development Authority ("BARDA"), pursuant to which the U.S. Department of Health and Human Services ("HHS") was obligated to fund certain of our costs incurred for research and development activities related to COVID-19 treatments. In July 2020, we entered into an agreement with entities acting at the direction of BARDA and the U.S. Department of Defense to manufacture and deliver filled and finished drug product of REGEN-COV to the U.S. government. The agreement, as subsequently amended, could result in payments to the Company of up to $465.9 million in the aggregate for bulk manufacturing of the drug substance, as well as fill/finish, storage, and other activities. See Note 2 for REGEN-COV net product sales recognized in connection with this agreement during 2020.

In January 2021, the Company announced an agreement with an entity acting on behalf of the U.S. Department of Defense and HHS to manufacture and deliver additional filled and finished drug product of REGEN-COV to the U.S. government. Pursuant to the agreement, the U.S. government is obligated to purchase all filled and finished doses of drug product delivered by June 30, 2021, and may accept doses during the period from July 1, 2021 through September 30, 2021 at its discretion. The U.S. government will acquire doses at the lowest treatment dose authorized or approved by the FDA for the indication authorized under the EUA, resulting in payments to the Company of up to $2.625 billion in the aggregate. A number of factors may impact available filled and finished supply by June 30, 2021, including manufacturing considerations and authorized dose level.

In August 2020, we entered into a collaboration agreement with Roche to develop, manufacture, and distribute REGEN-COV. We will continue to lead global development activities for REGEN-COV, and the parties will jointly fund certain ongoing studies, as well as any mutually agreed additional new global studies to evaluate further the potential of REGEN-COV in treating or preventing COVID-19. Roche will be responsible for securing regulatory approvals outside the United States, following the initial European Medicines Agency ("EMA") approval (if any), and conducting any additional studies specifically required for approval by regulators outside the United States.

Under the terms of the agreement, each party is obligated to dedicate a certain amount of manufacturing capacity to REGEN-COV each year. We will distribute the product in the United States and Roche will distribute the product outside of the United States. The parties will 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. Any profit sharing will commence after product manufactured by Roche receives regulatory authorization.

In April 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. The collaboration is governed by a Master Collaboration Agreement (the "Master Agreement") (including the form of a License Agreement and a Co-Commercialization Collaboration Agreement). Under the terms of the Master Agreement, we made an up-front payment of $400.0 million to Alnylam, which was recorded in Research and development expense during 2019. For each program, we will provide Alnylam with a specified amount of funding at program initiation and at lead candidate designation, and Alnylam is eligible to receive up to an aggregate of $200.0 million in clinical proof-of-principle milestones for eye or CNS programs.

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

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

In addition to the collaboration agreements discussed above, the Company has various other collaboration agreements that are not individually significant to its operating results or financial condition at this time. Pursuant to the terms of those agreements, the Company may be required to pay, or it may receive, additional amounts upon the achievement of various development and commercial milestones which in the aggregate could be significant. The Company may also incur, or get reimbursed for, significant research and development costs if the related product candidate(s) were to advance to late stage clinical trials. In addition, if any products related to these collaborations are approved for sale, the Company may be required to pay, or it may receive, royalties on future sales. The payment or receipt of these amounts, however, is contingent upon the occurrence of various future events.