The interim Condensed Consolidated Financial Statements of Regeneron Pharmaceuticals, Inc. and its subsidiaries ("~~Regeneron" or the "Company"~~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 ~~position, results of operations, and cash flows~~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, ~~2016~~2019 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, ~~2016.~~2019.

Certain reclassifications have been made to prior period amounts to conform with the current period's presentation.

Effective January 1, 2020, we changed the presentation of cost reimbursements from collaborators who are not deemed to be our customers from collaboration revenue to a reduction of the corresponding operating expense (i.e., either Research and development or Selling, general, and administrative) incurred by us. We also changed the presentation of amounts recognized in connection with up-front and development milestone payments received from collaboration revenue to Other operating income. We made these changes in presentation because we believe the new presentation is preferable, as it better reflects the nature of the Company’s costs incurred and revenues earned pursuant to arrangements with collaborators and enhances the comparability of our financial statements with industry peers.

The change in presentation has been applied retrospectively. The tables below present the impact of the change on the Company’s previously-filed Consolidated Balance Sheet as of December 31, 2019, and the Condensed Consolidated Statement of Operations and Condensed Consolidated Statement of Cash Flows as of and for the three months ended March 31, 2019. The Company’s previously-filed balance sheet has been updated to reflect the addition of the caption Other liabilities for the presentation of up-front and development milestones paid by collaborators that are deferred. There was no impact on the Company’s previously-filed Consolidated Statements of Stockholders’ Equity.

The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The extent to which the COVID-19 pandemic may directly or indirectly impact our business, financial condition, and results of operations is highly uncertain and subject to change. We considered the potential impact of the COVID-19 pandemic on our estimates and assumptions and there was not a material impact to our condensed consolidated financial statements as of and for the three months ended March 31, 2020; however, actual results could differ from those estimates and there may be changes to our estimates in future periods.

We adopted Accounting Standards Update 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"), as of January 1, 2020. ASU 2016-13 requires an entity to measure and recognize expected credit losses for certain financial instruments, including trade receivables, as an allowance that reflects the entity's current estimate of credit losses expected to be incurred. For available-for-sale debt securities with unrealized losses, the standard requires allowances to be recorded through net income instead of directly reducing the amortized cost of the investment under the previous other-than-temporary impairment model. The adoption of this standard did not have a material impact on our financial statements or a significant impact on our internal controls.

Effective April 1, 2020, the Company is solely responsible for the development and commercialization of Praluent^® in the United States and will record net product sales of Praluent in the United States. See Note 3 for further details.

The Company had product sales to certain customers that accounted for more than 10% of total gross product revenue for ~~each of~~ the three ~~and nine~~ months ended ~~September 30, 2017~~March 31, 2020 and ~~2016.~~2019. Sales to each of these customers as a percentage of the Company's total gross product revenue are as follows:

In arrangements where we do not deem our collaborator to be our customer, payments to and from our collaborator are presented in our statement of operations based on the nature of our business operations, the nature of the arrangement, including the contractual terms, and the nature of the payments, as summarized in the table and further described below.

When we are entitled to reimbursement of all or a portion of the research and development expenses that we incur under a collaboration, we record those reimbursable amounts in the period in which such costs are incurred. In connection with the commercialization phase of our collaborative arrangements, we may be obligated to perform commercialization-related activities on behalf of the collaboration. If we are reimbursed for all or a portion of costs incurred for the commercialization-related activities, we record those reimbursable amounts in the period in which such costs are incurred.

~~In November 2007, the~~Amounts recognized in our Statements of Operations in connection with our collaborations with Sanofi are detailed below:

The Company ~~entered into~~is party to a global, strategic collaboration with Sanofi to discover, develop, and commercialize fully human monoclonal antibodies (the "Antibody Collaboration"). ~~The Antibody Collaboration is governed by~~Under the companies' ~~Discovery and Preclinical Development Agreement ("~~Antibody ~~Discovery Agreement") and a~~ License and Collaboration Agreement (each as amended). Pursuant to the Antibody Discovery Agreement, Sanofi agreed to fund up to $130.0 million of the Company's research activities in 2017. The Company's Antibody Discovery Agreement with Sanofi will end on December 31, 2017 without any extension and, therefore, funding from Sanofi under the Antibody Discovery Agreement will cease after 2017.

Effective January 2018, the Company and Sanofi entered into a letter agreement (the "Letter Agreement") in connection with, among other matters, the allocation of additional funds to certain activities relating to dupilumab and REGN3500 (collectively, the "Dupilumab/REGN3500 Eligible Investments"). Refer to the "Immuno-Oncology" section below for further details regarding the Letter Agreement and Note 9 for additional information regarding shares purchased by us from Sanofi during the three months ended ~~September 30, 2017~~March 31, 2020 and ~~2016,~~2019.

Sanofi leads commercialization activities for products developed under the ~~Company recognized as research and development expense $22.6 million and $27.9 million, respectively, and during~~Antibody Collaboration, subject to the nine months ended September 30, 2017 and 2016, the Company recognized as research and development expense $68.2 million and $80.2 million, respectively, of antibody development expenses that the Company was obligatedCompany's right to ~~reimburse to Sanofi related to Praluent~~^®~~, Kevzara~~^® ~~(sarilumab), and Dupixent~~^® ~~(dupilumab).~~

payments, with milestone payments commencing after aggregate annual sales of ~~losses~~antibodies outside the United States (including Praluent) exceed $1.0 billion on a rolling twelve-month basis.

The following table summarizes contract balances in connection with the ~~companies commercializing Praluent, Kevzara, and Dupixent within Sanofi collaboration revenue.~~Company's Antibody Collaboration with Sanofi:

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 ~~2017,~~31, 2020 is the ~~U.S. Food~~last quarter for which Sanofi and ~~Drug Administration ("FDA"~~the Company will share profits and losses for Praluent under the LCA. The parties also entered into a Praluent Cross License & Commercialization Agreement (the "Praluent Agreement") ~~approved Dupixent~~pursuant to which, effective April 1, 2020, the Company, at its sole cost, is solely responsible for the ~~treatment~~development and commercialization of ~~adult patients with moderate-to-severe atopic dermatitis,~~Praluent in the United States, and in September 2017, the European Commission granted marketing authorization for Dupixent for use in adults with moderate-to-severe atopic dermatitis who are candidates for systemic therapy. In May 2017, the FDA approved KevzaraSanofi, at its sole cost, is solely responsible for the ~~treatment~~development and commercialization of ~~adult patients with moderately~~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 ~~severely active rheumatoid arthritis,~~supply drug substance to Sanofi and Sanofi will continue to supply finished product to Regeneron.

In ~~July~~ 2015, the Company and Sanofi entered into a collaboration to discover, 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"). ~~Pursuant to~~

Effective December 31, 2018, the Company and Sanofi entered into the Amended IO Discovery Agreement, ~~Sanofi will reimburse~~which narrowed the scope of the existing discovery and development activities conducted by the Company ~~for up~~("IO Development Activities") under the 2015 IO Discovery Agreement to ~~$200.0 million in 2017 to identify~~developing therapeutic bispecific antibodies targeting (i) BCMA and ~~validate potential immuno-oncology targets~~CD3 (the "BCMAxCD3 Program") and ~~develop therapeutic antibodies against such targets~~(ii) MUC16 and CD3 (the "MUC16xCD3 Program") through clinical proof-of-concept. 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. In addition, we and Sanofi will share equally, on an ongoing basis, the development costs for a MUC16xCD3 Program antibody.

Under the terms of the IO License and Collaboration Agreement, the parties are co-developing ~~the Company's~~and co-commercializing Libtayo (cemiplimab), an antibody ~~product candidate~~ targeting the receptor known as programmed cell death protein 1 ~~or PD-1 ("cemiplimab")~~(PD-1). The parties share equally, on an ongoing basis, agreed-upon development and commercialization expenses for ~~cemiplimab.~~

we may elect to purchase, in whole or in part, such shares from Sanofi. See Note 9 for additional information regarding shares purchased by us from Sanofi during the three months ended March 31, 2020 and 2019.

The Company has principal control over the development of Libtayo and leads commercialization activities in the United States (see Note 2 for related product sales information), while Sanofi leads commercialization activities outside of the United States and the parties equally share profits and losses from worldwide sales.

The following table summarizes contract balances in connection with the Company's IO Collaboration with Sanofi:

Other liabilities include up-front payments received from Sanofi for which recognition has been deferred.

The aggregate amount of the estimated consideration under the IO Collaboration related to the Company's obligation that was unsatisfied (or partially unsatisfied) as of March 31, 2020 was $1.087 billion. This amount is expected to be recognized over the remaining period in which the Company is obligated to satisfy its obligation in connection with performing development activities.

~~The~~Amounts recognized in our Statements of Operations in connection with our Bayer EYLEA collaboration ~~revenue the Company earned from Bayer is detailed below:~~are as follows::

Three Months Ended
September 30, Nine Months Ended
September 30,
Bayer Collaboration Revenue 2017 2016 2017 2016
EYLEA:
Regeneron's net profit in connection with commercialization of EYLEA outside the United States $ 205,367
$ 170,854
$ 571,126
$ 484,181
Reimbursement of Regeneron EYLEA development expenses 6,053
2,219
10,833
7,186
Other 15,714
6,077
36,910
45,924
Total EYLEA 227,134
179,150
618,869
537,291
Ang2 antibody and PDGFR-beta antibody:
Reimbursement of development expenses 7,325
7,433
15,614
14,165
Other 2,166
4,715
6,436
11,330
Total Ang2 antibody and PDGFR-beta antibody 9,491
12,148
22,050
25,495
$ 236,625
$ 191,298
$ 640,919
$ 562,786

~~Ang2 antibody outside the United States~~

In ~~September~~ 2016, the Company and Teva entered into a collaboration agreement (the "Teva Collaboration Agreement") to develop and commercialize fasinumab globally, excluding certain Asian countries that are subject to ~~the Company's~~our collaboration agreement with ~~MTPC (as described above). In connection with the Teva Collaboration Agreement, Teva made a $250.0 million non-refundable up-front payment in September 2016.~~Mitsubishi Tanabe Pharma Corporation. The Company leads global development activities, and the parties share development costs equally, on an ongoing ~~basis. The $250.0 million up-front payment was initially recorded as deferred revenue, and is being recognized ratably as revenue over the related performance period.~~

Amounts recognized in our Statements of Operations in connection with the Teva Collaboration ~~Agreement. In the second quarter of 2017, the Company earned, and recognized~~Agreement is as ~~a substantive milestone, a $25.0 million development milestone from Teva upon initiation of a Phase 3 trial.~~follows:

~~In April 2016, the Company entered into a license and collaboration agreement with Intellia Therapeutics, Inc. to advance CRISPR/Cas gene-editing technology for~~ ~~in vivo~~ ~~therapeutic development.~~ The ~~Company collaborates with Intellia to conduct research for the discovery, development, and commercialization of new therapies,~~following table summarizes contract balances in ~~addition to the research and technology development of the CRISPR/Cas platform. In~~ connection with the ~~execution of the agreement, the Company made a $75.0 million~~Teva Collaboration Agreement:

Other liabilities include up-front ~~payment, which was recorded as research~~ and development ~~expense~~milestone payments received from Teva for which recognition has been deferred.

The aggregate amount of estimated consideration under the Teva Collaboration Agreement related to the Company's obligation that was unsatisfied (or partially unsatisfied) as of March 31, 2020 was $225.1 million. This amount is expected to be recognized over the remaining period in ~~the second quarter of 2016. In May 2016, Intellia completed an initial public offering ("IPO") of its common stock; as part of the concurrent private placement,~~which the Company ~~purchased $50.0 million of Intellia common stock.~~

The Company's basic net income per share amounts have been 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:

Shares which have been excluded from diluted per share amounts because their effect would have been antidilutive, include the following:

Marketable securities as of ~~September 30, 2017~~March 31, 2020 and December 31, ~~2016~~2019 consist of both available-for-sale debt securities of investment grade issuers (see below and Note 6) as well as equity ~~securities.~~securities of publicly traded companies (see Note 6).

The following tables summarize the Company's investments in ~~marketable~~available-for-sale debt securities:

The Company classifies its investments in available-for-sale debt ~~security investments~~securities based on their contractual maturity dates. The available-for-sale debt securities listed as of ~~September 30, 2017~~March 31, 2020 mature at various dates through ~~September~~ ~~2022.~~March 2025. The fair values of available-for-sale debt security investments by contractual maturity consist of the following:

September 30, 2017 December 31, 2016
Maturities within one year $ 586,879
$ 503,481
Maturities after one year through five years 1,239,263
815,041
$ 1,826,142
$ 1,318,522
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.

There were no0 realized losses on sales of marketable securities, and realized gains were not material, for the three ~~and nine~~ months ended ~~September 30, 2017. Realized gains~~March 31, 2020 and ~~losses on sales of marketable securities were not material for the three and nine months ended September 30, 2016.~~2019.

~~As it relates~~With respect to marketable securities, for the three ~~and nine~~ months ended ~~September 30, 2017~~March 31, 2020 and ~~2016,~~2019, amounts reclassified from ~~accumulated~~Accumulated other comprehensive (loss) income ~~(loss)~~ into ~~other~~Other (expense) income, net were related to realized gains ~~and losses~~ on ~~sales.~~sales of available-for-sale debt securities (as described above).

The table below summarizes the Company's assets ~~that~~which are measured at fair value on a recurring ~~basis consist of the following:~~basis. The following fair value hierarchy is used to classify assets, based on inputs to valuation techniques utilized to measure fair value:

The Company ~~considers market liquidity in determining the fair value for these securities. The Company did not record any charges for other-than-temporary impairment~~held certain restricted equity securities as of ~~its Level 2 marketable securities during~~March 31, 2020 which are subject to transfer restrictions that expire at various dates through 2023.

During the three ~~and nine~~ months ended ~~September 30, 2017~~March 31, 2020 and ~~2016.~~

7.Inventories

Inventories consist of the following:

Deferred costs represent the costs of product manufactured and shipped to the Company's collaborators for which recognition of revenue has been ~~deferred.~~deferred (see Note 3).

The Company is subject to U.S. federal, state, and ~~Accrued Expenses~~

During the ~~non-cash portion~~three months ended March 31, 2020, we repurchased 719,167 shares of our Common Stock under the ~~related Note conversions. The Company~~program and recorded the cost of the shares received, or ~~$10.0~~$272.8 million, as Treasury ~~Stock during the first nine months~~Stock. As of ~~2016.~~

As described in Note 3, effective January 2018, we have agreed to ~~reduce a portion of the number of warrants held by the warrant holder. The reduction~~allow Sanofi to satisfy in ~~the number of warrants was determined based on the number of warrants~~whole or in part its funding obligations with respect to ~~which~~Libtayo development and/or Dupilumab/REGN3500 Eligible Investments by selling our Common Stock directly or indirectly owned by Sanofi. During the ~~warrant holder closed out its hedge position, provided that~~three months ended March 31, 2020, Sanofi elected to sell, and we elected to purchase (by issuing a credit towards the ~~warrant holder did not effect any purchases at~~amount owed by Sanofi), 43,627 shares of our Common Stock to satisfy Sanofi's funding obligation related to Libtayo development costs, and we recorded the cost of the shares received, or $21.4 million, as Treasury Stock. During the three months ended March 31, 2019, we purchased (by issuing a ~~price per share exceeding $535.00 per share,~~credit towards the amount owed by Sanofi) 106,972 shares of our Common Stock from Sanofi, and recorded the cost of the shares received, or $44.0 million, as Treasury Stock. In addition, during the ~~period starting on November 16,~~three months ended March 31, 2020, Sanofi elected to sell, and we elected to purchase (in cash), 85,287 shares of our Common Stock in connection with Sanofi's funding obligation for Dupilumab/REGN3500 Eligible Investments, and recorded the cost of the shares received, or $41.8 million, as Treasury Stock. During the three months ended March 31, 2019, Sanofi elected

~~2015~~to sell, and ~~ending no later than February 9, 2016. The Company was able~~we elected to ~~settle, at its option, any payments due under the amendment agreement in cash or by delivering~~purchase (in cash), 24,143 shares of our Common ~~Stock. As a result~~Stock in connection with Sanofi's funding obligation for Dupilumab/REGN3500 Eligible Investments, and recorded the cost of the ~~warrant holder closing out a portion of its hedge position in the first quarter of 2016, the Company paid a total of $135.2~~shares received, or $10.0 million, ~~to reduce the number of warrants held by such warrant holder by 360,406.~~

The ~~Company leases laboratory~~following provides a reconciliation of cash, cash equivalents, and ~~office facilities in Tarrytown, New York (the "Tarrytown Leases"). Prior to December 30, 2016, certain of~~restricted cash reported within the premises under the Tarrytown Leases had been accounted for as operating leases, while for certain other buildings the Company leased, the Company was deemed, in substance, to be the owner of the landlord's buildings (collectively, the "Build-to-Suit Buildings") in accordance with the application of FASB authoritative guidance. On December 30, 2016, the Company entered into a Purchase Agreement with BMR-Landmark at Eastview LLC and BMR-Landmark at Eastview IV LLC (collectively, "BMR"), pursuant to which the Company agreed to purchase BMR's Tarrytown, New York facilities (the "Facility") for a purchase price of $720.0 million. The Company occupies a significant portion of the Facility, with the remaining rentable area under leases to third-party tenants. In accordance with the terms of the Purchase Agreement, the Company paid $57.0 million toward the purchase price to BMR in December 2016.

Restricted cash consists of amounts held by financial institutions pursuant to contractual arrangements.

Included in accounts payable, ~~and~~ accrued expenses, and other liabilities as of ~~September 30, 2017~~March 31, 2020 and December 31, ~~2016~~2019 were ~~$24.5~~$72.6 million and ~~$28.2~~$133.7 million, respectively, of accrued capital expenditures. Included in accounts payable, ~~and~~ accrued expenses, and other liabilities as of ~~September 30, 2016~~March 31, 2019 and December 31, ~~2015~~2018 were ~~$33.9~~$54.4 million and ~~$50.7~~$54.5 million, respectively, of accrued capital expenditures.

~~The Company recognized an additional capital lease obligation of $201.2 million~~As described in ~~connection with the Company's lease of additional premises at its Tarrytown, New York facility~~Note 9, during the ~~nine~~three months ended ~~September 30, 2017 (see Note 10). No such~~March 31, 2020 and 2019, we purchased (by issuing a credit towards the amount ~~was recognized during the nine months ended September 30, 2016.~~owed by Sanofi) shares of our Common Stock from Sanofi to satisfy Sanofi's funding obligation related to Libtayo development costs.

From time to time, the Company is a party to legal proceedings in the course of the Company's business. Costs associated with the Company's involvement in legal proceedings are expensed as incurred. The outcome of any such proceedings, regardless of the merits, is inherently uncertain. The Company recognizes accruals for loss contingencies associated with such proceedings when it is probable that a liability will be incurred and the amount of loss can be reasonably estimated. As of March 31, 2020 and December 31, 2019, the Company had accruals for loss contingencies of $117.0 million and $100.0 million, respectively. 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.

The Company is a party to patent infringement litigation initiated by the Company involving its European Patent No. 1,360,287 (the "'287 Patent"), and its European Patent No. 2,264,163 (the "'163 ~~Patent"), and its U.S. Patent No. 8,502,018 (the "'018~~ Patent"). Each of these patents concerns genetically engineered mice capable of producing chimeric antibodies that are part human and part mouse. Chimeric antibody sequences can be used to produce high-affinity fully human monoclonal antibodies. In these proceedings, the Company claims infringement of several claims of the '287 Patent ~~the '163 Patent,~~ and the ~~'018~~'163 Patent (as applicable), and seeks, among other types of relief, an injunction and an account of profits in connection with the defendants' infringing acts, which may include, among other things, the making, use, keeping, sale, or offer for sale of genetically engineered mice (or certain cells from which they are derived) that infringe one or more claims of the '287 Patent and the '163 Patent (as applicable).

On September 25, 2013, the Company commenced patent infringement litigation against Kymab Ltd in the English High Court of Justice, Chancery Division, Patents Court, in London, asserting the '287 Patent and '163 Patent. Following a trial to adjudicate the claims of infringement and counterclaims of invalidity of the '287 Patent and the ~~'018~~'163 Patent, ~~(as applicable)~~the court issued a final judgment on February 1, 2016, finding that the asserted claims of the '287 and '163 Patents are novel, not obvious, and infringed by Kymab's genetically engineered mice. However, the court invalidated the '287 and '163 Patents on the ground of insufficiency. On appeal, the Court of Appeal (Civil Division of England and Wales) reversed the English High Court's decision and held that the '287 Patent and '163 Patent are both valid and infringed by Kymab and subsequently issued a final order, which enjoins Kymab from infringing the '287 Patent and '163 Patent (subject to certain exceptions) and requires Kymab to destroy or deliver to a third party all products

and antibodies and cells engineered to produce antibodies which infringe the '287 Patent and '163 Patent (subject to certain exceptions). ~~At this time,~~Thereafter, the Supreme Court of the United Kingdom granted Kymab's application for permission to appeal the order made by the Court of Appeal with respect to an issue of validity of the '287 Patent and the '163 Patent. An oral hearing was held on February 11–12, 2020, but a decision has not yet been announced. The provisions of the final order of the Court of Appeal are stayed pending final determination of Kymab's appeal to the Supreme Court of the United Kingdom. The Company has also been awarded a portion of the legal fees incurred by it in connection with the proceedings in the English High Court and the Court of Appeal described above. On July 31, 2019, the Company ~~is not able~~filed an action in the English High Court for a calculation of damages relating to ~~predict~~Kymab's infringement of the ~~outcome~~'287 Patent and the '163 Patent.

As described in greater detail below, the Company is currently a party to patent infringement actions initiated by Amgen Inc. (and/or its affiliated entities) against the Company ~~and~~and/or Sanofi (and/or the Company's and Sanofi's respective affiliated entities) in a number of jurisdictions relating to ~~Praluent, which~~Praluent. See Note 3 for a description of the ~~Company is jointly developing~~Company's and ~~commercializing~~Sanofi's arrangement regarding the costs resulting from or associated with ~~Sanofi.~~such actions.

In the United States, Amgen has asserted ~~a number~~claims of ~~U.S. patents, which were subsequently narrowed to~~ U.S. Patent Nos. 8,829,165 (the "'165 Patent") and 8,859,741 (the "'741 Patent"), and seeks 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 seeks a judgment of patent infringement of the asserted patents, monetary damages (together with interest), costs and expenses of the lawsuits, and attorneys' fees. AThe first jury trial in this litigation (the "First Trial") was held in the United States District Court for the District of Delaware (the "District Court") from March 8 to March 16, 2016. During the course of the ~~trial,~~First Trial, the District Court ruled as a matter of law in favor of Amgen that the asserted patent claims were not obvious, and in favor of the Company and the Sanofi defendants that there was no willful infringement of the asserted patent claims by the Company or the Sanofi defendants. On March 16, 2016, the jury returned a verdict in favor of Amgen in the First Trial, finding that the asserted claims of the '165 and '741 Patents were not invalid based on either a lack of written description or a lack of enablement. On ~~January 3,~~October 5, 2017, the District Court issued a final opinion and judgment, denying the Company and the Sanofi defendants' motions for new trial and judgment as a matter of law. The District Court also denied as moot Amgen's motion to strike the Company and the Sanofi defendants' request to obtain a judgment as a matter of law, which allowed the United States Court of Appeals for the Federal Circuit (the "Federal Circuit") to address the Company and the Sanofi defendants' patent invalidity arguments on appeal. On January 12, 2017, the Company and the Sanofi defendants filed a notice of appeal with the Federal Circuit. On April 19, 2017, the District Court granted Amgen's motion to amend the judgment on an accounting of supplemental damages and enhancement of such damages if deemed appropriate, but deferred the order until after the Federal Circuit issued a decision on the appeal. Oral argument on the appeal was held on June 6, 2017. On October 5, 2017, the Federal Circuit reversed in part the District Court's decision and remanded for a new trial on the issues of written description and ~~enablement, and, as discussed below, vacated the District Court's permanent injunction.~~enablement. In addition, it affirmed the District Court's ruling that Amgen's patents were not obvious. ~~The Federal Circuit further concluded~~

On January 3, 2019, the District Court held oral argument in the remanded proceedings on the Company and the Sanofi ~~defendants~~defendants' motion for judgment on the pleadings regarding Amgen's willful infringement claim. On January 18, 2019, the District Court entered an order (i) denying the Company and the Sanofi defendants' motion for summary judgment on validity, (ii) denying Amgen's motion for partial summary judgment on estoppel, and (iii) granting the Company and the Sanofi defendants' cross-motion for summary judgment on estoppel. On February 8, 2019, the District Court granted the Company and the Sanofi defendants' motion for judgment on the pleadings, thereby dismissing Amgen's claim of willful infringement. The second jury trial in this litigation (the "Second Trial") was held before the District Court in February 2019 to determine the validity of Amgen's asserted patent claims. On February 25, 2019, the jury returned a verdict in the Second Trial generally in favor of Amgen, finding that 2 claims of the '165 Patent and 1 claim of the '741 Patent were not ~~entitled~~invalid. The jury also found that 2 claims of the '165 Patent were invalid for lack of adequate written description while rejecting the lack of enablement challenges to ~~judgment~~those two claims. On August 28, 2019, the District Court ruled as a matter of law that Amgen's asserted patent claims are invalid based on lack of enablement. The District Court also conditionally denied the ~~issues~~Company and the Sanofi defendants' motion for a new trial. On October 23, 2019, Amgen filed a notice of ~~written description and enablement on this record.~~appeal of the District Court's decision with the Federal Circuit.

On ~~January 5, 2017, the District Court granted~~March 18, 2019, Amgen filed a renewed motion for a permanent injunction ~~prohibiting Regeneron~~to prohibit the Company and the Sanofi defendants from Commercializing Praluent in the United States ~~but subsequently delayed its imposition until February 21, 2017. The~~(a "Permanent Injunction"), and an oral hearing on this motion was held in June 2019. Previously, the Federal Circuit stayed and then vacated a Permanent Injunction granted by the ~~injunction pending appeal on February 8, 2017 and vacated it on October 5, 2017.~~District Court in connection with the First Trial. On August 28, 2019, the District Court dismissed as moot Amgen's renewed motion for a Permanent Injunction.

On July 25, 2016, Amgen filed a lawsuit against Regeneron, Sanofi-Aventis Groupe S.A., Sanofi-Synthelabo Limited, Aventis Pharma Limited, Sanofi Winthrop Industrie S.A., and Sanofi-Aventis Deutschland GmbH in the English High Court of Justice, Chancery Division, Patents Court, in London, seeking a declaration of infringement of Amgen's European Patent No. 2,215,124 (the "'124 Patent"), which pertains to PCSK9 monoclonal antibodies, by Praluent. The lawsuit also seeks a permanent injunction, damages, an accounting of profits, and costs and interest. On February 8, 2017, the court temporarily stayed this litigation on terms mutually agreed by the parties.

Also on July 25, 2016, Amgen filed a lawsuit for infringement of the '124 Patent against Regeneron, Sanofi-Aventis Groupe S.A., Sanofi Winthrop Industrie S.A., and Sanofi-Aventis Deutschland GmbH in the Regional Court of Düsseldorf, Germany (the "Düsseldorf Regional Court"), seeking a permanent injunction, an accounting of marketing activities, a recall of Praluent and its removal from distribution channels, and damages. ~~Oral~~On November 14, 2017, the Düsseldorf Regional Court issued a decision staying the infringement proceedings until a decision of the Opposition Division of the EPO concerning the pending opposition filed by the Company, Sanofi, and several other opponents against the '124 Patent (as discussed below). Following Amgen's request to reopen the proceedings in light of the issuance of the Preliminary Opinion (as defined below), the Düsseldorf Regional Court held an oral hearing on ~~this~~September 11, 2018 and ruled on December 10, 2018 that the infringement ~~lawsuit was held~~proceedings would be reopened. On July 11, 2019, the Düsseldorf Regional Court found that Praluent infringes the '124 Patent and granted an injunction prohibiting the Company and Sanofi's manufacture, sale, and marketing of Praluent in Germany (the "July 11 Decision"). Amgen subsequently enforced the injunction and, as a result, commercialization of Praluent in Germany has been discontinued. On July 12, 2019, the Company and Sanofi appealed the July 11 Decision to the Higher Regional Court of Düsseldorf (the "Higher Regional Court"). An oral hearing on the merits of the appeal to the Higher Regional Court (originally scheduled for April 2, 2020) has been rescheduled for November 5, 2020. On August 5, 2019 and October ~~19, 2017.~~31, 2019, the Higher Regional Court denied the Company and Sanofi's requests for a stay of preliminary enforcement of the July 11 Decision pending the appeal on the merits.

On September 26, 2016, Amgen filed a lawsuit for infringement of the '124 Patent in the Tribunal de grande instance in Paris, France against Regeneron, Sanofi-Aventis Groupe S.A., Sanofi Winthrop Industrie S.A., and Sanofi Chimie (subsequently added as a defendant). Amgen is seeking the prohibition of allegedly infringing activities with a €10,000 penalty per drug unit of Praluent produced in violation of the court order sought by Amgen; an appointment of an expert for the assessment of damages; disclosure of technical (including supply-chain) and accounting information to the expert and the court; provisional damages of €10.0 million (which would be awarded on an interim basis pending final determination); reimbursement of costs; publication of the ruling in three newspapers; and provisional enforcement of the decision to be issued, which would ensure enforcement of the decision (including any provisional damages) pending appeal. Amgen is not seeking a preliminary injunction in this proceeding at this time. On April 10, 2017, the Company and the Sanofi parties filed briefs seeking invalidation of certain of the claims of the '124 Patent, and Amgen filed a response on July 28, 2017. Oral hearing on this infringement lawsuit ~~is currently~~(originally scheduled for ~~June 29, 2018.~~February 12, 2019) has yet to be rescheduled.

On December 17, 2019, Amgen initiated a lawsuit alleging infringement of the Dutch designation of the '124 Patent in the District Court of The Hague in the Netherlands, against Sanofi-Aventis Netherlands B.V. and Sanofi-Aventis Groupe S.A. The Company has not been named as a defendant in this action. Amgen alleges, among other things, patent infringement based on the production, importation, and commercialization of Praluent (alirocumab) in the Netherlands. Amgen's requests are made on an accelerated basis and include, among other things, a request for a permanent injunction, damages, an order for customer information, a recall order, a destruction order, and an order for costs. A trial has been scheduled for October 30, 2020.

On December 20, 2019, Amgen filed a lawsuit for infringement of the Italian designation of the '124 Patent in the Tribunale di Milano - Enterprise Chamber in Milan, Italy, against Sanofi-Aventis Groupe S.A., Sanofi Chimie, and Sanofi SpA. The Company has not been named as a defendant in this action. Amgen alleges that the production, importation, and commercialization of Praluent (alirocumab) in Italy infringes the '124 Patent. The writ of summons filed by Amgen seeks, among other things, a declaration of infringement, a permanent injunction, withdrawal of product from the market, and damages.

On December 20, 2019, Amgen also filed a lawsuit alleging infringement of the Spanish designation of the '124 Patent in the Juzgado de lo Mercantil No. 5 (Commercial Court) in Barcelona, Spain, against Sanofi-Aventis, S.A. The Company has not been named as a defendant in this action. Amgen alleges, among other things, patent infringement based on the manufacture, offering for sale, introduction into the market, use, and importation or possession of Praluent (alirocumab) in Spain. Amgen seeks, among other things, a permanent injunction, withdrawal of Praluent from the market, seizure and destruction of Praluent from the market and in storage, and damages in the form of lost profits and costs and expenses.

The '124 Patent is also subject to opposition proceedings in the ~~European Patent Office~~EPO seeking to invalidate certain of its claims, which were initiated by Sanofi on February 24, 2016 and, separately, by the Company, Sanofi, and several other opponents on November 24, 2016. On December 13, 2017, the Opposition Division of the EPO issued a preliminary, non-binding opinion (the "Preliminary Opinion") regarding the validity of the '124 Patent, indicating that it currently considers the claims of a new request filed by Amgen in response to the opposition to satisfy the requirements for patentability. An oral hearing on the oppositions against the '124 Patent was held on November 28–30, 2018, at which the Opposition Division upheld the validity of the '124 Patent's claims in amended form. The Company and Sanofi filed notices of appeal to the Technical Board of Appeal (the "TBA") of the EPO on November 30, 2018. An oral hearing before the TBA has been rescheduled for October 28–29, 2020.

On May 19, 2017, Amgen filed a lawsuit for infringement of Amgen's Japanese Patent Nos. 5,906,333 (the "'333 Patent") and 5,705,288 (the "'288 Patent") in the Tokyo District Court Civil Division (the "Tokyo District Court") against Sanofi K.K. Amgen's complaint alleges that manufacturing, selling or otherwise transferring, and offering to sell or otherwise transfer Praluent (alirocumab) in Japan (as well

On March 20, 2017, the Company, Sanofi-Aventis U.S. LLC, and Genzyme Corporation filed a ~~complaint~~lawsuit against Amgen and Immunex Corporation, a wholly owned subsidiary of Amgen, in the United States District Court for the District of Massachusetts seeking a declaratory judgment that the Company's and the other plaintiffs' ~~commercializing~~Commercializing of Dupixent does not directly or indirectly infringe U.S. Patent No. 8,679,487 (the "'487 Patent") owned by Immunex Corporation relating to antibodies that bind the human interleukin-4 receptor. On May 1, 2017, the Company and the other plaintiffs filed a notice of voluntary dismissal of this action without prejudice.

On March 23, 2017, the Company, Sanofi-Aventis U.S. LLC, and Genzyme Corporation initiated an inter partes review ("IPR") in the United States Patent and Trademark Office ("USPTO") seeking a declaration of invalidity of the '487 Patent. On July 28 and 31, 2017, the same parties filed ~~two~~2 additional IPR petitions in the USPTO seeking declarations of invalidity of the '487 Patent based on different grounds (the "Additional IPR Petitions"). On October 4, 2017, the Patent Trial and Appeal Board ("PTAB") of the USPTO issued a decision on the first IPR petition and declined to institute an IPR proceeding to review the validity of the '487 Patent. ~~The~~On February 15, 2018, the PTAB issued two decisions instituting the Company's and Sanofi's Additional IPR Petitions ~~are still pending.~~on all claims of the '487 Patent for which review had been requested. Oral hearings on the Additional IPR Petitions before the PTAB were held on November 14, 2018. On February 14, 2019, the PTAB issued final written decisions on the Additional IPR Petitions, invalidating all 17 claims of the '487 Patent as obvious based on one of the Additional IPR Petitions while declining to hold the challenged claims of the '487 Patent invalid based on the other. In April 2019, the parties filed notices of appeal with the Federal Circuit appealing the PTAB's respective adverse final written decisions on the Additional IPR Petitions.

On April 5, 2017, Immunex Corporation filed a ~~complaint~~lawsuit against the Company, Sanofi, Sanofi-Aventis U.S. LLC, Genzyme Corporation, and Aventisub LLC in the United States District Court for the Central District of California seeking a judgment of patent infringement of the '487 Patent and a declaratory judgment of infringement of the '487 Patent, in each case by the Company's and the other defendants' Commercializing of Dupixent; monetary damages (together with interest); an order of willful infringement of the '487 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. Immunex is not seeking an injunction in this proceeding at this time. On June 21, 2017, the court denied a motion to dismiss Immunex's complaint previously filed by the Company and the Sanofi parties. On June

28, 2017, the Company and the Sanofi parties filed an answer to Immunex's complaint and counterclaims against Immunex and Amgen (which was amended on October 31, 2017 to, among other things, add an inequitable conduct allegation), and Immunex and Amgen filed an answer to the counterclaims on July 28, 2017. A ~~jury trial has been scheduled to start~~combined hearing on ~~March 19, 2019.~~

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. The Company is cooperating with this investigation. ~~The Company cannot predict the outcome or duration of this investigation or any other legal proceedings or any enforcement actions or other remedies that may be imposed on~~

In September 2019, the Company ~~arising out~~and Regeneron Healthcare Solutions, Inc., a wholly-owned subsidiary of ~~this investigation.~~

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

Our ~~total revenues were $1,500.7 million~~core business strategy is to maintain a strong foundation in ~~the third quarter~~basic scientific research and ~~$4,289.8 million in the first nine months of 2017, compared~~discovery-enabling technologies, and to ~~$1,220.1 million in the third quarter~~build on that foundation with our clinical development, manufacturing, and ~~$3,633.6 million in the first nine months of 2016.~~commercial capabilities. Our ~~net income was $388.3 million, or $3.32 per diluted share, in the third quarter~~objective is to continue to be an integrated, multi-product biotechnology company that provides patients and ~~$1,025.0 million, or $8.84 per diluted share, in the first nine months of 2017, compared to net income of $264.8 million, or $2.27 per diluted share, in the third quarter~~medical professionals with important options for preventing and ~~$642.4 million, or $5.51 per diluted share, in the first nine months of 2016. Refer to the "Results of Operations" section below for further details of our~~treating human diseases.

Selected financial ~~results.~~

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

~~We have 16~~All 22 of our product candidates in clinical development, ~~all of~~including the five U.S. Food and Drug Administration ("FDA") approved products which we are investigating in additional indications, were discovered in our research ~~laboratories. These consist of a Trap-based clinical program~~laboratories and ~~fully human monoclonal antibody product candidates, as~~are summarized ~~below. In addition to the product candidates in clinical development described below, we have ongoing studies for our marketed products. Each of the antibodies~~ in the table ~~below was generated using~~below. We believe that our ~~VelocImmune~~ability to develop product candidates is enhanced by the application of our VelociSuite^® ~~technology.~~ technology platforms. We continue to invest in the development of enabling technologies to assist in our efforts to identify, develop, manufacture, and commercialize new product candidates.

There are numerous uncertainties associated with drug development, including uncertainties related to safety and efficacy data from each phase of drug development (including any post-approval studies), uncertainties related to the enrollment and performance of clinical trials, changes in regulatory requirements, changes to drug pricing and reimbursement regulations and requirements, and changes in the competitive landscape affecting a product candidate. The planning, execution, and results of our clinical programs are significant factors that can affect our operating and financial results.

Refer to Part II, Item ~~1A,~~1A. "Risk Factors" for a description of these and other risks and uncertainties that may affect our clinical ~~programs.~~programs, including those related to the COVID-19 pandemic.

~~Our preclinical~~We are using our end-to-end antibody technologies to discover and develop brand new therapeutic antibodies for COVID-19. The Company is advancing REGN-COV2, a novel investigational antibody "cocktail" treatment designed to prevent and treat infection from the SARS-CoV-2 virus. In April, the Company moved its leading neutralizing antibodies into pre-clinical and clinical-scale cell production lines and plans to have supply available for clinical studies, which are expected to begin in June 2020. The Company is also working to rapidly scale-up manufacturing.

The Company also announced an expansion of its Other Transaction Agreement ("OTA") with BARDA, pursuant to which HHS is obligated to fund 80% of our costs incurred for certain research ~~programs include~~and development activities related to COVID-19 treatments.

Antibody

As of March 31, 2020, we were collaborating with Sanofi on the ~~areas~~global development and commercialization of ~~oncology/immuno-oncology, angiogenesis, ophthalmology, metabolic~~Dupixent, Praluent, Kevzara, and REGN3500 (the "Antibody Collaboration"). See discussion below for updates related ~~diseases, muscle diseases~~to the development and ~~disorders, inflammation and immune diseases, bone and cartilage, pain and neurobiology, cardiovascular diseases, and infectious diseases.~~

In 2018, we and Sanofi entered into a letter agreement (the "Letter Agreement") amending the LCA in connection with, among other matters, the allocation of additional funds to certain proposed activities relating to dupilumab and REGN3500 (collectively, the "Dupilumab/REGN3500 Eligible Investments"). Pursuant to the ~~extent they are sufficient~~Letter Agreement, we have agreed to allow Sanofi to satisfy in whole or in part its funding obligations with respect to the Dupilumab/REGN3500 Eligible Investments for ~~this purpose. We are obligated~~the quarterly periods commencing on January 1, 2018 and ending on September 30, 2020 by selling up to ~~use commercially reasonable efforts~~an aggregate of 600,000 shares (of which 410,661 currently remains available) of our Common Stock directly or indirectly owned by Sanofi. Refer to ~~supply clinical requirements of each drug candidate under~~ the ~~collaboration until commercial supplies of that drug candidate are being manufactured.~~"Immuno-Oncology" section below for further details regarding the Letter Agreement.

Under our collaboration agreement, Sanofi records product sales for commercialized products, and Regeneron has the right to ~~co-promote~~co-commercialize such products on a country-by-country basis. We have exercised our option to ~~co-promote~~co-commercialize Dupixent ~~Praluent,~~in the United States and ~~Kevzara~~ in certain countries outside the United States. We ~~have not exercised any~~currently anticipate commencing co-commercialization of ~~our options to co-promote these antibodies~~Dupixent in such countries outside the United ~~States; however, we retain~~States at the ~~right~~end of 2020 or early 2021. We supply certain commercial bulk product to ~~do so at a future date subject to the terms of the collaboration agreement.~~Sanofi. We and Sanofi ~~will~~ equally share profits and losses from sales within the United States. We and Sanofi share profits outside the United States on a sliding scale based on sales starting at 65% (Sanofi)/35% (us) and ending at 55% (Sanofi)/45% (us), and share losses outside the United States at 55% (Sanofi)/45% (us). In addition to profit and loss sharing, we are entitled to receive up to an aggregate of $250.0 million in milestone payments upon achievement of specified aggregate annual sales of antibodies outside the United States (including Praluent) on a rolling twelve-month basis. The Company will be entitled to receive the first sales milestone ~~payments, with milestone payments commencing after aggregate annual~~payment from Sanofi, in the amount of $50.0 million, when such sales outside the United States exceed $1.0 ~~billion on a rolling 12-month basis.~~billion.

In December 2019, the Company and Sanofi also announced their intent to restructure their antibody collaboration for Kevzara. The companies continue to ~~discover, develop,~~assess potential terms of this restructuring in light of the recently launched clinical programs evaluating Kevzara in patients hospitalized with COVID-19 infection.

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

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

Under the terms of the Amended IO Discovery Agreement, the Company is required to conduct development activities with respect to (i) the BCMAxCD3 Program through the earlier of clinical proof-of-concept or the expenditure of $70.0 million (the "BCMAxCD3 Program Costs Cap") and (ii) the MUC16xCD3 Program through the earlier of clinical proof-of-concept or the expenditure of $50.0 million (the "MUC16xCD3 Program Costs Cap"); provided that under certain circumstances, Sanofi ~~made~~will have the option to increase the MUC16xCD3 Program Costs Cap to $70.0 million by making a ~~$265.0 million non-refundable up-front~~ payment to ~~us.~~ the Company in the amount of $20.0 million.

Pursuant to the Amended IO Discovery Agreement, we will spend up to $1,090.0 million (IO Discovery Budget) to identify and validate potential immuno-oncology targets and develop therapeutic antibodies against such targets through clinical proof-of-concept. Sanofi will reimburse us for up to $825.0 million (IO Discovery Funding) of these costs, subject to certain annual limits (up to $200.0 million for 2017). The term of the IO Discovery Agreement will continue through the later of five years from the effective date of the IO Collaboration or the date the IO Discovery Budget is exhausted, subject to Sanofi's option to extend it for up to an additional three years for the continued development (and funding) of selected ongoing programs. Pursuant to the IO Discovery Agreement, we will beare primarily responsible for conducting the ~~design and conduct of all research activities,~~IO Development Activities (other than certain clinical trials that may be funded separately by Sanofi), including ~~target identification and validation,~~ antibody development, preclinical activities, toxicology studies, manufacture of ~~preclinical and~~ clinical supplies, filing of ~~IND~~Investigational New Drug Applications ("INDs"), and clinical development through proof-of-concept. We ~~will~~are obligated to reimburse Sanofi for half of the development costs they funded that are attributable to clinical development of antibody product candidates under the Amended IO Discovery Agreement from our share of ~~future~~ profits ~~if any,~~ from commercialized IO Collaboration ~~products to the extent they are sufficient for this purpose.~~ products.

With regard to ~~product candidates for which~~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 further described below).~~as amended. If Sanofi does not exercise its option to license rights to a product candidate, we will retain the exclusive right to develop and commercialize such product candidate and Sanofi will receive a royalty on sales. Pursuant to the Amended IO Discovery Agreement, the parties agreed that (i) if Sanofi exercises its option with respect to a BCMAxCD3 Program antibody, Sanofi will lead the development and global commercialization of such BCMAxCD3 Program antibody; and (ii) if Sanofi exercises its option with

respect to a MUC16xCD3 Program antibody, (x) we will lead the development of such MUC16xCD3 Program antibody and commercialization of such MUC16xCD3 Program antibody within the United States and (y) Sanofi will lead the commercialization of such MUC16xCD3 Program antibody outside of the United States.

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

Under the terms of the IO License and Collaboration Agreement, the parties ~~will~~are also ~~co-develop our~~co-developing and co-commercializing Libtayo (cemiplimab), an antibody ~~product candidate~~ targeting ~~PD-1 (cemiplimab).~~PD-1. We have principal control over the development of ~~cemiplimab,~~Libtayo, and the parties share equally, on an ongoing basis, development and commercialization expenses for ~~cemiplimab~~Libtayo. Under the Letter Agreement, we have agreed to allow Sanofi to satisfy in whole or in part its funding obligation with respect to Libtayo development costs for the quarterly periods commencing on October 1, 2017 and ending on September 30, 2020 by selling up to an aggregate of 800,000 shares (of which 330,253 currently remains available) of our Common Stock directly or indirectly owned by Sanofi.

If Sanofi desires to sell shares of our Common Stock during the term of the Letter Agreement to satisfy a ~~total~~portion or all of ~~$650.0 million. We will~~its funding obligations for the Libtayo development and/or, as noted above, Dupilumab/REGN3500 Eligible Investments, we may elect to purchase, in whole or in part, such shares from Sanofi. If we do not elect to purchase such shares, Sanofi may sell the applicable number of shares (subject to certain daily and quarterly limits) in one or more open-market transactions. Refer to the "Antibody" section above for a description of share transactions related to Dupilumab/REGN3500 Eligible Investments.

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

EYLEA outside the United States.

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

~~Commencing with the first commercial sale of EYLEA in a major market country outside the United States, we became~~We are obligated to reimburse Bayer for 50% of the development costs that it has incurred under the agreement from our share of the collaboration profits (including payments to us based on sales in Japan). The reimbursement payment in any quarter will equal 5% of the then outstanding repayment obligation, but never more than our share of the collaboration profits in the quarter unless we elect to reimburse Bayer at a faster rate. ~~As a result, we expect that a portion of our share of EYLEA profits outside the United States will be used to reimburse Bayer for this repayment obligation.~~

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

Fasinumab.

In ~~September~~ 2016, we entered into a collaboration agreement with Teva to develop and commercialize fasinumab globally, excluding certain Asian countries that are subject to our collaboration agreement with ~~MTPC (as described above)~~Mitsubishi Tanabe Pharma Corporation ("MTPC"). In connection with the agreement, Teva made a $250.0 million non-refundable up-front ~~payment in 2016.~~payment. We ~~will~~ lead global development activities, and the parties will share equally, on an ongoing basis, development costs under a global development plan. ~~In the second quarter~~As of ~~2017,~~March 31, 2020, we had earned ~~a $25.0~~an aggregate of $120.0 million of development ~~milestone~~milestones from Teva and we are entitled to receive up to an aggregate of ~~$435.0~~$340.0 million in additional development milestones and up to an aggregate of ~~$1,890.0 million~~$1.890 billion in contingent payments upon achievement of specified annual net sales amounts. We are responsible for the manufacture and supply of fasinumab globally.

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

~~Developing~~In April 2020, we entered into an agreement with Zai Lab Limited to develop and ~~commercializing new medicines entails significant risk~~commercialize REGN1979 in mainland China, Hong Kong, Taiwan, and ~~expense. Before significant revenues from~~Macau (the "Zai Territories"). In connection with the ~~commercialization of our antibody candidates or new indications for our marketed products can be realized, we (or our collaborators) must overcome~~agreement, Zai is obligated to make a number of hurdles which include successfully completing research and development and obtaining regulatory approval from the FDA and regulatory authorities in other countries. In addition, the biotechnology and pharmaceutical industries are rapidly evolving and highly competitive, and new developments may render our products and technologies uncompetitive or obsolete.

We are responsible for the manufacture and supply of clinical and commercial supplies of REGN1979 to Zai. If REGN1979 is commercialized in the Zai Territories, we will supply the product to Zai at a tiered purchase price, which ~~we expect to be reimbursed by our collaborators. Also, our research and development activities outside our collaborations, the costs~~is calculated as a percentage of which are not reimbursed, are expected to expand and require additional resources. We also expect to incur substantial costs related to the commercialization of Dupixent, Praluent, and Kevzara, as well as preparation for potential commercialization of other indications of dupilumab. Our financial results may fluctuate from quarter to quarter and will depend on, among other factors, the net sales of ~~our marketed products,~~ the ~~scope~~product (subject to adjustment in certain circumstances), and ~~progress of our research~~are eligible to receive up to $160.0 million in additional regulatory and ~~development efforts, the timing of certain expenses, the continuation of our collaborations, in particular with Sanofi and Bayer, including our share of collaboration profits or losses from~~ sales of commercialized products and the amount of reimbursement of our research and development expenses that we receive from collaborators, and the amount of income tax expense we incur, which is partly dependent on the profits or losses we earn in each of the countries in which we operate. We cannot predict whether or when new products or new indications for marketed products will receive regulatory approval or, if any such approval is received, whether we will be able to successfully commercialize such product(s) and whether or when they may become profitable.milestone payments.

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

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

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

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

Results of Operations

Three Months Ended March 31, 2020 and 2019

Net product sales of EYLEA in the United States increased for the three ~~and nine~~ months ended ~~September 30, 2017,~~March 31, 2020, compared to the same ~~periods~~period in ~~2016,~~2019, due to higher sales volume, partly offset by an increase in sales-related deductions primarily due to ~~payer sales mix~~higher rebates and ~~new rebate programs.~~

Effective April 1, 2020, the Company is ~~recorded~~solely responsible for the development and commercialization of Praluent in the United States and will record net product sales of ~~applicable provisions~~Praluent in the United States. Refer to "Collaboration Agreements - Collaborations with Sanofi - Antibody" section above for ~~rebates and chargebacks, distribution-related fees, and other sales-related deductions. The following table summarizes the provisions and credits/payments for sales-related deductions.~~further details.

During the three ~~and nine~~ months ended ~~September 30, 2017,~~March 31, 2020, the change in our share of profits (losses) in connection with commercialization of antibodies, compared to the same ~~periods~~period in ~~2016,~~2019, was primarily due to decreased reimbursement levels for Dupixent (dupilumab) subsequent to the receipt of the first positive Phase 3 trial results, and U.S. regulatory approval, in accordance with the terms of our collaboration agreement.

Regeneron's share of our collaboration agreement and (ii) an acceleration of the recognition of deferred revenue from an $85.0 million up-front payment and other payments in connection with Sanofi's decision to end our Antibody Discovery Agreement on December 31, 2017 without any extension.

The quarterly period ended March 31, 2020 is the last quarter for which Sanofi and the Company will share profits and losses for Praluent. As described above under "Collaboration Agreements - Collaborations with Sanofi - Antibody", effective April 1, 2020, the Company is solely responsible for the development and commercialization of Praluent in the United States. Under the new agreement, Sanofi is solely responsible for the development and commercialization of Praluent outside of the ~~IO Collaboration agreements.~~United States, and will pay the Company a 5% royalty on Sanofi’s net product sales of Praluent outside the United States.

Regeneron's net profit in connection with commercialization of EYLEA outside the United States is summarized ~~below.~~

Bayer records ~~revenue from~~net product sales of EYLEA outside the United States. Bayer provides us with an estimate of our share of the profit, including the percentage of sales in Japan that we earned, from commercialization of EYLEA outside the United States for the most recent fiscal quarter; these estimates are reconciled to actual results in the subsequent fiscal quarter, and our portion of the profit or loss is adjusted accordingly, as necessary.

Other revenue includes, but is not limited to:

Operating expenses in the first quarter of ~~2017. In March 2016, we entered into an agreement with Bayer governing the joint development~~2020 and commercialization outside the United States of nesvacumab, an antibody product candidate to Ang2, including in combination with aflibercept, for the treatment of ocular diseases or disorders. In connection with the agreement, Bayer made a $50.0 million non-refundable up-front payment to us, which was recorded as deferred revenue and is being recognized as revenue over the related performance period. Bayer is also obligated to pay 25% of global development costs and 50% of development costs exclusively for the territory outside the United States.

The following table summarizes our estimates of direct research and development expenses by clinical development program and other significant categories of research and development expenses. Direct research and development expenses are comprised primarily of costs paid to third parties for clinical and product development activities, including costs related to preclinical research activities, clinical trials, ~~drug filling, packaging, and labeling,~~ and the portion of research and development expenses incurred by our collaborators that we are obligated to reimburse. Indirect research and development expenses have not been allocated directly to each program, and primarily consist of costs to compensate personnel, overhead and infrastructure costs to maintain our facilities, ~~costs to manufacture bulk drug product (including pre-launch commercial supplies which were not capitalized as inventory) at our manufacturing facilities,~~ and other costs related to activities that benefit multiple projects. Clinical manufacturing costs primarily consist of costs to manufacture bulk drug product for clinical development purposes as well as related external drug filling, packaging, and labeling costs. Clinical manufacturing costs also includes pre-launch commercial supplies which did not meet the criteria to be capitalized as inventory.

Research and Development Expenses Three Months Ended
September 30, Increase Nine Months Ended
September 30, Increase
(In millions) 2017
2016^*
(Decrease) 2017
2016^*
(Decrease)
Direct research and development expenses:
Dupilumab $ 50.0
$ 54.2
$ (4.2 ) $ 150.0
$ 171.1
$ (21.1 )
Cemiplimab 33.7
11.0
22.7
78.3
27.3
51.0
Fasinumab 39.1
29.4
9.7
112.0
76.9
35.1
Praluent 21.2
21.5
(0.3 ) 61.1
61.3
(0.2 )
Suptavumab 17.0
8.4
8.6
31.4
18.4
13.0
Sarilumab 2.4
3.0
(0.6 ) 7.6
16.7
(9.1 )
Other product candidates in clinical development and other research programs 55.2
61.1
(5.9 ) 168.4
189.4
(21.0 )
Total direct research and development expenses 218.6
188.6
30.0
608.8
561.1
47.7
Indirect research and development expenses:
Payroll and benefits 145.3
142.5
2.8
438.5
421.9
16.6
Clinical manufacturing costs 97.7
122.7
(25.0 ) 300.9
309.6
(8.7 )
Research, licensing, and other development costs 17.1
40.6
(23.5 ) 47.1
139.6
(92.5 )
Occupancy and other operating costs 51.0
48.6
2.4
151.9
140.9
11.0
Total indirect research and development expenses 311.1
354.4
(43.3 ) 938.4
1,012.0
(73.6 )
Total research and development expenses $ 529.7
$ 543.0
$ (13.3 ) $ 1,547.2
$ 1,573.1
$ (25.9 )

* Certain prior year amounts have been reclassified to conform to the current year's presentation

There are numerous uncertainties associated with drug development, including uncertainties related to safety and efficacy data from each phase of drug development, uncertainties related to the enrollment and performance of clinical trials, changes in regulatory requirements, changes in the competitive landscape affecting a product candidate, and other risks and uncertainties described in Part II, Item ~~1A,~~1A. "Risk ~~Factors."~~Factors" (including those relating to the disruptions caused by the COVID-19 pandemic). There is also variability in the duration and costs necessary to develop a pharmaceutical product, potential opportunities and/or uncertainties related to future indications to be studied, and the estimated cost and scope of the projects. The lengthy process of seeking FDA and other applicable approvals, and subsequent compliance with applicable statutes and regulations, require the expenditure of substantial resources. Any failure by us to obtain, or delay in obtaining, regulatory approvals could materially adversely affect our business.

Selling, general, and administrative expenses increased ~~for~~in the ~~three months ended September 30, 2017,~~first quarter of 2020, compared to the same period in ~~2016,~~2019, primarily due to higher headcount and headcount-related costs, ~~to support the launches of Dupixent and Kevzara and~~ an increase in commercialization-related expenses for EYLEA, additional accruals for loss contingencies associated with ~~EYLEA~~ongoing litigation, and ~~Dupixent.~~higher contributions to independent not-for-profit patient assistance organizations. Selling, general, and administrative expenses ~~increased for the nine months ended September 30, 2017, compared to the same period in 2016, primarily due to higher headcount and headcount-related costs to support the launches~~also included non-cash compensation expense of Dupixent and Kevzara and an increase in commercialization-related expenses associated with EYLEA, Dupixent, and Kevzara, partly offset by lower commercialization-related expenses associated with Praluent. Selling, general, and administrative expenses included Non-Cash Compensation Expense of $47.7$40.3 million and ~~$146.2~~$43.8 million in the ~~third~~first quarter of 2020 and ~~first nine months of 2017, respectively, and $49.4 million and $157.2 million in the third quarter and first nine months of 2016,~~2019, respectively.

Other operating (income) expense, net, includes recognition of a portion of amounts previously deferred in connection with ~~Sanofi. Cost~~up-front and development milestone payments, as applicable, received in connection with Sanofi IO, Teva, and MTPC collaborative arrangements.

Other income (expense), net, in the first quarter of ~~collaboration and contract manufacturing increased for the nine months ended September 30, 2017,~~2020, compared to the same period in 2016, primarily due to costs we incurred in connection with validating our Limerick manufacturing commercial facility related to products that are in collaboration with Sanofi, partly offset by the fact that the first nine months of 2016 included royalties payable to Genentech based on sales of EYLEA outside the United States (which ended in May 2016). Cost of collaboration and contract manufacturing2019, was ~~also adversely~~negatively impacted by inventory write-offs and reserves totaling $50.6 million in the first nine months of 2017 primarily related to product that no longer met quality specifications, compared to $6.8 million in the first nine months of 2016.

~~The~~Our effective tax rate for the three ~~and nine~~ months ended ~~September 30, 2017 and 2016~~March 31, 2020 was positively impacted, compared to the U.S. federal statutory rate, primarily by ~~the tax benefit associated with~~ stock-based compensation, ~~the domestic manufacturing deduction,~~ and, ~~the federal tax credit for increased research activities, offset by the negative impact of losses incurred~~to a lesser extent, income earned in foreign jurisdictions with tax rates lower than the U.S. federal statutory rate and ~~the non-tax deductible Branded Prescription Drug Fee.~~federal tax credits for research activities. Our effective tax rate for the three months ended ~~September 30, 2016~~March 31, 2019 was ~~also~~ positively impacted, compared to the U.S. federal statutory rate, primarily by ~~changes to~~the federal tax ~~reserves.~~credits for research activities, stock-based compensation, the foreign-derived intangible income deduction, and income earned in foreign jurisdictions with tax rates lower than the U.S. federal statutory rate.

Our financial condition is summarized as follows:

~~Additionally, as~~As of ~~September 30, 2017,~~March 31, 2020, we also had borrowing availability of $750.0 million under a revolving credit ~~facility (see further description under "Credit Facility" below).~~facility.

Capital expenditures ~~were $165.0 million and $361.5 million~~ in the first ~~nine months~~quarter of ~~2017 and 2016, respectively. Capital expenditures in the first nine months of 2017 primarily~~2020 included costs ~~in connection~~associated with ~~renovations and additions to certain buildings at~~(i) the expansion of our manufacturing facilities in Rensselaer, New York and Limerick, Ireland, ~~manufacturing facilities, as well as, to~~including construction of a ~~lesser extent,~~fill/finish facility and related equipment, and (ii) laboratory expansion and renovations at our Tarrytown, New York ~~laboratory and office~~ facilities. Capital expenditures in the first nine months of 2016 primarily included costs in connection with renovations of our Limerick, Ireland manufacturing facility, tenant improvement and associated costs at our leased Tarrytown, New York facilities, renovations to certain areas of our Rensselaer, New York manufacturing facilities, the purchase of an office building near our Rensselaer manufacturing facilities, and purchases of equipment. Capital expenditures decreased in the first nine months of 2017, compared to the first nine months of 2016, in part due to less capital expenditures in connection with renovations at our Limerick, Ireland manufacturing facility as by the end of 2016 a substantial portion of the initial build-out of the plant had been completed. We expect to incur capital expenditures of ~~approximately $100~~$510 million to ~~$120~~$590 million ~~during~~for the ~~fourth quarter~~full year of ~~2017.~~2020 primarily in connection with these projects.

In November 2019, our board of directors authorized a share repurchase program to repurchase up to $1.0 billion of our Common Stock. The share repurchase program permits the Company to effect 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 ~~$242.1 million~~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 ~~warrant holders to reduce~~ the ~~maximum~~timing or number of shares of ~~Common Stock issuable upon exercise of the warrants. No warrants remained outstanding as of December 31, 2016.~~

During the ~~Facility and to reimburse us for the $57.0 million payment~~first quarter of 2020, we ~~made to BMR in December 2016.~~

A summary of our critical accounting policies and use of estimates are presented in Part II, Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations" of our Annual Report on Form 10-K for the fiscal year ended December 31, 2019 (filed February 7, 2020). Except as described in Note 1 to our Condensed Consolidated Financial Statements included in this report, there were no material changes to our critical accounting policies and use of estimates during the three months ended March 31, 2020.

~~See Note 15 to our Condensed Consolidated Financial Statements for a summary~~As of March 31, 2020, the future adoption of recently issued accounting ~~standards.~~standards is not expected to have a material impact on the Company's financial position or results of operations.

Our market risks, and the way we manage them, are summarized in Part II, Item 7A, "Quantitative and Qualitative Disclosures About Market Risk" of our Annual Report on Form 10-K for the fiscal year ended December 31, ~~2016~~2019 (filed February ~~9, 2017)~~7, 2020).

Our management, with the participation of our principal executive officer and principal financial officer, conducted an evaluation of the effectiveness of our disclosure controls and procedures (as such term is defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the "Exchange Act")), as of the end of the period covered by this report. Based on this evaluation, our principal executive officer and principal financial officer each concluded that, as of the end of such period, our disclosure controls and procedures were effective in ensuring that information required to be disclosed by us in the reports that we file or submit under the Exchange Act is recorded, processed, summarized, and reported on a timely basis, and is accumulated and communicated to our management, including our principal executive officer and principal financial officer, as appropriate to allow timely decisions regarding required disclosures.

There has been no change in our internal control over financial reporting (as such term is defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the quarter ended ~~September 30, 2017~~March 31, 2020 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

~~From time~~The information called for by this item is incorporated herein by reference to ~~time, we are a party to legal proceedings~~the information set forth in the course of our business, including those described in our Annual Report on Form 10-K for the year ended December 31, 2016 (filed February 9, 2017), our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017 (filed May 4, 2017), our Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2017 (filed August 3, 2017), and those described below. The outcome of any such proceedings, regardless of the merits, is inherently uncertain. For a description of risks relating to these and other legal proceedings we face, see Part II, Item 1A. "Risk Factors," including the discussion under the headings entitled "Risks Related to Intellectual Property and Market Exclusivity," "Regulatory and Litigation Risks," and "Risks Related to Our Common Stock."

We operate in an environment that involves a number of significant risks and uncertainties. We caution you to read the following risk factors, which have affected, and/or in the future could affect, our business, prospects, operating results, and financial condition. The risks described below include forward-looking statements, and actual events and our actual results may differ materially from these forward-looking statements. Additional risks and uncertainties not currently known to us or that we currently deem immaterial may also impair our business, prospects, operating results, and financial condition. Furthermore, additional risks and uncertainties are described under other captions in this report and should also be considered by our investors. For purposes of this section, references to our products encompass products marketed by us and/or our collaborators under our collaboration agreements with them, unless otherwise stated or required by the context.

In December 2019, a novel strain of coronavirus, SARS-CoV-2, causing a disease referred to as COVID-19, was reported to have surfaced in Wuhan, China. It has since spread to multiple other countries; and, in March 2020, the World Health Organization declared the COVID-19 outbreak a pandemic. This pandemic has adversely affected or has the potential to adversely affect, among other things, the economic and financial markets and labor resources of the countries in which we operate, our manufacturing and supply chain operations, research and development efforts, commercial operations and sales force, administrative personnel, third-party service providers, business partners and customers, and the demand for some of our marketed products.

The COVID-19 pandemic has resulted in travel and other restrictions to reduce the spread of the disease, including governmental orders across the globe, which, among other things, direct individuals to shelter at their places of residence, direct businesses and governmental agencies to cease non-essential operations at physical locations, prohibit certain non-essential gatherings, maintain social distancing, and order cessation of non-essential travel. As a result of these recent developments, we have implemented work-from-home policies for a significant part of our employees (except those deemed critical, such as those working in our laboratories and manufacturing facilities). The effects of shelter-in-place and social distancing orders, government-imposed quarantines, and work-from-home policies may negatively impact productivity, disrupt our business, and delay our clinical programs and development timelines, the magnitude of which will depend, in part, on the length and severity of the restrictions and other

limitations on our ability to conduct our business in the ordinary course. Such restrictions and limitations may also negatively impact our access to regulatory authorities (which may be affected, among other things, by travel restrictions and may be delayed in responding to inquiries, reviewing filings, and conducting inspections); our ability to perform regularly scheduled quality checks and maintenance; and our ability to obtain services from third-party specialty vendors and other providers orto access their expertise as fully and timely as needed.The COVID-19 pandemic may also result in the loss of some of our key personnel, either temporarily or permanently. In addition, our sales and marketing efforts may be impacted by postponement of face-to-face meetings and restrictions on access by non-essential personnel to hospitals or clinics, all of which could slow adoption and implementation of our marketed products, resulting in lower net product sales. For example, while the impact of shelter-in-place and social distancing orders, physicians' office closures, and delays in the treatment of patients following the COVID-19 pandemic on our net product sales of EYLEA for the three months ended March 31, 2020 was limited, overall U.S. EYLEA demand was lower in April 2020 compared to the same period of 2019. In addition to other potential impacts of the COVID-19 pandemic on net product sales, we expect to see continued adverse impact on new patient starts for all products while these measures remain in place. See Part I, Item 2. "Management's Discussion and Analysis of Financial Condition and Results of Operations - Results of Operations" for a discussion of our net product sales. Demand for some or all of our marketed products may continue to be reduced while the shelter-in-place or social distancing orders are in effect and, as a result, some of our inventory may become obsolete and may need to be written off, impacting our operating results. These and similar, and perhaps more severe, disruptions in our operations may materially adversely impact our business, operating results, and financial condition.

Quarantines, shelter-in-place, social distancing, and similar government orders (or the perception that such orders, shutdowns, or other restrictions on the conduct of business operations could occur) related to COVID-19 or other infectious diseases are impacting personnel at our research and manufacturing facilities, our suppliers, and other third parties on which we rely, and may impact the availability or cost of materials produced by or purchased from such parties, which could result in a disruption in our supply chain. While some materials may be obtained from more than one supplier, port closures and other restrictions resulting from the COVID-19 pandemic could disrupt our supply chain or limit our ability to obtain sufficient materials for the production and development of our products and product candidates as well as our research efforts.

In addition, infections and deaths related to COVID-19 may disrupt the United States' healthcare and healthcare regulatory systems. Such disruptions could divert healthcare resources away from, or materially delay, FDA review and potential approval of our product candidates and new indications for our marketed products. It is unknown how long these disruptions could continue. In addition, our clinical trials are likely to be affected by the COVID-19 pandemic. Site initiation and patient enrollment may be delayed due to prioritization of hospital resources toward the COVID-19 pandemic, and some patients may not be able to comply with clinical trial protocols if quarantines impede patient movement or interrupt healthcare services. Similarly, our ability to recruit and retain patients and principal investigators and site staff who, as healthcare providers, may have heightened exposure to COVID-19, could be delayed or disrupted. For example, as noted above in Part I, Item 2. "Management's Discussion and Analysis of Financial Condition and Results of Operations - Overview - Programs in Clinical Development," we have had to adjust the development timelines for many of our clinical programs that are either currently enrolling patients or have not yet commenced due to the COVID-19 pandemic. The disruptions caused by the COVID-19 pandemic may impact the progress of our clinical trials, including the readouts of trial results. Further, while we are focused on developing novel therapies to address the COVID-19 pandemic, our research programs and the development of our other product candidates may need to be de-prioritized. Any elongation or de-prioritization of our research programs and clinical trials or delay in regulatory review resulting from such disruptions could materially affect the development and study of our product candidates, which would increase our operating expenses and may have a material adverse effect on our operating results.

While the potential economic impact brought by, and the duration of, the COVID-19 pandemic may be difficult to assess or predict, it is currently resulting in significant disruption of global financial markets. This disruption, if sustained or recurrent, could make it more difficult for us to access capital if needed. In addition, a recession or market correction resulting from the spread of COVID-19 could materially affect our business and the value of our Common Stock.

The global COVID-19 pandemic continues to rapidly evolve. The ultimate impact of this pandemic is highly uncertain and subject to change. We do not yet know the full extent of potential delays or impacts on our business, our clinical trials, healthcare systems, or the global economy as a whole. These effects could have a material impact on our operations.

To the extent the COVID-19 pandemic adversely affects our business, prospects, operating results, or financial condition, it may also have the effect of heightening many of the other risks described in this "Risk Factors" section.

EYLEA net sales represent a substantial portion of our revenues and this concentration of our net sales in a single product makes us substantially dependenton that product. For the ~~nine~~three months ended ~~September 30, 2017~~March 31, 2020 and ~~2016,~~2019, EYLEA net sales in the United States represented 64% and ~~68%~~78% of our total revenues, respectively. If we were to experience difficulty with the commercialization of EYLEA in the United States or if Bayer were to experience any difficulty with the commercialization of EYLEA outside the United States (including as a result of the COVID-19 pandemic discussed above), or if we and Bayer are unable to maintain current marketing approvals of EYLEA, we may experience a reduction in revenue and may not be able to sustain profitability, and our business, prospects, operating results, and financial condition would be materially harmed.

In addition, we have been increasingly dependent on our share of profits from the commercialization of Dupixent under our Antibody Collaboration with Sanofi. If we or Sanofi were to experience any difficulty with the commercialization of Dupixent or if we or Sanofi are unable to maintain current marketing approvals of Dupixent, we may experience a reduction in revenue and our business, prospects, operating results, and financial condition would be materially harmed.

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

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

We and ~~Bayer~~our collaborators are subject to significant ongoing regulatory obligations and oversight with respect to ~~EYLEA~~the products we or they commercialize for ~~its~~the products' currently approved indications in the United States, EU, and other countries where ~~the product is~~such products are approved. If we or ~~Bayer~~our collaborators fail to maintain regulatory compliance for ~~EYLEA for its~~such products' currently approved indications (including because the product does not meet the relevant endpoints of any required post-approval studies, or for any of the reasons discussed below under "Risks Related to Maintaining Approval of Our Marketed Products and the Development and Obtaining Approval of Our Product Candidates and New Indications for Our Marketed Products - Obtaining and maintaining regulatory approval for drug products is costly, time-consuming, and highly uncertain"), ~~EYLEA~~the applicable marketing approval may be withdrawn, which would materially harm our business, prospects, operating results, and financial condition. Failure to comply may also subject us to sanctions, product recalls, or withdrawals of previously approved marketing applications. See also "Risks Related to Manufacturing and Supply - ~~If we fail~~Our or our collaborators' failure to meet the stringent requirements of governmental regulation in the manufacture of drug products or product candidates we could ~~incur~~result in incurring substantial remedial costs, delays in the development or approval of our product candidates or new indications for our marketed products and/or in their commercial launch if they obtain regulatory approval, and a reduction in sales" below.

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

Our future revenues and profitability will be adversely affected in a material manner if such third-party payors do not adequately defray or reimburse the cost of our marketed products to patients. If these entities do not provide coverage and reimbursement with respect to our marketed products or provide an insufficient level of coverage and reimbursement, such products may be too costly for many patients to afford them, and physicians may not prescribe them. Many third-party payors cover only selected drugs, or may prefer selected drugs, making drugs that are not covered or preferred by such payors more expensive for patients. Third-party payors may also require prior authorization for reimbursement, or require failure on another type of treatment before covering a particular drug, particularly with respect to higher-priced drugs. As our currently marketed products and product candidates are biologics, bringing them to market may cost more than bringing traditional, small-molecule drugs to market due to the complexity associated with the research, development, production, supply, and regulatory review of such products. Given cost sensitivities in many health care systems (which will likely be exacerbated as a result of the COVID-19 pandemic), our currently marketed products and product candidates are likely to be subject to continued pricing pressures, which may have an adverse impact on our business, prospects, operating results, and financial condition.

In addition, in order for private insurance and governmental payors (such as Medicare and Medicaid in the United ~~States, there~~States) to reimburse the cost of our marketed products, we must maintain, among other things, our FDA registration and our National Drug Code, formulary approval by pharmacy benefits managers, and recognition by insurance companies and the Centers for Medicare & Medicaid Services (the "CMS"). There is ~~an increased focus from~~no certainty that we will be able to obtain or maintain the ~~federal government~~applicable requirements for reimbursement (including relevant formulary coverage, as discussed further below) of our current and ~~others on analyzing the impact of various regulatory programs on the federal deficit,~~future marketed products, which could result in increased pressure on federal programs to reduce costs, including limiting federal healthcare expenditures. For example, in September 2011 the Office of Inspector General (OIG) of the Department of Health and Human Services issued a report entitled "Review of Medicare Part B Avastin and Lucentis Treatments for Age-Related Macular Degeneration" in which the OIG details possible savings to the Medicare program by using off-label, repackaged Avastin rather than Lucentis for the treatment of wet AMD. A reduction in the availability or extent of reimbursement from U.S. government programs couldmay have a material adverse effect on ~~the sales of EYLEA. Economic pressure on state budgets may also have a similar impact. In addition,~~our business.

Government and other third-party ~~payers~~payors (including pharmacy benefit management companies) are challenging the prices charged for healthcare products and increasingly limiting, and attempting to limit, both coverage and level of reimbursement for prescription drugs, such as by requiring outcomes-based or other pay-for-performance pricing arrangements. They are also imposing restrictions on eligible patient populations and the reimbursement process, including by means of required prior authorizations and utilization management criteria, such as step therapy (i.e., requiring the use of less costly medications before more costly medications are approved for coverage). Some states are also considering legislation that would control the prices and reimbursement of prescription drugs, and state Medicaid programs are increasingly requesting manufacturers to pay supplemental rebates and requiring prior authorization by the state program for use of any prescription drug for which supplemental rebates are not being paid. It is likely that federal and state legislatures and health agencies will continue to focus on additional health care reform measures in the future that will impose additional constraints on prices and reimbursements for our marketed products; this trend may be further accelerated as a result of the COVID-19 pandemic.

In addition, pharmacy benefit management companies often develop formularies to reduce their cost for medications. The breadth of the products covered by formularies varies considerably from one pharmacy benefit management company to another. Failure to be included in such formularies or to achieve favorable formulary status may negatively impact the utilization and market share of our marketed products. If our marketed products are not included within an adequate number of formularies, adequate reimbursement levels are not provided, the eligible insured patient population for our products is ~~too expensive~~limited, or a key payor refuses to provide reimbursement for ~~most patients~~our products in a particular jurisdiction altogether, this could have a material adverse effect on our and our collaborators' ability to ~~afford without health insurance coverage, if adequate~~commercialize the applicable product.

In certain foreign countries, pricing, coverage, and level of reimbursement ~~by third-party payers, including Medicare~~of prescription drugs are subject to governmental control, and ~~Medicaid in the United States, is not available,~~we and our ~~ability~~collaborators may be unable to obtain coverage, pricing, and/or reimbursement on terms that are favorable to us or necessary for us or our collaborators to successfully commercialize EYLEA will be materially adversely impacted. Our sales and potential profits and our business, prospects, operating results, and financial condition would be materially harmed. See also "Risks Related to Commercialization of Products - ~~The successful commercialization of~~ our marketed products ~~as well as~~in those countries. In some foreign countries, the proposed pricing for a drug must be approved before it may be lawfully marketed. The requirements governing drug pricing and reimbursement vary widely from country to country, and may take into account the clinical effectiveness, cost, and service impact of existing, new, and emerging drugs and treatments. For example, the EU provides options for its member states to restrict the range of medicinal products for which their national health insurance systems provide reimbursement and to control the prices of medicinal products for human use. A member state may approve a specific price for the medicinal product or it may instead adopt a system of direct or indirect controls on the profitability of the company placing the medicinal product on the market. Our results of operations may suffer if we or our ~~late-stage product candidates~~collaborators are unable to market our products in foreign countries or ~~new indications~~if coverage and reimbursement for our marketed products ~~if approved, will depend on obtaining and maintaining coverage and reimbursement for use of these products from third-party payers, including Medicare and Medicaid~~ in ~~the United States, and these payers may not cover~~foreign countries is limited or adequately reimburse for use of our products or may do so at levels that make our products uncompetitive and/or unprofitable, which would materially harm our business, prospects, operating results, and financial condition~~" below.~~

There is substantial competition in the biotechnology and pharmaceutical industries from biotechnology, pharmaceutical, and chemical companies. Many of our competitors have substantially greater research, preclinical and clinical product development and manufacturing capabilities, as well as financial, marketing, and human resources, than we do. Our smaller competitors may also enhance their competitive position if they acquire or discover patentable inventions, form collaborative arrangements, or

merge with larger pharmaceutical or biotechnology companies. There is significant actual and potential future competition for ~~eye disease products is very competitive.~~each of our marketed products.

EYLEA faces significant competition in the marketplace. For example, EYLEA competes in one or more of its approved indications with other VEGF inhibitors, including Novartis AG and Genentech/~~Roche~~Roche's Lucentis^®(ranibizumab) and Novartis' Beovu^® (brolucizumab). Ophthalmologists are ~~collaborating on the commercialization and further development~~also using off-label, third-party repackaged versions of aGenentech/Roche's approved VEGF ~~antibody fragment, Lucentis,~~antagonist, bevacizumab, for the treatment of ~~various eye indications. Lucentis is approved in one or more jurisdictions for the treatment~~certain of ~~wet AMD, macular edema following~~EYLEA's indications, and we are aware of another company developing an ophthalmic formulation of such product. In DME and RVO, ~~(including CRVO and BRVO), DME, diabetic retinopathy, and mCNV. Competitors are~~EYLEA also ~~exploring the development of a biosimilar version of Lucentis; in particular, Pfenex Inc. is developing PF582 (a Phase 1b/2a trial in patients~~competes with wet AMD has been completed), Formycon AG (in collaboration with Bioeq GmbH) is developing FYB201 (currently in a Phase 3 trial in patients with wet AMD), and Samsung Bioepis is developing SB11 (currently in a Phase 3 trial in patients with wet AMD).

~~See~~The market for Dupixent's current and potential future indications is also ~~"Risks Related~~competitive. In atopic dermatitis, there are several topical ointments or agents either approved or in development. In addition, a number of companies are developing antibodies against IL-13, IL-13Ra1, OX40, IL-31R, and/or IL-1alpha. Several companies are also studying JAK inhibitors for atopic dermatitis. In asthma, competitors to ~~Commercialization~~Dupixent include antibodies against the IL-5 ligand or the IL-5 receptor or immunoglobulin E; and some of ~~Products -~~ these antibodies, if approved in this indication, may also compete with Dupixent in CRSwNP. Dupixent also faces competition from orally administered small molecule agents and inhaled products in asthma and potential future indications. There are several other potentially competitive products in development that may compete with Dupixent in either or both of the atopic dermatitis and asthma indications, as well as potential future indications, including antibodies against thymic stromal lymphopoietin ("TSLP"), the IL-33 ligand, or the IL-33 receptor (ST2).

Libtayo also faces significant competition. There are several competitors that are marketing and/or developing antibodies against PD-1 and/or PDL-1, including Merck's Keytruda^® (pembrolizumab), Bristol-Myers Squibb's Opdivo^® (nivolumab), Roche's Tecentriq^® (atezolizumab), and AstraZeneca's Imfinzi^®(durvalumab).

Our other late-stage and earlier-stage clinical candidates in development are all fully human antibodies, which were generated using our VelocImmune^® technology. Our antibody generation technologies and other late-stage and earlier-stage clinical candidates face competition from many pharmaceutical and biotechnology companies using various technologies. We are aware of other pharmaceutical and biotechnology companies actively engaged in the research and development of antibody-based products against targets that are also the targets of our early- and late-stage product candidates. We are also aware of other companies developing or marketing small molecules that may compete with our antibody-based product candidates in various indications, if such product candidates obtain regulatory approval in those indications. If any of these or other competitors announces a successful clinical study involving a product that may be ~~unsuccessful in continuing the commercialization~~competitive with one of ~~our marketed products or in commercializing~~ our product candidates or ~~new indications~~the grant of marketing approval by a regulatory agency for ~~our marketed products, if approved, which would materially and adversely affect~~a competitive product, such developments may have an adverse effect on our business ~~profitability,~~or future prospects. In addition, the first product to reach the market in a therapeutic area is often at a significant competitive advantage relative to later entrants to the market. Accordingly, the relative speed with which we, or our collaborators, can develop our product candidates, complete the clinical trials and approval processes, and, if such product candidates are approved for marketing and sale, supply commercial quantities to the market is expected to continue to be an important competitive factor. Due to the uncertainties associated with developing biopharmaceutical products, we may not be the first to obtain marketing approval for a product against any particular target, which may have a material adverse effect on our business or future ~~prospects" below.~~prospects.

While we have established our own sales and marketing organization for EYLEA in the United States for its currently approved indications, we have no sales, marketing, commercial, or distribution capabilities for EYLEA outside the United States.

a Co-Promotion and Distribution Agreement with Bayer's Japanese affiliate, as in effect from time to time) for sales, marketing, and distribution of EYLEA in countries outside the United States.

If we and our collaborators are unsuccessful in continuing to commercialize ~~EYLEA,~~the marketed products subject to such collaborations, or if Bayer or Sanofi terminate their respective collaborations with us, our ~~ability to sustain profitability~~business, prospects, operating results, and financial condition would be materially impaired. We have limited commercial capabilities outside the United States and would have to develop or outsource these capabilities. Therefore, termination of the Bayer collaboration agreement, our Antibody Collaboration, or our IO Collaboration would create substantial new and additional risks to the successful commercialization of ~~EYLEA,~~the applicable products, particularly outside the United States. For additional information regarding our ~~collaboration~~collaborations with Bayer and Sanofi, see "Risks Related to Our Reliance on Third Parties - If our collaboration with Bayer for EYLEA is terminated, or Bayer materially breaches its obligations thereunder, our business, prospects, operating results, and financial condition, and our ability to continue to develop EYLEA and commercialize EYLEA outside the United States in the time expected, or at all, would be materially harmed" below and "Risks Related to Our Reliance on Third Parties - If our Antibody Collaboration or our IO Collaboration with Sanofi is terminated, our business, prospects, operating results, and financial condition, and our ability to develop, manufacture, and commercialize certain of our products and product candidates in the time expected, or at all, would be materially harmed" below.

Our sales of ~~EYLEA~~products we commercialize in the United States and ~~Bayer's~~our collaborators' sales of ~~EYLEA~~products they commercialize under our collaboration agreements with them in the United States and other countries (which impact our share of any profits or losses from the commercialization of these products under the relevant collaboration agreements and, therefore, our results of operations) may be reduced if ~~EYLEA~~the applicable product is imported into those countries from lower priced markets, whether legally or illegally (a practice known as parallel trading or reimportation). Parallel traders (who may repackage or otherwise alter the original product or sell it through alternative channels such as mail order or the Internet) take advantage of the price differentials between markets arising from factors including sales costs, market conditions (such as intermediate trading stages), tax rates, or national regulation of prices. Under our arrangement with Bayer, pricing and reimbursement for EYLEA outside the United States is the responsibility of Bayer. Prices for EYLEA in jurisdictions outside the United States are based on local market economics and competition and are likely to differ from country to country. In the United States, prices for pharmaceuticals are generally higher than in the bordering nations of Canada and Mexico and our sales of EYLEA in the United States may be reduced if EYLEA marketed in those nations is imported into the United States. Parallel-trading practices also are of particular relevance to the EU, where they have been encouraged by the current regulatory framework. These types of imports may exert pressure on the pricing of EYLEA in a particular market or reduce our or Bayer's sales, thereby adversely affecting our results of operations. In addition, there are proposals to legalize the import of pharmaceuticals from outside the United States into the United States. If such proposals were implemented, our future revenues derived from EYLEA sales could be reduced.

Even if clinical trials demonstrate the safety and effectiveness of any of our product candidates for a specific disease and the necessary regulatory approvals are obtained, the commercial success of any of our product candidates or new indications for our marketed products will depend upon, among other things, their acceptance by patients, the medical community, and third-party payors and on our and our collaborators' ability to successfully manufacture, market, and distribute those products in substantial commercial quantities or to establish and manage the required infrastructure to do so, including large-scale information technology systems and a large-scale distribution network. Establishing and maintaining sales, marketing, and distribution capabilities are expensive and time-consuming. Even if we obtain regulatory approval for our product candidates or new indications, if they are not successfully commercialized, we will not be able to recover the significant investment we have made in developing such products and our business, prospects, operating results, and financial condition would be severely harmed.

The commercial success of our products may also be adversely affected by guidelines or recommendations to healthcare providers, administrators, payors, and patient communities that result in decreased use of our products. Such guidelines or recommendations may be published not only by governmental agencies, but also professional societies, practice management groups, private foundations, and other interested parties.

Our product candidates are delivered either by intravenous infusion or by intravitreal or subcutaneous injections, which are generally less well received by patients than tablet or capsule delivery and this could adversely affect the commercial success of those products if they receive marketing approval.

We sell EYLEA, Libtayo, and ARCALYST in the United States to several distributors and specialty pharmacies. Under this distribution model, the distributors and specialty pharmacies generally take physical delivery of product and generally sell the product directly to healthcare providers. For the three months ended March 31, 2020, our gross product sales of such products to two customers accounted on a combined basis for 90% of our total gross product revenue. We expect this significant customer concentrationto continue for the foreseeable future. Our ability to generate and grow sales of these products will depend, in part, on the extent to which our distributors and specialty pharmacies are able to provide adequate distribution of these products to healthcare providers. Although we believe we can find additional distributors, if necessary, our revenue during any period of disruption could suffer and we might incur additional costs. In addition, ~~there~~these customers are ~~proposals~~responsible for a significant portion of our net trade accounts receivable balances. The loss of any large customer, a significant reduction in sales we make to ~~legalize~~them, any cancellation of orders they have made with us, or any failure to pay for the ~~import~~products we have shipped to them could adversely affect our results of ~~pharmaceuticals from~~operations.

We have limited commercial capabilities outside the United States and do not currently have an organization for the sales, marketing, and distribution of marketed products outside the United States. ~~If such proposals were implemented,~~We will need to establish commercial capabilities outside the United States as a result of any exercise of our ~~future revenues derived from~~option to co-commercialize a product outside the United States. For example, we recently exercised our option under the Antibody Collaboration to co-commercialize Dupixent ~~Praluent,~~in certain jurisdictions outside the United States. In addition, there may be other circumstances in which we need to establish commercial capabilities outside the United States, including because we decide to commercialize a particular product independently; we are unable to find an appropriate collaborator; or ~~Kevzara~~our existing collaborator decides not to opt in, decides to opt out, or breaches its obligations to us with respect to a particular product.

In order to commercialize or co-commercialize any products outside the United States, we must build our sales, marketing, distribution, managerial, and other non-technical capabilities in the relevant markets or make arrangements with third parties to perform these services, which would likely be expensive and time consuming and could delay product launch or the co-commercialization of a product in one or more markets outside the United States. We cannot be ~~reduced.~~certain that we will be able to successfully develop commercial capabilities outside the United States within an acceptable time frame or at all. These and other difficulties relating to commercializing our products outside the United States may severely harm our business, prospects, operating results, and financial condition.

We cannot sell or market products without regulatory approval. If we or our collaborators do not maintain regulatory approval for our marketed products, and obtain regulatory approval for our product candidates or new indications of our marketed products the value of our company and our business, prospects, operating results, and financial condition will be materially harmed. If we are unable to obtain regulatory approval for our product candidates, or if we(or are materially delayed in doing ~~so,~~so), the value of our Company and our business, prospects, operating results, and financial condition may be materially harmed.

In the United States, we (which, for purposes of this risk factor, includes our collaborators, unless otherwise stated or required by the context) must obtain and maintain approval from the FDA for each drug we intend to sell. Obtaining FDA approval is typically a lengthy and expensive process, and approval is highly uncertain. We cannot predict with certainty if or when we might submit for regulatory approval for any of our product candidates currently under development. Any approvals we may obtain may not cover all of the clinical indications for which we are seeking approval. Also, an approval might contain

The FDA may also require us to conduct additional clinical trials after granting approval of a product. Its ability to do so has been enhanced by the Food and Drug Administration Amendments Act of 2007, pursuant to which the FDA has the explicit authority to require postmarketing studies (also referred to as post-approval or Phase 4 studies), labeling changes based on new safety information, and compliance with FDA-approved risk evaluation and mitigation strategies. Post-approval studies, whether conducted by us or by others and whether mandated by regulatory agencies or voluntary, and other data about our marketed products (or data about products similar to our marketed products that implicate an entire class of products or are perceived to do so) may result in changes in product labeling, restrictions on use, product withdrawal or recall, loss of approval, or lower sales of our products.

According to the FDA policies under the Prescription Drug User Fee Act, the FDA system of review times for new drugs includes standard review and priority review. Standard review can be accomplished in a ~~ten-month~~10-month time frame from the time the application is filed by the FDA (filing date), which typically occurs approximately 60 days following submission of the application by the applicant. The FDA has stated the goal to act on 90% of standard new molecular entity ~~(NME)~~("NME") New Drug Application ~~(NDA)~~("NDA") and original BLA submissions within 10 months of the filing date. A priority review designation is given to drugs that treat a serious condition and offer major advances in treatment, or provide a treatment where no adequate therapy exists, and may also be afforded to a human drug application based on a priority review voucher. The FDA has stated the goal to act on 90% of priority NME NDA and original BLA submissions within six months of the filing date. However, the FDA's review goals are subject to change and the duration of the FDA's review depends on a number of factors, including the number and types of other applications that are submitted to the FDA around the same time period or are pending. Even if any of our applications receives a priority review designation, we may not ultimately be able to obtain approval of our application within a time frame consistent with the FDA's stated review goals or at all, and such designation may not actually lead to a faster development or regulatory review or approval process.

The FDA enforces Good Clinical Practices ~~(GCPs)~~("GCPs") and other regulations through periodic inspections of trial sponsors, clinical research organizations ~~(CROs)~~("CROs"), principal investigators, and trial sites. If we or any of the third parties conducting our clinical studies are determined to have failed to fully comply with GCPs, the study protocol or applicable regulations, the clinical data generated in those studies may be deemed unreliable. This could result in non-approval of our product candidates by the FDA, or we or the FDA may decide to conduct additional inspections or require additional clinical studies, which would delay our development programs, require us to incur additional costs, and could substantially harm our business, prospects, operating results, and financial condition.

Before approving a new drug or biologic product, the FDA requires that the facilities at which the product will be manufactured or advanced through the supply chain be in compliance with current Good Manufacturing Practices, or cGMP, requirements and regulations governing the manufacture, shipment, and storage of the product. These cGMP requirements and regulations are not prescriptive instructions on how to manufacture products, but rather a series of principles that must be observed during manufacturing; as a result, their implementation may not be clearly delineated and may present a challenging task. Manufacturing product candidates in compliance with these regulatory requirements is complex, time-consuming, and expensive. To be successful, our products must be manufactured in compliance with regulatory requirements, and at competitive costs. If we or any of our ~~product collaborators, or~~ third-party manufacturers, product packagers, labelers, or other parties performing steps in the supply chain are unable to maintain regulatory compliance, the FDA can impose regulatory sanctions, including, among other things, refusal to approve a pending application for a new drug or biologic product, or revocation of a pre-existing approval. For ~~example, on October 28, 2016, the FDA issued a Complete Response Letter relating to the BLA for Kevzara, which referred to certain~~

In addition to the FDA and other regulatory agency regulations in the United States, we are subject to a variety of foreign regulatory requirements governing human clinical trials, manufacturing, marketing and approval of drugs, and commercial sale and distribution of drugs in foreign countries. The foreign regulatory approval process is similarly ~~likely to be~~ a lengthy and expensive process, the result of which is highly uncertain, and foreign regulatory requirements include all of the risks associated with FDA approval as well as country specific regulations. We and our collaborators must maintain regulatory compliance for the products we or they commercialize in foreign jurisdictions. From time to time, we may hold a product's marketing approval in a jurisdiction outside the United States where we may have less experience and where our regulatory capabilities may be more limited. In addition, actions by a regulatory agency in a country or region with respect to a product candidate may have an impact on the approval process for that product candidate in another country or region. Foreign regulatory authorities often also have the authority to require post-approval studies, which involve various risks similar to those described ~~above.~~above, and may ask for additional data in order to begin a clinical study. Whether or not we obtain FDA approval for a product in the United States, we must obtain approval of the product by the comparable regulatory authorities in foreign countries before we can ~~conduct clinical trials of or~~ market that product or any other product in those countries.

As described above, we must conduct extensive testing of our product candidates and new indications of our marketed products before we can obtain regulatory approval to market and sell them. We need to conduct both preclinical animal testing and human clinical trials. Conducting such studies is a lengthy, time-consuming, and expensive process. These tests and trials may not achieve favorable results for many reasons, including, among others, failure of the product candidate to demonstrate safety or efficacy, the development of serious or life-threatening adverse events (or side effects) caused by or connected with exposure to the product candidate (or prior or concurrent exposure to other products or product candidates), difficulty in enrolling and maintaining subjects in a clinical trial, lack of sufficient supplies of the product candidate or comparator drug, and the failure of clinical investigators, trial monitors, contractors, consultants, or trial subjects to comply with the trial plan, protocol, or applicable regulations related to the FDA's Good Laboratory ~~Practices (GLPs)~~Practice requirements ("GLPs") or GCPs. A clinical trial may fail because it did not include and retain a sufficient number of patients to detect the endpoint being measured or reach statistical significance. A clinical trial may also fail because the dose(s) of the investigational drug included in the trial were either too low or too high to determine the optimal effect of the investigational drug in the disease setting.

We will need to reevaluate any drug candidate that does not test favorably and either conduct new studies, which are expensive and time consuming, or abandon that drug development program. If preclinical testing yields unfavorable results, product candidates may not advance to clinical trials. The failure of clinical trials to demonstrate the safety and effectiveness of our clinical candidates

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

Furthermore, some of our products and product candidates (such as ~~cemiplimab)~~Libtayo and Dupixent) are studied in combination with agents and treatments developed by us or our collaborators. There may be additional risks and unforeseen safety issues resulting from such combined administration, any of which may materially adversely impact clinical development of these product candidates and our ability to obtain regulatory approval.

Only a small minority of all research and development programs ultimately result in commercially successful drugs. Clinical trials may not demonstrate statistically sufficient effectiveness and safety to obtain the requisite regulatory approvals for these product candidates in these indications. Many companies in the biopharmaceutical industry, including our ~~company,~~Company, have suffered significant setbacks in clinical trials, even after promising results have been obtained in earlier trials. In a number of instances, we have terminated the development of product candidates due to a lack of or only modest effectiveness, and clinical trials evaluating our product candidates failed to meet the relevant endpoints. For example, in August 2017, we reported that the Phase 3 study evaluating suptavumab, ~~(REGN2222),~~ an antibody to ~~respiratory syncytial virus (RSV),~~RSV, did not meet its primary endpoint of preventing medically-attended RSV infections in ~~infants and that~~infants; as a result, we ~~planned to discontinue~~have discontinued further clinical development of this antibody.

Many of our clinical trials are conducted under the oversight of ~~Independent~~independent Data Monitoring Committees ~~(IDMCs)~~("DMCs"). These independent oversight bodies are made up of external experts who review the progress of ongoing clinical trials, including available safety and efficacy data, and make recommendations concerning a trial's continuation, modification, or termination based on interim, unblinded data. Any of our ongoing clinical trials may be discontinued or amended in response to recommendations made by responsible ~~IDMCs~~DMCs based on their review of such interim trial results. For example, in ~~September 2009, a~~April 2018, the DMC monitoring the ongoing safety and efficacy of our Phase 3 ~~trial that was evaluating ZALTRAP as a first-line treatment for metastatic pancreatic cancer in combination with gemcitabine was discontinued at the recommendation~~clinical trials of ~~an IDMC after a planned analysis of interim efficacy data determined~~fasinumab recommended that the ~~trial would not meet its efficacy endpoint.~~higher dose-regimens be discontinued based on the risk-benefit assessment and that the program may continue with lower dose-regimens of fasinumab. As a result, the osteoarthritis trials were modified accordingly and we discontinued dosing patients in the clinical study of fasinumab in chronic low back pain in patients with concomitant osteoarthritis of the knee and hip since this study was using only higher doses. The recommended termination or material modification of any of our ongoing late-stage clinical trials by ~~an IDMC~~a DMC could negatively impact the future development of our product candidate(s), and our business, prospects, operating results, and financial condition may be materially harmed.

We are studying our antibody-based product candidates in a wide variety of indications in clinical trials. Many of these trials are exploratory studies designed to evaluate the safety profile of these compounds and to identify what diseases and uses, if any, are best suited for these product candidates. These product candidates may not demonstrate the requisite efficacy and/or safety profile to support continued development for some or all of the indications that are being, or are planned to be, studied, which would diminish our clinical "pipeline" and could negatively affect our future prospects and the value of our ~~company.~~Company.

During the conduct of clinical trials, patients report changes in their health, including illnesses, injuries, and discomforts, to their study doctor. Often, it is not possible to determine whether or not the drug candidate being studied caused these conditions. Various illnesses, injuries, and discomforts have been reported from time-to-time during clinical trials of our product candidates and new indications for our marketed products. It is possible that as we test our drug candidates or new indications in larger, longer, and more extensive clinical programs, or as use of these drugs becomes more widespread if they receive regulatory approval, illnesses, injuries, and discomforts that were observed in earlier trials, as well as conditions that did not occur or went undetected in previous trials, will be reported by patients. Many times, side effects are only detectable after investigational drugs are tested in large-scale, Phase 3 clinical trials or, in some cases, after they are made available to patients after approval. If additional clinical experience indicates that any of our product candidates or new indications for our marketed products has many side effects or causes serious or life-threatening side effects, the development of the product candidate may be delayed or fail, or, if the product candidate has received regulatory approval, such approval may be revoked, which would severely harm our business, prospects, operating results, and financial condition.

With respect to EYLEA, ~~is being studied in additional indications, and aflibercept is being studied as a combination product. There~~there are many potential safety concerns associated with significant blockade of VEGF that may limit our ability to further successfully ~~develop and/or~~ commercialize ~~aflibercept.~~EYLEA. These serious and potentially life-threatening risks, based on clinical and preclinical experience of VEGF inhibitors, include bleeding, intestinal perforation, hypertension, proteinuria, congestive heart

failure, heart attack, and stroke. Other VEGF blockers have reported side effects that became evident only after large-scale trials or after marketing approval when large numbers of patients were treated. There are risks inherent in the intravitreal administration of drugs like aflibercept (such as intraocular inflammation ("IOI"), sterile and culture positive endophthalmitis, corneal decomposition, retinal detachment, and retinal tear), which can cause injury to the eye and other complications. ~~For example, in our Phase 3 trials of~~The side effects previously reported for EYLEA ~~in wet AMD, the most frequent ocular adverse events were~~include conjunctival hemorrhage, macular degeneration, eye pain, retinal hemorrhage, and vitreous floaters. In addition, commercialization of EYLEA or our other products may be impacted by actions of third parties on which we rely, such as manufacturers of syringes or other devices used in the administration of our products. For example, in February 2018, we issued a letter to healthcare professionals providing updated guidance relating to reports of IOI following EYLEA injections. In this letter, we noted that while our review did not identify any association of IOI rates with the EYLEA drug itself, an association was seen with certain batches of the syringe that were included in specific lots of final packaged EYLEA kits. These and other complications or issues or side effects could harm further development and/or commercialization of EYLEA.

Dupixent and Libtayo are being studied in additional indications, as shown in the table under Part I, Item 2. "Management's Discussion and Analysis of Financial Condition and Results of Operations - Programs in Clinical Development." There is no guarantee that marketing approval of Dupixent or Libtayo (as applicable) in any of these indications will be successfully obtained. The side effects previously reported for Dupixent include hypersensitivity reactions, conjunctivitis and keratitis, injection-site reactions, eye and eyelid inflammation, cold sores, oropharyngeal pain, and eosinophilia; and the side effects previously reported for Libtayo include certain immune-mediated adverse reactions, such as pneumonitis, colitis, hepatitis, endocrinopathies, nephritis, and dermatologic reactions, as well as infusion-related reactions, cellulitis, sepsis, pneumonia, urinary tract infection, fatigue, rash, and diarrhea. These and other complications or side effects could harm further development and/or commercialization of ~~aflibercept.~~

There also are risks inherent in subcutaneous injections (which are used for administering most of our antibody-based products and product ~~candidates, including Dupixent, Praluent, and Kevzara)~~candidates), such as injection-site reactions (including redness, itching, swelling, pain, and tenderness) and other side effects. These and other complications or side effects could harm further development and/or commercialization of our antibody-based products and product candidates ~~including Dupixent, Praluent, or Kevzara.~~utilizing this method of administration.

In addition to the safety, efficacy, manufacturing, and regulatory hurdles faced by our product candidates, the administration of recombinant proteins frequently causes an immune response, resulting in the creation of antibodies against the therapeutic protein. The antibodies can have no effect or can totally neutralize the effectiveness of the protein, or require that higher doses be used to obtain a therapeutic effect. In some cases, the antibody can cross-react with the patient's own proteins, resulting in an "auto-immune" type disease. Whether antibodies will be created can often not be predicted from preclinical or clinical experiments, and their detection or appearance is often delayed, so neutralizing antibodies may be detected at a later date, in some cases even after pivotal clinical trials have been completed.

If we are unable to continue to develop suitable product formulations or manufacturing processes to support large-scale clinical testing of our product candidates, including our antibody-based product candidates, we may be unable to supply necessary materials for our clinical trials, which would delay or prevent the development of our product candidates. Similarly, if we are unable, directly or through our collaborators or third parties, to supply sufficient quantities of our products or develop formulations of our product candidates suitable for commercial use, we will be unable to obtain regulatory approval for those product candidates.

Many of our products ~~(including Dupixent, Praluent, and Kevzara)~~ are used and ~~if approved,~~ some of our products and product candidates may be used, if approved, in combination with a drug-delivery device, including a pre-filled syringe, patch pump, auto-injector, or other delivery system. For example, in the United States EYLEA is approved in the 2mg pre-filled syringe. The success of our products and product candidates may depend to a significant extent on the performance of such devices, some of which may be novel or comprised of complex components. Given the increased complexity of the review process when approval of the product and device is sought under a single marketing application and the additional risks resulting from a product candidate's designation as a combination product discussed below, our product candidates used with such drug-delivery devices may be substantially delayed in receiving regulatory approval or may not be approved at all. The FDA review process and criteria for such applications isare not ~~a well-established area,~~well established, which could also lead to delays in the approval process. In addition, some of these drug-delivery devices may be provided by single-source, third-party providers or our collaborators. In any such case, we may be dependent on the sustained cooperation of those third-party providers or collaborators to supply and manufacture the devices; to conduct the studies and prepare related documentation required for approval or clearance by the applicable regulatory agencies; and to continue to meet the applicable regulatory and other requirements to maintain approval or clearance once it has been received. Failure to successfully develop or supply the devices, delays in or failure of the studies conducted by us, our collaborators, or third-party providers, or failure of our ~~company,~~Company, our collaborators, or the third-party providers to obtain or maintain regulatory approval or clearance of the devices could result in increased development costs, delays in or failure to obtain regulatory approval, and associated delays in a product or product candidate reaching the market. Loss of regulatory approval or clearance of a device that is used with our product may also result in the removal of our product from the market. Further, failure to successfully develop or supply and manufacture these devices, or to gain or maintain their approval, could adversely affect sales of the related products.

In the United States, each component of a combination product is subject to the requirements established by the FDA for that type of component, whether a drug, biologic, or device. The determination whether a product is a combination product or two separately regulated products is made by the FDA on a case-by-case basis. Although a single marketing application is generally sufficient for the approval, clearance, or licensure of a combination product, the FDA may determine that separate marketing applications are necessary. In addition, submitting separate marketing applications may be necessary to receive some benefit that accrues only from approval under a particular type of application. This could significantly increase the resources and time required to bring a particular combination product to market.

Our business requires using sensitive and proprietary technology and other information that we protect as trade secrets. We seek to prevent improper disclosure of these trade secrets through confidentiality agreements. If our trade secrets are improperly disclosed, by our current or former employees, our collaborators, or otherwise, it ~~would~~could help our competitors and adversely affect our business. We will be able to protect our proprietary rights only to the extent that our proprietary technologies and other information are covered by valid and enforceable patents or are effectively maintained as trade secrets. The patent position of biotechnology companies, including our ~~company,~~Company, involves complex legal and factual questions and, therefore, enforceability cannot be predicted with certainty. Our patents may be challenged, invalidated, held to be unenforceable, or circumvented. Patent applications filed outside the United States may be challenged by other parties, for example, by filing third-party observations that argue against patentability or an opposition. Such opposition proceedings are increasingly common in the EU and are costly to defend. For example, our European Patent No. ~~1,360,287 was, and our European Patent No.~~ 2,264,163 is the subject of opposition proceedings in the ~~EPO,~~European Patent Office (the "EPO") (currently pending before its Boards of Appeal), as described in ~~Part I, Item 3. "Legal Proceedings" of~~Note 11 to our ~~Annual Report on Form 10-K for the year ended December 31, 2016 and Part II, Item 1. "Legal Proceedings" of our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017.~~Condensed Consolidated Financial Statements included in this report. We have pending patent applications in the ~~USPTO,~~United States Patent and Trademark Office (the "USPTO"), the EPO, and the patent offices of other foreign jurisdictions, and it is likely that we will need to defend patents from challenges by others from time to time in the future. Certain of our U.S. patents may also be challenged by parties who file a request for post-grant review or inter partes ~~reexamination~~ review under the America Invents Act of 2011 or ex parte reexamination. For example, on February 11, 2020, anonymous parties filed two requests for ex parte reexamination of two of our patents - U.S. Patent Nos. 10,406,226 (the "'226 Patent") and 10,464,992 (the "'992 Patent"). The '226 Patent concerns methods for manufacturing VEGF antagonist fusion proteins, including aflibercept, and the '992 Patent concerns formulations and vials containing VEGF antagonist fusion proteins, including aflibercept. The USPTO has granted both requests to initiate reexamination proceedings. Post-grant proceedings are increasingly common in the United States and are costly to defend. Our patent rights may not provide us with a proprietary position or competitive advantages against competitors. Furthermore, even if the outcome is favorable to us, the enforcement of our intellectual property rights can be extremely expensive and time consuming.

Our commercial success depends significantly on our ability to operate without infringing the patents and other proprietary rights of ~~others.~~others (including those relating to trademarks, copyrights, and trade secrets). Other parties may allege that they own blocking patents to our products in clinical development or even to products that have received regulatory approval and are being or have been commercialized, either because they claim to hold proprietary rights to the composition of a product or the way it is manufactured or the way it is used. Moreover, other parties may allege that they have blocking patents to antibody-based products made using our VelocImmune technology, or any other of our technologies, either because of the way the antibodies are discovered or produced or because of a proprietary composition covering an antibody or the antibody's target.

We have been in the past, are currently, and may in the future be involved in patent litigation and other proceedings involving patents and other intellectual property. For example, we and/or Sanofi are currently party to patent infringement proceedings initiated by Amgen against us ~~and~~and/or Sanofi relating to Praluent as described in Part I, Item 3. "Legal Proceedings" of our Annual Report on Form 10-K for the year ended December 31, 2016 and Part II, Item 1. "Legal Proceedings" of our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017, our Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2017, and this report; and patent infringement proceedings relating to Dupixent, as described in ~~Part II, Item 1. "Legal Proceedings" of~~Note 11 to our ~~Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017, our Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2017, and this report.~~Condensed Consolidated Financial Statements. In addition, we are currently party to patent infringement proceedings initiated by us relating to our ~~European Patent No. 1,360,287, our European Patent No. 2,264,163, and our U.S. Patent No. 8,502,018, all of which~~patents that concern genetically altered mice capable of producing chimeric antibodies that are part human and part mouse, as described in ~~Part I, Item 3. "Legal Proceedings" of~~Note 11 to our Annual Report on Form 10-K for the year ended December 31, 2016 and Part II, Item 1. "Legal Proceedings" of our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017, our Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2017, and this report (as applicable).Condensed Consolidated Financial Statements.

We are aware of patents and pending patent applications owned by others that respectively claim antibodies to IL-4R and methods of treating conditions including atopic dermatitis and asthma with such antibodies; antibodies to IL-6R and methods of treating conditions including rheumatoid arthritis with such antibodies; antibodies to PCSK9 and methods of treating hypercholesterolemia with such antibodies; and antibodies to PD-1 and methods of treating cancer with such antibodies. In addition to Dupixent (dupilumab), Libtayo (cemiplimab), Praluent (alirocumab), and Kevzara (sarilumab), our late-stage antibody-based pipeline includes fasinumab, an antibody to NGF; ~~and cemiplimab,~~evinacumab, an antibody to ~~PD-1, intended~~ANGPTL3; REGN-EB3, a multi-antibody therapy for ~~the treatment of certain cancer indications including advanced cutaneous squamous cell carcinoma. With respect~~Ebola; garetosmab, an antibody to ~~Dupixent, we are aware of certain patents owned by Immunex Corporation,~~Activin A; pozelimab, an antibody to C5; and REGN1979, a wholly owned subsidiary of Amgen. These patents include U.S. Patent No. 8,679,487 (currently subject to the patent infringement proceedings described in Part II, Item 1. "Legal Proceedings" of our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017, our Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2017,bispecific antibody targeting CD20 and ~~this report) and European Patent No. 2,292,665 (the '665 Patent) and are generally directed to antibodies that bind to IL-4R.~~CD3.

Patent holders could assert claims against us for damages and seek to prevent us from manufacturing, selling, or developing our products or product candidates, and a court may find that we are infringing validly issued patents of others. In the event that the manufacture, use, or sale of any of our products or product candidates infringes on the patents or violates other proprietary rights of others, we may be prevented from pursuing product development, manufacturing, and commercialization of those drugs and may be required to pay costly damages. In addition, in the event that we assert our patent rights against other parties that we believe are infringing our patent rights, such parties may challenge the validity of our patents and we may become the target of litigation, which may result in an outcome that is unfavorable to us. Any of these adverse developments may materially harm our business, prospects, operating results, and financial condition. In any event, legal disputes are likely to be costly and time consuming to defend.

We seek to obtain licenses to patents when, in our judgment, such licenses are needed or advisable. For example, in August 2018, we and Sanofi entered into a license agreement with Bristol-Myers Squibb, E. R. Squibb & Sons, and Ono Pharmaceutical to obtain a license under certain patents owned and/or exclusively licensed by one or more of these parties that includes the right to develop and sell Libtayo. If any licenses are required, we may not be able to obtain such licenses on commercially reasonable terms, if at all. The failure to obtain any such license could prevent us from developing or commercializing any one or more of our products or product candidates, which could severely harm our business.

In the pharmaceutical and biotechnology industries, the majority of an innovative product's commercial value is usually realized during the period in which it has market exclusivity. In the United States and some other countries, when market exclusivity expires and generic versions of a product are approved and marketed, there usually are very substantial and rapid declines in the product's sales.

If our late-stage product candidates or other clinical candidates are approved for marketing in the United States or elsewhere, market exclusivity for those products will generally be based upon patent rights and/or certain regulatory forms of exclusivity. As described above under "If we cannot protect the confidentiality of our trade secrets, or our patents or other means of defending our intellectual property are insufficient to protect our proprietary rights, our business and competitive position will be harmed," the scope and enforceability of our patent rights may vary from country to country. The failure to obtain patent and other intellectual property rights, or limitations on the use, or the loss, of such rights could materially harm us. Absent patent protection or regulatory exclusivity for our products, it is possible, both in the United States and elsewhere, that generic, biosimilar, and/or ~~biosimilar~~interchangeable versions of those products may be approved and marketed, which would likely result in substantial and rapid reductions in revenues from sales of those products.

Under the federal ~~PPACA, enacted in 2010,~~Patient Protection and Affordable Care Act (the "PPACA"), there is an abbreviated path in the United States for regulatory approval of products that are demonstrated to be "biosimilar" or "interchangeable" with an FDA-approved biological product. The PPACA provides a regulatory mechanism that allows for FDA approval of biologic drugs that are similar to ~~(but not generic copies of)~~ innovative drugs on the basis of less extensive data than is required by a full BLA. Under this regulation, an application for approval of a biosimilar may be filed four years after approval of the innovator product. However, qualified innovative biological products ~~will~~ receive 12 years of regulatory exclusivity, meaning that the FDA may not approve a biosimilar version until 12 years after the innovative biological product was first approved by the FDA. However, the term of regulatory exclusivity may not remain at 12 years in the United States and could be ~~shortened.~~shortened if, for example, the PPACA is amended.

A number of jurisdictions outside of the United States have also established abbreviated pathways for regulatory approval of biological products that are biosimilar to earlier versions of biological products. For example, the EU has had an established regulatory pathway for biosimilars since 2005.

The increased likelihood of biosimilar competition has increased the risk of loss of innovators' market exclusivity. It is also not possible to predict changes in United States regulatory law that might reduce biological product regulatory exclusivity. Due to this risk, and uncertainties regarding patent protection, ~~if our late-stage product candidates or other clinical candidates are approved for marketing,~~ it is not possible to predict the length of market exclusivity for any particular product we currently or may in the future commercialize with certainty based solely on the expiration of the relevant patent(s) or the current forms of regulatory exclusivity. ~~It is also not possible to predict changes~~

~~Our~~We have large-scale manufacturing operations in Rensselaer, New York and Limerick, Ireland. Manufacturing facilities operated by us and by third-party contract manufacturers engaged by us would be inadequate to produce the active pharmaceutical ingredients of ~~(a)~~ our current marketed products ~~including EYLEA, Dupixent, Praluent,~~ and ~~Kevzara, and (b)~~ our ~~antibody-based~~ product candidates in sufficient clinical quantities if our clinical pipeline advances as planned. In addition to expanding our internal capacity, we intend to continue to rely on our collaborators, ~~as well as~~and may also rely on contract manufacturers, to produce commercial quantities of drug material needed for commercialization of our ~~products to the extent such quantities are not manufactured at our own facility.~~products. As we increase our production in anticipation of potential regulatory approval for our late-stage ~~antibody-based~~ product candidates, our current manufacturing capacity will likely not be sufficient, and ~~we may depend~~our dependence on our collaborators and/or contract manufacturers may increase, to produce adequate quantities of drug material for both commercial and clinical purposes. We rely entirely on other parties and our collaborators for filling and finishing ~~services.~~services, including with respect to drug-delivery devices (such as a pre-filled syringe, patch pump, auto-injector, or other delivery system). Generally, in order for other parties to perform any step in the manufacturing and supply chain, we must transfer technology to the other party, which can be time consuming and may not be successfully accomplished without considerable cost and expense, or at all. We will have to depend on these other parties to perform effectively on a timely basis and to comply with regulatory requirements. If for any reason they are unable to do so, and as a result

we are unable to directly or through other parties manufacture and supply sufficient commercial and clinical quantities of our products on acceptable terms, or if we should encounter delays or other difficulties ~~in our relationships~~ with our collaborators, contract manufacturers, warehouses, shipping, testing laboratories, or other parties involved in our supply chain which adversely affect the timely manufacture and supply of our products or product candidates, our business, prospects, operating results, and financial condition may be materially harmed.

~~We have acquired~~In addition to our existing manufacturing facilities in Rensselaer, New York and ~~are renovating a 400,000 square foot facility in~~ Limerick, Ireland, ~~to expand our manufacturing capacity to support our global supply chain. In the future,~~ we may lease, operate, purchase, or construct additional facilities to conduct expanded manufacturing ~~activities.~~or other related activities in the future. Expanding our manufacturing capacity to supply commercial quantities of the active pharmaceutical ingredients for our marketed products and our late-stage product candidates if they are approved for marketing, and to supply clinical drug material to support the continued growth of our clinical programs, will require substantial additional expenditures, time, and various regulatory approvals and permits. ~~In addition, the Limerick, Ireland facility remains subject to securing certain governmental permits, and there is no guarantee that we will be able to obtain the remaining required permits~~This also holds true for establishing fill/finish capabilities in the ~~contemplated timeframe, or at all.~~future, for which we have taken initial steps. Further, we will need to hire and train significant numbers of employees and managerial personnel to staff our expanding manufacturing and supply chain ~~operations.~~operations, as well as any future fill/finish activities. Start-up costs can be large, and scale-up entails significant risks related to process development and manufacturing yields. In addition, we may face difficulties or delays in developing or acquiring the necessary production equipment and technology to manufacture sufficient quantities of our product candidates at reasonable costs and in compliance with applicable regulatory requirements. The FDA and analogous foreign regulatory authorities must determine that our existing and any expanded manufacturing facilities and any future fill/finish activities comply, or continue to comply, with cGMP requirements for both clinical and commercial production and license them, or continue to license them, accordingly, and such facilities must also comply with applicable environmental, safety, and other governmental permitting requirements. We may not successfully expand or establish sufficient manufacturing or any future fill/finish capabilities or manufacture our products economically or in compliance with cGMPs and other regulatory requirements, and we and our collaborators may not be able to build or procure additional capacity in the required timeframe to meet commercial demand for our late-stage product candidates if they receive regulatory approval, and to continue to meet the requirements of our clinical programs. This would interfere with our efforts to successfully commercialize our marketed products, ~~including EYLEA, Dupixent, Praluent, and Kevzara,~~ and could also delay or require us to discontinue one or more of our clinical development programs. As a result, our business, prospects, operating results, and financial condition could be materially harmed.

Our ability to continue to manufacture products in our Rensselaer, New York and Limerick, Ireland facilities and at additional facilities ~~(such as the Limerick, Ireland facility)~~(if any) in the future or(including our ability to conduct any fill/finish activities in the future), the ability of our collaborators to manufacture products at their facilities, and our ability to utilize other third parties to produce our products, to supply raw materials or other products, or to perform fill/finish services or other steps in our manufacture and supply chain, depends on our and their ability to operate without infringing the patents or other intellectual property rights of others. Other parties may allege that our or our collaborators' manufacturing activities, or the activities of other third parties involved in our manufacture and supply chain (which may be located in jurisdictions outside the United States), infringe patents or other intellectual property rights. A judicial or regulatory decision in favor of one or more parties making such allegations could directly or indirectly preclude the manufacture of our products to which those intellectual property rights apply on a temporary or permanent basis, which could materially harm our business, prospects, operating results, and financial condition.

~~We have large-scale manufacturing operations in Rensselaer, New York and are in the process of building a large-scale manufacturing facility in Limerick, Ireland.~~ We use our manufacturing facilities primarily to produce bulk product for commercial supply of our marketed products and clinical and preclinical candidates for ourselves and our collaborations. We also plan to use such facilities to produce bulk product for commercial supply of new indications of our marketed products and new product candidates if they are approved for marketing. If our clinical candidates are discontinued or their clinical development is delayed, if the launch of new indications for our marketed products or new product candidates is delayed or does not occur, or if such products are launched and the launch is unsuccessful or the product is subsequently recalled or marketing approval is rescinded, we may have to absorb one hundred percent of related overhead costs and inefficiencies, as well as similar costs of third-party contract manufacturers performing services for us. In addition, if we or our collaborators experience excess inventory, it may be necessary to write down or ~~even~~ write off such excess inventory or incur an impairment charge with respect to the facility where such product is manufactured, which could adversely affect our operating results.

WeBulk drug materials are currently ~~manufacture all of our bulk drug materials~~manufactured at our manufacturing facilities in Rensselaer, New ~~York.~~York and Limerick, Ireland, as well as at our collaborators' facilities. We and our collaborators would be unable to manufacture these materials if ~~our Rensselaer facilities~~the relevant facility were to cease production due to regulatory requirements or actions, business interruptions, labor shortages or disputes, contaminations, fire, natural disasters, acts of war or terrorism, or other problems.

Many of our products and product candidates are very difficult to manufacture. As our products and product candidates are biologics, they require processing steps that are more difficult than those required for most chemical pharmaceuticals. Accordingly, multiple steps are needed to control the manufacturing processes. Problems with these manufacturing processes, even minor deviations from the normal process or from the materials used in the manufacturing process (which may not be detectable by us or our collaborators in a timely manner), could lead to product defects or manufacturing failures, resulting in lot failures, product recalls, product liability claims, and insufficient inventory. Also, the complexity of our manufacturing process may make it difficult, time-consuming, and expensive to transfer our technology to our collaborators or contract manufacturers.

Also, certain raw materials or other products necessary for the manufacture and formulation of our marketed products and product candidates, some of which are difficult to source, are provided by single-source unaffiliated third-party suppliers. In addition, we rely on certain third parties or our collaborators to perform filling, finishing, distribution, laboratory testing, and other services related to the manufacture of our marketed products and product candidates, and to supply various raw materials and other products. We would be unable to obtain these raw materials, other products, or services for an indeterminate period of time if any of these third parties were to cease or interrupt production or otherwise fail to supply these materials, products, or services to us for any reason, including due to regulatory requirements or actions (including recalls), adverse financial developments at or affecting the supplier, failure by the supplier to comply with cGMPs, contaminations, business interruptions, or labor shortages or ~~disputes.~~disputes (in each case, including as a result of the COVID-19 pandemic). In any such circumstances, we may not be able to engage a backup or alternative supplier or service provider in a timely manner or at all. This, in turn, could materially and adversely affect our or our collaborators' ability to manufacture or supply marketed products and product candidates, which could materially and adversely affect our business and future prospects.

Certain of the raw materials required in the manufacture and ~~the formulation~~testing of our products and product candidates may be derived from biological sources, including mammalian tissues, bovine serum, and human serum albumin. There are certain ~~European~~ regulatory restrictions on using these biological source materials. If we or our collaborators are required to substitute for these sources to comply with ~~European~~such regulatory requirements, our clinical development or commercial activities may be delayed or interrupted.

We and our collaborators and other third-party providers are required to maintain compliance with cGMPs, and are subject to inspections by the FDA or comparable agencies in other jurisdictions to confirm such compliance. Changes of suppliers or modifications of methods of manufacturing may require amending our application(s) to the FDA or such comparable foreign agencies and acceptance of the change by the FDA or such comparable foreign agencies prior to release of product(s). Because we produce multiple products and product candidates at our ~~facility~~facilities in Rensselaer, New York ~~including EYLEA, Dupixent, Praluent, Kevzara, ZALTRAP,~~ and ~~ARCALYST,~~Limerick, Ireland, there are increased risks associated with cGMP compliance. Our inability, or the inability of our collaborators and third-party fill/finish or other service providers, to demonstrate ongoing cGMP compliance could require us to engage in lengthy and expensive remediation efforts, withdraw or recall product, halt or interrupt clinical trials, and/or interrupt commercial supply of any marketed products, and could also delay or prevent our obtaining regulatory approval for our late-stage product candidates or new indications for our marketed products. For example, on October 28, 2016, the FDA issued a Complete Response Letter relating to the BLA for Kevzara, which referred to certain deficiencies identified during a routine cGMP inspection of the Sanofi fill-and-finish facility in Le Trait, France. While the BLA for Kevzara has since been approved by the FDA, this delayed the FDA approval of Kevzara. Any delay, interruption, or other issue that arises in the manufacture, fill/finish, packaging, or storage of any drug product or product candidate as a result of a failure of our facilities or the facilities or operations of our collaborators or other third parties to pass any regulatory agency inspection or maintain cGMP compliance could significantly impair our ability to develop, obtain approval for, and successfully commercialize our products, which would substantially harm our business, prospects, operating results, and financial condition. Any finding of non-compliance could also increase our costs, cause us to delay the development of our product candidates, result in delay in our obtaining, or our not obtaining, regulatory approval of product candidates or new indications for our marketed products, and cause us to lose revenue from any marketed products, which could be seriously detrimental to our business, prospects, operating results, and financial condition.

The testing, manufacturing, marketing, and sale of drugs for use in people expose us to product liability risk. Any informed consent or waivers obtained from people who enroll in our clinical trials may not protect us from liability or the cost of litigation. We may also be subject to claims by patients who use our approved products, or our product candidates if those product candidates receive regulatory approval and become commercially available, that they have been injured by a side effect associated with the drug. Even in a circumstance in which we do not believe that an adverse event is related to our products or product candidates, the related investigation may be time consuming or inconclusive and may have a negative impact on our reputation or business. We may face product liability claims and be found responsible even if injury arises from the acts or omissions of third parties who provide fill/finish or other services. To the extent we maintain product liability insurance in relevant periods, such insurance may not cover all potential liabilities or may not completely cover any liability arising from any such litigation. Moreover, in the future we may not have access to liability insurance or be able to maintain our insurance on acceptable terms.

The FDA regulates the marketing and promotion of our products, which must comply with the Food, Drug, and Cosmetic Act and applicable FDA implementing standards. The FDA's review of promotional activities includes healthcare provider-directed and direct-to-consumer advertising as well as sales representatives' communications. The FDA may take enforcement action for promoting unapproved uses of a product or other violations of its advertising laws and regulations.

In addition to FDA and related regulatory requirements, we are subject to health care "fraud and abuse" laws, such as the federal False Claims Act, the anti-kickback provisions of the federal Social Security Act, and other state and federal laws and regulations. Federal and state anti-kickback laws prohibit, among other things, payments or other remuneration to induce or reward someone to purchase, prescribe, endorse, or recommend a product that is reimbursed under federal or state healthcare programs. If we provide payments or other remuneration to a healthcare professional to induce the prescribing of our products, we could face liability under state and federal anti-kickback laws. Recently, the Bipartisan Budget Act of 2018 increased the criminal and civil penalties that can be imposed for violating certain federal health care laws, including the federal anti-kickback statute.

Federal false claims laws prohibit any person from knowingly presenting, or causing to be presented, a false claim for payment to the federal government, or knowingly making, or causing to be made, a false statement to get a false claim paid. Pharmaceutical companies have been prosecuted under these laws for a variety of alleged promotional and marketing activities, such as allegedly providing free product to customers with the expectation that the customers would bill federal programs for the product; reporting to pricing services inflated average wholesale prices that were then used by federal programs to set reimbursement rates; engaging in promotion for uses that the FDA has not approved, known as off-label uses, that caused claims to be submitted to Medicaid for

non-covered off-label uses; and submitting inflated best price information to the Medicaid Rebate program. The majority of states also have statutes or regulations similar to the federal anti-kickback law and false claims laws, which apply to items and services reimbursed under Medicaid and other state programs, or, in several states, apply regardless of the ~~payer.~~payor. Sanctions under these federal and state laws may include civil monetary penalties, exclusion of a manufacturer's products from reimbursement under government programs, criminal fines, and imprisonment. Even if it is determined that we have not violated these laws, government investigations into these issues typically require the expenditure of significant resources and generate negative publicity, which would harm our business, prospects, operating results, and financial condition. Because of the breadth of these laws and the narrowness of the safe harbors, it is possible that some of our business activities could be challenged under one or more of such laws.

As part of the PPACA, the federal government requires that pharmaceutical manufacturers record any "transfers of value" made to U.S. prescribers and certain other healthcare providers and teaching hospitals. Information provided by companies is aggregated and posted annually on an "Open Payments" website, which is managed by CMS, the agency responsible for implementing these disclosure requirements. We ~~will need to~~ continue to dedicate significant resources to comply with these requirements and need to be prepared to comply with additional reporting obligations outside of the United States that may apply in the future. The PPACA also includes various provisions designed to strengthen fraud-and-abuse enforcement, such as increased funding for enforcement efforts and the lowering of the intent requirement of the federal anti-kickback statute and criminal health care fraud statute such that a person or entity no longer needs to have actual knowledge of this statute or specific intent to violate it. In addition, several states have legislation requiring pharmaceutical companies to establish marketing compliance programs, file periodic reports with the state, or make periodic public disclosures on sales, marketing, pricing, clinical trials, and other activities. Many of these requirements and standards are new or uncertain, and the penalties for failure to comply with these requirements may be unclear. If we are found not to be in full compliance with these laws, we could face enforcement actions, fines, and other penalties, and could receive adverse publicity, which would harm our business, prospects, operating results, and financial condition. Additionally, access to such data by fraud-and-abuse investigators and industry critics may draw scrutiny to our collaborations with reported entities.

We cannot ensure that our compliance controls, policies, and procedures will in every instance protect us from acts committed by our employees, agents, contractors, or collaborators that would violate the laws or regulations of the jurisdictions in which we operate, including, without limitation, healthcare, employment, foreign corrupt practices, trade restrictions and sanctions, environmental, competition, and patient privacy and other privacy laws and regulations. Such improper actions could subject us to civil or criminal investigations, and monetary and injunctive penalties, and could adversely impact our ability to conduct business, operating results, and reputation.

In particular, our business activities outside of the United States are subject to the Foreign Corrupt Practices Act, or FCPA, and similar anti-bribery or anti-corruption laws, regulations or rules of other countries in which we operate, including the U.K. Bribery Act. The FCPA generally prohibits offering, promising, giving, or authorizing others to give anything of value, either directly or indirectly, to a non-U.S. government official in order to influence official action, or otherwise obtain or retain business. The FCPA also requires public companies to make and keep books and records that accurately and fairly reflect the transactions of the corporation and to devise and maintain an adequate system of internal accounting controls. Our business is heavily regulated and therefore involves significant interaction with public officials, including officials of non-U.S. governments. Additionally, in many other countries, the health care providers who prescribe pharmaceuticals are employed by their government, and the purchasers of pharmaceuticals are government entities; therefore, our dealings with these prescribers and purchasers are subject to regulation under the FCPA. Recently the Securities and Exchange Commission, or SEC, and Department of Justice have increased their FCPA enforcement activities with respect to pharmaceutical companies. There is no certainty that all of our employees, agents, contractors, or collaborators, or those of our affiliates, will comply with all applicable laws and regulations, particularly given the high level of complexity of these laws. Violations of these laws and regulations could result in fines, criminal sanctions against us, our officers, or our employees, requirements to obtain export licenses, cessation of business activities in sanctioned countries, implementation of compliance programs, and prohibitions on the conduct of our business. Any such violations could include prohibitions on our ability to offer our products in one or more countries and could materially damage our reputation, our brand, our ~~international expansion efforts,~~ability to expand internationally, our ability to attract and retain employees, and our business, prospects, operating results, and financial condition.

As a ~~biopharmaceutical~~fully integrated biotechnology company with significant research and development and manufacturing operations, we are subject to extensive environmental, health, and safety laws and regulations, including those governing the use of hazardous materials. Our research and development and manufacturing activities involve the controlled use of chemicals, infectious agents (such as viruses, bacteria, and fungi), radioactive compounds, and other hazardous materials. The cost of compliance with environmental, health, and safety regulations is substantial. If an accident involving these materials or an environmental discharge were to occur, we could be held liable for any resulting damages, or face regulatory actions, which could exceed our resources or insurance coverage.

We are subject to changing rules and regulations of various federal and state governmental authorities as well as the stock exchange on which our Common Stock is listed. These entities, including the SEC and The NASDAQ Stock Market LLC, have issued a significant number of new and increasingly complex requirements and regulations over the course of the last several years and continue to develop additional requirements and regulations in response to laws enacted by Congress, including the Sarbanes-Oxley Act of 2002 and ~~most recently,~~ the Dodd-Frank Wall Street Reform and Protection Act, or the Dodd-Frank Act. There are significant corporate governance and executive compensation-related provisions in the Dodd-Frank Act that expressly authorized or required the SEC to adopt additional rules in these areas, a number of which have yet to be fully implemented. Our efforts to comply with these requirements and regulations have resulted in, and are likely to continue to result in, an increase in expenses and a diversion of management's time from other business activities.

All aspects of our business, including research and development, manufacturing, marketing, pricing, sales, ~~litigation, and~~ intellectual property rights, and the framework for dispute resolution and asserting our rights against others, are subject to extensive legislation and regulation. Changes in applicable federal and state laws and agency regulations could have a materially negative impact on our business. These include:

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

We have operations and conduct business outside the United States and we plan to expand these activities. Consequently, we are, and will continue to be, subject to risks related to operating in foreign countries, which include:



		(Mark One)
~~(X)~~☒	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the quarterly period ended~~September 30, 2017~~
		March 31, 2020
	OR

~~( )~~☐	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the transition period from __________ to __________



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

~~incorporation or organization)~~

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



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



Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.	Yes	☒	No	☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).	Yes	☒	No	☐



~~Large accelerated filer~~	X		~~Accelerated filer~~
~~Non-accelerated filer~~		~~(Do not check if a smaller reporting company)~~	~~Smaller reporting company~~
			~~Emerging growth company~~

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.
☐



~~Yes~~			No	X
Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).	Yes	☐	No	☒



Class of Common Stock		Number of Shares
Class A Stock, $.001 par value		~~1,911,456~~1,848,970
Common Stock, $.001 par value		~~105,528,158~~110,673,311



		Page Numbers
PART I	FINANCIAL INFORMATION

Item 1.	Financial Statements (unaudited)	2

	Condensed Consolidated Balance Sheets as of ~~September 30, 2017~~March 31, 2020 and December 31, ~~2016~~2019	2

	Condensed Consolidated Statements of Operations and Comprehensive Income for the Three ~~and Nine~~ Months Ended ~~September 30, 2017~~March 31, 2020 and ~~2016~~2019	3

	Condensed Consolidated Statements of ~~Cash Flows~~Stockholders' Equity for the ~~Nine~~Three Months Ended ~~September 30, 2017~~March 31, 2020 and ~~2016~~2019	4

	~~Notes to~~ Condensed Consolidated ~~Financial~~ Statements of Cash Flows for the Three Months Ended March 31, 2020 and 2019	5

	~~Item 2.~~Notes to Condensed Consolidated Financial Statements	~~Management's Discussion and Analysis of Financial Condition and Results of Operations~~	216

Item 3.2.	~~Quantitative~~Management's Discussion and ~~Qualitative Disclosures About Market Risk~~Analysis of Financial Condition and Results of Operations	5023

Item 4.3.	~~Controls~~Quantitative and ~~Procedures~~Qualitative Disclosures About Market Risk	5043

~~PART II~~Item 4.	Controls and Procedures	43

PART II	OTHER INFORMATION

Item 1.	Legal Proceedings	5043

Item 1A.	Risk Factors	5243

Item 6.2.	~~Exhibits~~Unregistered Sales of Equity Securities and Use of Proceeds	8173

~~SIGNATURE PAGE~~Item 6.	82Exhibits	74

SIGNATURE PAGE		75


	September 30,			December 31,			March 31,			December 31,
	2017			2016			2020			2019
ASSETS
Current assets:
Cash and cash equivalents	$	792,065		$	535,203		$	2,208.2		$	1,617.8
Marketable securities	586,879			503,481			1,795.2			1,596.5
Accounts receivable - trade, net	1,532,693			1,343,368			2,063.1			2,100.0
Accounts receivable from Sanofi	217,478			92,989
Accounts receivable from Bayer	221,278			175,263
Accounts receivable - Sanofi							468.3			260.6
Accounts receivable - other							401.8			425.0
Inventories	641,588			399,356			1,480.9			1,415.5
Prepaid expenses and other current assets	143,761			130,528			226.6			273.7
Total current assets	4,135,742			3,180,188			8,644.1			7,689.1

Marketable securities	1,327,303			864,260			3,236.4			3,256.8
Property, plant, and equipment, net	2,274,529			2,083,421			2,944.6			2,890.4
Deferred tax assets	927,023			825,303			771.2			824.2
Other assets	36,618			20,294
Other noncurrent assets							161.2			144.7
Total assets	$	8,701,215		$	6,973,466		$	15,757.5		$	14,805.2

LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
Accounts payable and accrued expenses	$	818,426		$	879,096
Capital and facility lease obligations	—			129,557
Deferred revenue from Sanofi, current portion	187,036			115,267
Deferred revenue - other, current portion	132,832			116,397
Other current liabilities	334			1,178
Accounts payable							$	347.8		$	418.1
Accrued expenses and other current liabilities							1,143.2			1,211.4
Deferred revenue - Sanofi							398.0			310.5
Deferred revenue - other							81.2			71.6
Other liabilities - Sanofi							85.0			85.0
Total current liabilities	1,138,628			1,241,495			2,055.2			2,096.6

Capital and facility lease obligations	702,317			351,569
Deferred revenue from Sanofi	408,786			503,474
Finance lease liabilities							715.2			713.9
Deferred revenue - Sanofi							16.2			27.7
Deferred revenue - other	274,666			327,298			65.9			77.6
Other long-term liabilities	125,225			100,385
Other liabilities - Sanofi							450.5			482.0
Other noncurrent liabilities							321.5			317.7
Total liabilities	2,649,622			2,524,221			3,624.5			3,715.5

Stockholders' equity:
Preferred Stock, $.01 par value; 30,000,000 shares authorized; issued and outstanding - none	—			—			—			—
Class A Stock, convertible, $.001 par value; 40,000,000 shares authorized; shares issued and outstanding - 1,911,456 in 2017 and 2016	2			2
Common Stock, $.001 par value; 320,000,000 shares authorized; shares issued - 109,255,150 in 2017 and 107,860,567 in 2016	109			108
Class A Stock, convertible, $.001 par value; 40,000,000 shares authorized; shares issued and outstanding - 1,848,970 in 2020 and 2019							—			—
Common Stock, $.001 par value; 320,000,000 shares authorized; shares issued - 116,025,758 in 2020 and 113,288,103 in 2019							0.1			0.1
Additional paid-in capital	3,570,673			3,029,993			5,211.4			4,428.6
Retained earnings	2,773,214			1,748,222			8,004.4			7,379.8
Accumulated other comprehensive income (loss)	23,835			(12,840		)
Treasury Stock, at cost; 3,763,868 shares in 2017 and 2016	(316,240		)	(316,240		)
Accumulated other comprehensive (loss) income							(9.1		)	21.1
Treasury Stock, at cost; 5,683,562 shares in 2020 and 4,860,123 shares in 2019							(1,073.8		)	(739.9		)
Total stockholders' equity	6,051,593			4,449,245			12,133.0			11,089.7
Total liabilities and stockholders' equity	$	8,701,215		$	6,973,466		$	15,757.5		$	14,805.2

The accompanying notes are an integral part of the financial statements.


	Three Months Ended September 30,						Nine Months Ended September 30,						Three Months Ended March 31,
	2017			2016			2017			2016			2020			2019
Statements of Operations
Revenues:
Net product sales	$	957,367		$	857,468		$	2,739,745		$	2,475,869		$	1,236.7		$	1,104.4
Sanofi collaboration revenue	245,175			144,392			677,670			527,500			246.9			(18.0		)
Bayer collaboration revenue	236,625			191,298			640,919			562,786			281.4			264.0
Other revenue	61,506			26,964			231,446			67,445			63.2			22.2
	1,500,673			1,220,122			4,289,780			3,633,600			1,828.2			1,372.6

Expenses:
Research and development	529,749			543,047			1,547,159			1,573,089			583.9			486.1
Selling, general, and administrative	306,766			270,045			910,520			851,760			367.3			291.1
Cost of goods sold	46,388			29,901			149,774			150,090			78.8			70.9
Cost of collaboration and contract manufacturing	57,844			14,327			141,547			74,923			138.5			101.2
Other operating (income) expense, net													(40.4		)	(56.7		)
	940,747			857,320			2,749,000			2,649,862			1,128.1			892.6

Income from operations	559,926			362,802			1,540,780			983,738			700.1			480.0

Other income (expense):
Other income, net	11,861			3,575			2,048			8,937
Interest expense, net	(6,182		)	(496		)	(19,084		)	(4,387		)
Other (expense) income, net													(25.4		)	73.8
Interest expense													(6.1		)	(7.7		)
	5,679			3,079			(17,036		)	4,550			(31.5		)	66.1

Income before income taxes	565,605			365,881			1,523,744			988,288			668.6			546.1

Income tax expense	(177,288		)	(101,077		)	(498,752		)	(345,881		)	44.0			85.0

Net income	$	388,317		$	264,804		$	1,024,992		$	642,407		$	624.6		$	461.1

Net income per share - basic	$	3.64		$	2.53		$	9.66		$	6.14		$	5.69		$	4.23
Net income per share - diluted	$	3.32		$	2.27		$	8.84		$	5.51		$	5.43		$	3.99

Weighted average shares outstanding - basic	106,706			104,833			106,108			104,586			109.8			108.9
Weighted average shares outstanding - diluted	117,028			116,466			115,994			116,567			115.1			115.5

Statements of Comprehensive Income
Net income	$	388,317		$	264,804		$	1,024,992		$	642,407		$	624.6		$	461.1
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on marketable securities	21,485			(8,103		)	36,645			(11,471		)
Unrealized gain on cash flow hedges	2			—			30			—
Unrealized (loss) gain on debt securities													(28.8		)	16.1
Unrealized loss on cash flow hedges													(1.4		)	(1.0		)
Comprehensive income	$	409,804		$	256,701		$	1,061,667		$	630,936		$	594.4		$	476.2

The accompanying notes are an integral part of the financial statements.



	Class A Stock		Common Stock				Additional Paid-in Capital			Retained Earnings		Accumulated Other Comprehensive Income (Loss)			Treasury Stock					Total Stockholders' Equity
	Shares	Amount	Shares		Amount		Additional Paid-in Capital			Retained Earnings		Accumulated Other Comprehensive Income (Loss)			Shares		Amount			Total Stockholders' Equity
Balance, December 31, 2019	1.8	—	113.3		$	0.1	$	4,428.6		$	7,379.8	$	21.1		(4.9	)	$	(739.9	)	$	11,089.7
Issuance of Common Stock for equity awards granted under long-term incentive plans	—	—	3.1		—		817.4			—		—			—		—			817.4
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations	—	—	(0.4	)	—		(155.1		)	—		—			—		—			(155.1		)
Issuance/distribution of Common Stock for 401(k) Savings Plan	—	—	—		—		12.5			—		—			—		2.1			14.6
Repurchases of Common Stock	—	—	—		—		—			—		—			(0.8	)	(336.0		)	(336.0		)
Stock-based compensation charges	—	—	—		—		108.0			—		—			—		—			108.0
Net income	—	—	—		—		—			624.6		—			—		—			624.6
Other comprehensive loss, net of tax	—	—	—		—		—			—		(30.2		)	—		—			(30.2		)
Balance, March 31, 2020	1.8	—	116.0		$	0.1	$	5,211.4		$	8,004.4	$	(9.1	)	(5.7	)	$	(1,073.8	)	$	12,133.0

Balance, December 31, 2018	1.9	—	111.1		$	0.1	$	3,911.6		$	5,254.3	$	(12.3	)	(4.0	)	$	(396.4	)	$	8,757.3
Issuance of Common Stock for equity awards granted under long-term incentive plans	—	—	0.6		—		140.9			—		—			—		—			140.9
Common Stock tendered upon exercise of stock options and vesting of restricted stock for employee tax obligations	—	—	—		—		(10.7		)	—		—			—		—			(10.7		)
Issuance of Common Stock for 401(k) Savings Plan	—	—	—		—		4.3			—		—			0.1		6.2			10.5
Repurchases of Common Stock	—	—	—		—		—			—		—			(0.1	)	(54.0		)	(54.0		)
Stock-based compensation charges	—	—	—		—		114.8			—		—			—		—			114.8
Adjustment upon adoption of new accounting standard	—	—	—		—		—			9.7		—			—		—			9.7
Net income	—	—	—		—		—			461.1		—			—		—			461.1
Other comprehensive income, net of tax	—	—	—		—		—			—		15.1			—		—			15.1
Balance, March 31, 2019	1.9	—	111.7		$	0.1	$	4,160.9		$	5,725.1	$	2.8		(4.0	)	$	(444.2	)	$	9,444.7

The accompanying notes are an integral part of the financial statements.



	December 31, 2019
Balance Sheet Data:	As Previously Reported		Adjustments			As Revised
Accrued expenses and other current liabilities	$	1,086.8	$	124.6		$	1,211.4
Deferred revenue - Sanofi (current)	$	395.5	$	(85.0	)	$	310.5
Deferred revenue - other (current)	$	196.2	$	(124.6	)	$	71.6
Other liabilities - Sanofi (current)	—		$	85.0		$	85.0
Deferred revenue - Sanofi (noncurrent)	$	509.7	$	(482.0	)	$	27.7
Deferred revenue - other (noncurrent)	$	109.3	$	(31.7	)	$	77.6
Other liabilities - Sanofi (noncurrent)	—		$	482.0		$	482.0
Other noncurrent liabilities	$	286.0	$	31.7		$	317.7



	Three Months Ended March 31, 2019
Statement of Operations Data:	As Previously Reported		Adjustments			As Revised
Sanofi collaboration revenue	$	246.4	$	(264.4	)	$	(18.0	)
Bayer collaboration revenue	$	276.2	$	(12.2	)	$	264.0
Other revenue	$	84.8	$	(62.6	)	$	22.2
Total revenues	$	1,711.8	$	(339.2	)	$	1,372.6

Research and development	$	641.8	$	(155.7	)	$	486.1
Selling, general, and administrative	$	410.8	$	(119.7	)	$	291.1
Cost of collaboration and contract manufacturing⁽¹⁾	$	108.3	$	(7.1	)	$	101.2
Other operating (income) expense, net	—		$	(56.7	)	$	(56.7	)
Total operating expenses	$	1,231.8	$	(339.2	)	$	892.6

⁽¹⁾ In addition to the reclassification of certain amounts in connection with the change in accounting presentation described above, the Company also reclassified certain immaterial reimbursements that were previously classified as collaboration revenue to Cost of collaboration and contract manufacturing.



	Three Months Ended March 31, 2019
Cash Flows Data:	As Previously Reported			Adjustments			As Revised
Cash flows from operating activities:
Increase in deferred revenue	$	426.5		$	(345.4	)	$	81.1
(Decrease) increase in accounts payable, accrued expenses, and other liabilities	$	(19.6	)	$	345.4		$	325.8



	Commission File ~~Number~~ Number:	0-19034



	Rebates & Chargebacks			Distribution- Related Fees			Other Sales- Related Deductions			Total
Balance as of December 31, 2016	$	12,712		$	29,465		$	3,674		$	45,851
Provisions	121,599			140,860			33,518			295,977
Credits/payments	(108,811		)	(136,272		)	(21,444		)	(266,527		)
Balance as of September 30, 2017	$	25,500		$	34,053		$	15,748		$	75,301

Balance as of December 31, 2015	$	6,419		$	48,313		$	517		$	55,249
Provisions	63,510			113,755			22,812			200,077
Credits/payments	(62,503		)	(135,483		)	(19,587		)	(217,573		)
Balance as of September 30, 2016	$	7,426		$	26,585		$	3,742		$	37,753



Nature/Type of Payment		Statement of Operations Presentation
Regeneron's share of profits or losses in connection with commercialization of products		Collaboration revenue
Reimbursement for manufacturing of commercial supplies		Collaboration revenue
Royalties and/or sales-based milestones earned		Collaboration revenue
Reimbursement of Regeneron's research and development expenses		Reduction to Research and development expenses
Regeneron's obligation for its share of collaborator's research and development expenses		Research and development expense
Up-front and development milestone payments to collaborator		Research and development expense
Reimbursement of Regeneron's commercialization-related expenses		Reduction to Selling, general, and administrative expense
Regeneron's obligation to pay collaborator for its share of gross profits when Regeneron is deemed to be the principal		Cost of goods sold
Up-front and development milestones earned (when we have a combined unit of account which includes a license and providing research and development services)		Other operating income



	Statement of Operations Classification	Three Months Ended March 31,
	Statement of Operations Classification	2020			2019
Antibody:
Regeneron's share of profits (losses) in connection with commercialization of antibodies	Sanofi collaboration revenue	$	170.9		$	(27.8	)
Reimbursement for manufacturing of commercial supplies	Sanofi collaboration revenue	$	80.1		$	14.5
Reimbursement of research and development expenses	Reduction of Research and development expense	$	77.6		$	74.5
Regeneron's obligation for its share of Sanofi research and development expenses	Research and development expense	$	(16.7	)	$	(7.4	)
Reimbursement of commercialization-related expenses	Reduction of Selling, general, and administrative expense	$	91.2		$	116.6

Immuno-oncology:
Regeneron's share of losses in connection with commercialization of Libtayo outside the United States	Sanofi collaboration revenue	$	(6.2	)	$	(4.7	)
Reimbursement for manufacturing of commercial supplies	Sanofi collaboration revenue	$	2.1		—
Reimbursement of research and development expenses	Reduction of Research and development expense	$	39.9		$	46.4
Reimbursement of commercialization-related expenses	Reduction of Selling, general, and administrative expense	$	10.4		$	2.2
Regeneron's obligation for Sanofi's share of Libtayo U.S. gross profits	Cost of goods sold	$	(26.8	)	$	(12.4	)
Amounts recognized in connection with up-front payments received	Other operating income	$	16.5		$	26.3



	Three Months Ended September 30,		Nine Months Ended September 30,
(Shares in thousands)	2017	2016	2017	2016
Stock options	4,515	7,687	8,892	7,842
Restricted stock	—	19	—	19
Convertible senior notes	—	3	—	—


	Amortized		Unrealized					Fair		Amortized		Unrealized					Fair
As of September 30, 2017	Cost Basis		Gains		Losses			Value
As of March 31, 2020										Cost Basis		Gains		Losses			Value
Corporate bonds	$	1,564,391	$	2,789	$	(2,691	)	$	1,564,489	$	4,128.3	$	20.7	$	(31.6	)	$	4,117.4
U.S. government and government agency obligations	189,647		56		(645		)	189,058		73.7		1.4		—			75.1
Municipal bonds	4,614		—		(8		)	4,606
Sovereign bonds										36.0		1.2		—			37.2
Commercial paper	61,464		—		—			61,464		162.6		0.1		—			162.7
Certificates of deposit	6,525		—		—			6,525		77.4		0.1		(0.3		)	77.2
Equity securities	57,251		30,789		—			88,040
	$	1,883,892	$	33,634	$	(3,344	)	$	1,914,182	$	4,478.0	$	23.5	$	(31.9	)	$	4,469.6

As of December 31, 2016
As of December 31, 2019
Corporate bonds	$	1,076,964	$	630	$	(4,743	)	$	1,072,851	$	3,960.5	$	27.8	$	(0.2	)	$	3,988.1
U.S. government and government agency obligations	132,923		58		(641		)	132,340		54.3		0.2		(0.1		)	54.4
Municipal bonds	7,663		1		(20		)	7,644
Sovereign bonds										26.9		0.4		—			27.3
Commercial paper	63,074		1		—			63,075		92.3		—		—			92.3
Certificates of deposit	42,612		—		—			42,612		72.3		0.1		—			72.4
Equity securities	57,251		5,551		(13,583		)	49,219
	$	1,380,487	$	6,241	$	(18,987	)	$	1,367,741	$	4,206.3	$	28.5	$	(0.3	)	$	4,234.5



	September 30, 2017		December 31, 2016
Maturities within one year	$	586,879	$	503,481
Maturities after one year through five years	1,239,263		815,041
	$	1,826,142	$	1,318,522



	Less than 12 Months					12 Months or Greater		Total
As of March 31, 2020	Fair Value		Unrealized Loss			Fair Value	Unrealized Loss	Fair Value		Unrealized Loss
Corporate bonds	$	1,990.1	$	(31.6	)	—	—	$	1,990.1	$	(31.6	)
Certificates of deposit	49.5		(0.3		)	—	—	49.5		(0.3		)
	$	2,039.6	$	(31.9	)	—	—	$	2,039.6	$	(31.9	)

As of December 31, 2019
Corporate bonds	$	257.2	$	(0.2	)	—	—	$	257.2	$	(0.2	)
U.S. government and government agency obligations	17.3		(0.1		)	—	—	17.3		(0.1		)
	$	274.5	$	(0.3	)	—	—	$	274.5	$	(0.3	)



			Fair Value Measurements at Reporting Date Using
As of September 30, 2017	Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)
Available-for-sale marketable securities:
Corporate bonds	$	1,564,489	—		$	1,564,489
U.S. government and government agency obligations	189,058		—		189,058
Municipal bonds	4,606		—		4,606
Commercial paper	61,464		—		61,464
Certificates of deposit	6,525		—		6,525
Equity securities	88,040		$	88,040	—
	$	1,914,182	$	88,040	$	1,826,142

As of December 31, 2016
Available-for-sale marketable securities:
Corporate bonds	$	1,072,851	—		$	1,072,851
U.S. government and government agency obligations	132,340		—		132,340
Municipal bonds	7,644		—		7,644
Commercial paper	63,075		—		63,075
Certificates of deposit	42,612		—		42,612
Equity securities	49,219		$	49,219	—
	$	1,367,741	$	49,219	$	1,318,522



	Notional Amount
Interest rate swap contracts	$	75,000
Interest rate cap contracts	$	75,000


ITEM 2.	MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS



	Three Months Ended March 31,
(In millions, except per share data)	2020		2019^*
Revenues	$	1,828.2	$	1,372.6
Net income	$	624.6	$	461.1
Net income per share - diluted	$	5.43	$	3.99

^*Certain revisions have been made to the previously reported March 31, 2019 revenues. See Note 1 to our Condensed Consolidated Financial Statements for further details.



•Product		Disease Area⁽¹⁾	Territory
•Product		Disease Area⁽¹⁾	U.S.	EU	Japan	ROW⁽⁶⁾
EYLEA (aflibercept) Injection⁽²⁾	-	Neovascular age-related macular degeneration ("wet AMD")	a	a	a	a
	-	Diabetic macular edema ("DME")	a	a	a	a
	-	Macular edema following retinal vein occlusion ("RVO"), which includes macular edema following central retinal vein occlusion ("CRVO") and macular edema following branch retinal vein occlusion ("BRVO")	a	a	a	a
	-	Myopic choroidal neovascularization ("mCNV")		a	a	a
	-	Diabetic retinopathy	a
	-	Neovascular glaucoma ("NVG")			a
Dupixent(dupilumab) ~~Injection.~~ ~~On March 28, 2017, the the U.S. Food~~Injection⁽³⁾	-	Atopic dermatitis (in adults and ~~Drug Administration (FDA) approved Dupixent for the treatment of adult~~adolescents)⁽⁷⁾	a	a	a	a
	-	Asthma (in adults and adolescents)	a	a	a	a
	-	Chronic rhinosinusitis with nasal polyposis ("CRSwNP")	a	a	a	a
Libtayo (cemiplimab) Injection⁽³⁾⁽⁴⁾	-	Metastatic or locally advanced cutaneous squamous cell carcinoma ("CSCC")	a	a		a
Praluent (alirocumab) Injection⁽⁸⁾	-	LDL-lowering in heterozygous familial hypercholesterolemia ("HeFH") or clinical atherosclerotic cardiovascular disease ("ASCVD") (in adults)	a	a	a	a
Praluent (alirocumab) Injection⁽⁸⁾	-	Cardiovascular risk reduction in patients with ~~moderate-to-severe atopic dermatitis whose~~established cardiovascular disease is not adequately controlled with topical prescription therapies or when those therapies are not advisable. The launch of Dupixent commenced in March following the FDA approval. Sanofi records product sales for Dupixent, and we and Sanofi share profits and losses from sales of Dupixent. We have exercised our option to co-promote Dupixent in the United States and thus far have not exercised our option to co-promote Dupixent outside the United States.

		a		a				a
•	Kevzara(sarilumab) Solution for Subcutaneous Injection~~. In January 2017, Health Canada approved Kevzara for the treatment of adult patients with moderately to severely active rheumatoid~~⁽³⁾	-	Rheumatoid arthritis (RA) who have an inadequate response to or intolerance to one or more biologic or non-biologic disease modifying anti-rheumatic drugs (DMARDs). This was the first approval of Kevzara worldwide. On May 22, 2017, the FDA approved Kevzara for the treatment of adult patients with moderately to severely active rheumatoid arthritis who have an inadequate response or intolerance to one or more DMARDs. In June 2017, the European Commission granted marketing authorization for Kevzara in combination with methotrexate (MTX) for the treatment of moderately to severely active rheumatoid arthritis in adult patients who have responded inadequately to, or who are intolerant to one or more DMARDs; Kevzara may be used as monotherapy in case of intolerance to MTX or when treatment with MTX is inappropriate. In September 2017, the Pharmaceuticals and Medical Devices Agency (PMDA) in Japan approved Kevzara for the treatment of adult patients with rheumatoid arthritis who have had an inadequate response to conventional treatments.

("RA") (in adults)		a		a		a		a
•	ARCALYST^® (rilonacept) Injection for Subcutaneous Use ~~is available in the United States for the treatment of~~	-	Cryopyrin-Associated Periodic Syndromes ~~(CAPS)~~("CAPS"), including Familial Cold Auto-inflammatory Syndrome ~~(FCAS)~~("FCAS") and Muckle-Wells Syndrome (MWS), in adults and children 12 years and older. CAPS are a group of rare, inherited, auto-inflammatory conditions characterized by life-long, recurrent symptoms of rash, fever/chills, joint pain, eye redness/pain, and fatigue. Intermittent, disruptive exacerbations or flares can be triggered at any time by exposure to cooling temperatures, stress, exercise, or other unknown stimuli.

("MWS")		a
•	ZALTRAP^®(ziv-aflibercept) Injection for Intravenous Infusion~~, known~~⁽⁵⁾	-	Metastatic colorectal cancer ("mCRC")	a	a	a	a

⁽¹⁾Refer to label information in each territory for specific indication
⁽²⁾In collaboration with Bayer (outside the ~~scientific literature~~United States)
⁽³⁾ In collaboration with Sanofi
⁽⁴⁾Marketed as ~~VEGF Trap, is available~~Libtayo (cemiplimab-rwlc) Injection in the United States EU, and certain other countries for treatment, in combination with 5-fluorouracil, leucovorin, irinotecan (FOLFIRI), of patients with metastatic colorectal cancer (mCRC) that is resistant to or has progressed following an oxaliplatin-containing regimen.
⁽⁵⁾ Pursuant to a 2015 amended and restated ZALTRAP agreement, Sanofi is solely responsible for the development and commercialization of ZALTRAP, and Sanofi pays us a percentage of aggregate net product sales of ~~ZALTRAP.~~ZALTRAP
⁽⁶⁾ Rest of world. Checkmark in this column indicates that the product has received marketing approval in at least one country outside of the United States, European Union ("EU"), or Japan
⁽⁷⁾ Approval in Japan is for adults and adolescents 15 years of age and older
⁽⁸⁾ In collaboration with Sanofi prior to April 2020. Effective April 2020, the Company is solely responsible for the development and commercialization of Praluent in the United States, and Sanofi is solely responsible for the development and commercialization of Praluent outside of the United States. Pursuant to the April 2020 agreement, Sanofi will pay us a percentage of aggregate net product sales of Praluent outside the United States. Refer to "Collaboration Agreements" section below for further details.



Net Product Sales of Regeneron-Discovered Products⁽¹⁾	Three Months Ended September 30,				Nine Months Ended September 30,
(In millions)	2017		2016		2017		2016
EYLEA in the United States	$	953.3	$	853.6	$	2,727.1	$	2,465.4
ARCALYST	4.1		3.9		12.6		10.5
Net product sales recorded by Regeneron	$	957.4	$	857.5	$	2,739.7	$	2,475.9

EYLEA outside of the United States⁽¹⁾	$	563.7	$	470.8	$	1,590.0	$	1,375.9
EYLEA global	$	1,517.0	$	1,324.4	$	4,317.1	$	3,841.3

Global net product sales recorded by Sanofi⁽¹⁾:
Praluent in the United States	$	31.8	$	31.6	$	89.8	$	61.9
Praluent outside of the United States	17.6		6.6		41.6		13.8
Praluent global	49.4		38.2		131.4		75.7
Dupixent	88.9		—		117.6		—
Kevzara	3.0		—		3.8		—
ZALTRAP	21.7		18.0		58.6		56.0
Net product sales recorded by Sanofi	$	163.0	$	56.2	$	311.4	$	131.7

⁽¹⁾As described in the "Overview" section above, Bayer records net product sales of EYLEA outside the United States and Sanofi records global net product sales of Praluent, Dupixent, Kevzara, and ZALTRAP.



Note: For purposes of the table above, a program is classified in Phase 1, 2, or 3 clinical development after recruiting for the corresponding study or studies has commenced
^*(a)In collaboration with Sanofi
^(b)In collaboration with Teva and Mitsubishi Tanabe Pharma
^(c) FDA granted orphan drug designation
^(d)FDA granted Breakthrough Therapy designation
^(e) FDA granted Fast Track designation
^(f) Sanofi did not opt-in to or elected not to continue to co-develop the product candidate. Under the terms of our agreement, Sanofi is entitled to receive royalties on any future ~~global~~ sales of the product candidate.
^**(g) Antibodies targeting the Ang2 receptor and ligand in ophthalmology were previously included in our antibody collaboration with Sanofi. Under the terms of our agreement, Sanofi is entitled to receive royalties on any future global sales of the product candidate and a potential development milestone.
^*** ~~Sanofi did not opt-in to the product candidate. Under the terms of our agreement, Sanofi is entitled to receive royalties on any future sales of the product candidate.~~ We and the Biomedical Advanced Research Development Authority ~~(BARDA)~~("BARDA") of the U.S. Department of Health and Human Services ~~(HHS)~~("HHS") are parties to agreements ~~(including an agreement executed in September 2017 - see "Other Programs" below for further information)~~ whereby HHS provides certain funding to support research, development, and manufacturing of ~~a monoclonal antibody therapy~~these antibodies.
^(h) Studied as monotherapy and in combination with other antibodies and treatments
⁽ⁱ⁾ Information in this column relates to U.S., EU, and Japan regulatory submissions only
^(j) In collaboration with Sanofi prior to April 2020. Effective April 2020, the Company is solely responsible for the ~~treatment~~development and commercialization of ~~Ebola virus infection.~~Praluent in the United States, and Sanofi is solely responsible for the development and commercialization of Praluent outside of the United States. Refer to "Collaboration Agreements" section below for further details.
^(k) As described in the section preceding the table above and Part II, Item 1A. "Risk Factors," development timelines may be further subject to change as a result of the impact of the COVID-19 pandemic



~~Trap-based Clinical Program:~~
		~~2017 Events to Date~~		~~2017-2018 Plans (next 12 months)~~
~~EYLEA~~	Ÿ	~~Bayer received regulatory approval for EYLEA for various indications and continued to pursue regulatory applications for marketing approval in additional countries~~	Ÿ	~~Bayer to submit for additional regulatory approvals outside the United States for various indications~~
			Ÿ	~~Regulatory agency decisions on applications outside the United States for various indications~~
	Ÿ	~~Completed patient enrollment in Phase 3 study for the treatment of NPDR in patients without DME~~	Ÿ	~~File sBLA with FDA for every 12-week dosing interval in wet AMD~~
			Ÿ	~~Report data from Phase 3 study for the treatment of NPDR in patients without DME~~
			Ÿ	~~Submit sBLA for NPDR in patients without DME~~
			Ÿ	~~Report results from Phase 2 co-formulation studies of nesvacumab/aflibercept~~



~~Antibody-based Clinical Programs:~~
		~~2017 Events to Date~~		~~2017-2018 Plans (next 12 months)~~
~~Dupixent (dupilumab; IL-4R Antibody)~~	Ÿ	~~Presented detailed results from one-year Phase 3 CHRONOS study at the Annual Meeting of the American Academy of Dermatology~~	Ÿ	~~Submit for additional regulatory approvals in atopic dermatitis outside the United States~~
			Ÿ	~~Regulatory agency decisions on atopic dermatitis applications outside the United States~~
	Ÿ	~~FDA approved Dupixent for the treatment of adults with moderate-to-severe atopic dermatitis~~	Ÿ	~~Initiate Phase 3 studies in younger pediatric patients in atopic dermatitis~~
	Ÿ	~~Initiated Phase 3 study in adolescent patients (12-17 years of age) with atopic dermatitis~~	Ÿ	~~Submit sBLA for asthma in adult/adolescent patients~~
	Ÿ	~~Regulatory applications submitted for atopic dermatitis in Japan and various other jurisdictions outside the United States~~	Ÿ	~~Submit for EU regulatory approval in asthma in adult/adolescent patients~~
			Ÿ	~~Initiate Phase 3 study in EoE~~
	Ÿ	~~Reported positive results from the LIBERTY AD CAFÉ study in atopic dermatitis~~	Ÿ	~~Initiate Phase 2 study in peanut allergy~~
	Ÿ	~~European Commission granted marketing approval for Dupixent for the treatment of adults with moderate-to-severe atopic dermatitis~~
	Ÿ	~~Initiated Phase 3 study in pediatric patients (6-11 years of age) with asthma~~
	Ÿ	~~Reported positive top-line results from Phase 3 LIBERTY ASTHMA QUEST trial~~
	Ÿ	~~Reported positive top-line results from Phase 3 LIBERTY ASTHMA VENTURE study~~
	Ÿ	~~Reported positive results from Phase 2 study in EoE~~
	Ÿ	~~FDA granted orphan drug designation for the treatment of EoE~~
	Ÿ	~~Completed patient enrollment in Phase 3 study in nasal polyps~~
~~Praluent (PCSK9 Antibody)~~	Ÿ	~~Permanent injunction barring commercialization of Praluent in the United States suspended on February 8, 2017 and vacated on October 5, 2017~~	Ÿ	~~Complete and report results from ODYSSEY OUTCOMES study~~
			Ÿ	~~Submit for additional regulatory approvals outside the United States~~
	Ÿ	~~FDA approved sBLA for monthly dosing regimen~~	Ÿ	~~Regulatory agency decisions on applications outside the United States~~
	Ÿ	~~FDA granted orphan drug designation for treatment of HoFH~~	Ÿ	~~File sBLA with FDA for use with apheresis~~
	Ÿ	~~Reported positive results from two Phase 3b/4 trials in patients with diabetes~~	Ÿ	~~Initiate Phase 3 pediatric studies in HoFH and HeFH~~
	Ÿ	~~ODYSSEY study data presented at the European Society of Cardiology (ESC) Congress~~
	Ÿ	~~Initiated Phase 3 study in HoFH~~



~~Antibody-based Clinical Programs (continued):~~
		~~2017 Events to Date~~		~~2017-2018 Plans (next 12 months)~~
~~Kevzara (sarilumab; IL-6R Antibody)~~	Ÿ	~~Regulatory applications submitted in various jurisdictions outside the United States~~	Ÿ	~~Submit for additional regulatory approvals outside of the United States~~
	Ÿ	~~Health Canada approved Kevzara for the treatment of adult patients with RA~~	Ÿ	~~Regulatory agency decisions on applications outside the United States~~
	Ÿ	~~Resubmitted BLA and FDA accepted for review~~	Ÿ	~~Continue patient enrollment in Phase 2 study in pcJIA~~
	Ÿ	~~FDA approved Kevzara for the treatment of adult patients with RA~~
	Ÿ	~~European Commission granted marketing authorization for Kevzara for the treatment of adult patients with RA~~
~~Suptavumab (RSV-F Antibody)~~	Ÿ	~~Completed patient enrollment in Phase 3 study~~
	Ÿ	~~Reported results from Phase 3 study, and discontinued further clinical development~~
~~Cemiplimab (REGN2810; PD-1 Antibody)~~	Ÿ	~~Continued patient enrollment in Phase 1 and Phase 2 studies~~	Ÿ	~~Report interim data from pivotal Phase 2 CSCC study~~
	Ÿ	~~Reported positive preliminary results from Phase 1 trial in patients with advanced CSCC~~	Ÿ	~~Submit BLA for CSCC~~
	Ÿ	~~FDA granted Breakthrough Therapy designation for the treatment of adults with metastatic CSCC and adults with locally advanced and unresectable CSCC~~	Ÿ	~~Submit for regulatory approval in CSCC in the EU~~
			Ÿ	~~Initiate additional studies in non-small cell lung cancer~~
	Ÿ	~~Initiated Phase 3 study in first-line treatment for non-small cell lung cancer~~	Ÿ	~~Continue patient enrollment in various studies~~
	Ÿ	~~Initiated potentially pivotal Phase 2 study in BCC~~
	Ÿ	~~Initiated Phase 3 study in cervical cancer~~
~~Fasinumab (NGF Antibody)~~	Ÿ	~~Continued patient enrollment in Phase 3 long-term safety study in osteoarthritis~~	Ÿ	~~Continue patient enrollment in Phase 3 studies in osteoarthritis~~
	Ÿ	~~Initiated Phase 3 efficacy study in osteoarthritis~~	Ÿ	~~Initiate additional Phase 3 studies in osteoarthritis~~
			Ÿ	~~Initiate Phase 3 program in chronic low back pain~~
~~Evinacumab (Angptl-3 Antibody)~~	Ÿ	~~FDA granted Breakthrough Therapy designation for the treatment of hypercholesterolemia in patients with HoFH~~	Ÿ	~~Initiate Phase 3 study in HoFH~~
			Ÿ	~~Initiate Phase 2 study in severe hypertriglyceridemia~~
	Ÿ	~~Reported positive Phase 2 results at medical conferences~~	Ÿ	~~Initiate Phase 2 study in refractory hypercholesterolemia (both HeFH and non-FH)~~
	Ÿ	~~Data and analysis from genetics, preclinical, and clinical study published in the~~ ~~New England Journal of Medicine~~
~~Nesvacumab/aflibercept (Ang2 Antibody co-formulated with aflibercept)~~	Ÿ	~~Completed patient enrollment in Phase 2 ONYX study in wet AMD~~	Ÿ	~~Report results from ONYX and RUBY Phase 2 studies~~
~~Trevogrumab (GDF8 Antibody)~~	Ÿ	~~Initiated Phase 1 combination therapy study with REGN2477~~	Ÿ	~~Complete Phase 1 combination study~~
	Ÿ	~~Completed patient enrollment in Phase 1 combination therapy study~~

Three Months Ended
March 31,

(Shares in millions)

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