Exelixis (EXEL) 10-Q 6 May 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Apr. 02, 2021	Apr. 26, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Apr. 2, 2021
Document Transition Report	false
Entity File Number	000-30235
Entity Registrant Name	EXELIXIS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3257395
Entity Address, Address Line One	1851 Harbor Bay Parkway
Entity Address, City or Town	Alameda,
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94502
City Area Code	650
Local Phone Number	837-7000
Title of 12(b) Security	Common Stock $.001 Par Value per Share
Trading Symbol	EXEL
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		313,387,205
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000939767
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Apr. 02, 2021	Jan. 01, 2021
Current assets:
Cash and cash equivalents	$ 370,209	$ 319,217
Short-term investments	815,285	887,319
Trade receivables, net	177,673	160,875
Inventory	24,757	20,973
Prepaid expenses and other current assets	46,341	57,011
Total current assets	1,434,265	1,445,395
Long-term investments	328,860	330,751
Property and equipment, net	78,453	67,384
Deferred tax assets, net	160,598	156,711
Goodwill	63,684	63,684
Other long-term assets	124,682	73,408
Total assets	2,190,542	2,137,333
Current liabilities:
Accounts payable	13,821	23,632
Accrued compensation and benefits	37,945	51,189
Accrued clinical trial liabilities	59,762	52,251
Rebates and fees due to customers	31,468	20,683
Accrued collaboration liabilities	13,461	12,456
Other current liabilities	56,880	44,447
Total current liabilities	213,337	204,658
Long-term portion of deferred revenues	9,760	3,755
Long-term portion of operating lease liabilities	52,837	49,086
Other long-term liabilities	3,421	721
Total liabilities	279,355	258,220
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value, 10,000 shares authorized and no shares issued	0	0
Common stock, $0.001 par value; 400,000 shares authorized; issued and outstanding: 313,262 and 311,627 at March 31, 2021 and December 31, 2020, respectively	313	312
Additional paid-in capital	2,354,103	2,321,895
Accumulated other comprehensive income	2,740	4,476
Accumulated deficit	(445,969)	(447,570)
Total stockholders’ equity	1,911,187	1,879,113
Total liabilities and stockholders’ equity	$ 2,190,542	$ 2,137,333

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Apr. 02, 2021	Jan. 01, 2021
Preferred stock
Par value (in dollars per share)	$ 0.001	$ 0.001
Shares authorized (in shares)	10,000,000	10,000,000
Shares issued (in shares)	0	0
Common stock
Par value (in dollars per share)	$ 0.001	$ 0.001
Shares authorized (in shares)	400,000,000	400,000,000
Shares issued (in shares)	313,262,000	311,627,000
Shares outstanding (in shares)	313,262,000	311,627,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Revenues:
Total revenues	$ 270,230	$ 226,915
Operating expenses:
Cost of goods sold	13,198	9,289
Research and development	159,288	101,877
Selling, general and administrative	102,351	62,940
Total operating expenses	274,837	174,106
Income (loss) from operations	(4,607)	52,809
Interest income	2,682	7,220
Other income (expense), net	(90)	6
Income (loss) before income taxes	(2,015)	60,035
Provision for (benefit from) income taxes	(3,616)	11,423
Net income	$ 1,601	$ 48,612
Net income per share:
Basic (in dollars per share)	$ 0.01	$ 0.16
Diluted (in dollars per share)	$ 0	$ 0.15
Weighted-average common shares outstanding:
Basic (in shares)	312,473	305,388
Diluted (in shares)	321,287	315,839
Net product revenues
Revenues:
Total revenues	$ 227,212	$ 193,880
License revenues
Revenues:
Total revenues	27,528	20,879
Collaboration services revenues
Revenues:
Total revenues	$ 15,490	$ 12,156

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 1,601	$ 48,612
Other comprehensive income (loss):
Net unrealized losses on available-for-sale debt securities, net of tax impact of $499 and $941, respectively	(1,736)	(3,291)
Comprehensive income (loss)	$ (135)	$ 45,321

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Statement of Comprehensive Income [Abstract]
Net unrealized losses on available-for-sale debt securities, tax impact	$ 499	$ 941

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (loss)	Accumulated Deficit
Beginning balance (in shares) at Jan. 03, 2020		304,831
Beginning balance at Jan. 03, 2020	$ 1,685,970	$ 305	$ 2,241,947	$ 3,069	$ (559,351)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	48,612				48,612
Other comprehensive loss	(3,291)			(3,291)
Issuance of common stock under equity incentive plans (in shares)		949
Issuance of common stock under equity incentive plans	4,172	$ 1	4,171
Stock transactions associated with taxes withheld on equity awards	(1,793)		(1,793)
Stock-based compensation	13,982		13,982
Ending balance (in shares) at Apr. 03, 2020		305,780
Ending balance at Apr. 03, 2020	$ 1,747,652	$ 306	2,258,307	(222)	(510,739)
Beginning balance (in shares) at Jan. 01, 2021	311,627	311,627
Beginning balance at Jan. 01, 2021	$ 1,879,113	$ 312	2,321,895	4,476	(447,570)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,601				1,601
Other comprehensive loss	(1,736)			(1,736)
Issuance of common stock under equity incentive plans (in shares)		1,635
Issuance of common stock under equity incentive plans	4,202	$ 1	4,201
Stock transactions associated with taxes withheld on equity awards	(6,646)		(6,646)
Stock-based compensation	$ 34,653		34,653
Ending balance (in shares) at Apr. 02, 2021	313,262	313,262
Ending balance at Apr. 02, 2021	$ 1,911,187	$ 313	$ 2,354,103	$ 2,740	$ (445,969)

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Statement of Cash Flows [Abstract]
Net income	$ 1,601	$ 48,612
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	3,227	2,175
Stock-based compensation	34,653	13,982
Non-cash lease expense	1,221	1,174
Deferred taxes	(3,388)	10,128
Other, net	6,578	(888)
Changes in operating assets and liabilities:
Trade receivables, net	(17,690)	(18,270)
Inventory	(2,090)	(4,695)
Prepaid expenses and other assets	1,872	(2,863)
Deferred revenue	13,422	8,850
Accounts payable and other liabilities	138	(2,131)
Net cash provided by operating activities	39,544	56,074
Cash flows from investing activities:
Purchases of property, equipment and other	(13,557)	(2,961)
Purchases of investments	(331,612)	(251,505)
Proceeds from maturities and sales of investments	407,424	287,086
Net cash provided by investing activities	62,255	32,620
Cash flows from financing activities:
Proceeds from issuance of common stock under equity incentive plans	2,791	3,938
Taxes paid related to net share settlement of equity awards	(5,441)	(1,793)
Net cash (used in) provided by financing activities	(2,650)	2,145
Net increase in cash, cash equivalents and restricted cash equivalents	99,149	90,839
Cash, cash equivalents and restricted cash equivalents at beginning of period	320,772	268,137
Cash, cash equivalents and restricted cash equivalents at end of period	419,921	358,976
Non-cash operating activities:
Right-of-use assets obtained in exchange for lease obligations	$ 4,893	$ 576

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	3 Months Ended
	Apr. 02, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Organization Exelixis, Inc. (Exelixis, we, our or us) is an oncology-focused biotechnology company that strives to accelerate the discovery, development and commercialization of new medicines for difficult-to-treat cancers. Our drug discovery and development capabilities and commercialization platform are the foundations upon which we intend to bring to market novel, effective and tolerable therapies to provide cancer patients with additional treatment options. Since we were founded in 1994, four products resulting from our discovery efforts have progressed through clinical development, received regulatory approval and established a commercial presence in various geographies around the world. Two are derived from cabozantinib, our flagship molecule, an inhibitor of multiple tyrosine kinases including MET, AXL, VEGF receptors and RET. Our cabozantinib products are: CABOMETYX® (cabozantinib) tablets approved for advanced renal cell carcinoma (RCC), both alone and in combination with Bristol Myers Squibb Company’s OPDIVO® (nivolumab), and for previously treated hepatocellular carcinoma (HCC); and COMETRIQ® (cabozantinib) capsules approved for progressive, metastatic medullary thyroid cancer. For these types of cancer, cabozantinib has become or is becoming a standard of care. Beyond these approved indications, cabozantinib is currently the focus of a broad clinical development program and is being investigated both alone and in combination with other therapies in a wide variety of cancers. The other two products resulting from our discovery efforts are: COTELLIC® (cobimetinib), an inhibitor of MEK, approved as part of multiple regimens to treat advanced melanoma and marketed under a collaboration with Genentech, Inc. (a member of the Roche Group) (Genentech); and MINNEBRO® (esaxerenone), an oral, non-steroidal, selective blocker of the mineralocorticoid receptor, approved for the treatment of hypertension in Japan and licensed to Daiichi Sankyo Company, Limited (Daiichi Sankyo). We remain committed to expanding our oncology product pipeline through our drug discovery efforts, which encompass both small molecule and biologics programs with multiple modalities and mechanisms of action. Basis of Presentation The accompanying Condensed Consolidated Financial Statements include the accounts of Exelixis and those of our wholly-owned subsidiaries. These entities’ functional currency is the U.S. dollar. All intercompany balances and transactions have been eliminated. The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the U.S. for interim financial information and pursuant to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements. In our opinion, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair presentation of our financial statements for the periods presented have been included. Operating results for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021 or for any future period. The accompanying Condensed Consolidated Financial Statements and Notes thereto should be read in conjunction with our Consolidated Financial Statements and Notes thereto for the year ended December 31, 2020, included in our Annual Report on Form 10-K submitted to the SEC on February 10, 2021. We have adopted a 52- or 53-week fiscal year policy that generally ends on the Friday closest to December 31 st . Fiscal year 2021, which is a 52-week fiscal year, will end on December 31, 2021 and fiscal year 2020, which was a 52-week fiscal year, ended on January 1, 2021. For convenience, references in this report as of and for the three months ended April 2, 2021 and April 3, 2020, and as of and for the fiscal year ended January 1, 2021, are indicated as being as of and for the fiscal periods ended March 31, 2021 and March 31, 2020 and the year ended December 31, 2020, respectively. Segment Information We operate in one business segment that focuses on the discovery, development and commercialization of new medicines for difficult-to-treat cancers. Our Chief Executive Officer, as the chief operating decision-maker, manages and allocates resources to our operations on a total consolidated basis. Consistent with this decision-making process, our Chief Executive Officer uses consolidated, single-segment financial information for purposes of evaluating performance, forecasting future period financial results, allocating resources and setting incentive targets. All of our long-lived assets are located in the U.S. See “Note 2. Revenues” for enterprise-wide disclosures about product sales, revenues from major customers and revenues by geographic region. Use of Estimates The preparation of the accompanying Condensed Consolidated Financial Statements conforms to accounting principles generally accepted in the U.S., which requires management to make judgments, estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenues and expenses, and related disclosures. On an ongoing basis, we evaluate our significant estimates. We base our estimates on historical experience and on various other market-specific and other relevant assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from those estimates. Reclassifications Certain prior period amounts in the accompanying Condensed Consolidated Financial Statements have been reclassified to conform to the current period presentation. Such reclassifications did not impact previously reported total revenues, income from operations, net income, total assets, total liabilities or total stockholders’ equity. Significant Accounting Policies Except for the foreign currency forward contracts for non-designated hedges, there have been no material changes to our significant accounting policies during the three months ended March 31, 2021 , as compared to the significant accounting policies disclosed in Note 1 – Significant Accounting Policies included in the our Annual Report on Form 10-K for the year ended December 31, 2020. Foreign Currency Forward Contracts for Non-Designated Hedges We may use forward foreign currency exchange contracts (forward contracts) to hedge certain operational exposures resulting from potential changes in foreign currency exchange rates. Our strategy is to enter into foreign currency forward contracts so that increases or decreases in our foreign currency exposures are offset by gains or losses on the foreign currency forward contracts thereby mitigating the risks and volatility associated with our foreign currency transactions. We do not apply hedge accounting treatment to these non-designated hedging instruments. We do not hold or issue derivative instruments for trading or speculative purposes. Our foreign currency forward contracts are generally short-term in duration. Given the short duration of the forward contracts, amounts recorded generally are not significant. We account for our derivative instruments as either assets or liabilities on our Condensed Consolidated Balance Sheets and measure them at fair value. Derivatives not designated as hedging instruments are adjusted to fair value through earnings in other income (expense), net in the Condensed Consolidated Statements of Income. Recently Adopted Accounting Pronouncements On January 1, 2021, we adopted the Accounting Standards Board’s (FASB) Accounting Standards Update (ASU) 2019-12, Income Taxes (Topic 740)-Simplifying the Accounting for Income Taxes (ASU 2019-12). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to the general principles in Accounting Standards Codification (ASC) Topic 740, Income Taxes and clarifying and amending existing guidance. Our adoption of ASU 2019-12 did not have a significant impact on the accompanying Condensed Consolidated Financial Statements. Recent Accounting Pronouncements Not Yet Adopted There were no new accounting pronouncements issued since our filing of the Annual Report on Form 10-K for the year ended December 31, 2020, which could have a significant effect on our condensed consolidated financial statements.

Revenues

Revenues	3 Months Ended
	Apr. 02, 2021
Revenue from Contract with Customer [Abstract]
REVENUES	REVENUES Revenues consisted of the following (in thousands): Three Months Ended March 31, 2021 2020 Product revenues: Gross product revenues $ 314,205 $ 252,566 Discounts and allowances (86,993) (58,686) Net product revenues 227,212 193,880 Collaboration revenues: License revenues 27,528 20,879 Collaboration services revenues 15,490 12,156 Total collaboration revenues 43,018 33,035 Total revenues $ 270,230 $ 226,915 The percentage of total revenues by customer who individually accounted for 10% or more of our total revenues were as follows: Three Months Ended March 31, 2021 2020 Affiliates of CVS Health Corporation 15 % 18 % Affiliates of AmerisourceBergen Corporation 14 % 11 % Affiliates of McKesson Corporation 13 % 15 % Ipsen Pharma SAS 13 % 13 % Affiliates of Optum Specialty Pharmacy 9 % 12 % The percentage of trade receivables by customer who individually accounted for 10% or more of our trade receivables were as follows: March 31, 2021 December 31, 2020 Ipsen Pharma SAS 22 % 23 % Affiliates of McKesson Corporation 18 % 12 % Affiliates of AmerisourceBergen Corporation 16 % 11 % Affiliates of CVS Health Corporation 12 % 11 % Takeda Pharmaceutical Company Limited 5 % 10 % Revenues by geographic region were as follows (in thousands): Three Months Ended March 31, 2021 2020 U.S. $ 229,957 $ 196,596 Europe 33,806 29,036 Japan 6,467 1,283 Total revenues $ 270,230 $ 226,915 Total revenues include net product revenues attributed to geographic regions based on the ship-to location and license and collaboration services revenues attributed to geographic regions based on the location of our collaboration partners’ headquarters. Net product revenues and license revenues are recorded in accordance with ASC Topic 606, Revenue from Contracts with Customers (Topic 606). License revenues include the recognition of the portion of milestones payments allocated to the transfer of intellectual property licenses for which it had become probable in the current period that the milestone would be achieved and a significant reversal of revenues would not occur, as well as royalty revenues and our share of profits under our collaboration agreement with Genentech. Collaboration services revenues were recorded in accordance with ASU 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606 and by analogy to Topic 606. Collaboration services revenues include the recognition of deferred revenues for the portion of upfront and milestone payments allocated to our research and development services performance obligations, development cost reimbursements earned under our collaboration agreements, product supply revenues, net of product supply costs, and the royalties we paid to GlaxoSmithKline (GSK) on sales of products containing cabozantinib by our collaboration partners. We received notification that, effective January 1, 2021, Royalty Pharma plc (Royalty Pharma) acquired from GSK all rights, title and interest in royalties on net product sales containing cabozantinib for non-U.S. markets for the full term of the royalty and for the U.S. market through September 2026, after which time U.S. royalties will revert back to GSK. Net product revenues by product were as follows (in thousands): Three Months Ended March 31, 2021 2020 CABOMETYX $ 223,595 $ 189,216 COMETRIQ 3,617 4,664 Net product revenues $ 227,212 $ 193,880 Product Sales Discounts and Allowances The activities and ending reserve balances for each significant category of discounts and allowances, which constitute variable consideration, were as follows (in thousands): Chargebacks, Discounts for Prompt Payment and Other Other Customer Credits/Fees and Co-pay Assistance Rebates Total Balance at December 31, 2020 $ 9,853 $ 3,279 $ 17,404 $ 30,536 Provision related to sales made in: Current period 52,470 8,054 25,232 85,756 Prior periods (27) (2) 1,266 1,237 Payments and customer credits issued (49,636) (5,622) (15,935) (71,193) Balance at March 31, 2021 $ 12,660 $ 5,709 $ 27,967 $ 46,336 The allowance for chargebacks, discounts for prompt payment and other are recorded as a reduction of trade receivables, net and the remaining reserves are recorded as rebates and fees due to customers or as other current liabilities in the accompanying Condensed Consolidated Balance Sheets. Contract Assets and Liabilities We receive payments from our collaboration partners based on billing schedules established in each contract. Amounts are recorded as accounts receivable when our right to consideration is unconditional. We may also recognize revenue in advance of the contractual billing schedule and such amounts are recorded as a contract asset when recognized. We may be required to defer recognition of revenue for upfront and milestone payments until we perform our obligations under these arrangements, and such amounts are recorded as deferred revenue upon receipt or when due. For those contracts that have multiple performance obligations, contract assets and liabilities are reported on a net basis at the contract level. Contract assets and liabilities were as follows (in thousands): March 31, 2021 December 31, 2020 Contract assets $ — $ — Contract liabilities: Current portion (1) $ 9,207 $ 1,790 Long-term portion (2) 9,760 3,755 Total contract liabilities $ 18,967 $ 5,545 ____________________ (1) Presented in other current liabilities in the accompanying Condensed Consolidated Balance Sheets. (2) Presented in the long-term portion of deferred revenues in the accompanying Condensed Consolidated Balance Sheets. During the three months ended March 31, 2021 and 2020, we recognized $2.5 million and $1.6 million, respectively, in revenues that were included in the beginning deferred revenues balance for those periods. During the three months ended March 31, 2021, and 2020, we recognized $27.8 million and $18.8 million, respectively, in revenues for performance obligations satisfied in previous periods. Such revenues were primarily related to royalty payments allocated to the license performance obligations for our collaborations with Ipsen Pharma SAS (Ipsen), Takeda Pharmaceutical Company Limited (Takeda), Daiichi Sankyo Company, Limited (Daiichi Sankyo) and Genentech Inc. (a member of the Roche Group) (Genentech). As of March 31, 2021 , $87.3 million of t he combined transaction prices for our Ipsen and Takeda collaborations were allocated to performance obligations that had not yet been satisfied. See “Note 3. Collaboration Agreements - Cabozantinib Collaborations - Performance Obligations and Transaction Prices for our Ipsen and Takeda Collaborations” to our Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2020 for information about the expected timing to satisfy these performance obligations.

Collaboration Agreements And In

Collaboration Agreements And In-Licensing Arrangements	3 Months Ended
	Apr. 02, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
COLLABORATION AGREEMENTS AND IN-LICENSING ARRANGEMENTS	COLLABORATION AGREEMENTS AND IN-LICENSING ARRANGEMENTS We have established multiple collaborations with leading pharmaceutical companies for the commercialization and further development of our cabozantinib franchise. Additionally, we have entered into several research collaborations and in-licensing arrangements to further enhance our early-stage pipeline and expand our ability to discover, develop and commercialize novel therapies with the goal of providing new treatment options for cancer patients and their physicians. We also entered into other collaborations with leading pharmaceutical companies for other compounds and programs in our portfolio. See “Note 3. Collaboration Agreements” to our Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2020, or as further described below, for additional information on each of our collaboration agreements and in-licensing arrangements. Cabozantinib Collaborations Ipsen Collaboration In February 2016, we entered into a collaboration agreement with Ipsen for the commercialization and further development of cabozantinib. Under the terms of the collaboration agreement, as amended, Ipsen received exclusive commercialization rights for current and potential future cabozantinib indications outside of the U.S. and Japan. We have also agreed to collaborate with Ipsen on the development of cabozantinib for current and potential future indications. The parties’ efforts are governed through a joint steering committee and appropriate subcommittees established to guide and oversee the collaboration’s operation and strategic direction; provided, however, that we retain final decision-making authority with respect to cabozantinib’s ongoing development. Revenues under the collaboration agreement with Ipsen were as follows (in thousands): Three Months Ended March 31, 2021 2020 License revenues $ 22,451 $ 17,949 Collaboration services revenues 11,355 11,087 Total $ 33,806 $ 29,036 As of March 31, 2021 , $44.8 million of the tr ansaction price was allocated to our research and development services performance obligations that has not yet been satisfied. Takeda Collaboration In January 2017, we entered into a collaboration and license agreement with Takeda, which was subsequently amended effective March 2018, May 2019 and September 2020 to, among other things, modify the amount of reimbursements we are eligible to receive for costs associated with our required pharmacovigilance activities, modify the amount of milestones we are eligible to receive, and modify certain cost sharing obligations related to the Japan-specific development costs associated with CONTACT-01 and CONTACT-02 clinical trials. Pursuant to this collaboration and license agreement, as amended, Takeda has exclusive commercialization rights for current and potential future cabozantinib indications in Japan, and the parties have agreed to collaborate on the clinical development of cabozantinib in Japan. The operation and strategic direction of the parties’ collaboration is governed through a joint executive committee and appropriate subcommittees. Revenues under the collaboration agreement with Takeda were as follows (in thousands): Three Months Ended March 31, 2021 2020 License revenues $ 1,301 $ — Collaboration services revenues 4,135 1,069 Total $ 5,436 $ 1,069 As of March 31, 2021, $42.5 million of the transaction price was allocated to our research and development services performance obligations that has not yet been satisfied. GSK & Royalty Pharma In October 2002, we established a product development and commercialization collaboration agreement with GSK, that required us to pay a 3% royalty to GSK on the worldwide net sales of any product incorporating cabozantinib by us and our collaboration partners. As disclosed in Note 2, we received notification that, effective January 1, 2021, Royalty Pharma acquired from GSK all rights, title and interest in royalties on net product sales containing cabozantinib for non-U.S. markets for the full term of the royalty and for the U.S. market through September 2026, after which time U.S. royalties will revert back to GSK. Royalties earned by GSK and Royalty Pharma in connection with our sales of cabozantinib are included in cost of goods sold and as a reduction of collaboration services revenues for sales by our collaboration partners. Such royalties were $10.1 million and $8.1 million during the three months ended March 31, 2021 and 2020, respectively. Genentech Collaboration In December 2006, we out-licensed the development and commercialization of cobimetinib to Genentech under a worldwide collaboration agreement. In November 2015, the U.S. Food and Drug Administration (FDA) approved cobimetinib, under the brand name COTELLIC, in combination with Genentech’s ZELBORAF® (vemurafenib) for the treatment of patients with BRAF V600E or V600K mutation-positive advanced melanoma. COTELLIC in combination with ZELBORAF has also been approved in the European Union and multiple additional countries for use in the same indication. In July 2020, the FDA also approved COTELLIC for use in combination with ZELBORAF and TECENTRIQ® (atezolizumab) for the treatment of patients with BRAF V600 mutation-positive advanced melanoma in previously untreated patients. License revenues under the collaboration agreement with Genentech were as follows (in thousands): Three Months Ended March 31, 2021 2020 Profits on U.S. commercialization $ 1,794 $ 1,407 Royalty revenues on ex-U.S. sales $ 951 $ 1,309 Research Collaborations and In-Licensing Arrangements

Cash and Investments

Cash and Investments	3 Months Ended
	Apr. 02, 2021
Investments, Debt and Equity Securities [Abstract]
CASH AND INVESTMENTS	CASH AND INVESTMENTS Cash, Cash Equivalents and Restricted Cash Equivalents A reconciliation of cash, cash equivalents, and restricted cash equivalents reported in the accompanying Condensed Consolidated Balance Sheets to the amount reported within the accompanying Condensed Consolidated Statements of Cash Flows was as follows (in thousands): March 31, 2021 December 31, 2020 Cash and cash equivalents $ 370,209 $ 319,217 Restricted cash equivalents included in other long-term assets 49,712 1,555 Cash, cash equivalents, and restricted cash equivalents as reported in the accompanying Condensed Consolidated Statements of Cash Flows $ 419,921 $ 320,772 Restricted cash equivalents are used to collateralize letters of credit and consist of money-market funds and certificates of deposit with original maturities of 90 days or less. The restricted cash equivalents are classified as other long-term assets based upon the remaining term of the underlying restriction. As of March 31, 2021, restricted cash equivalents included $48.2 million of short-term investments as collateral under our standby letter of credit entered into in January 2021 as guarantee of our obligation to fund our portion of the total tenant improvements related to our build-to-suit lease at our corporate campus. Cash, Cash Equivalents, Restricted Cash Equivalents and Investments Cash, cash equivalents, restricted cash equivalents and investments consisted of the following (in thousands): March 31, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 667,071 $ 219 $ (1) $ 667,289 Corporate bonds 495,490 3,609 (275) 498,824 U.S. Treasury and government-sponsored enterprises 148,208 83 (7) 148,284 Municipal bonds 27,776 64 (8) 27,832 Total debt securities available-for-sale 1,338,545 3,975 (291) 1,342,229 Cash 52,757 — — 52,757 Money market funds 105,775 — — 105,775 Certificates of deposit 63,305 — — 63,305 Total cash, cash equivalents, restricted cash equivalents and investments $ 1,560,382 $ 3,975 $ (291) $ 1,564,066 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 569,456 $ 372 $ — $ 569,828 Corporate bonds 543,520 5,244 (7) 548,757 U.S. Treasury and government-sponsored enterprises 208,326 232 (4) 208,554 Municipal bonds 28,680 83 (1) 28,762 Total debt securities available-for-sale 1,349,982 5,931 (12) 1,355,901 Cash 82,176 — — 82,176 Money market funds 40,761 — — 40,761 Certificates of deposit 60,004 — — 60,004 Total cash, cash equivalents, restricted cash equivalents and investments $ 1,532,923 $ 5,931 $ (12) $ 1,538,842 Interest receivable was $3.6 million and $4.5 million as of March 31, 2021 and December 31, 2020, respectively, and is included in prepaid expenses and other current assets in the accompanying Condensed Consolidated Balance Sheets. Realized gains and losses on the sales of investments were insignificant during the three months ended March 31, 2021 and 2020. We manage credit risk associated with our investment portfolio through our investment policy, which limits purchases to high-quality issuers and limits the amount of our portfolio that can be invested in a single issuer. The fair value and gross unrealized losses on debt securities available-for-sale in an unrealized loss position were as follows (in thousands): March 31, 2021 Fair Value Gross Unrealized Losses Commercial paper $ 4,722 $ (1) Corporate bonds 131,468 (275) U.S. Treasury and government-sponsored enterprises 31,981 (7) Municipal bonds 12,120 (8) Total $ 180,291 $ (291) December 31, 2020 Fair Value Gross Unrealized Losses Corporate bonds $ 28,445 $ (7) U.S. Treasury and government-sponsored enterprises 21,989 (4) Municipal bonds 5,865 (1) Total $ 56,299 $ (12) All securities presented have been in an unrealized loss position for less than 12 months. There were 53 and 14 investments in an unrealized loss position as of March 31, 2021 and December 31, 2020, respectively. During the three months ended March 31, 2021 and 2020, we did not record an allowance for credit losses or other impairment charges on our investment securities. Based upon our quarterly impairment review, we determined that the unrealized losses were not attributed to credit risk but were primarily associated with changes in interest rates and market liquidity. Based on the scheduled maturities of our investments, we determined that it was more likely than not that we will hold these investments for a period of time sufficient for a recovery of our cost basis. The fair value of debt securities available-for-sale by contractual maturity was as follows (in thousands): March 31, 2021 December 31, 2020 Maturing in one year or less $ 1,021,369 $ 1,034,150 Maturing after one year through five years 320,860 321,751 Total debt securities available-for-sale $ 1,342,229 $ 1,355,901

Forward Currency Contracts

Forward Currency Contracts	3 Months Ended
	Apr. 02, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
FORWARD CURRENCY CONTRACTS	FORWARD CURRENCY CONTRACTS In January 2021, we initiated an operational hedging program and entered into forward contracts to hedge certain operational exposures for the changes in foreign currency exchanges rates associated with assets or liabilities denominated in foreign currencies, primarily the Euro. As of March 31, 2021, we had one forward contract outstanding to sell €9.3 million. The forward contract has a maturity of three months, is recorded at fair value and is included in prepaid expenses and other current assets in the Condensed Consolidated Balance Sheets. The fair value of the forward contract at March 31, 2021 was not material. The forward contract is considered a Level 2 in the fair value hierarchy of our fair value measurements. For the three months ended March 31, 2021, we recognized $0.4 million of gains on the maturity of our forward contracts, which is included in other income (expense), net on our Condensed Consolidated Statements of Income.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Apr. 02, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Fair value reflects the amounts that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value hierarchy has the following three levels: • Level 1 - quoted prices (unadjusted) in active markets for identical assets and liabilities; • Level 2 - inputs other than level 1 that are observable either directly or indirectly, such as quoted prices in active markets for similar instruments or on industry models using data inputs, such as interest rates and prices that can be directly observed or corroborated in active markets; • Level 3 - unobservable inputs that are supported by little or no market activity that are significant to the fair value measurement The classifications within the fair value hierarchy of our financial assets that were measured and recorded at fair value on a recurring basis were as follows (in thousands): March 31, 2021 Level 1 Level 2 Total Commercial paper $ — $ 667,289 $ 667,289 Corporate bonds — 498,824 498,824 U.S. Treasury and government-sponsored enterprises — 148,284 148,284 Municipal bonds — 27,832 27,832 Total debt securities available-for-sale — 1,342,229 1,342,229 Money market funds 105,775 — 105,775 Certificates of deposit — 63,305 63,305 Total financial assets carried at fair value $ 105,775 $ 1,405,534 $ 1,511,309 December 31, 2020 Level 1 Level 2 Total Commercial paper $ — $ 569,828 $ 569,828 Corporate bonds — 548,757 548,757 U.S. Treasury and government-sponsored enterprises — 208,554 208,554 Municipal bonds — 28,762 28,762 Total debt securities available-for-sale — 1,355,901 1,355,901 Money market funds 40,761 — 40,761 Certificates of deposit — 60,004 60,004 Total financial assets carried at fair value $ 40,761 $ 1,415,905 $ 1,456,666 When available, we value investments based on quoted prices for those financial instruments, which is a Level 1 input. Our remaining investments are valued using third-party pricing sources, which use observable market prices, interest rates and yield curves observable at commonly quoted intervals for similar assets as observable inputs for pricing, which is a Level 2 input. The carrying amount of our remaining financial assets and liabilities, which include cash, receivables and payables, approximate their fair values due to their short-term nature.

Inventory

Inventory	3 Months Ended
	Apr. 02, 2021
Inventory Disclosure [Abstract]
INVENTORY	INVENTORY Inventory consisted of the following (in thousands): March 31, 2021 December 31, 2020 Raw materials $ 7,988 $ 7,773 Work in process 21,873 20,610 Finished goods 5,786 7,291 Total $ 35,647 $ 35,674 Balance Sheet classification: Current portion included in inventory $ 24,757 $ 20,973 Long-term portion included in other long-term assets 10,890 14,701 Total $ 35,647 $ 35,674 Write-downs related to excess and expiring inventory were $2.1 million and $0.2 million for the three months ended March 31, 2021 and 2020, respectively.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Apr. 02, 2021
Share-based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION We allocated the stock-based compensation expense for our equity incentive plans and our Employee Stock Purchase Plan (ESPP) as follows (in thousands): Three Months Ended March 31, 2021 2020 Research and development $ 12,396 $ 5,086 Selling, general and administrative 22,257 8,896 Total stock-based compensation expense $ 34,653 $ 13,982 Stock-based compensation for each type of award under our equity incentive plans and ESPP were as follows (in thousands): Three Months Ended March 31, 2021 2020 Stock options $ 4,694 $ 4,994 Restricted stock units 11,669 7,797 Performance stock units 17,947 496 ESPP 343 695 Total stock-based compensation expense $ 34,653 $ 13,982 As of March 31, 2021 , 9,272,614 sh ares were available for grant under the Exelixis, Inc. 2017 Equity Incentive Plan (as amended and restated, the 2017 Plan). The share reserve is reduced by 1 share for each share issued pursuant to a stock option and 1.5 shares for full value awards granted in the form of restricted stock units (RSUs). During the three months ended March 31, 2021, we granted 881,440 stock options with a weighted average exercise price of $21.75 per share and a weighted average grant date fair value of $9.88 per s hare. As of March 31, 2021, there were 15,688,044 stock options outstanding and $30.7 million of related unrecognized compensation expense. During the three months ended March 31, 2021, we granted 3,059,698 service-based restricted stock units (RSUs) with a weighted average grant date fair value of $21.43 per share. As of March 31, 2021, there were 8,282,867 RSUs outstanding and $155.9 million of related unrecognized compensation expense. Stock options and RSUs granted to employees during the three months ended March 31, 2021 have vesting conditions and contractual lives of a similar nature to those described in “Note 8. Employee Benefit Plans” of the Notes to Consolidated Financial Statements included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2020. In March 2021, we awarded 1,027,650 (the target amount) performance-based restricted stock units (PSUs), subject to a performance and a market condition (the 2021 PSUs). Pursuant to the terms of 2021 PSUs, the holders of the awards may earn up to 200% of the target amount of shares, depending on the level of achievement of the performance condition related to certain net product revenues and a total shareholder return (TSR) market condition. The TSR market condition is based on our relative TSR percentile rank compared to companies in the NASDAQ Biotechnology Index during the performance period, which is January 2, 2021 through December 29, 2023. Fifty percent of the shares earned subject to the performance and market conditions will vest at the end of the performance period and the remainder will vest approximately one year later subject to employee’s continuous service. The 2021 PSUs will be forfeited if the performance condition at or above a threshold level is not achieved by December 29, 2023. A Monte Carlo simulation model was used to determine the grant date fair value of $24.54 for the 2021 PSUs based on the following assumptions: Fair value of the Company’s common stock on grant date $ 21.31 Expected volatility 49 % Risk-free interest rate 0.29 % Dividend yield — % The Monte Carlo simulation model also assumed correlations of returns of the stock prices of the Company’s common stock and the common stock of a peer group of companies and historical stock price volatility of the peer group of companies. The valuation model also used terms based on the length of the performance period and compound annual growth rate goals for total stockholder return based on the provisions of the award. As of March 31, 2021, there were 8,767,305 PSUs outstanding and $161.2 million of related unrecognized compensation expense. Expense recognition for PSUs commences when it is determined that achievement of the performance target is probable. During the three months ended March 31, 2021, we achieved additional performance targets for 461,532 additional PSUs granted during 2019. For more information about our PSUs, see “Note 8. Employee Benefit Plans” of the Notes to Consolidated Financial Statements included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2020.

Provision For (Benefit From) In

Provision For (Benefit From) Income Taxes	3 Months Ended
	Apr. 02, 2021
Income Tax Disclosure [Abstract]
PROVISION FOR (BENEFIT FROM) INCOME TAXES	PROVISION FOR (BENEFIT FROM) INCOME TAXESThe effective tax rate for the three months ended March 31, 2021 differed from the U.S. federal statutory tax rate of 21% primarily due to excess tax benefits related to the exercise of certain stock options, in relation to the generation of a small pre-tax loss during the period. The effective tax rate for the three months ended March 31, 2020 differed from U.S. federal statutory tax rate of 21% primarily due to excess tax benefits related to the exercise of certain stock options during the period and the generation of federal tax credits.

Net Income Per Share

Net Income Per Share	3 Months Ended
	Apr. 02, 2021
Earnings Per Share [Abstract]
NET INCOME PER SHARE	NET INCOME PER SHARE Net income per share - basic and diluted, were computed as follows (in thousands, except per share amounts): Three Months Ended March 31, 2021 2020 Numerator: Net income $ 1,601 $ 48,612 Denominator: Weighted-average common shares outstanding — basic 312,473 305,388 Dilutive securities 8,814 10,451 Weighted-average common shares outstanding — diluted 321,287 315,839 Net income per share — basic $ 0.01 $ 0.16 Net income per share — diluted $ 0.00 $ 0.15 Dilutive securities included outstanding stock options and PSOs, unvested RSUs and PSUs and ESPP contributions. Certain potential common shares were excluded from our calculation of weighted-average common shares outstanding - diluted because either they would have had an anti-dilutive effect on net income per share or they were related to shares from PSUs that were contingently issuable and the contingency had not been satisfied at the end of the reporting period. The weighted-average potential common shares excluded from our calculation were as follows (in thousands): Three Months Ended March 31, 2021 2020 Anti-dilutive securities and contingently issuable shares excluded 10,007 12,014

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Apr. 02, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIESIn September 2019, we received a notice letter regarding an Abbreviated New Drug Application (ANDA) submitted to the FDA by MSN Pharmaceuticals, Inc. (MSN), requesting approval to market a generic version of CABOMETYX tablets. MSN’s initial notice letter included a Paragraph IV certification with respect to our U.S. Patent Nos. 8,877,776, 9,724,342, 10,034,873 and 10,039,757, which are listed in the Approved Drug Products with Therapeutic Equivalence Evaluations, also referred to as the Orange Book. MSN’s initial notice letter did not provide a Paragraph IV certification against U.S. Patent No. 7,579,473, the composition of matter patent, or U.S. Patent No. 8,497,284, a method of use patent. On October 29, 2019, we filed a complaint in the United States District Court for the District of Delaware for patent infringement against MSN asserting U.S. Patent No. 8,877,776 arising from MSN’s ANDA filing with the FDA. On November 20, 2019, MSN filed its response to the complaint, alleging that U.S. Patent No. 8,877,776 is invalid and not infringed. On May 5, 2020, we received notice from MSN that it had amended its ANDA to assert additional Paragraph IV certifications. The ANDA now requests approval to market a generic version of CABOMETYX tablets prior to expiration of the two previously unasserted CABOMETYX patents: U.S. Patent No. 7,579,473 and U.S. Patent No. 8,497,284. On May 11, 2020, we filed a complaint in the United States District Court for the District of Delaware for patent infringement against MSN asserting U.S. Patent No. 7,579,473 and U.S. Patent No. 8,497,284 arising from MSN’s amended ANDA filing with the FDA. Neither of our complaints alleges infringement of U.S. Patent Nos. 9,724,342, 10,034,873 and 10,039,757. On May 22, 2020, MSN filed its response to the complaint, alleging that each of U.S. Patent No. 7,579,473 and U.S. Patent No. 8,497,284 is invalid and not infringed. On March 23, 2021, MSN filed its First Amended Answer and Counterclaims (amending its prior filing from May 22, 2020), seeking, among other things, a declaratory judgment that U.S. Patent No. 9,809,549 is invalid and would not be infringed by MSN if its generic version of CABOMETYX tablets were approved by the FDA. On April 7, 2021, we filed our response to MSN’s First Amended Answer and Counterclaims, denying, among other things, that U.S. Patent No. 9,809,549 is invalid or would not be infringed. In our complaints, we are seeking, among other relief, an order that the effective date of any FDA approval of the ANDA would be a date no earlier than the expiration of all of U.S. Patent No. 7,579,473, U.S. Patent No. 8,497,284 and U.S. Patent No. 8,877,776, the latest of which expires on October 8, 2030, and equitable relief enjoining MSN from infringing these patents. These lawsuits against MSN have been consolidated, and a bench trial has been scheduled for May 2022. In May 2021, we received a notice letter from Teva Pharmaceuticals USA, Inc. (Teva) regarding an ANDA Teva submitted to the FDA, requesting approval to market a generic version of CABOMETYX tablets. Teva’s notice letter included a Paragraph IV certification with respect to our U.S. Patent Nos. 9,724,342 (formulations), 10,034,873 (methods of treatment) and 10,039,757 (methods of treatment), which are listed in the Orange Book and expire in 2033, 2031 and 2031, respectively. Teva’s notice letter did not provide a Paragraph IV certification against any additional CABOMETYX patents. We are reviewing the details of the Paragraph IV certification notice. The sale of any generic version of CABOMETYX earlier than its patent expiration could significantly decrease our revenues derived from the U.S. sales of CABOMETYX and thereby materially harm our business, financial condition and results of operations. It is not possible at this time to determine the likelihood of an unfavorable outcome or estimate of the amount or range of any potential loss. We may also from time to time become a party or subject to various other legal proceedings and claims, either asserted or unasserted, which arise in the ordinary course of business. Some of these proceedings have involved, and may involve in the future, claims that are subject to substantial uncertainties and unascertainable damages.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Apr. 02, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Consolidation	The accompanying Condensed Consolidated Financial Statements include the accounts of Exelixis and those of our wholly-owned subsidiaries. These entities’ functional currency is the U.S. dollar. All intercompany balances and transactions have been eliminated.
Basis of Presentation	The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the U.S. for interim financial information and pursuant to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements. In our opinion, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair presentation of our financial statements for the periods presented have been included. Operating results for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021 or for any future period. The accompanying Condensed Consolidated Financial Statements and Notes thereto should be read in conjunction with our Consolidated Financial Statements and Notes thereto for the year ended December 31, 2020, included in our Annual Report on Form 10-K submitted to the SEC on February 10, 2021.
Fiscal Period	We have adopted a 52- or 53-week fiscal year policy that generally ends on the Friday closest to December 31 st
Segment Information	Segment Information We operate in one business segment that focuses on the discovery, development and commercialization of new medicines for difficult-to-treat cancers. Our Chief Executive Officer, as the chief operating decision-maker, manages and allocates resources to our operations on a total consolidated basis. Consistent with this decision-making process, our Chief
Use of Estimates	Use of Estimates The preparation of the accompanying Condensed Consolidated Financial Statements conforms to accounting principles generally accepted in the U.S., which requires management to make judgments, estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenues and expenses, and related disclosures. On an ongoing basis, we evaluate our significant estimates. We base our estimates on historical experience and on various other market-specific and other relevant assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from those estimates.
Reclassifications	ReclassificationsCertain prior period amounts in the accompanying Condensed Consolidated Financial Statements have been reclassified to conform to the current period presentation. Such reclassifications did not impact previously reported total revenues, income from operations, net income, total assets, total liabilities or total stockholders’ equity.
Foreign Currency Forward Contracts for Non-Designated Hedges	Foreign Currency Forward Contracts for Non-Designated Hedges We may use forward foreign currency exchange contracts (forward contracts) to hedge certain operational exposures resulting from potential changes in foreign currency exchange rates. Our strategy is to enter into foreign currency forward contracts so that increases or decreases in our foreign currency exposures are offset by gains or losses on the foreign currency forward contracts thereby mitigating the risks and volatility associated with our foreign currency transactions. We do not apply hedge accounting treatment to these non-designated hedging instruments. We do not hold or issue derivative instruments for trading or speculative purposes. Our foreign currency forward contracts are generally short-term in duration. Given the short duration of the forward contracts, amounts recorded generally are not significant. We account for our derivative instruments as either assets or liabilities on our Condensed Consolidated Balance Sheets and measure them at fair value. Derivatives not designated as hedging instruments are adjusted to fair value through earnings in other income (expense), net in the Condensed Consolidated Statements of Income.
Recently Adopted Accounting Pronouncements and Recent Accounting Pronouncements Not Yet Adopted	Recently Adopted Accounting Pronouncements On January 1, 2021, we adopted the Accounting Standards Board’s (FASB) Accounting Standards Update (ASU) 2019-12, Income Taxes (Topic 740)-Simplifying the Accounting for Income Taxes (ASU 2019-12). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to the general principles in Accounting Standards Codification (ASC) Topic 740, Income Taxes and clarifying and amending existing guidance. Our adoption of ASU 2019-12 did not have a significant impact on the accompanying Condensed Consolidated Financial Statements. Recent Accounting Pronouncements Not Yet Adopted There were no new accounting pronouncements issued since our filing of the Annual Report on Form 10-K for the year ended December 31, 2020, which could have a significant effect on our condensed consolidated financial statements.
Revenues	Total revenues include net product revenues attributed to geographic regions based on the ship-to location and license and collaboration services revenues attributed to geographic regions based on the location of our collaboration partners’ headquarters. Net product revenues and license revenues are recorded in accordance with ASC Topic 606, Revenue from Contracts with Customers (Topic 606). License revenues include the recognition of the portion of milestones payments allocated to the transfer of intellectual property licenses for which it had become probable in the current period that the milestone would be achieved and a significant reversal of revenues would not occur, as well as royalty revenues and our share of profits under our collaboration agreement with Genentech. Collaboration services revenues were recorded in accordance with ASU 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606 and by analogy to Topic 606. Collaboration services revenues include the recognition of deferred revenues for the portion of upfront and milestone payments allocated to our research and development services performance obligations, development cost reimbursements earned under our collaboration agreements, product supply revenues, net of product supply costs, and the royalties we paid to GlaxoSmithKline (GSK) on sales of products containing cabozantinib by our collaboration partners. We received notification that, effective January 1, 2021, Royalty Pharma plc (Royalty Pharma) acquired from GSK all rights, title and interest in royalties on net product sales containing cabozantinib for non-U.S. markets for the full term of the royalty and for the U.S. market through September 2026, after which time U.S. royalties will revert back to GSK. The allowance for chargebacks, discounts for prompt payment and other are recorded as a reduction of trade receivables, net and the remaining reserves are recorded as rebates and fees due to customers or as other current liabilities in the accompanying Condensed Consolidated Balance Sheets. Contract Assets and Liabilities

Revenues (Tables)

Revenues (Tables)	3 Months Ended
	Apr. 02, 2021
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	Revenues consisted of the following (in thousands): Three Months Ended March 31, 2021 2020 Product revenues: Gross product revenues $ 314,205 $ 252,566 Discounts and allowances (86,993) (58,686) Net product revenues 227,212 193,880 Collaboration revenues: License revenues 27,528 20,879 Collaboration services revenues 15,490 12,156 Total collaboration revenues 43,018 33,035 Total revenues $ 270,230 $ 226,915 Net product revenues by product were as follows (in thousands): Three Months Ended March 31, 2021 2020 CABOMETYX $ 223,595 $ 189,216 COMETRIQ 3,617 4,664 Net product revenues $ 227,212 $ 193,880
Schedule of Concentration Risks	The percentage of total revenues by customer who individually accounted for 10% or more of our total revenues were as follows: Three Months Ended March 31, 2021 2020 Affiliates of CVS Health Corporation 15 % 18 % Affiliates of AmerisourceBergen Corporation 14 % 11 % Affiliates of McKesson Corporation 13 % 15 % Ipsen Pharma SAS 13 % 13 % Affiliates of Optum Specialty Pharmacy 9 % 12 % The percentage of trade receivables by customer who individually accounted for 10% or more of our trade receivables were as follows: March 31, 2021 December 31, 2020 Ipsen Pharma SAS 22 % 23 % Affiliates of McKesson Corporation 18 % 12 % Affiliates of AmerisourceBergen Corporation 16 % 11 % Affiliates of CVS Health Corporation 12 % 11 % Takeda Pharmaceutical Company Limited 5 % 10 %
Revenues Disaggregated by Geographic Region	Revenues by geographic region were as follows (in thousands): Three Months Ended March 31, 2021 2020 U.S. $ 229,957 $ 196,596 Europe 33,806 29,036 Japan 6,467 1,283 Total revenues $ 270,230 $ 226,915
Schedule of Activities and Ending Reserve Balances for Significant Categories of Discounts and Allowances	The activities and ending reserve balances for each significant category of discounts and allowances, which constitute variable consideration, were as follows (in thousands): Chargebacks, Discounts for Prompt Payment and Other Other Customer Credits/Fees and Co-pay Assistance Rebates Total Balance at December 31, 2020 $ 9,853 $ 3,279 $ 17,404 $ 30,536 Provision related to sales made in: Current period 52,470 8,054 25,232 85,756 Prior periods (27) (2) 1,266 1,237 Payments and customer credits issued (49,636) (5,622) (15,935) (71,193) Balance at March 31, 2021 $ 12,660 $ 5,709 $ 27,967 $ 46,336
Schedule of Other Assets and Other Liabilities	Contract assets and liabilities were as follows (in thousands): March 31, 2021 December 31, 2020 Contract assets $ — $ — Contract liabilities: Current portion (1) $ 9,207 $ 1,790 Long-term portion (2) 9,760 3,755 Total contract liabilities $ 18,967 $ 5,545 ____________________ (1) Presented in other current liabilities in the accompanying Condensed Consolidated Balance Sheets.

Collaboration Agreements And _2

Collaboration Agreements And In-Licensing Arrangements (Tables)	3 Months Ended
	Apr. 02, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Collaborative Revenues Under Collaboration Agreement	Revenues under the collaboration agreement with Ipsen were as follows (in thousands): Three Months Ended March 31, 2021 2020 License revenues $ 22,451 $ 17,949 Collaboration services revenues 11,355 11,087 Total $ 33,806 $ 29,036 Revenues under the collaboration agreement with Takeda were as follows (in thousands): Three Months Ended March 31, 2021 2020 License revenues $ 1,301 $ — Collaboration services revenues 4,135 1,069 Total $ 5,436 $ 1,069 Three Months Ended March 31, 2021 2020 Profits on U.S. commercialization $ 1,794 $ 1,407 Royalty revenues on ex-U.S. sales $ 951 $ 1,309

Cash and Investments (Tables)

Cash and Investments (Tables)	3 Months Ended
	Apr. 02, 2021
Investments, Debt and Equity Securities [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash	A reconciliation of cash, cash equivalents, and restricted cash equivalents reported in the accompanying Condensed Consolidated Balance Sheets to the amount reported within the accompanying Condensed Consolidated Statements of Cash Flows was as follows (in thousands): March 31, 2021 December 31, 2020 Cash and cash equivalents $ 370,209 $ 319,217 Restricted cash equivalents included in other long-term assets 49,712 1,555 Cash, cash equivalents, and restricted cash equivalents as reported in the accompanying Condensed Consolidated Statements of Cash Flows $ 419,921 $ 320,772
Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash	A reconciliation of cash, cash equivalents, and restricted cash equivalents reported in the accompanying Condensed Consolidated Balance Sheets to the amount reported within the accompanying Condensed Consolidated Statements of Cash Flows was as follows (in thousands): March 31, 2021 December 31, 2020 Cash and cash equivalents $ 370,209 $ 319,217 Restricted cash equivalents included in other long-term assets 49,712 1,555 Cash, cash equivalents, and restricted cash equivalents as reported in the accompanying Condensed Consolidated Statements of Cash Flows $ 419,921 $ 320,772
Schedule of Investments by Security Type	Cash, cash equivalents, restricted cash equivalents and investments consisted of the following (in thousands): March 31, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 667,071 $ 219 $ (1) $ 667,289 Corporate bonds 495,490 3,609 (275) 498,824 U.S. Treasury and government-sponsored enterprises 148,208 83 (7) 148,284 Municipal bonds 27,776 64 (8) 27,832 Total debt securities available-for-sale 1,338,545 3,975 (291) 1,342,229 Cash 52,757 — — 52,757 Money market funds 105,775 — — 105,775 Certificates of deposit 63,305 — — 63,305 Total cash, cash equivalents, restricted cash equivalents and investments $ 1,560,382 $ 3,975 $ (291) $ 1,564,066 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 569,456 $ 372 $ — $ 569,828 Corporate bonds 543,520 5,244 (7) 548,757 U.S. Treasury and government-sponsored enterprises 208,326 232 (4) 208,554 Municipal bonds 28,680 83 (1) 28,762 Total debt securities available-for-sale 1,349,982 5,931 (12) 1,355,901 Cash 82,176 — — 82,176 Money market funds 40,761 — — 40,761 Certificates of deposit 60,004 — — 60,004 Total cash, cash equivalents, restricted cash equivalents and investments $ 1,532,923 $ 5,931 $ (12) $ 1,538,842
Schedule of Fair Value and Gross Unrealized Losses of Investments Available-for-Sale in an Unrealized Loss Position	The fair value and gross unrealized losses on debt securities available-for-sale in an unrealized loss position were as follows (in thousands): March 31, 2021 Fair Value Gross Unrealized Losses Commercial paper $ 4,722 $ (1) Corporate bonds 131,468 (275) U.S. Treasury and government-sponsored enterprises 31,981 (7) Municipal bonds 12,120 (8) Total $ 180,291 $ (291) December 31, 2020 Fair Value Gross Unrealized Losses Corporate bonds $ 28,445 $ (7) U.S. Treasury and government-sponsored enterprises 21,989 (4) Municipal bonds 5,865 (1) Total $ 56,299 $ (12)
Schedule of Fair Value of Cash Equivalents and Investments by Contractual Maturity	The fair value of debt securities available-for-sale by contractual maturity was as follows (in thousands): March 31, 2021 December 31, 2020 Maturing in one year or less $ 1,021,369 $ 1,034,150 Maturing after one year through five years 320,860 321,751 Total debt securities available-for-sale $ 1,342,229 $ 1,355,901

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Apr. 02, 2021
Fair Value Disclosures [Abstract]
Schedule of Classification of Financial Assets Measured and Recorded at Fair Value on a Recurring Basis	The classifications within the fair value hierarchy of our financial assets that were measured and recorded at fair value on a recurring basis were as follows (in thousands): March 31, 2021 Level 1 Level 2 Total Commercial paper $ — $ 667,289 $ 667,289 Corporate bonds — 498,824 498,824 U.S. Treasury and government-sponsored enterprises — 148,284 148,284 Municipal bonds — 27,832 27,832 Total debt securities available-for-sale — 1,342,229 1,342,229 Money market funds 105,775 — 105,775 Certificates of deposit — 63,305 63,305 Total financial assets carried at fair value $ 105,775 $ 1,405,534 $ 1,511,309 December 31, 2020 Level 1 Level 2 Total Commercial paper $ — $ 569,828 $ 569,828 Corporate bonds — 548,757 548,757 U.S. Treasury and government-sponsored enterprises — 208,554 208,554 Municipal bonds — 28,762 28,762 Total debt securities available-for-sale — 1,355,901 1,355,901 Money market funds 40,761 — 40,761 Certificates of deposit — 60,004 60,004 Total financial assets carried at fair value $ 40,761 $ 1,415,905 $ 1,456,666

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Apr. 02, 2021
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consisted of the following (in thousands): March 31, 2021 December 31, 2020 Raw materials $ 7,988 $ 7,773 Work in process 21,873 20,610 Finished goods 5,786 7,291 Total $ 35,647 $ 35,674 Balance Sheet classification: Current portion included in inventory $ 24,757 $ 20,973 Long-term portion included in other long-term assets 10,890 14,701 Total $ 35,647 $ 35,674

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Apr. 02, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Allocated Employee Stock-Based Compensation Expense	We allocated the stock-based compensation expense for our equity incentive plans and our Employee Stock Purchase Plan (ESPP) as follows (in thousands): Three Months Ended March 31, 2021 2020 Research and development $ 12,396 $ 5,086 Selling, general and administrative 22,257 8,896 Total stock-based compensation expense $ 34,653 $ 13,982 Stock-based compensation for each type of award under our equity incentive plans and ESPP were as follows (in thousands): Three Months Ended March 31, 2021 2020 Stock options $ 4,694 $ 4,994 Restricted stock units 11,669 7,797 Performance stock units 17,947 496 ESPP 343 695 Total stock-based compensation expense $ 34,653 $ 13,982
Schedule Of Share-Based Payment Award, Equity Instruments Other Than Options, Valuation Assumptions	A Monte Carlo simulation model was used to determine the grant date fair value of $24.54 for the 2021 PSUs based on the following assumptions: Fair value of the Company’s common stock on grant date $ 21.31 Expected volatility 49 % Risk-free interest rate 0.29 % Dividend yield — %

Net Income Per Share (Tables)

Net Income Per Share (Tables)	3 Months Ended
	Apr. 02, 2021
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share	Net income per share - basic and diluted, were computed as follows (in thousands, except per share amounts): Three Months Ended March 31, 2021 2020 Numerator: Net income $ 1,601 $ 48,612 Denominator: Weighted-average common shares outstanding — basic 312,473 305,388 Dilutive securities 8,814 10,451 Weighted-average common shares outstanding — diluted 321,287 315,839 Net income per share — basic $ 0.01 $ 0.16 Net income per share — diluted $ 0.00 $ 0.15
Schedule of Potential Shares of Common Stock Not Included in the Computation of Diluted Net Income (Loss) Per Share	The weighted-average potential common shares excluded from our calculation were as follows (in thousands): Three Months Ended March 31, 2021 2020 Anti-dilutive securities and contingently issuable shares excluded 10,007 12,014

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies (Details)	3 Months Ended
	Apr. 02, 2021productsegment
Organization And Summary Of Significant Policies [Line Items]
Number of business segments | segment	1
Resulting from discovery efforts
Organization And Summary Of Significant Policies [Line Items]
Number of products that entered in the commercial marketplace	4
Products derived from cabozantinib
Organization And Summary Of Significant Policies [Line Items]
Number of products that entered in the commercial marketplace	2
Products derived from other compounds
Organization And Summary Of Significant Policies [Line Items]
Number of products that entered in the commercial marketplace	2

Revenues - Revenues by Disaggre

Revenues - Revenues by Disaggregated Category (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 270,230	$ 226,915
Gross product revenues
Disaggregation of Revenue [Line Items]
Total revenues	314,205	252,566
Discounts and allowances
Disaggregation of Revenue [Line Items]
Total revenues	(86,993)	(58,686)
Net product revenues
Disaggregation of Revenue [Line Items]
Total revenues	227,212	193,880
License revenues
Disaggregation of Revenue [Line Items]
Total revenues	27,528	20,879
Collaboration services revenues
Disaggregation of Revenue [Line Items]
Total revenues	15,490	12,156
Total collaboration revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 43,018	$ 33,035

Revenues - Revenues Disaggregat

Revenues - Revenues Disaggregated by Significant Customer (Details) - Customer Concentration Risk	3 Months Ended		12 Months Ended
	Apr. 02, 2021	Apr. 03, 2020	Jan. 01, 2021
Affiliates of CVS Health Corporation | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	15.00%	18.00%
Affiliates of CVS Health Corporation | Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	12.00%		11.00%
Affiliates of AmerisourceBergen Corporation | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	14.00%	11.00%
Affiliates of AmerisourceBergen Corporation | Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	16.00%		11.00%
Affiliates of McKesson Corporation | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	13.00%	15.00%
Affiliates of McKesson Corporation | Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	18.00%		12.00%
Ipsen Pharma SAS | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	13.00%	13.00%
Ipsen Pharma SAS | Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	22.00%		23.00%
Affiliates of Optum Specialty Pharmacy | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	9.00%	12.00%
Takeda Pharmaceutical Company Limited | Accounts Receivable
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percent of total revenues	5.00%		10.00%

Revenues - Revenues Disaggreg_2

Revenues - Revenues Disaggregated by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 270,230	$ 226,915
U.S.
Disaggregation of Revenue [Line Items]
Total revenues	229,957	196,596
Europe
Disaggregation of Revenue [Line Items]
Total revenues	33,806	29,036
Japan
Disaggregation of Revenue [Line Items]
Total revenues	$ 6,467	$ 1,283

Revenues - Net Product Revenues

Revenues - Net Product Revenues Disaggregated by Product (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Disaggregation of Revenue [Line Items]
Net product revenues	$ 270,230	$ 226,915
CABOMETYX
Disaggregation of Revenue [Line Items]
Net product revenues	223,595	189,216
COMETRIQ
Disaggregation of Revenue [Line Items]
Net product revenues	3,617	4,664
Net product revenues
Disaggregation of Revenue [Line Items]
Net product revenues	$ 227,212	$ 193,880

Revenues - Activities and Endin

Revenues - Activities and Ending Reserve Balances for Significant Categories of Discounts and Allowances (Details) $ in Thousands	3 Months Ended
	Apr. 02, 2021USD ($)
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2020	$ 30,536
Provision related to sales made in:
Current period	85,756
Prior periods	1,237
Payments and customer credits issued	(71,193)
Balance at March 31, 2021	46,336
Chargebacks, Discounts for Prompt Payment and Other
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2020	9,853
Provision related to sales made in:
Current period	52,470
Prior periods	(27)
Payments and customer credits issued	(49,636)
Balance at March 31, 2021	12,660
Other Customer Credits/Fees and Co-pay Assistance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2020	3,279
Provision related to sales made in:
Current period	8,054
Prior periods	(2)
Payments and customer credits issued	(5,622)
Balance at March 31, 2021	5,709
Rebates
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2020	17,404
Provision related to sales made in:
Current period	25,232
Prior periods	1,266
Payments and customer credits issued	(15,935)
Balance at March 31, 2021	$ 27,967

Revenues - Contract Assets and

Revenues - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020	Jan. 01, 2021
Revenue from Contract with Customer [Abstract]
Contract assets	$ 0		$ 0
Current portion	9,207		1,790
Long-term portion	9,760		3,755
Total contract liabilities	18,967		$ 5,545
Contract revenue recognized, including revenue from deferred revenue beginning balance	2,500	$ 1,600
Revenues recognized for performance obligations satisfied in previous periods	27,800	$ 18,800
Remaining performance obligation	$ 87,300

Collaboration Agreements And _3

Collaboration Agreements And In-Licensing Arrangements - Collaboration Revenues under the Collaboration Agreement with Ipsen (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 270,230	$ 226,915
Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	33,806	29,036
License revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	27,528	20,879
License revenues | Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	22,451	17,949
Collaboration services revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	15,490	12,156
Collaboration services revenues | Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 11,355	$ 11,087

Collaboration Agreements And _4

Collaboration Agreements And In-Licensing Arrangements - Ipsen Collaboration Narrative (Details) $ in Millions	Apr. 02, 2021USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation	$ 87.3
Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation	$ 44.8

Collaboration Agreements And _5

Collaboration Agreements And In-Licensing Arrangements - Collaboration Revenues under the Collaboration Agreement with Takeda (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 270,230	$ 226,915
Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	5,436	1,069
License revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	27,528	20,879
License revenues | Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	1,301	0
Collaboration services revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	15,490	12,156
Collaboration services revenues | Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 4,135	$ 1,069

Collaboration Agreements And _6

Collaboration Agreements And In-Licensing Arrangements - Takeda Collaboration Narrative (Details) $ in Millions	Apr. 02, 2021USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation	$ 87.3
Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation	$ 42.5

Collaboration Agreements And _7

Collaboration Agreements And In-Licensing Arrangements - GSK (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Collaboration Agreement with GlaxoSmithKline
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty expense	$ 10.1	$ 8.1
GSK
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percent of royalty on net sale	3.00%

Collaboration Agreements And _8

Collaboration Agreements And In-Licensing Arrangements - Royalty Revenues under the Collaboration Agreement with Genentech (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty revenues on ex-U.S. sales	$ 270,230	$ 226,915
Collaborative Arrangement with Genentech
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Profits on U.S. commercialization	1,794	1,407
Royalty revenues on ex-U.S. sales	$ 951	$ 1,309

Collaboration Agreements And _9

Collaboration Agreements And In-Licensing Arrangements - In-Licensing Collaborations (Details) $ in Millions	3 Months Ended
	Apr. 02, 2021USD ($)
Collaborative Agreement With Adagene
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment	$ 14
Collaborative arrangement maximum amount eligible for development milestones	55
Collaborative arrangement maximum amount eligible for regulatory milestones	200
Maximum amount eligible for commercial milestones under collaborations agreement	525
Collaborative Agreement With WuXi Bio
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment	14
Collaborative arrangement maximum amount eligible for development milestones	18.5
Collaborative arrangement maximum amount eligible for regulatory milestones	30
Maximum amount eligible for commercial milestones under collaborations agreement	$ 80

Cash and Investments - Reconcil

Cash and Investments - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Apr. 02, 2021	Jan. 01, 2021	Apr. 03, 2020	Jan. 03, 2020
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 370,209	$ 319,217
Restricted cash equivalents included in other long-term assets	49,712	1,555
Cash, cash equivalents, and restricted cash equivalents as reported in the accompanying Condensed Consolidated Statements of Cash Flows	$ 419,921	$ 320,772	$ 358,976	$ 268,137

Cash and Investments - Investme

Cash and Investments - Investments by Security Type (Details) - USD ($) $ in Thousands	Apr. 02, 2021	Jan. 01, 2021
Debt securities available-for-sale:
Amortized Cost	$ 1,338,545	$ 1,349,982
Gross Unrealized Gains	3,975	5,931
Gross Unrealized Losses	(291)	(12)
Fair Value	1,342,229	1,355,901
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	1,560,382	1,532,923
Gross Unrealized Gains	3,975	5,931
Gross Unrealized Losses	(291)	(12)
Fair Value	1,564,066	1,538,842
Commercial paper
Debt securities available-for-sale:
Amortized Cost	667,071	569,456
Gross Unrealized Gains	219	372
Gross Unrealized Losses	(1)	0
Fair Value	667,289	569,828
Corporate bonds
Debt securities available-for-sale:
Amortized Cost	495,490	543,520
Gross Unrealized Gains	3,609	5,244
Gross Unrealized Losses	(275)	(7)
Fair Value	498,824	548,757
U.S. Treasury and government-sponsored enterprises
Debt securities available-for-sale:
Amortized Cost	148,208	208,326
Gross Unrealized Gains	83	232
Gross Unrealized Losses	(7)	(4)
Fair Value	148,284	208,554
Municipal bonds
Debt securities available-for-sale:
Amortized Cost	27,776	28,680
Gross Unrealized Gains	64	83
Gross Unrealized Losses	(8)	(1)
Fair Value	27,832	28,762
Cash
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	52,757	82,176
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	52,757	82,176
Money market funds
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	105,775	40,761
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	105,775	40,761
Certificates of deposit
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	63,305	60,004
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 63,305	$ 60,004

Cash and Investments - Narrativ

Cash and Investments - Narrative (Details)	Apr. 02, 2021USD ($)investment	Jan. 01, 2021USD ($)investment	Apr. 03, 2020USD ($)
Investments, Debt and Equity Securities [Abstract]
Restricted cash short-term investments	$ 48,200,000
Interest receivable	$ 3,600,000	$ 4,500,000
Number of investments in an unrealized loss position | investment	53	14
Allowance for credit losses	$ 0		$ 0

Cash and Investments - Fair Val

Cash and Investments - Fair Value and Gross Unrealized Losses of Investments Available-for-Sale in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Apr. 02, 2021	Jan. 01, 2021
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	$ 180,291	$ 56,299
Gross Unrealized Losses	(291)	(12)
Commercial paper
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	4,722
Gross Unrealized Losses	(1)
Corporate bonds
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	131,468	28,445
Gross Unrealized Losses	(275)	(7)
U.S. Treasury and government-sponsored enterprises
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	31,981	21,989
Gross Unrealized Losses	(7)	(4)
Municipal bonds
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	12,120	5,865
Gross Unrealized Losses	$ (8)	$ (1)

Cash and Investments - Fair V_2

Cash and Investments - Fair Value of Cash Equivalents and Investments by Contractual Maturity (Details) - USD ($) $ in Thousands	Apr. 02, 2021	Jan. 01, 2021
Investments, Debt and Equity Securities [Abstract]
Maturing in one year or less	$ 1,021,369	$ 1,034,150
Maturing after one year through five years	320,860	321,751
Total debt securities available-for-sale	$ 1,342,229	$ 1,355,901

Forward Currency Contracts (Det

Forward Currency Contracts (Details) - 3 months ended Apr. 02, 2021 - Foreign Exchange Forward € in Millions, $ in Millions	USD ($)	EUR (€)forwardContract
Derivative Instruments, Gain (Loss) [Line Items]
Number of contract | forwardContract		1
Derivative notional amount | €		€ 9.3
Derivative term of contract	3 months
Gain on derivative instruments, pretax | $	$ 0.4

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Apr. 02, 2021	Jan. 01, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	$ 1,342,229	$ 1,355,901
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	1,342,229	1,355,901
Total financial assets carried at fair value	1,511,309	1,456,666
Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	0	0
Total financial assets carried at fair value	105,775	40,761
Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	1,342,229	1,355,901
Total financial assets carried at fair value	1,405,534	1,415,905
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	667,289	569,828
Commercial paper | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	667,289	569,828
Commercial paper | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	0	0
Commercial paper | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	667,289	569,828
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	498,824	548,757
Corporate bonds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	498,824	548,757
Corporate bonds | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	0	0
Corporate bonds | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	498,824	548,757
U.S. Treasury and government-sponsored enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	148,284	208,554
U.S. Treasury and government-sponsored enterprises | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	148,284	208,554
U.S. Treasury and government-sponsored enterprises | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	0	0
U.S. Treasury and government-sponsored enterprises | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	148,284	208,554
Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	27,832	28,762
Municipal bonds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	27,832	28,762
Municipal bonds | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	0	0
Municipal bonds | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale		28,762
Money market funds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	105,775	40,761
Money market funds | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	105,775	40,761
Money market funds | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Certificates of deposit | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	63,305	60,004
Certificates of deposit | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Certificates of deposit | Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 63,305	$ 60,004

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020	Jan. 01, 2021
Inventory [Line Items]
Raw materials	$ 7,988		$ 7,773
Work in process	21,873		20,610
Finished goods	5,786		7,291
Total	35,647		35,674
Inventory write-down	2,100	$ 200
Current portion included in inventory
Inventory [Line Items]
Total	24,757		20,973
Long-term portion included in other long-term assets
Inventory [Line Items]
Total	$ 10,890		$ 14,701

Stock-Based Compensation - Allo

Stock-Based Compensation - Allocated Employee Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 34,653	$ 13,982
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	12,396	5,086
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 22,257	$ 8,896

Stock-Based Compensation - Base

Stock-Based Compensation - Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 34,653	$ 13,982
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	4,694	4,994
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	11,669	7,797
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	17,947	496
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 343	$ 695

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2021	Apr. 02, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)		9,272,614
Reduction in share reserve after stock option or stock appreciation award (in shares)		1
Reduction in share reserve after all other awards (in shares)		1.5
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted in the period (in shares)		881,440
Options granted in the period (in dollars per share)		$ 21.75
Weighted average grant-date fair value (in dollars per share)		$ 9.88
Options outstanding (in shares)		15,688,044
Unrecognized compensation expense		$ 30.7
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense		$ 155.9
Number of awards granted (in shares)		3,059,698
Weighted average grant date fair value, awarded (in dollars per share)		$ 21.43
Number of awards outstanding (in shares)		8,282,867
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense		$ 161.2
Number of awards granted (in shares)	1,027,650
Weighted average grant date fair value, awarded (in dollars per share)		$ 24.54
Number of awards outstanding (in shares)		8,767,305
Maximum potential to vest	200.00%
Performance stock units | Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting award percentage	50.00%
Performance stock units | Share-based Payment Arrangement, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
Performance stock units | Probable
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards outstanding (in shares)		461,532

Stock-Based Compensation - Esti

Stock-Based Compensation - Estimate Grant-Date Fair Value (Details) - Performance stock units	3 Months Ended
	Apr. 02, 2021$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, awarded (in dollars per share)	$ 24.54
Fair value of the company's common stock on grant date (in dollars per share)	$ 21.31
Expected volatility	49.00%
Risk-free interest rate	0.29%
Dividend yield	0.00%

Net Income Per Share - Computat

Net Income Per Share - Computation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Numerator:
Net income	$ 1,601	$ 48,612
Denominator:
Weighted-average common shares outstanding - basic (in shares)	312,473	305,388
Dilutive securities (in shares)	8,814	10,451
Weighted-average common shares outstanding - diluted (in shares)	321,287	315,839
Net income per share - basic (in dollars per share)	$ 0.01	$ 0.16
Net income per share - diluted (in dollars per share)	$ 0	$ 0.15

Net Income Per Share - Potentia

Net Income Per Share - Potential Shares of Common Stock Not Included in the Computation of Diluted Net Income (Loss) Per Share (Details) - shares shares in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Share-based Payment Arrangement
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities and contingently issuable shares excluded (in shares)	10,007	12,014