Exelixis (EXEL) 10-Q 30 Apr 24 2024 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 29, 2024	Apr. 22, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 29, 2024
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, $0.001 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)		291,292,704
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000939767
Current Fiscal Year End Date	--01-03

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 29, 2024	Dec. 29, 2023
Current assets:
Cash and cash equivalents	$ 259,561	$ 262,994
Short-term investments	703,695	732,308
Trade receivables, net	240,577	237,407
Inventory	21,106	17,323
Prepaid expenses and other current assets	67,490	67,926
Total current assets	1,292,429	1,317,958
Long-term investments	629,561	728,717
Property and equipment, net	127,222	128,731
Deferred tax assets, net	361,578	361,145
Goodwill	63,684	63,684
Right-of-use assets and other	329,278	342,122
Total assets	2,803,752	2,942,357
Current liabilities:
Accounts payable	26,069	33,768
Accrued compensation and benefits	72,958	93,325
Accrued clinical trial liabilities	59,337	71,615
Rebates and fees due to customers	75,651	59,619
Accrued collaboration liabilities	34,704	27,533
Other current liabilities	104,291	108,417
Total current liabilities	373,010	394,277
Long-term portion of operating lease liabilities	201,466	189,944
Other long-term liabilities	101,268	94,224
Total liabilities	675,744	678,445
Commitments and contingencies (Note 10)
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: 295,032 and 302,793 at March 31, 2024, and December 31, 2023, respectively	295	303
Additional paid-in capital	2,391,865	2,440,710
Accumulated other comprehensive loss	(5,204)	(3,750)
Accumulated deficit	(258,948)	(173,351)
Total stockholders’ equity	2,128,008	2,263,912
Total liabilities and stockholders' equity	$ 2,803,752	$ 2,942,357

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 29, 2024	Dec. 29, 2023
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)	295,032,000	302,793,000
Shares outstanding (in shares)	295,032,000	302,793,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Revenues:
Total revenues	$ 425,226	$ 408,788
Operating expenses:
Cost of goods sold	21,256	14,315
Research and development	227,689	234,246
Selling, general and administrative	113,984	131,397
Restructuring	32,835	0
Total operating expenses	395,764	379,958
Income from operations	29,462	28,830
Interest income	19,894	19,502
Other expense, net	(89)	(54)
Income before income taxes	49,267	48,278
Provision for income taxes	11,950	8,250
Net income	$ 37,317	$ 40,028
Net income per share:
Basic (in dollars per share)	$ 0.12	$ 0.12
Diluted (in dollars per share)	$ 0.12	$ 0.12
Weighted-average common shares outstanding:
Basic (in shares)	300,757	324,420
Diluted (in shares)	305,530	326,279
Net product revenues
Revenues:
Total revenues	$ 378,523	$ 363,400
License revenues
Revenues:
Total revenues	44,676	38,292
Collaboration services revenues
Revenues:
Total revenues	$ 2,027	$ 7,096

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 37,317	$ 40,028
Other comprehensive income (loss):
Net unrealized gains (losses) on available-for-sale debt securities, net of tax impact of $433 and $(1,507), respectively	(1,454)	5,232
Comprehensive income	$ 35,863	$ 45,260

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net unrealized gains (losses) on available-for-sale debt securities, tax impact	$ 433	$ (1,507)

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 Loss	Retained Earnings (Accumulated Deficit)
Beginning balance (in shares) at Dec. 30, 2022		323,951
Beginning balance at Dec. 30, 2022	$ 2,488,427	$ 324	$ 2,536,849	$ (14,521)	$ (34,225)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	40,028				40,028
Other comprehensive income (loss)	5,232			5,232
Issuance of common stock under equity incentive plans (in shares)		1,034
Issuance of common stock under equity incentive plans	7,080	$ 1	7,079
Stock transactions associated with taxes withheld on equity awards	(2,523)		(2,523)
Stock-based compensation	16,892		16,892
Ending balance (in shares) at Mar. 31, 2023		324,985
Ending balance at Mar. 31, 2023	$ 2,555,136	$ 325	2,558,297	(9,289)	5,803
Beginning balance (in shares) at Dec. 29, 2023	302,793	302,793
Beginning balance at Dec. 29, 2023	$ 2,263,912	$ 303	2,440,710	(3,750)	(173,351)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	37,317				37,317
Other comprehensive income (loss)	(1,454)			(1,454)
Issuance of common stock under equity incentive plans (in shares)		877
Issuance of common stock under equity incentive plans	8,438	$ 1	8,437
Stock transactions associated with taxes withheld on equity awards	(6,994)		(6,994)
Repurchases of common stock (in shares)		(8,638)
Repurchases of common stock	(192,541)	$ (9)	(69,618)		(122,914)
Stock-based compensation	$ 19,330		19,330
Ending balance (in shares) at Mar. 29, 2024	295,032	295,032
Ending balance at Mar. 29, 2024	$ 2,128,008	$ 295	$ 2,391,865	$ (5,204)	$ (258,948)

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Statement of Cash Flows [Abstract]
Net income	$ 37,317	$ 40,028
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	6,378	6,855
Stock-based compensation	19,113	16,661
Non-cash lease expense	6,764	6,731
Acquired in-process research and development technology	19,500	36,500
Other, net	9,206	(3,743)
Changes in operating assets and liabilities:
Trade receivables, net	(3,170)	(19,178)
Inventory	1,715	(8,370)
Prepaid expenses and other assets	10,075	10,372
Accrued collaboration liabilities	(3,829)	(1,864)
Accounts payable and other liabilities	(34,247)	416
Net cash provided by operating activities	68,822	84,408
Cash flows from investing activities:
Purchases of property, equipment and other, net	(9,691)	(12,024)
Acquired in-process research and development technology	(8,500)	(36,500)
Purchases of investments	(138,468)	(311,837)
Proceeds from maturities and sales of investments	268,452	310,769
Net cash provided by (used in) investing activities	111,793	(49,592)
Cash flows from financing activities:
Payments for repurchases of common stock	(185,375)	0
Proceeds from issuance of common stock under equity incentive plans	8,315	7,143
Taxes paid related to net share settlement of equity awards	(6,988)	(2,557)
Net cash provided by (used in) financing activities	(184,048)	4,586
Net increase (decrease) in cash and cash equivalents	(3,433)	39,402
Cash and cash equivalents at beginning of period	262,994	502,677
Cash and cash equivalents at end of period	$ 259,561	$ 542,079

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 29, 2024
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 company innovating next-generation medicines and combination regimens at the forefront of cancer care. Through the commitment of our drug discovery, development and commercialization resources, we have produced four marketed pharmaceutical products, two of which are formulations of our flagship molecule, cabozantinib. We continue to evolve our product portfolio, leveraging our investments, expertise and strategic partnerships, to target an expanding range of tumor types and indications with our clinically differentiated pipeline of small molecules and biotherapeutics, including antibody-drug conjugates (ADCs). Sales related to cabozantinib account for the majority of our revenues. Cabozantinib is an inhibitor of multiple tyrosine kinases including MET, AXL, VEGF receptors and RET and has been approved by the U.S. Food and Drug Administration (FDA) and in other countries: as CABOMETYX® (cabozantinib) tablets for advanced renal cell carcinoma (RCC) (both alone and in combination with Bristol-Myers Squibb Company’s (BMS) nivolumab), for previously treated hepatocellular carcinoma (HCC) and for previously treated, radioactive iodine (RAI)-refractory differentiated thyroid cancer (DTC); and as COMETRIQ® (cabozantinib) capsules for progressive, metastatic medullary thyroid cancer. For physicians treating these types of cancer, cabozantinib has become or is becoming an important medicine in their selection of effective therapies. The other two products resulting from our discovery efforts are: COTELLIC® (cobimetinib), an inhibitor of MEK approved as part of multiple combination regimens to treat specific forms of 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). Basis of Presentation The accompanying unaudited 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. We have adopted a 52- or 53-week fiscal year policy that generally ends on the Friday closest to December 31 st . Fiscal year 2024, which is a 53-week fiscal year, will end on January 3, 2025 and fiscal year 2023, which was a 52-week fiscal year, ended on December 29, 2023. For convenience, references in this report as of and for the fiscal period ended March 29, 2024, and as of and for the fiscal years ending January 3, 2025 and ended December 29, 2023 are indicated as being as of and for the period ended March 31, 2024, and the years ending December 31, 2024 and ended December 31, 2023, respectively. The accompanying 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, 2024 are not necessarily indicative of the results that may be expected for the year ending December 31, 2024 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 fiscal year ended December 31, 2023, included in Part II, Item 8 of our Annual Report on Form 10-K, filed with the SEC on February 6, 2023 (Fiscal 2023 Form 10-K). 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 There have been no material changes to our significant accounting policies during the three months ended March 31, 2024, as compared to the significant accounting policies disclosed in “Note 1. Organization and Summary of Significant Accounting Policies” of the “Notes to Consolidated Financial Statements” included in Part II, Item 8 of our Fiscal 2023 Form 10-K. Recently Adopted Accounting Pronouncements There were no new accounting pronouncements adopted by us since our filing of the Fiscal  2023 Form 10-K, which could have a significant effect on our Condensed Consolidated Financial Statements. Recent Accounting Pronouncements Not Yet Adopted In November 2023, the Financial Accounting Standards Board (FASB) issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which enhances the disclosures required for operating segments in our annual and interim consolidated financial statements. ASU 2023-07 is effective for us in our annual reporting for fiscal 2024 and for interim period reporting beginning in fiscal 2025 on a retrospective basis. Early adoption is permitted. We are currently evaluating the impact of ASU 2023-07 on our Consolidated Financial Statements. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosure s, which enhances the disclosures required for income taxes in our annual consolidated financial statements. ASU 2023-09 is effective for us in our annual reporting for fiscal 2025 on a prospective basis. Early adoption and retrospective reporting are permitted. We are currently evaluating the impact of ASU 2023-09 on our Consolidated Financial Statements.

Revenues

Revenues	3 Months Ended
	Mar. 29, 2024
Revenue from Contract with Customer [Abstract]
REVENUES	REVENUES Revenues consisted of the following (in thousands): Three Months Ended March 31, 2024 2023 Product revenues: Gross product revenues $ 563,785 $ 521,322 Discounts and allowances (185,262) (157,922) Net product revenues 378,523 363,400 Collaboration revenues: License revenues 44,676 38,292 Collaboration services revenues 2,027 7,096 Total collaboration revenues 46,703 45,388 Total revenues $ 425,226 $ 408,788 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, 2024 2023 Affiliates of AmerisourceBergen Corporation 19 % 17 % Affiliates of McKesson Corporation 18 % 17 % Affiliates of CVS Health Corporation 17 % 17 % Accredo Health, Incorporated 12 % 12 % Affiliates of Optum Specialty Pharmacy 10 % 10 % The percentage of trade receivables by customer who individually accounted for 10% or more of our trade receivables were as follows: March 31, 2024 December 31, 2023 Affiliates of McKesson Corporation 26 % 21 % Affiliates of AmerisourceBergen Corporation 20 % 17 % Ipsen Pharma SAS 19 % 19 % Affiliates of CVS Health Corporation 15 % 20 % Cardinal Health, Inc. 10 % 11 % Total revenues by geographic region were as follows (in thousands): Three Months Ended March 31, 2024 2023 U.S. $ 381,937 $ 367,441 Europe 35,703 33,534 Japan 7,586 7,813 Total revenues $ 425,226 $ 408,788 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 Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers . License revenues include the recognition of the portion of milestone 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 are recorded in accordance with ASC Topic 808, Collaborative Arrangements. 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 on sales of products containing cabozantinib by our collaboration partners. Net product revenues by product were as follows (in thousands): Three Months Ended March 31, 2024 2023 CABOMETYX $ 376,417 $ 361,773 COMETRIQ 2,106 1,627 Net product revenues $ 378,523 $ 363,400 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, 2023 $ 25,221 $ 19,721 $ 39,898 $ 84,840 Provision related to sales made in: Current period 115,134 17,725 54,093 186,952 Prior periods (625) (1,162) 97 (1,690) Payments and customer credits issued (111,424) (17,768) (36,953) (166,145) Balance at March 31, 2024 $ 28,306 $ 18,516 $ 57,135 $ 103,957 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 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 are primarily related to Ipsen Pharma SAS (Ipsen) and contract liabilities are primarily related to deferred revenues from Takeda Pharmaceutical Company Limited (Takeda). Contract assets and liabilities were as follows (in thousands): March 31, 2024 December 31, 2023 Contract assets (1) $ 1,343 $ 1,321 Contract liabilities: Current portion (2) $ 4,054 $ 5,406 Long-term portion (3) 4,922 5,524 Total contract liabilities $ 8,976 $ 10,930 ____________________ (1) Presented in other long-term assets in the accompanying Condensed Consolidated Balance Sheets. (2) Presented in other current liabilities in the accompanying Condensed Consolidated Balance Sheets. (3) Presented in other long-term liabilities in the accompanying Condensed Consolidated Balance Sheets. During the three months ended March 31, 2024 and 2023, we recognized $1.6 million and $2.0 million, respectively, in revenues that were included in the beginning deferred revenues balance for those periods. During the three months ended March 31, 2024 and 2023, we recognized $45.9 million and $37.9 million, respectively, in revenues for performance obligations satisfied in previous periods. Such revenues were primarily related to royalty payments allocated to our license performance obligations for our collaborations with Ipsen, Takeda, Daiichi Sankyo and Genentech. As of March 31, 2024, $52.8 million of t he co mbined transaction prices for our Ipsen a nd Takeda collaborations were allocated to research and development services performance obligations that had not yet been satisfied. See “Note 3. Collaboration Agreements and Business Development Activities” of the “Notes to Consolidated Financial Statements” included in Part II, Item 8 of our Fiscal 2023 Form 10-K for additional information about the expected timing to satisfy these performance obligations.

Collaboration Agreements And Bu

Collaboration Agreements And Business Development Activities	3 Months Ended
	Mar. 29, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
COLLABORATION AGREEMENTS AND BUSINESS DEVELOPMENT ACTIVITIES	COLLABORATION AGREEMENTS AND BUSINESS DEVELOPMENT ACTIVITIES We have established multiple collaborations with leading biopharmaceutical companies for the commercialization and further development of our cabozantinib franchise. Additionally, we have made considerable progress under our existing research collaboration 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. Historically, we also entered into other collaborations with leading biopharmaceutical companies pursuant to which we out-licensed other compounds and programs in our portfolio. See “Note 3. Collaboration Agreements and Business Development Activities” of the “Notes to Consolidated Financial Statements” included in Part II, Item 8 of our Fiscal 2023 Form 10-K, as further described below, for additional information on certain of our collaboration agreements and in-licensing arrangements. Cabozantinib Commercial Collaborations Ipsen Collaboration In February 2016, we entered into a collaboration and license agreement with Ipsen, which was subsequently amended, for the commercialization and further development of cabozantinib. Under 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, 2024 2023 License revenues $ 36,861 $ 29,812 Collaboration services revenues (1,158) 3,722 Total collaboration revenues $ 35,703 $ 33,534 As of March 31, 2024, $28.4 million of the transaction price for this collaboration agreement, as amended, was allocated to our research and development services performance obligation 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, for the commercialization and further development of cabozantinib. Under the collaboration agreement, as amended, Takeda received 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, 2024 2023 License revenues $ 2,710 $ 2,849 Collaboration services revenues 3,185 3,374 Total collaboration revenues $ 5,895 $ 6,223 As of March 31, 2024 , $24.4 million of the transaction price for this collaboration agreement, as amended, was allocated to our research and development services performance obligations that have not yet been satisfied. Royalty Pharma In October 2002, we established a product development and commercialization collaboration agreement with GlaxoSmithKline (now GSK plc, or GSK), that required us to pay a 3% royalty to GSK on the worldwide net sales of any product containing cabozantinib sold by us and our collaboration partners. 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. Royalty fees earned by 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 royalty fees earned by Royalty Pharma were $16.7 million and $15.4 million during the three months ended March 31, 2024 and 2023, respectively. Research Collaborations, In-Licensing Arrangements and Other Business Development Activities We enter into collaborative arrangements with other pharmaceutical or biotechnology companies to develop and commercialize oncology assets or other intellectual property. Our research collaborations and in-licensing arrangements are intended to 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. Our research collaborations, in-licensing arrangements and other strategic transactions generally include upfront payments for the purchase or in-licensing of intellectual property, development, regulatory and commercial milestone payments and royalty payments, in each case contingent upon the occurrence of certain future events linked to the success of the asset in development. Certain of our research collaborations provide us exclusive options that give us the right to license programs developed under the research collaborations for further discovery and development. When we decide to exercise the options, we are required to pay an exercise fee and then assume the responsibilities for all subsequent development, manufacturing and commercialization. As part of the 2024 Restructuring Plan (as defined below), we have terminated certain of our in-licensing collaboration arrangements including Aurigene, BioInvent International AB, Cybrexa Therapeutics LLC, NBE-Therapeutics AG and STORM Therapeutics LTD. The termination of these agreements will be effective in April 2024. During the three months ended March 31, 2024 , we recognized $22.8 million within research and development expenses on the Condensed Consolidated Statements of Income, primarily related to development milestone payments for the costs of intellectual property that have not yet achieved technological feasibility, research and development funding and other fees. As of March 31, 2024, in conjunction with the active collaborative in-licensing arrangements and asset purchase agreements, we are subject to potential future development milestone payments of up to $509.6 million, regulatory milestone payments of up to $365.4 million and commercial milestone payments of up to $2.5 billion, each in the aggregate per product or target, as well as royalties on future net sales of products.

Cash and Investments

Cash and Investments	3 Months Ended
	Mar. 29, 2024
Investments, Debt and Equity Securities [Abstract]
CASH AND INVESTMENTS	CASH AND INVESTMENTS Cash, Cash Equivalents and Investments Cash, cash equivalents and investments consisted of the following (in thousands): March 31, 2024 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 203,117 $ — $ — $ 203,117 Corporate bonds 808,010 670 (4,712) 803,968 U.S. Treasury and government-sponsored enterprises 384,773 63 (2,376) 382,460 Municipal bonds 7,880 — (32) 7,848 Total debt securities available-for-sale 1,403,780 733 (7,120) 1,397,393 Cash 19 — — 19 Money market funds 133,132 — — 133,132 Certificates of deposit 62,273 — — 62,273 Total cash, cash equivalents and investments $ 1,599,204 $ 733 $ (7,120) $ 1,592,817 December 31, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 214,016 $ — $ — $ 214,016 Corporate bonds 870,870 1,652 (4,277) 868,245 U.S. Treasury and government-sponsored enterprises 409,157 414 (2,250) 407,321 Municipal bonds 7,880 10 (49) 7,841 Total debt securities available-for-sale 1,501,923 2,076 (6,576) 1,497,423 Money market funds 154,287 — — 154,287 Certificates of deposit 72,309 — — 72,309 Total cash, cash equivalents and investments $ 1,728,519 $ 2,076 $ (6,576) $ 1,724,019 Interest receivable was $11.9 million and $13.1 million as of March 31, 2024 and December 31, 2023, 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 immaterial during the three months ended March 31, 2024 and 2023. We manage credit risk associated with our investment portfolio through our investment policy, which limits purchases to high-quality issuers and 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, 2024 In an Unrealized Loss Position Less than 12 Months In an Unrealized Loss Position 12 Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Corporate bonds $ 358,757 $ (1,814) $ 215,894 $ (2,898) $ 574,651 $ (4,712) U.S. Treasury and government-sponsored enterprises 217,026 (951) 109,223 (1,425) 326,249 (2,376) Municipal bonds 1,879 (1) 5,969 (31) 7,848 (32) Total $ 577,662 $ (2,766) $ 331,086 $ (4,354) $ 908,748 $ (7,120) December 31, 2023 In an Unrealized Loss Position Less than 12 Months In an Unrealized Loss Position 12 Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Corporate bonds $ 255,958 $ (847) $ 281,837 $ (3,430) $ 537,795 $ (4,277) U.S. Treasury and government-sponsored enterprises 163,339 (406) 155,452 (1,844) 318,791 (2,250) Municipal bonds — — 5,951 (49) 5,951 (49) Total $ 419,297 $ (1,253) $ 443,240 $ (5,323) $ 862,537 $ (6,576) There were 263 and 230 debt securities available-for-sale in an unrealized loss position as of March 31, 2024 and December 31, 2023, respectively. During the three months ended March 31, 2024, 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 values of debt securities available-for-sale by contractual maturity were as follows (in thousands): March 31, 2024 December 31, 2023 Maturing in one year or less $ 767,832 $ 768,706 Maturing after one year through five years 629,561 728,717 Total debt securities available-for-sale $ 1,397,393 $ 1,497,423

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 29, 2024
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; and • 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, 2024 Level 1 Level 2 Total Commercial paper $ — $ 203,117 $ 203,117 Corporate bonds — 803,968 803,968 U.S. Treasury and government-sponsored enterprises — 382,460 382,460 Municipal bonds — 7,848 7,848 Total debt securities available-for-sale — 1,397,393 1,397,393 Money market funds 133,132 — 133,132 Certificates of deposit — 62,273 62,273 Total financial assets carried at fair value $ 133,132 $ 1,459,666 $ 1,592,798 December 31, 2023 Level 1 Level 2 Total Commercial paper $ — $ 214,016 $ 214,016 Corporate bonds — 868,245 868,245 U.S. Treasury and government-sponsored enterprises — 407,321 407,321 Municipal bonds — 7,841 7,841 Total debt securities available-for-sale — 1,497,423 1,497,423 Money market funds 154,287 — 154,287 Certificates of deposit — 72,309 72,309 Total financial assets carried at fair value $ 154,287 $ 1,569,732 $ 1,724,019 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. When necessary, we record impairments of long-lived assets for the amount by which the fair value is less than the carrying value of these assets. When an impairment indicator exists, we calculate the undiscounted value of the projected cash flows for the asset, or asset group, and compare this estimated amount to the carrying amount. If the carrying amount is greater, we record an impairment loss for the excess of carrying value over fair value. In addition, in all cases of an impairment review, we reevaluate the remaining useful lives of the assets and modify them, as appropriate. In connection with the 2024 Restructuring Plan, we determined certain long-lived assets were impaired. The fair value was determined using an income approach where certain level 3 inputs were used, including estimates and assumptions on the timing and amount of discounted cash flows. See “Note 11. Restructuring” for additional information. The carrying amount of our remaining financial assets and liabilities, which include receivables and payables, approximate their fair values due to their short-term nature. Forward Foreign Currency Contracts We have entered into forward foreign currency exchange contracts that are not designated as hedges for accounting purposes to hedge certain operational exposures for the changes in foreign currency exchange rates associated with assets or liabilities denominated in foreign currencies, primarily the Euro. As of March 31, 2024 , we had one forward contract outstanding to sell €3.6 million. The forward contract with a maturity of three months is recorded at fair value and is included in other current liabilities in the accompanying Condensed Consolidated Balance Sheets. The unrealized gain on the forward contract is immaterial as of March 31, 2024. The forward contract is considered a Level 2 in the fair value hierarchy of our fair value measurements. The net realized gains (losses) we recognized on the maturity of forward contracts were immaterial for each of the three months ended March 31, 2024 and 2023 and are included in other expense, net on our Condensed Consolidated Statements of Income.

Inventory

Inventory	3 Months Ended
	Mar. 29, 2024
Inventory Disclosure [Abstract]
INVENTORY	INVENTORY Inventory consisted of the following (in thousands): March 31, 2024 December 31, 2023 Raw materials $ 3,117 $ 7,313 Work in process 56,906 59,422 Finished goods 14,795 9,581 Total $ 74,818 $ 76,316 Balance Sheet classification: Current portion included in inventory $ 21,106 $ 17,323 Long-term portion included in other long-term assets 53,712 58,993 Total $ 74,818 $ 76,316

Stockholders_ Equity

Stockholders’ Equity	3 Months Ended
	Mar. 29, 2024
Share-Based Payment Arrangement [Abstract]
STOCKHOLDERS’ EQUITY	STOCKHOLDERS’ EQUITY Stock-based Compensation We have several equity incentive plans under which we granted stock options and restricted stock units (RSUs), including performance-based restricted stock units (PSUs), to employees and directors. As of March 31, 2024, 22.5 million sh ares were available for grant under the 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 2 shares for full value awards, including RSUs and PSUs. We allocated the stock-based compensation expense for our equity incentive plans and our 2000 Employee Stock Purchase Plan (ESPP) as follows (in thousands): Three Months Ended March 31, 2024 2023 Research and development $ 3,892 $ 3,252 Selling, general and administrative 15,221 13,409 Total stock-based compensation expense $ 19,113 $ 16,661 Stock-based compensation expense for each type of award under our equity incentive plans and ESPP were as follows (in thousands): Three Months Ended March 31, 2024 2023 Stock options $ 1,738 $ 2,207 Restricted stock units 15,434 12,607 Performance stock units 727 794 Employee stock purchase plan 1,214 1,053 Total stock-based compensation expense $ 19,113 $ 16,661 During the three months ended March 31, 2024, we granted 0.1 million stock options with a weighted-average exercise price of $23.24 per share and a weighted-average grant date fair value of $10.08 per share. As of March 31, 2024 , there were 7.7 million stock options outstanding and $8.1 million of related unrecognized compensation expense. In February 2024, we awarded to certain employees an aggregate of 1.3 million RSUs (the target number) that are subject to a total shareholder return (TSR) market condition (the 2024 TSR-based RSUs). 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 December 30, 2023 through January 1, 2027. Depending on the results relative to the TSR market condition, the holders of the 2024 TSR-based RSUs may earn up to 175% of the target number of shares. 50% of the shares earned pursuant to the 2024 TSR-based RSU awards will vest at the end of the performance period, and the remainder will vest approximately one year later, subject to an employee’s continuous service. These 2024 TSR-based RSUs will be forfeited if the market condition at or above a threshold level is not achieved at the end of the performance period on January 1, 2027. We used a Monte Carlo simulation model and the following weighted-average assumptions to determine the weighted-average grant date fair value of $20.19 per share for the 2024 TSR-based RSUs: Fair value of Exelixis common stock on grant date $ 21.71 Expected volatility 36.68 % Risk-free interest rate 4.42 % Dividend yield — % The Monte Carlo simulation model assumed correlations of returns of the stock prices of Exelixis 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 TSR based on the provisions of the awards. During the three months ended March 31, 2024, we granted 2.8 million service-based RSUs with a weighted- average grant date fair value of $21.87 per share. As of March 31, 2024 , there were 15.5 million RSUs outstanding, including RSUs that are subject to a TSR market condition, and $221.8 million of related unrecognized compensation expense. Service-based RSUs granted to employees during the three months ended March 31, 2024 have vesting conditions and contractual lives of a similar nature to those described in “Note 8. Stockholders’ Equity” of the “Notes to Consolidated Financial Statements” included in Part II, Item 8 of our Fiscal 2023 Form 10-K. As of March 31, 2024, there were 2.5 million PSUs outstanding, of which 0.9 million PSUs relate to awards that we either achieved the performance goal or determined that attainment of the performance goal was probable. Expense recognition for PSUs commences when it is determined that attainment of the performance goal is probable. As of March 31, 2024, the remaining unrecognized stock-based compensation expense for the PSUs that were either achieved or deemed probable of achievement was $3.5 million. The total unrecognized compensation expense for the PSUs for which we have not yet determined that attainment of the performance goal is probable was $37.8 million. For more information about our PSUs, see “Note 8. Stockholders’ Equity” of the “Notes to Consolidated Financial Statements” included in Part II, Item 8 of our Fiscal 2023 Form 10-K. Common Stock Repurchases In January 2024, our Board of Directors authorized a stock repurchase program to acquire up to $450 million of our outstanding common stock before the end of 2024. During the three months ended March 31, 2024, we repurchased 8.6 million shares of common stock under our stock repurchase program for an aggregate purchase price of $190.7 million. As of March 31, 2024, approximately $259.3 million remained available for future stock repurchases before the end of 2024, pursuant to our stock repurchase program. Stock repurchases under the program may be made from time to time through a variety of methods, which may include open market purchases, in block trades, 10b5-1 trading plans, accelerated share repurchase transactions, exchange transactions, or any combination of such methods. The timing and amount of any stock repurchases under the stock repurchase program will be based on a variety of factors, including ongoing assessments of the capital needs of the business, alternative investment opportunities, the market price of our common stock and general market conditions. The program does not obligate us to acquire any particular amount of our common stock, and the stock repurchase program may be modified, suspended or discontinued at any time without prior notice.

Provision For Income Taxes

Provision For Income Taxes	3 Months Ended
	Mar. 29, 2024
Income Tax Disclosure [Abstract]
PROVISION FOR INCOME TAXES	PROVISION FOR INCOME TAXES The effective tax rate for the three months ended March 31, 2024, was 24.3%, as compared to 17.1% for the corresponding period in 2023. The effective tax rate for the three months ended March 31, 2024, differed from the U.S. federal statutory tax rate of 21% primarily due to state taxes and interest on uncertain tax positions, offset by the generation of federal tax credits. The effective tax rates for the three months ended March 31, 2023, 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 during the period and the generation of federal tax credits, partially offset by state taxes.

Net Income Per Share

Net Income Per Share	3 Months Ended
	Mar. 29, 2024
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, 2024 2023 Numerator: Net income $ 37,317 $ 40,028 Denominator: Weighted-average common shares outstanding — basic 300,757 324,420 Dilutive securities 4,773 1,859 Weighted-average common shares outstanding — diluted 305,530 326,279 Net income per share — basic $ 0.12 $ 0.12 Net income per share — diluted $ 0.12 $ 0.12 Basic net income per share is computed using the weighted-average number of common shares outstanding during the period. The diluted net income per share is computed using the weighted-average number of shares and dilutive potential common shares outstanding during the period. Dilutive shares outstanding includes the dilutive effect of in-the-money options, unvested RSUs (including TSR-based RSUs), unvested PSUs when the performance condition is met and ESPP contributions. The dilutive effect of such equity awards is calculated based on the average share price for each fiscal period using the treasury stock method. 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, 2024 2023 Anti-dilutive securities and contingently issuable shares excluded 8,893 15,592

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 29, 2024
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal Proceedings MSN I ANDA Litigation In September 2019, we received a notice letter regarding an Abbreviated New Drug Application (ANDA) submitted to the FDA by MSN Pharmaceuticals, Inc. (individually and collectively with certain of its affiliates, including MSN Laboratories Private Limited, referred to as 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. Patents No. 8,877,776 (salt and polymorphic forms), 9,724,342 (formulations), 10,034,873 (methods of treatment) and 10,039,757 (methods of treatment), which are listed in the Approved Drug Products with Therapeutic Equivalence Evaluations, also referred to as the Orange Book, for CABOMETYX. MSN’s initial notice letter did not provide a Paragraph IV certification against U.S. Patents No. 7,579,473 (composition of matter) or 8,497,284 (methods of treatment), each of which is listed in the Orange Book. On October 29, 2019, we filed a complaint in the United States District Court for the District of Delaware (the Delaware District Court) for patent infringement against MSN asserting infringement of 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 the asserted claims of U.S. Patent No. 8,877,776 are invalid and not infringed. On May 5, 2020, we received notice from MSN that it had amended its ANDA to include additional Paragraph IV certifications. In particular, the May 5, 2020 amended ANDA requested approval to market a generic version of CABOMETYX tablets prior to expiration of two previously unasserted CABOMETYX patents: U.S. Patents No. 7,579,473 and 8,497,284. On May 11, 2020, we filed a complaint in the Delaware District Court for patent infringement against MSN asserting infringement of U.S. Patents No. 7,579,473 and 8,497,284 arising from MSN’s amended ANDA filing with the FDA. Neither of our complaints have alleged infringement of U.S. Patents No. 9,724,342, 10,034,873 and 10,039,757. On May 22, 2020, MSN filed its response to the complaint, alleging that the asserted claims of U.S. Patents No. 7,579,473 and 8,497,284 are 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 (salt and polymorphic forms) is invalid and would not be infringed by MSN if its generic version of CABOMETYX tablets were approved by the FDA. U.S. Patent No. 9,809,549 is not listed in the Orange Book. 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. The two lawsuits comprising this litigation (collectively referred to as MSN I), numbered Civil Action Nos. 19-02017 and 20-00633, were consolidated in April 2021. On October 1, 2021, pursuant to a stipulation between us and MSN, the Delaware District Court entered an order that (i) MSN’s submission of its ANDA constitutes infringement of certain claims relating to U.S. Patents No. 7,579,473 and 8,497,284, if those claims are not found to be invalid, and (ii) upon approval, MSN’s commercial manufacture, use, sale or offer for sale within the U.S., and importation into the U.S., of MSN’s ANDA product prior to the expiration of U.S. Patents No. 7,579,473 and 8,497,284 would also infringe certain claims of each patent, if those claims are not found to be invalid. Then, on October 12, 2021, pursuant to a separate stipulation between us and MSN, the Delaware District Court entered an order dismissing MSN’s counterclaims with respect to U.S. Patent No. 9,809,549. In our MSN I complaints, we sought, among other relief, an order that the effective date of any FDA approval of MSN’s ANDA be a date no earlier than the expiration of all of U.S. Patents No. 7,579,473, 8,497,284 and 8,877,776, the latest of which expires on October 8, 2030, and equitable relief enjoining MSN from infringing these patents. In an effort to streamline the case, the parties narrowed their assertions. On April 8, 2022, MSN withdrew its validity challenge to U.S. Patent No. 8,877,776. On April 14, 2022, we agreed not to assert U.S. Patent No. 8,497,284 at trial and MSN, correspondingly, agreed to withdraw its validity challenges to U.S. Patent No. 8,497,284, as well as claims 1-4 and 6-7 of U.S. Patent No. 7,579,473. As a result of this narrowing, the trial addressed two issues: (1) infringement of claim 1 of the U.S. Patent No. 8,877,776; and (2) validity of claim 5 of the U.S. Patent No. 7,579,473. A bench trial for MSN I occurred in May 2022, and on January 19, 2023, the Delaware District Court issued a ruling rejecting MSN’s invalidity challenge to U.S. Patent No. 7,759,473. The Delaware District Court also ruled that MSN’s proposed ANDA product does not infringe U.S. Patent No. 8,877,776 and entered judgment that the effective date of any final FDA approval of MSN’s ANDA shall not be a date earlier than August 14, 2026, the expiration date of U.S. Patent No. 7,759,473. Final judgment was entered on January 30, 2023. This ruling in MSN I does not impact our separate and ongoing MSN II lawsuit (as defined below). MSN II ANDA Litigation On January 11, 2022, we received notice from MSN that it had further amended its ANDA to assert additional Paragraph IV certifications. In particular, the January 11, 2022 amended ANDA requested approval to market a generic version of CABOMETYX tablets prior to expiration of three previously-unasserted CABOMETYX patents that are now listed in the Orange Book: U.S. Patents No. 11,091,439 (crystalline salt forms), 11,091,440 (pharmaceutical composition) and 11,098,015 (methods of treatment). On February 23, 2022, we filed a complaint in the Delaware District Court for patent infringement against MSN asserting infringement of U.S. Patents No. 11,091,439, 11,091,440 and 11,098,015 arising from MSN’s further amendment of its ANDA filing with the FDA. On February 25, 2022, MSN filed its response to the complaint, alleging that the asserted claims of U.S. Patents No. 11,091,439, 11,091,440 and 11,098,015 are invalid and not infringed. On June 7, 2022, we received notice from MSN that it had further amended its ANDA to assert an additional Paragraph IV certification. As currently amended, MSN’s ANDA now requests approval to market a generic version of CABOMETYX tablets prior to expiration of a previously-unasserted CABOMETYX patent that is now listed in the Orange Book: U.S. Patent No. 11,298,349 (pharmaceutical composition). On July 18, 2022, we filed a complaint in the Delaware District Court for patent infringement against MSN asserting infringement of U.S. Patent No. 11,298,349 arising from MSN’s further amendment of its ANDA filing with the FDA. On August 9, 2022, MSN filed its response to the complaint, alleging that the asserted claims of U.S. Patent No. 11,298,349 are invalid and not infringed and amended its challenges to U.S. Patents No. 11,091,439, 11,091,440 and 11,098,015 to allege that these patents are not enforceable based on equitable grounds. The two lawsuits comprising this litigation (collectively referred to as MSN II), numbered Civil Action Nos. 22-00228 and 22-00945, were consolidated in October 2022 and involve Exelixis patents that are different from those asserted in the MSN I litigation described above. On June 21, 2022, pursuant to a stipulation between us and MSN, the Delaware District Court entered an order that (i) MSN’s submission of its ANDA constitutes infringement of certain claims relating to U.S. Patents No. 11,091,439, 11,091,440 and 11,098,015, if those claims are not found to be invalid, and (ii) upon approval, MSN’s commercial manufacture, use, sale or offer for sale within the U.S., and importation into the U.S., of MSN’s ANDA product prior to the expiration of U.S. Patents No. 11,091,439, 11,091,440 and 11,098,015 would also infringe certain claims of each patent, if those claims are not found to be invalid. In our MSN II complaints, we are seeking, among other relief, an order that the effective date of any FDA approval of MSN’s ANDA would be a date no earlier than the expiration of all of U.S. Patents No. 11,091,439, 11,091,440, 11,098,015 and 11,298,349, the latest of which expires on February 10, 2032, and equitable relief enjoining MSN from infringing these patents. On September 28, 2023, the Delaware District Court granted the parties’ stipulation of dismissal of MSN’s equitable defenses and counterclaims. A bench trial occurred in October 2023, and a judgment is expected during the first half of 2024. Teva ANDA Litigation In May 2021, we received notice letters regarding an ANDA Teva submitted to the FDA by Teva Pharmaceutical Industries Limited, Teva Pharmaceuticals Development, Inc. and Teva Pharmaceuticals USA, Inc. (individually and collectively referred to as Teva), requesting approval to market a generic version of CABOMETYX tablets. Teva’s notice letters included a Paragraph IV certification with respect to our U.S. Patents No. 9,724,342 (formulations), 10,034,873 (methods of treatment) and 10,039,757 (methods of treatment), which are listed in the Orange Book. Teva’s notice letters did not provide a Paragraph IV certification against any additional CABOMETYX patents. On June 17, 2021, we filed a complaint in the Delaware District Court for patent infringement against Teva asserting infringement of U.S. Patents No. 9,724,342, 10,034,873 and 10,039,757 arising from Teva’s ANDA filing with the FDA. On August 27, 2021, Teva filed its answer and counterclaims to the complaint, alleging that the asserted claims of U.S. Patents No. 9,724,342, 10,034,873 and 10,039,757 are invalid and not infringed. On September 17, 2021, we filed an answer to Teva’s counterclaims. On July 29, 2022, we received notice from Teva that it had amended its ANDA to assert an additional Paragraph IV certification. As amended, Teva’s ANDA now requests approval to market a generic version of CABOMETYX tablets prior to expiration of a previously-unasserted CABOMETYX patent that is now listed in the Orange Book: U.S. Patent No. 11,298,349 (pharmaceutical composition). On September 2, 2022, we filed a complaint in the Delaware District Court for patent infringement against Teva, asserting infringement of U.S. Patent No. 11,298,349 arising from Teva’s amended ANDA filing with the FDA. We sought, among other relief, an order that the effective date of any FDA approval of Teva’s ANDA be a date no earlier than the expiration of all of U.S. Patents No. 9,724,342, 10,034,873, 10,039,757 and 11,298,349, the latest of which expires on July 9, 2033, and equitable relief enjoining Teva from infringing these patents. On September 30, 2022, the parties filed a stipulation to consolidate the two lawsuits, numbered Civil Action Nos. 21-00871 and 22-01168, and to stay all proceedings, which was granted by the Delaware District Court on October 3, 2022. Following a similar order granted by the Delaware District Court on February 9, 2022 to stay all proceedings with respect to Civil Action No. 21-00871, this case remained administratively closed, and Civil Action No. 22-01168 was administratively closed on October 3, 2022. On July 18, 2023, we entered into a settlement and license agreement (the Teva Settlement Agreement) with Teva to end these litigations. Pursuant to the terms of the Teva Settlement Agreement, we will grant Teva a license to market its generic version of CABOMETYX in the U.S. beginning on January 1, 2031, if approved by the FDA and subject to conditions and exceptions common to agreements of this type. On September 15, 2023, the parties filed a joint stipulation of dismissal with the Delaware District Court, and on September 19, 2023, the Delaware District Court granted the parties’ stipulation and dismissed the case without prejudice. Cipla ANDA Litigation On February 6, 2023, we received a notice letter regarding an ANDA submitted to the FDA by Cipla, Ltd. and Cipla USA, Inc. (individually and collectively referred to as Cipla), including a Paragraph IV certification with respect to our U.S. Patents No. 8,877,776 (salt and polymorphic forms), 9,724,342 (formulations), 10,039,757 (methods of treatment), 11,091,439 (crystalline salt forms), 11,091,440 (pharmaceutical composition), 11,098,015 (methods of treatment) and 11,298,349 (pharmaceutical composition). Cipla’s notice letter did not provide a Paragraph IV certification against any additional CABOMETYX patents. On March 16, 2023, we filed a complaint in the Delaware District Court for patent infringement against Cipla asserting infringement of U.S. Patents No. 8,877,776, 11,091,439, 11,091,440, 11,098,015 and 11,298,349 arising from Cipla’s ANDA filing with the FDA. Cipla’s ANDA requests approval to market a generic version of CABOMETYX tablets prior to the expiration of the aforementioned patents. We are seeking, among other relief, an order that the effective date of any FDA approval of Cipla’s ANDA would be a date no earlier than the expiration of all of U.S. Patents No. 8,877,776, 11,091,439, 11,091,440, 11,098,015 and 11,298,349, the latest of which expires on February 10, 2032, and equitable relief enjoining Cipla from infringing these patents. On May 4, 2023, we filed, under seal, a stipulation and proposed order to stay all proceedings, and the Delaware District Court, in a sealed order on the same day, granted the proposed order and administratively closed the case. On May 5, 2023, the Delaware District Court issued a redacted version of the May 4, 2023 stipulation and proposed order. On March 27, 2024, we received notice from Cipla that it had amended its ANDA to assert additional Paragraph IV certifications. The ANDA now requests approval to market generic versions of CABOMETYX tablets with 20 mg and 40 mg dosage strengths (in addition to the 60 mg dosage strength contemplated by Cipla’s original ANDA) prior to expiration of U.S. Patents No. 8,877,776, 9,724,342, 10,039,757, 11,091,439, 11,091,440, 11,098,015 and 11,298,349. We are evaluating Cipla’s additional Paragraph IV certifications. 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.

Restructuring

Restructuring	3 Months Ended
	Mar. 29, 2024
Restructuring and Related Activities [Abstract]
RESTRUCTURING	RESTRUCTURING Our Board of Directors authorized, and we implemented, a corporate restructuring plan (the 2024 Restructuring Plan) to reduce our workforce and rebalance our cost structure in alignment with our strategic priorities. Restructuring expenses expected to be incurred under the 2024 Restructuring Plan include severance and employee-related costs; asset impairment; and contract termination and other exit costs. During the three months ended March 31, 2024, we recognized $32.8 million in expenses associated with the 2024 Restructuring Plan which are presented in restructuring in the accompanying Condensed Consolidated Statements of Income. In connection with the 2024 Restructuring Plan, we exited two leases in the Greater Philadelphia area and the right-of-use assets, related leasehold improvements and certain other long-lived assets were remeasured and recorded at fair value, see “Note 5. Fair Value” for additional information. We incurred the majority of the charges related to the 2024 Restructuring Plan in the three months ended March 31, 2024, and expect the 2024 Restructuring Plan to be substantially completed by the end of the second quarter of 2024. The expected pre-tax charges are estimates and are subject to a number of assumptions and actual results may vary from the estimates provided. The restructuring activities and balances as of and for the three months ended March 31, 2024 were as follows (in thousands): Three Months Ended March 31, 2024 Accrued at December 31, 2023 Initial Costs Non-cash Charges Cash Payments Accrued at March 31, 2024 (2) Total Costs Incurred to Date Total Expected Plan Costs Severance and employee-related costs $ — $ 15,656 $ — $ (13,868) $ 1,788 $ 15,656 $ 15,656 Contract termination and other exit costs (1) — 4,861 — (18) 4,843 4,861 5,044 Asset impairment — 12,318 (12,318) — — 12,318 12,318 Total restructuring $ — $ 32,835 $ (12,318) $ (13,886) $ 6,631 $ 32,835 $ 33,018 __________________ (1) Contract termination costs consist of accruals for costs to be incurred without future economic benefit, and other exit costs expensed as incurred. (2) As of March 31, 2024, substantially all restructuring liabilities have been recorded in other current liabilities in the accompanying Condensed Consolidated Balance Sheets.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net income	$ 37,317	$ 40,028

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 29, 2024 shares
Trading Arrangements, by Individual
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Dana T. Aftab [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Dana T. Aftab, our Executive Vice President, Discovery and Translational Research, and Chief Scientific Officer, an officer for purposes of Section 16 of the Exchange Act, entered into a pre-arranged stock trading plan on May 25, 2023, which was subsequently modified on February 27, 2024. As modified, Dr. Aftab’s trading plan provides for the sale of up to 194,656 shares of our common stock (including shares obtained from the exercise of vested stock options covered by the trading plan) between May 30, 2024 and September 30, 2025. This trading plan is intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act and Exelixis’ policies regarding transactions in Exelixis securities.
Name	Dana T. Aftab
Title	Executive Vice President, Discovery and Translational Research, and Chief Scientific Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	May 25, 2023
Arrangement Duration	488 days
Aggregate Available	194,656
Jeffrey J. Hessekiel [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Jeffrey J. Hessekiel, our Executive Vice President, General Counsel and Secretary, an officer for purposes of Section 16 of the Exchange Act, entered into a pre-arranged stock trading plan on February 28, 2024. Mr. Hessekiel’s trading plan provides for the sale of up to 200,000 shares of our common stock (including shares obtained from the exercise of vested stock options covered by the trading plan) between May 29, 2024 and December 31, 2024. This trading plan is intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act and Exelixis’ policies regarding transactions in Exelixis securities.
Name	Jeffrey J. Hessekiel
Title	Executive Vice President, General Counsel and Secretary
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	February 28, 2024
Arrangement Duration	216 days
Aggregate Available	200,000
Jack L Wyszomierski [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Jack L Wyszomierski, a member of our Board of Directors, entered into a pre-arranged stock trading plan on February 12, 2024. Mr. Wyszomierski’s trading plan provides for the sale of up to 19,973 shares of our common stock (including shares obtained from the exercise of vested stock options covered by the trading plan) between May 13, 2024 and June 12, 2024. This trading plan is intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act and Exelixis’ policies regarding transactions in Exelixis securities.
Name	Jack L Wyszomierski
Title	Board of Directors
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	February 12, 2024
Arrangement Duration	30 days
Aggregate Available	19,973

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 29, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Consolidation	The accompanying unaudited 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.
Fiscal Period	We have adopted a 52- or 53-week fiscal year policy that generally ends on the Friday closest to December 31 st . Fiscal year 2024, which is a 53-week fiscal year, will end on January 3, 2025 and fiscal year 2023, which was a 52-week fiscal year, ended on December 29, 2023. For convenience, references in this report as of and for the fiscal period ended March 29, 2024, and as of and for the fiscal years ending January 3, 2025 and ended December 29, 2023 are indicated as being as of and for the period ended March 31, 2024, and the years ending December 31, 2024 and ended December 31, 2023, respectively.
Basis of Presentation	The accompanying 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, 2024 are not necessarily indicative of the results that may be expected for the year ending December 31, 2024 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 fiscal year ended December 31, 2023, included in Part II, Item 8 of our Annual Report on Form 10-K, filed with the SEC on February 6, 2023 (Fiscal 2023 Form 10-K).
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.
Recently Adopted Accounting Pronouncements and Recent Accounting Pronouncements Not Yet Adopted	Recently Adopted Accounting Pronouncements There were no new accounting pronouncements adopted by us since our filing of the Fiscal  2023 Form 10-K, which could have a significant effect on our Condensed Consolidated Financial Statements. Recent Accounting Pronouncements Not Yet Adopted In November 2023, the Financial Accounting Standards Board (FASB) issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which enhances the disclosures required for operating segments in our annual and interim consolidated financial statements. ASU 2023-07 is effective for us in our annual reporting for fiscal 2024 and for interim period reporting beginning in fiscal 2025 on a retrospective basis. Early adoption is permitted. We are currently evaluating the impact of ASU 2023-07 on our Consolidated Financial Statements. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosure s, which enhances the disclosures required for income taxes in our annual consolidated financial statements. ASU 2023-09 is effective for us in our annual reporting for fiscal 2025 on a prospective basis. Early adoption and retrospective reporting are permitted. We are currently evaluating the impact of ASU 2023-09 on our 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 Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers . License revenues include the recognition of the portion of milestone 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 are recorded in accordance with ASC Topic 808, Collaborative Arrangements. 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 on sales of products containing cabozantinib by our collaboration partners. 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 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 are primarily related to Ipsen Pharma SAS (Ipsen) and contract liabilities are primarily related to deferred revenues from Takeda Pharmaceutical Company Limited (Takeda).

Revenues (Tables)

Revenues (Tables)	3 Months Ended
	Mar. 29, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	Revenues consisted of the following (in thousands): Three Months Ended March 31, 2024 2023 Product revenues: Gross product revenues $ 563,785 $ 521,322 Discounts and allowances (185,262) (157,922) Net product revenues 378,523 363,400 Collaboration revenues: License revenues 44,676 38,292 Collaboration services revenues 2,027 7,096 Total collaboration revenues 46,703 45,388 Total revenues $ 425,226 $ 408,788 Net product revenues by product were as follows (in thousands): Three Months Ended March 31, 2024 2023 CABOMETYX $ 376,417 $ 361,773 COMETRIQ 2,106 1,627 Net product revenues $ 378,523 $ 363,400
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, 2024 2023 Affiliates of AmerisourceBergen Corporation 19 % 17 % Affiliates of McKesson Corporation 18 % 17 % Affiliates of CVS Health Corporation 17 % 17 % Accredo Health, Incorporated 12 % 12 % Affiliates of Optum Specialty Pharmacy 10 % 10 % The percentage of trade receivables by customer who individually accounted for 10% or more of our trade receivables were as follows: March 31, 2024 December 31, 2023 Affiliates of McKesson Corporation 26 % 21 % Affiliates of AmerisourceBergen Corporation 20 % 17 % Ipsen Pharma SAS 19 % 19 % Affiliates of CVS Health Corporation 15 % 20 % Cardinal Health, Inc. 10 % 11 %
Schedule of Revenues Disaggregated by Geographic Region	Total revenues by geographic region were as follows (in thousands): Three Months Ended March 31, 2024 2023 U.S. $ 381,937 $ 367,441 Europe 35,703 33,534 Japan 7,586 7,813 Total revenues $ 425,226 $ 408,788
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, 2023 $ 25,221 $ 19,721 $ 39,898 $ 84,840 Provision related to sales made in: Current period 115,134 17,725 54,093 186,952 Prior periods (625) (1,162) 97 (1,690) Payments and customer credits issued (111,424) (17,768) (36,953) (166,145) Balance at March 31, 2024 $ 28,306 $ 18,516 $ 57,135 $ 103,957
Schedule of Other Assets and Other Liabilities	Contract assets and liabilities were as follows (in thousands): March 31, 2024 December 31, 2023 Contract assets (1) $ 1,343 $ 1,321 Contract liabilities: Current portion (2) $ 4,054 $ 5,406 Long-term portion (3) 4,922 5,524 Total contract liabilities $ 8,976 $ 10,930 ____________________ (1) Presented in other long-term assets in the accompanying Condensed Consolidated Balance Sheets. (2) Presented in other current liabilities in the accompanying Condensed Consolidated Balance Sheets. (3) Presented in other long-term liabilities in the accompanying Condensed Consolidated Balance Sheets.

Collaboration Agreements And _2

Collaboration Agreements And Business Development Activities (Tables)	3 Months Ended
	Mar. 29, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Collaborative Revenues Under Collaboration and License Agreement	Revenues under the collaboration agreement with Ipsen were as follows (in thousands): Three Months Ended March 31, 2024 2023 License revenues $ 36,861 $ 29,812 Collaboration services revenues (1,158) 3,722 Total collaboration revenues $ 35,703 $ 33,534 Revenues under the collaboration agreement with Takeda were as follows (in thousands): Three Months Ended March 31, 2024 2023 License revenues $ 2,710 $ 2,849 Collaboration services revenues 3,185 3,374 Total collaboration revenues $ 5,895 $ 6,223

Cash and Investments (Tables)

Cash and Investments (Tables)	3 Months Ended
	Mar. 29, 2024
Investments, Debt and Equity Securities [Abstract]
Schedule of Investments by Security Type	Cash, cash equivalents and investments consisted of the following (in thousands): March 31, 2024 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 203,117 $ — $ — $ 203,117 Corporate bonds 808,010 670 (4,712) 803,968 U.S. Treasury and government-sponsored enterprises 384,773 63 (2,376) 382,460 Municipal bonds 7,880 — (32) 7,848 Total debt securities available-for-sale 1,403,780 733 (7,120) 1,397,393 Cash 19 — — 19 Money market funds 133,132 — — 133,132 Certificates of deposit 62,273 — — 62,273 Total cash, cash equivalents and investments $ 1,599,204 $ 733 $ (7,120) $ 1,592,817 December 31, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt securities available-for-sale: Commercial paper $ 214,016 $ — $ — $ 214,016 Corporate bonds 870,870 1,652 (4,277) 868,245 U.S. Treasury and government-sponsored enterprises 409,157 414 (2,250) 407,321 Municipal bonds 7,880 10 (49) 7,841 Total debt securities available-for-sale 1,501,923 2,076 (6,576) 1,497,423 Money market funds 154,287 — — 154,287 Certificates of deposit 72,309 — — 72,309 Total cash, cash equivalents and investments $ 1,728,519 $ 2,076 $ (6,576) $ 1,724,019
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, 2024 In an Unrealized Loss Position Less than 12 Months In an Unrealized Loss Position 12 Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Corporate bonds $ 358,757 $ (1,814) $ 215,894 $ (2,898) $ 574,651 $ (4,712) U.S. Treasury and government-sponsored enterprises 217,026 (951) 109,223 (1,425) 326,249 (2,376) Municipal bonds 1,879 (1) 5,969 (31) 7,848 (32) Total $ 577,662 $ (2,766) $ 331,086 $ (4,354) $ 908,748 $ (7,120) December 31, 2023 In an Unrealized Loss Position Less than 12 Months In an Unrealized Loss Position 12 Months or Greater Total Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Corporate bonds $ 255,958 $ (847) $ 281,837 $ (3,430) $ 537,795 $ (4,277) U.S. Treasury and government-sponsored enterprises 163,339 (406) 155,452 (1,844) 318,791 (2,250) Municipal bonds — — 5,951 (49) 5,951 (49) Total $ 419,297 $ (1,253) $ 443,240 $ (5,323) $ 862,537 $ (6,576)
Schedule of Fair Value of Cash Equivalents and Investments by Contractual Maturity	The fair values of debt securities available-for-sale by contractual maturity were as follows (in thousands): March 31, 2024 December 31, 2023 Maturing in one year or less $ 767,832 $ 768,706 Maturing after one year through five years 629,561 728,717 Total debt securities available-for-sale $ 1,397,393 $ 1,497,423

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 29, 2024
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Financial Assets Measured 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, 2024 Level 1 Level 2 Total Commercial paper $ — $ 203,117 $ 203,117 Corporate bonds — 803,968 803,968 U.S. Treasury and government-sponsored enterprises — 382,460 382,460 Municipal bonds — 7,848 7,848 Total debt securities available-for-sale — 1,397,393 1,397,393 Money market funds 133,132 — 133,132 Certificates of deposit — 62,273 62,273 Total financial assets carried at fair value $ 133,132 $ 1,459,666 $ 1,592,798 December 31, 2023 Level 1 Level 2 Total Commercial paper $ — $ 214,016 $ 214,016 Corporate bonds — 868,245 868,245 U.S. Treasury and government-sponsored enterprises — 407,321 407,321 Municipal bonds — 7,841 7,841 Total debt securities available-for-sale — 1,497,423 1,497,423 Money market funds 154,287 — 154,287 Certificates of deposit — 72,309 72,309 Total financial assets carried at fair value $ 154,287 $ 1,569,732 $ 1,724,019

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Mar. 29, 2024
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consisted of the following (in thousands): March 31, 2024 December 31, 2023 Raw materials $ 3,117 $ 7,313 Work in process 56,906 59,422 Finished goods 14,795 9,581 Total $ 74,818 $ 76,316 Balance Sheet classification: Current portion included in inventory $ 21,106 $ 17,323 Long-term portion included in other long-term assets 53,712 58,993 Total $ 74,818 $ 76,316

Stockholders_ Equity (Tables)

Stockholders’ Equity (Tables)	3 Months Ended
	Mar. 29, 2024
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 2000 Employee Stock Purchase Plan (ESPP) as follows (in thousands): Three Months Ended March 31, 2024 2023 Research and development $ 3,892 $ 3,252 Selling, general and administrative 15,221 13,409 Total stock-based compensation expense $ 19,113 $ 16,661 Stock-based compensation expense for each type of award under our equity incentive plans and ESPP were as follows (in thousands): Three Months Ended March 31, 2024 2023 Stock options $ 1,738 $ 2,207 Restricted stock units 15,434 12,607 Performance stock units 727 794 Employee stock purchase plan 1,214 1,053 Total stock-based compensation expense $ 19,113 $ 16,661
Schedule Of Share-Based Payment Award, Equity Instruments Other Than Options, Valuation Assumptions	We used a Monte Carlo simulation model and the following weighted-average assumptions to determine the weighted-average grant date fair value of $20.19 per share for the 2024 TSR-based RSUs: Fair value of Exelixis common stock on grant date $ 21.71 Expected volatility 36.68 % Risk-free interest rate 4.42 % Dividend yield — %

Net Income Per Share (Tables)

Net Income Per Share (Tables)	3 Months Ended
	Mar. 29, 2024
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted 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, 2024 2023 Numerator: Net income $ 37,317 $ 40,028 Denominator: Weighted-average common shares outstanding — basic 300,757 324,420 Dilutive securities 4,773 1,859 Weighted-average common shares outstanding — diluted 305,530 326,279 Net income per share — basic $ 0.12 $ 0.12 Net income per share — diluted $ 0.12 $ 0.12
Schedule of Potential Shares of Common Stock Not Included in the Computation of Diluted Net Income Per Share	The weighted-average potential common shares excluded from our calculation were as follows (in thousands): Three Months Ended March 31, 2024 2023 Anti-dilutive securities and contingently issuable shares excluded 8,893 15,592

Restructuring (Tables)

Restructuring (Tables)	3 Months Ended
	Mar. 29, 2024
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Activities	The restructuring activities and balances as of and for the three months ended March 31, 2024 were as follows (in thousands): Three Months Ended March 31, 2024 Accrued at December 31, 2023 Initial Costs Non-cash Charges Cash Payments Accrued at March 31, 2024 (2) Total Costs Incurred to Date Total Expected Plan Costs Severance and employee-related costs $ — $ 15,656 $ — $ (13,868) $ 1,788 $ 15,656 $ 15,656 Contract termination and other exit costs (1) — 4,861 — (18) 4,843 4,861 5,044 Asset impairment — 12,318 (12,318) — — 12,318 12,318 Total restructuring $ — $ 32,835 $ (12,318) $ (13,886) $ 6,631 $ 32,835 $ 33,018 __________________ (1) Contract termination costs consist of accruals for costs to be incurred without future economic benefit, and other exit costs expensed as incurred. (2) As of March 31, 2024, substantially all restructuring liabilities have been recorded in other current liabilities in the accompanying Condensed Consolidated Balance Sheets.

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies (Details)	3 Months Ended
	Mar. 29, 2024 product segment
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 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
	Mar. 29, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Total revenues	$ 425,226	$ 408,788
Gross product revenues
Disaggregation of Revenue [Line Items]
Total revenues	563,785	521,322
Discounts and allowances
Disaggregation of Revenue [Line Items]
Total revenues	(185,262)	(157,922)
Net product revenues
Disaggregation of Revenue [Line Items]
Total revenues	378,523	363,400
License revenues
Disaggregation of Revenue [Line Items]
Total revenues	44,676	38,292
Collaboration services revenues
Disaggregation of Revenue [Line Items]
Total revenues	2,027	7,096
Total collaboration revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 46,703	$ 45,388

Revenues - Revenues Disaggregat

Revenues - Revenues Disaggregated by Concentration Risks (Details) - Customer Concentration Risk	3 Months Ended		12 Months Ended
	Mar. 29, 2024	Mar. 31, 2023	Dec. 29, 2023
Affiliates of AmerisourceBergen Corporation | Revenue
Concentration Risk [Line Items]
Percent of total revenues	19%	17%
Affiliates of AmerisourceBergen Corporation | Accounts Receivable
Concentration Risk [Line Items]
Percent of total revenues	20%		17%
Affiliates of McKesson Corporation | Revenue
Concentration Risk [Line Items]
Percent of total revenues	18%	17%
Affiliates of McKesson Corporation | Accounts Receivable
Concentration Risk [Line Items]
Percent of total revenues	26%		21%
Affiliates of CVS Health Corporation | Revenue
Concentration Risk [Line Items]
Percent of total revenues	17%	17%
Affiliates of CVS Health Corporation | Accounts Receivable
Concentration Risk [Line Items]
Percent of total revenues	15%		20%
Accredo Health, Incorporated | Revenue
Concentration Risk [Line Items]
Percent of total revenues	12%	12%
Affiliates of Optum Specialty Pharmacy | Revenue
Concentration Risk [Line Items]
Percent of total revenues	10%	10%
Ipsen Pharma SAS | Accounts Receivable
Concentration Risk [Line Items]
Percent of total revenues	19%		19%
Cardinal Health, Inc. | Accounts Receivable
Concentration Risk [Line Items]
Percent of total revenues	10%		11%

Revenues - Revenues Disaggreg_2

Revenues - Revenues Disaggregated by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Total revenues	$ 425,226	$ 408,788
U.S.
Disaggregation of Revenue [Line Items]
Total revenues	381,937	367,441
Europe
Disaggregation of Revenue [Line Items]
Total revenues	35,703	33,534
Japan
Disaggregation of Revenue [Line Items]
Total revenues	$ 7,586	$ 7,813

Revenues - Net Product Revenues

Revenues - Net Product Revenues Disaggregated by Product (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Total revenues	$ 425,226	$ 408,788
Net product revenues
Disaggregation of Revenue [Line Items]
Total revenues	378,523	363,400
CABOMETYX
Disaggregation of Revenue [Line Items]
Total revenues	376,417	361,773
COMETRIQ
Disaggregation of Revenue [Line Items]
Total revenues	$ 2,106	$ 1,627

Revenues - Activities and Endin

Revenues - Activities and Ending Reserve Balances for Significant Categories of Discounts and Allowances (Details) $ in Thousands	3 Months Ended
	Mar. 29, 2024 USD ($)
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2023	$ 84,840
Provision related to sales made in:
Current period	186,952
Prior periods	(1,690)
Payments and customer credits issued	(166,145)
Balance at March 31, 2024	103,957
Chargebacks, Discounts for Prompt Payment and Other
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2023	25,221
Provision related to sales made in:
Current period	115,134
Prior periods	(625)
Payments and customer credits issued	(111,424)
Balance at March 31, 2024	28,306
Other Customer Credits/Fees and Co-pay Assistance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2023	19,721
Provision related to sales made in:
Current period	17,725
Prior periods	(1,162)
Payments and customer credits issued	(17,768)
Balance at March 31, 2024	18,516
Rebates
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at December 31, 2023	39,898
Provision related to sales made in:
Current period	54,093
Prior periods	97
Payments and customer credits issued	(36,953)
Balance at March 31, 2024	$ 57,135

Revenues - Contract Assets and

Revenues - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023	Dec. 29, 2023
Revenue from Contract with Customer [Abstract]
Contract assets	$ 1,343		$ 1,321
Contract liabilities:
Current portion	4,054		5,406
Long-term portion	4,922		5,524
Total contract liabilities	8,976		$ 10,930
Disaggregation of Revenue [Line Items]
Contract revenue recognized, including revenue from deferred revenue beginning balance	1,600	$ 2,000
Ipsen, Takeda, Daiichi Sankyo and Genentech Collaborations
Disaggregation of Revenue [Line Items]
Revenues recognized for performance obligations satisfied in previous periods	45,900	$ 37,900
Ipsen And Takeda Collaborations
Disaggregation of Revenue [Line Items]
Remaining performance obligation	$ 52,800

Collaboration Agreements And _3

Collaboration Agreements And Business Development Activities - Collaboration Revenues under the Collaboration Agreement with Ipsen (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 425,226	$ 408,788
Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	35,703	33,534
License revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	44,676	38,292
License revenues | Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	36,861	29,812
Collaboration services revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	2,027	7,096
Collaboration services revenues | Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ (1,158)	$ 3,722

Collaboration Agreements And _4

Collaboration Agreements And Business Development Activities - Ipsen Collaboration Narrative (Details) $ in Millions	Mar. 29, 2024 USD ($)
Collaborative Arrangement with Ipsen
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation	$ 28.4

Collaboration Agreements And _5

Collaboration Agreements And Business Development Activities - Collaboration Revenues under the Collaboration Agreement with Takeda (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 425,226	$ 408,788
Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	5,895	6,223
License revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	44,676	38,292
License revenues | Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	2,710	2,849
Collaboration services revenues
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	2,027	7,096
Collaboration services revenues | Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Total revenues	$ 3,185	$ 3,374

Collaboration Agreements And _6

Collaboration Agreements And Business Development Activities - Takeda Collaboration Narrative (Details) $ in Millions	Mar. 29, 2024 USD ($)
Collaborative Arrangement with Takeda
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation	$ 24.4

Collaboration Agreements And _7

Collaboration Agreements And Business Development Activities -Royalty Pharma Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Collaborative Arrangements with Glaxo Smith Kline
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percent of royalty on net sale	3%
Collaborative Arrangements with Royalty Pharma
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty expense	$ 16.7	$ 15.4

Collaboration Agreements And _8

Collaboration Agreements And Business Development Activities - Research Collaborations and In-Licensing Arrangements Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Asset Acquisition [Line Items]
Research and development	$ 227,689	$ 234,246
Research Collaborations, In-Licensing Arrangements and Other Business Development Activities
Asset Acquisition [Line Items]
Research and development	22,800
Collaborative arrangement, maximum aggregate development milestone payments	509,600
Collaborative arrangement, maximum aggregate regulatory milestone payments	365,400
Collaborative arrangement, rights and obligations, maximum aggregate commercial milestone payments	$ 2,500,000

Cash and Investments - Investme

Cash and Investments - Investments by Security Type (Details) - USD ($) $ in Thousands	Mar. 29, 2024	Dec. 29, 2023
Debt securities available-for-sale:
Amortized Cost	$ 1,403,780	$ 1,501,923
Gross Unrealized Gains	733	2,076
Gross Unrealized Losses	(7,120)	(6,576)
Fair Value	1,397,393	1,497,423
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	1,599,204	1,728,519
Gross Unrealized Gains	733	2,076
Gross Unrealized Losses	(7,120)	(6,576)
Fair Value	1,592,817	1,724,019
Commercial paper
Debt securities available-for-sale:
Amortized Cost	203,117	214,016
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	203,117	214,016
Corporate bonds
Debt securities available-for-sale:
Amortized Cost	808,010	870,870
Gross Unrealized Gains	670	1,652
Gross Unrealized Losses	(4,712)	(4,277)
Fair Value	803,968	868,245
U.S. Treasury and government-sponsored enterprises
Debt securities available-for-sale:
Amortized Cost	384,773	409,157
Gross Unrealized Gains	63	414
Gross Unrealized Losses	(2,376)	(2,250)
Fair Value	382,460	407,321
Municipal bonds
Debt securities available-for-sale:
Amortized Cost	7,880	7,880
Gross Unrealized Gains	0	10
Gross Unrealized Losses	(32)	(49)
Fair Value	7,848	7,841
Cash
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	19
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	19
Money market funds
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	133,132	154,287
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	133,132	154,287
Certificates of deposit
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Amortized Cost	62,273	72,309
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 62,273	$ 72,309

Cash and Investments - Narrativ

Cash and Investments - Narrative (Details)	Mar. 29, 2024 USD ($) investment	Dec. 29, 2023 USD ($) investment
Investments, Debt and Equity Securities [Abstract]
Interest receivable	$ 11,900,000	$ 13,100,000
Number of investments in an unrealized loss position | investment	263	230
Allowance for credit losses	$ 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	Mar. 29, 2024	Dec. 29, 2023
Fair Value
In an Unrealized Loss Position Less than 12 Months	$ 577,662	$ 419,297
In an Unrealized Loss Position 12 Months or Greater	331,086	443,240
Total	908,748	862,537
Gross Unrealized Losses
In an Unrealized Loss Position Less than 12 Months	(2,766)	(1,253)
In an Unrealized Loss Position 12 Months or Greater	(4,354)	(5,323)
Total	(7,120)	(6,576)
Corporate bonds
Fair Value
In an Unrealized Loss Position Less than 12 Months	358,757	255,958
In an Unrealized Loss Position 12 Months or Greater	215,894	281,837
Total	574,651	537,795
Gross Unrealized Losses
In an Unrealized Loss Position Less than 12 Months	(1,814)	(847)
In an Unrealized Loss Position 12 Months or Greater	(2,898)	(3,430)
Total	(4,712)	(4,277)
U.S. Treasury and government-sponsored enterprises
Fair Value
In an Unrealized Loss Position Less than 12 Months	217,026	163,339
In an Unrealized Loss Position 12 Months or Greater	109,223	155,452
Total	326,249	318,791
Gross Unrealized Losses
In an Unrealized Loss Position Less than 12 Months	(951)	(406)
In an Unrealized Loss Position 12 Months or Greater	(1,425)	(1,844)
Total	(2,376)	(2,250)
Municipal bonds
Fair Value
In an Unrealized Loss Position Less than 12 Months	1,879	0
In an Unrealized Loss Position 12 Months or Greater	5,969	5,951
Total	7,848	5,951
Gross Unrealized Losses
In an Unrealized Loss Position Less than 12 Months	(1)	0
In an Unrealized Loss Position 12 Months or Greater	(31)	(49)
Total	$ (32)	$ (49)

Cash and Investments - Fair V_2

Cash and Investments - Fair Value of Cash Equivalents and Investments by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 29, 2024	Dec. 29, 2023
Investments, Debt and Equity Securities [Abstract]
Maturing in one year or less	$ 767,832	$ 768,706
Maturing after one year through five years	629,561	728,717
Total debt securities available-for-sale	$ 1,397,393	$ 1,497,423

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Mar. 29, 2024	Dec. 29, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	$ 1,397,393	$ 1,497,423
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	1,397,393	1,497,423
Total financial assets carried at fair value	1,592,798	1,724,019
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	133,132	154,287
Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	1,397,393	1,497,423
Total financial assets carried at fair value	1,459,666	1,569,732
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	203,117	214,016
Commercial paper | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	203,117	214,016
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	203,117	214,016
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	803,968	868,245
Corporate bonds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	803,968	868,245
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	803,968	868,245
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	382,460	407,321
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	382,460	407,321
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	382,460	407,321
Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	7,848	7,841
Municipal bonds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total debt securities available-for-sale	7,848	7,841
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	7,848	7,841
Money market funds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	133,132	154,287
Money market funds | Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	133,132	154,287
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	62,273	72,309
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	$ 62,273	$ 72,309

Fair Value Measurements - Narra

Fair Value Measurements - Narratives (Details) - Foreign Exchange Forward € in Millions	3 Months Ended
	Mar. 29, 2024 EUR (€) derivative_instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of contract | derivative_instrument	1
Derivative notional amount | €	€ 3.6
Derivative term of contract	3 months

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Mar. 29, 2024	Dec. 29, 2023
Inventory [Line Items]
Raw materials	$ 3,117	$ 7,313
Work in process	56,906	59,422
Finished goods	14,795	9,581
Total	74,818	76,316
Current portion included in inventory
Inventory [Line Items]
Total	21,106	17,323
Long-term portion included in other long-term assets
Inventory [Line Items]
Total	$ 53,712	$ 58,993

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 29, 2024	Mar. 29, 2024	Jan. 31, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reduction in share reserve after stock option or stock appreciation award (in shares)		1
Reduction in share reserve after all other awards (in shares)		2
Options granted in the period (in shares)		100,000
Options granted in the period (in dollars per share)		$ 23.24
Options, weighted-average grant date fair value (in dollars per share)		$ 10.08
Options outstanding (in shares)		7,700,000
Options, unrecognized compensation expense		$ 8,100
Repurchases of common stock		$ 192,541
January 2024 Repurchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase program, authorized amount			$ 450,000
Repurchases of common stock (in shares)		8,600,000
Repurchases of common stock		$ 190,700
Stock repurchase program, remaining authorized repurchase amount		$ 259,300
TSR-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted (in shares)	1,300,000
Maximum potential to vest	175%
Weighted average grant date fair value, awarded (in dollars per share)		$ 20.19
TSR-Based Restricted Stock Units | Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting award percentage	50%
TSR-Based Restricted Stock Units | Share-based Payment Arrangement, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted (in shares)		2,800,000
Weighted average grant date fair value, awarded (in dollars per share)		$ 21.87
Number of awards outstanding (in shares)		15,500,000
Share-based payment arrangement, nonvested award, excluding option, cost not yet recognized, amount		$ 221,800
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards outstanding (in shares)		2,500,000
Share-based payment arrangement, nonvested award, excluding option, cost not yet recognized, amount		$ 3,500
Performance Shares, Target Achieved Or Probable
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards outstanding (in shares)		900,000
Share-based payment arrangement, nonvested award, excluding option, cost not yet recognized, amount		$ 37,800
Amended And Restated 2017 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)		22,500,000

Stockholders_ Equity - Schedule

Stockholders’ Equity - Schedule of Allocated Employee Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 19,113	$ 16,661
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	3,892	3,252
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 15,221	$ 13,409

Stockholders_ Equity - Schedu_2

Stockholders’ Equity - Schedule of Employee Service Share - Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 19,113	$ 16,661
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,738	2,207
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	15,434	12,607
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	727	794
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,214	$ 1,053

Stockholders_ Equity - Estimate

Stockholders’ Equity - Estimate Grant-Date Fair Value (Details) - TSR-Based Restricted Stock Units	3 Months Ended
	Mar. 29, 2024 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, awarded (in dollars per share)	$ 20.19
Fair value of Exelixis common stock on grant date (in dollars per share)	$ 21.71
Expected volatility	36.68%
Risk-free interest rate	4.42%
Dividend yield	0%

Provision For Income Taxes (Det

Provision For Income Taxes (Details)	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Effective income tax rate	24.30%	17.10%

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
	Mar. 29, 2024	Mar. 31, 2023
Numerator:
Net income	$ 37,317	$ 40,028
Denominator:
Weighted-average common shares outstanding - basic (in shares)	300,757	324,420
Dilutive securities (in shares)	4,773	1,859
Weighted-average common shares outstanding - diluted (in shares)	305,530	326,279
Net income per share - basic (in dollars per share)	$ 0.12	$ 0.12
Net income per share - diluted (in dollars per share)	$ 0.12	$ 0.12

Net Income Per Share - Potentia

Net Income Per Share - Potential Shares of Common Stock Not Included in the Computation of Diluted Net Income Per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
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)	8,893	15,592

Commitments and Contingencies (

Commitments and Contingencies (Details)	Jan. 11, 2022 patent	Oct. 31, 2022 lawsuit	Sep. 30, 2022 lawsuit	Apr. 30, 2021 lawsuit
Other Commitments [Line Items]
Number of lawsuits			2	2
MSN II ANDA
Other Commitments [Line Items]
Number of lawsuits		2
Number of patents allegedly infringed | patent	3

Restructuring - Narrative (Deta

Restructuring - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 29, 2024 USD ($) lease	Mar. 31, 2023 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 32,835	$ 0
2024 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 32,835
2024 Restructuring Plan | Lease Termination
Restructuring Cost and Reserve [Line Items]
Number of leases | lease	2

Restructuring - Restructuring A

Restructuring - Restructuring Activities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Restructuring Reserve [Roll Forward]
Initial Costs	$ 32,835	$ 0
2024 Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	0
Initial Costs	32,835
Non-cash Charges	(12,318)
Cash Payments	(13,886)
Ending balance	6,631
Total Costs Incurred to Date	32,835
Total Expected Plan Costs	33,018
Severance and employee-related costs | 2024 Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	0
Initial Costs	15,656
Non-cash Charges	0
Cash Payments	(13,868)
Ending balance	1,788
Total Costs Incurred to Date	15,656
Total Expected Plan Costs	15,656
Contract termination and other exit costs | 2024 Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	0
Initial Costs	4,861
Non-cash Charges	0
Cash Payments	(18)
Ending balance	4,843
Total Costs Incurred to Date	4,861
Total Expected Plan Costs	5,044
Asset impairment | 2024 Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	0
Initial Costs	12,318
Non-cash Charges	(12,318)
Cash Payments	0
Ending balance	0
Total Costs Incurred to Date	12,318
Total Expected Plan Costs	$ 12,318