Galapagos (GLPG) 20-F 28 Mar 24 2023 FY Annual report (foreign) Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2023 shares
Entity Addresses [Line Items]
Document Type	20-F
Document Registration Statement	false
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Document Shell Company Report	false
Entity File Number	001-37384
Entity Registrant Name	GALAPAGOS NV
Entity Incorporation, State or Country Code	C9
Entity Address, Address Line One	Generaal De Wittelaan L11 A3
Entity Address, City or Town	Mechelen
Entity Address, Country	BE
Entity Address, Postal Zip Code	2800
Title of 12(b) Security	American Depositary Shares, each representing one
Security Exchange Name	NASDAQ
Trading Symbol	GLPG
Entity Common Stock, Shares Outstanding	65,897,071
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Accounting Standard	International Financial Reporting Standards
Entity Shell Company	false
Entity Central Index Key	0001421876
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Auditor Name	BDO Bedrijfsrevisoren BV
Auditor Firm ID	1432
Auditor Location	Zaventem, Belgium
Amendment Flag	false
Document Financial Statement Error Correction [Flag]	false
Business Contact [Member]
Entity Addresses [Line Items]
Entity Address, Address Line One	Generaal De Wittelaan L11 A3
Entity Address, City or Town	Mechelen
Entity Address, Country	BE
Entity Address, Postal Zip Code	2800
Contact Personnel Fax Number	32 15 342 901
Contact Personnel Name	Stoffels IMC BV (permanently represented by Dr. Paul Stoffels)

Consolidated Statement of Finan

Consolidated Statement of Financial Position € in Thousands, $ in Millions	Dec. 31, 2023 EUR (€)	Dec. 31, 2022 EUR (€)
Assets
Goodwill	€ 69,557	€ 69,813
Intangible assets	127,906	146,354
Property, plant and equipment	126,321	154,252
Deferred tax assets	1,126	1,363
Non-current R&D incentives receivables	141,252	119,941
Other non-current assets	29,645	5,778
Non-current assets	495,807	497,501
Inventories	73,978	52,925
Trade and other receivables	28,449	40,429
Current R&D incentives receivables	37,436	26,126
Current financial investments	3,517,698	3,585,945
Cash and cash equivalents	166,803	508,117
Other current assets	15,140	23,307
Current assets from continuing operations	3,839,504	4,236,850
Assets classified as held for sale	22,085
Total current assets	3,861,589	4,236,850
Total assets	4,357,396	4,734,351
Equity and liabilities
Share capital	293,937	293,604
Share premium account	2,736,994	2,735,557
Other reserves	(5,890)	(4,853)
Translation differences	(1,201)	(1,593)
Accumulated losses	(228,274)	(496,689)
Total equity	2,795,566	2,526,026
Retirement benefit liabilities	2,293	5,540
Deferred tax liabilities	23,607	20,148
Non-current lease liabilities	4,944	14,692
Other non-current liabilities	31,570	21,808
Non-current deferred income	1,071,193	1,623,599
Non-current liabilities	1,133,607	1,685,787
Current lease liabilities	4,652	7,209
Trade and other liabilities	135,201	148,675
Current tax payable	56	1,022
Current deferred income	256,270	365,631
Current liabilities from continuing operations	396,179	522,538
Liabilities associated with assets classified as held for sale	32,044
Total current liabilities	428,223	522,538
Total liabilities	1,561,830	2,208,325
Total equity and liabilities	€ 4,357,396	€ 4,734,351

Consolidated Statement of Opera

Consolidated Statement of Operations - EUR (€) € in Thousands, shares in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Consolidated Statement of Operations
Collaboration revenues	€ 239,724	€ 241,249	€ 234,384
Total net revenues	239,724	241,249	234,384
Research and development expenses	(241,294)	(269,797)	(320,503)
Sales and marketing expenses	(5,676)	(3,480)	(3,776)
General and administrative expenses	(128,289)	(135,155)	(127,744)
Other operating income	47,272	36,127	46,071
Operating loss	(88,263)	(131,056)	(171,568)
Fair value adjustments and net exchange differences	16,252	51,498	61,462
Other financial income	80,249	18,563	3,057
Other financial expenses	(2,613)	(9,854)	(12,353)
Income/loss before tax	5,625	(70,849)	(119,402)
Income taxes	(9,613)	(572)	(1,389)
Net loss from continuing operations	(3,988)	(71,421)	(120,791)
Net income from discontinued operations, net of tax	215,685	(146,570)	17,560
Net loss	211,697	(217,991)	(103,231)
Net loss attributable to:
Owners of the parent	€ 211,697	€ (217,991)	€ (103,231)
Basic loss per share (in EUR per share)	€ 3.21	€ (3.32)	€ (1.58)
Diluted loss per share (in EUR per share)	3.21	(3.32)	(1.58)
Basic loss per share from continuing operations (in EUR per share)	€ (0.06)	€ (1.09)	€ (1.84)
Weighted average number of shares - Basic (in '000 shares)	65,884	65,699	65,500

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income/Loss (-) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Consolidated Statement of Comprehensive Income/Loss (-)
Net loss	€ 211,697	€ (217,991)	€ (103,231)
Items that will not be reclassified subsequently to profit or loss:
Re-measurement of defined benefit obligation	(1,037)	5,324	730
Items that may be reclassified subsequently to profit or loss:
Translation differences, arisen from translating foreign activities	392	129	736
Realization of translation differences upon sale/liquidation of foreign operations			731
Other comprehensive income/loss (-), net of income tax	(645)	5,453	2,197
Total comprehensive loss attributable to:
Owners of the parent	211,052	(212,538)	(101,034)
Total comprehensive loss attributable to owners of the parent arises from:
Continuing operations	(4,564)	(65,953)	(118,594)
Discontinued operations	€ 215,616	€ (146,586)	€ 17,560

Consolidated Statement of Chang

Consolidated Statement of Changes in Equity - EUR (€) € in Thousands	Share capital.	Share premium account	Translation differences	Other reserves	Accumulated losses	Total
Balance at beginning of year at Dec. 31, 2020	€ 291,312	€ 2,727,840	€ (3,189)	€ (10,907)	€ (334,701)	€ 2,670,355
Net loss					(103,231)	(103,231)
Other comprehensive income			1,467	730		2,197
Total comprehensive income / loss (-)			1,467	730	(103,231)	(101,034)
Share-based compensation					70,726	70,726
Exercise of subscription rights	763	2,551				3,314
Balance at end of year at Dec. 31, 2021	292,075	2,730,391	(1,722)	(10,177)	(367,205)	2,643,362
Net loss					(217,991)	(217,991)
Other comprehensive income			129	5,324		5,453
Total comprehensive income / loss (-)			129	5,324	(217,991)	(212,538)
Share-based compensation					88,506	88,506
Exercise of subscription rights	1,530	5,166				6,695
Balance at end of year at Dec. 31, 2022	293,604	2,735,557	(1,593)	(4,853)	(496,689)	2,526,026
Net loss					211,697	211,697
Other comprehensive income			392	(1,037)		(645)
Total comprehensive income / loss (-)			392	(1,037)	211,697	211,052
Share-based compensation					56,718	56,718
Exercise of subscription rights	333	1,437				1,770
Balance at end of year at Dec. 31, 2023	€ 293,937	€ 2,736,994	€ (1,201)	€ (5,890)	€ (228,274)	€ 2,795,566

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Consolidated Statement of Cash Flows
Net income/loss (-)	€ 211,697	€ (217,991)	€ (103,231)
Adjustment for non-cash transactions	99,291	117,296	57,718
Adjustment for items to disclose separately under operating cash flow	(65,763)	(4,533)	11,227
Adjustment for items to disclose under investing and financing cash flows	(16,688)	(3,789)	(28,847)
Change in working capital other than deferred income	(31,373)	32,313	23,337
Cash used for other liabilities related to the acquisition of subsidiaries		(28,164)
Decrease in deferred income	(661,062)	(383,618)	(453,720)
Cash used in operations	(463,898)	(488,487)	(493,516)
Interest paid	(3,809)	(12,463)	(12,540)
Interest received	69,907	4,839	2,913
Income taxes paid	(8,170)	(4,433)	(684)
Net cash flows used in operating activities	(405,970)	(500,544)	(503,827)
Purchase of property, plant and equipment	(18,706)	(27,389)	(54,205)
Purchase of and expenditure in intangible fixed assets	(567)	(9,558)	(3,674)
Proceeds from disposal of property, plant and equipment	2,426	739
Purchase of current financial investments	(3,390,178)	(2,728,634)	(1,561,015)
Investment income received related to current financial investments	14,765	2,996	12
Sale of current financial investments	3,484,411	1,641,602	2,127,380
Disposals Of Subsidiaries Net Of Cash Disposed			28,696
Cash out from acquisition of subsidiaries, net of cash acquired	(7,000)	(115,270)
Cash advances and loans to third parties		(10,000)
Acquisition of financial assets held at fair value through profit or loss	13,965
Proceeds from sale of financial assets held at fair value through profit or loss			4,045
Net cash flows generated from/used in (-) investing activities	71,186	(1,245,514)	541,238
Payment of lease liabilities and other debts	(6,771)	(8,182)	(7,190)
Proceeds from capital and share premium increases from exercise of subscription rights	1,770	6,695	3,314
Net cash flows used in financing activities	(5,001)	(1,487)	(3,876)
Increase/decrease (-) in cash and cash equivalents	(339,785)	(1,747,545)	33,535
Cash and cash equivalents at beginning of year	508,117	2,233,368	2,143,071
Effect of exchange rate differences on cash and cash equivalents	(1,522)	22,293	56,763
Cash and cash equivalents at end of year	€ 166,810	€ 508,117	€ 2,233,368

General information

General information	12 Months Ended
	Dec. 31, 2023
General information.
General information	Notes to Consolidated Financial Statements 1. General information Galapagos NV is a limited liability company incorporated in Belgium and has its registered office at Generaal De Wittelaan L11 A3, 2800 Mechelen, Belgium. In the notes to the consolidated financial statements, references to “we,” “us,” “the group” or “Galapagos” include Galapagos NV together with its subsidiaries. We refer to note 33 for a list of consolidated companies. We are a global biotechnology company with operations in Europe and the US dedicated to developing medicines focusing on oncology and immunology. The components of the result presented in the financial statements include the results of the companies mentioned in note 33 Consolidated companies as of December 31, 2023. Our operations had 1,123 employees on December 31, 2023 (as compared to 1,338 employees on December 31, 2022) mainly working in our operating facilities in Mechelen (the Belgian headquarters), the Netherlands, France, Switzerland, Germany, Italy, Spain and the United Kingdom. Effective as from July 1, 2023 we transferred our drug discovery and research activities in Romainville, France, and 121 employees exclusively dedicated to the operation of these activities to NovAliX, who assumes all ongoing research and discovery activities in Romainville. On January 31, 2024 we announced that we successfully completed the transfer of the Jyseleca® business to Alfasigma, including the European and UK Marketing Authorizations, the commercial, medical and development activities for Jyseleca® and approximately 400 positions in 14 European countries. The transfer of our Jyseleca® business has been determined to meet the criteria to be classified as held for sale and discontinued operations in our financial statements for the year ended December 31, 2023. We also presented all income statement items fully related to the Jyseleca® business to be transferred on a separate line “Net profit/loss (-) from discontinued operations, net of tax” in our consolidated income statement. The consolidated income statement for all comparative periods reported in these consolidated financial statements were restated as well to show the discontinued operations on a separate line. Our continuing operations had 646 employees as at December 31, 2023 (as compared to 724 employees as at December 31, 2022) mainly working in our operating facilities in Mechelen (the Belgian headquarters), the Netherlands, France, Switzerland, and the United States. We refer to note 33 for a list of companies included in the discontinued operations and to note 5 for more details on the discontinued operations. ​

Summary of significant transact

Summary of significant transactions	12 Months Ended
	Dec. 31, 2023
Summary of significant transactions
Summary Of Significant Transaction [Text Block]	2. Summary of significant transactions ​ ​ TRANSFER OF JYSELECA BUSINESS TO ALFASIGMA ​ On October 30, 2023, we signed a letter of intent contemplating a transfer of the Jyseleca® business to Alfasigma. The final share and asset purchase agreement was signed on December 30, 2023 and the transaction was closed on January 31, 2024. The transfer includes the European and UK Marketing Authorizations, and the commercial, medical affairs and development activities for Jyseleca®. In connection with the completion of the transaction, approximately 400 of our positions in 14 European countries transferred to Alfasigma to support business continuity and ongoing patient access for the Jyseleca® business. We received a €50 million upfront payment in connection with the transfer, at closing of the transaction in 2024, and are entitled to receive potential milestone payments totaling €120 million and mid-single to mid-double-digit royalties on European sales. We will contribute up to €40 million by June 2025 to Alfasigma for Jyseleca® related development activities. In addition, we plan to streamline our remaining operations and further build efficiencies, with an envisaged reduction of approximately 100 positions across the organization. Effective January 31, 2024, following the closing of the transaction between us and Alfasigma for the transfer the Jyseleca® business, we assigned our rights and obligations under the Gilead filgotinib collaboration to Alfasigma, except for our right to receive royalties from Gilead on net sales in the Gilead Territory under a separate agreement between Gilead and us entered into in October 2023. On January 31, 2024, we also signed a transition agreement with Alfasigma enacting the responsibilities and services that will be provided by the parties during a transition period for the transfer of the business. The gradual transfer of our remaining inventories to Alfasigma is also governed by this agreement. We refer to note 5 for more details on the discontinued operations. ​ GILEAD COLLABORATION AGREEMENT ​ On July 14, 2019 we and Gilead announced that we entered into a 10-year global research and development collaboration. Through this agreement, Gilead gained exclusive access to our innovative portfolio of compounds, including clinical and preclinical programs and a proven drug discovery platform. At inception of this collaboration in 2019, we received an upfront payment €3,569.8 million ($3.95 billion) and a €960.1 million ($1.1 billion) equity investment from Gilead. We identified the following three performance obligations as part of this collaboration: (i) the transfer of an extended license on ziritaxestat GLPG1690 (this performance obligation was satisfied completely in 2019), (ii) the granting of exclusive access to our drug discovery platform (i.e. the IP, technology, expertise and capabilities) during the collaboration period and exclusive option rights on our current and future clinical programs after Phase 2 (or, in certain circumstances, the first Phase 3 study) outside Europe and (iii) an increased cost share from 20 /50 on the global development activities of filgotinib, as a result of the revised license and collaboration agreement. In the years thereafter (2020-2023), the collaboration agreement relating to filgotinib was restated several times (see further in this chapter). We however retain the following performance obligations, (i) the granting of exclusive access to our drug discovery platform (i.e. the IP, technology, expertise and capabilities) during the collaboration period and exclusive option rights on our current and future clinical programs after Phase 2 (or, in certain circumstances, the first Phase 3 study) outside Europe and (ii) an increased cost share from 20 This second performance obligation was transferred to Alfasigma on 31 January 2024, when we closed the transaction for the transfer of the Jyseleca business to Alfasigma and the (amended and restated) collaboration agreement relating to filgotinib was assigned to Alfasigma as a consequence thereof. Terms of the collaboration relating to our drug discovery platform ​ We will fund and lead all discovery and development autonomously until the end of Phase 2. After the completion of a qualifying Phase 2 study (or, in certain circumstances, the first Phase 3 study), Gilead will have the option to acquire a license to the compound outside Europe. If the option is exercised, we and Gilead will co-develop the compound and share costs equally. Gilead will maintain option rights to our programs through the 10-year term of the collaboration. This term can be extended for up to an additional three years thereafter for those programs, if any, that have entered clinical development prior to the end of the collaboration term. In addition a final term extension can be granted in certain circumstances. Gilead will make a $150 million opt-in payment per program and will owe no subsequent milestones. We will receive tiered royalties ranging from 20%-24% on net sales of all our products licensed by Gilead in all countries outside Europe as part of the agreement. Revised filgotinib collaboration Since the revised agreement of December 2020, we assumed all development, manufacturing, commercialization and certain other rights for filgotinib in Europe. Since January 1, 2021, we bear the full future development costs for certain studies (defined as “Group A activities”), in lieu of the equal cost split contemplated by the previous agreement. The 50/50 global development cost sharing arrangement continued for certain other studies. All commercial economics on filgotinib in Europe were transferred to us as of January 1, 2022, subject to payment of tiered royalties of 8% to 15% of net sales in Europe to Gilead, starting in 2024. In connection with all the amendments to the existing arrangement for the commercialization and development of filgotinib, Gilead paid us €172.6 million in total in previous years. Since the amendment of December 2020, we are also no longer eligible to receive any future milestone payments relating to filgotinib in Europe. Other terms of the original license agreement remained in effect. On October 30, 2023, we and Gilead agreed to amend the Filgotinib Agreement by terminating the existing 50/50 global development cost sharing arrangement with us bearing the costs going forward, and to terminate our obligation to pay tiered royalties to Gilead on net sales of Jyseleca® in Europe, in addition to other amendments. Effective January 31, 2024, following the closing of the transaction between Galapagos and Alfasigma for the transfer of the Jyseleca® business, Galapagos assigned its rights and obligations under the filgotinib collaboration to Alfasigma, except for Galapagos’ right to receive royalties from Gilead on net sales in the Gilead Territory under a separate agreement between Gilead and Galapagos entered into in October 2023. ​ Gilead remains responsible for commercial activities outside of Europe. Terms of the equity investment As part of the research and development collaboration of 2019 Gilead also entered into a share subscription agreement with us. Gilead’s equity investment consisted of a subscription for new Galapagos shares. This equity subscription took place at closing of the transaction, on August 23, 2019 and increased Gilead’s stake in Galapagos from approximately 12.3% to 22.04% of the then issued and outstanding shares in Galapagos. In addition, the extraordinary general meeting of shareholders of October 22, 2019 approved the issuance of Warrant A and initial Warrant B allowing Gilead to further increase its ownership of Galapagos to up to 29.9% of the company’s issued and outstanding shares. On 6 November 2019, Gilead exercised warrant A and increased its ownership in Galapagos to 25.10% of the then outstanding shares. The initial Warrant B has a term of five years and an exercise price per share equal to the greater of (i) 120% multiplied by the arithmetic mean of the 30-day daily volume weighted average trading price of Galapagos’ shares as traded on Euronext Brussels and Euronext Amsterdam, and (ii) €140.59. Subsequent Warrant B is still subject to approval by an extraordinary general meeting of shareholders. This Extraordinary General Meeting of Shareholders shall take place between 57 and 59 months after the closing of the subscription agreement (August 23, 2019) and this warrant will have substantially similar terms, including as to exercise price, to the initial Warrant B. On 31 December 2023 the value of the subsequent Warrant B decreased to €0.05 million, driven by the decrease of our share price, and of the implied volatility in 2023. The agreement also includes a 10-year standstill restricting Gilead’s ability to propose a business combination with or acquisition of Galapagos or increase its stake in Galapagos beyond 29.9% of the company’s issued and outstanding shares, subject to limited exceptions. Gilead’s ownership amounted to 25.35% at December 31, 2023. Since 22, Evolution of the total transaction price The transaction price is currently composed of a fixed part, being non-refundable upfront and license fees and a variable part, being milestone payments, sales based milestones and sales based royalties, and cost reimbursements for R&D activities delivered. Milestone payments are included in the transaction price of the arrangement to the extent that it is highly probable that a significant reversal of revenue will not occur. Milestone payments received from Gilead are recognized in revenue over time till the end of the development plan. Sales based milestones and sales based royalties are also part of the arrangement and are recognized as revenues at a point in time at the moment they occur. The €4.0 billion “upfront consideration” per December 31, 2021 originates from our initial filgotinib agreement with Gilead of 2015 (€275.6 million), €3.6 billion from the initial allocation of the total upfront consideration received through the 2019 collaboration (see beginning of this section) and 172.6 million resulting from amendments to our filgotinib collaboration in 2020 ( 160.0 million) and 12.6 million in 2021 (amendment relating to the Diversity study). We refer to our previous years financial statements for more detailed information. The below table summarizes the changes in the transaction price during 2022 and 2023 of our collaboration with Gilead: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 Other movements in 2022 December 31, 2022 Other movements in 2023 December 31, 2023 ​ ​ (Euro, in thousands) Allocation of transaction price ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Upfront consideration ​ € 4,018,016 ​ ​ ​ ​ € 4,018,016 ​ ​ ​ ​ € 4,018,016 Milestones achieved ​ ​ 194,363 ​ € 18,238 ​ ​ 212,601 ​ ​ ​ ​ ​ 212,601 Royalties ​ ​ 19,984 ​ ​ 10,726 ​ ​ 30,710 ​ € 9,466 ​ ​ 40,176 Impact initial valuation of share subscription ​ ​ 124,604 ​ ​ ​ ​ ​ 124,604 ​ ​ ​ ​ ​ 124,604 ​ ​ ​ 4,356,967 ​ ​ 28,964 ​ ​ 4,385,931 ​ ​ 9,466 ​ ​ 4,395,397 Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrants issuance liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Warrant A ​ ​ (43,311) ​ ​ ​ ​ ​ (43,311) ​ ​ ​ ​ ​ (43,311) Initial warrant B ​ ​ (2,545) ​ ​ ​ ​ ​ (2,545) ​ ​ ​ ​ ​ (2,545) Subsequent warrant B ​ ​ (2,442) ​ ​ 1,714 ​ ​ (728) ​ ​ 674 ​ ​ (54) ​ ​ ​ 4,308,669 ​ ​ 30,678 ​ ​ 4,339,347 ​ ​ 10,140 ​ ​ 4,349,487 Allocation to performance obligations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ziritaxestat ​ ​ 666,967 ​ ​ ​ ​ ​ 666,967 ​ ​ ​ ​ ​ 666,967 Filgotinib (1) ​ ​ 1,343,214 ​ ​ 28,964 ​ ​ 1,372,178 ​ ​ 9,466 ​ ​ 1,381,644 Drug discovery platform (10 years) ​ € 2,298,489 ​ € 1,714 ​ € 2,300,203 ​ € 674 ​ € 2,300,876 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) With regard to the additional consideration received as a result of the Option, License and Collaboration agreement (July 14, 2019) allocated to the filgotinib performance obligation, we assumed the existence of a significant financing component estimated to €44.5 million as of December 31, 2019 reflecting the time value of money on the estimated recognition period. This financing component was reassessed to €57.3 million on December 31, 2021, to €58.7 million on December 31, 2022 and to €39.8 million on December 31, 2023. ​ TRANSFER OF THE DRUG DISCOVERY AND RESEARCH ACTIVITES IN ROMAINVILLE (FRANCE) TO NOVALIX Effective as from July 1, 2023 we transferred our drug discovery and research activities in Romainville and employees exclusively dedicated to the operation of these activities to NovAliX, who assumes all ongoing research and discovery activities in Romainville. In return, we are committed to utilizing the research capabilities and expertise of NovAliX through a five year-collaboration and within the context of our R&D portfolio during which we are committed to purchase for a total of €73.8 million services from NovAliX. We made an upfront payment amounting to €8.3 million at closing of the transaction which will be released over the five year-period. The loss realized on disposal of the disposal group, on closing of the transaction, was capitalized as an advance and will gradually be released through our income statement in accordance with the progress of our future purchase commitment. We refer to note 28 of these consolidated financial statements for more details on this transaction.

Significant accounting policies

Significant accounting policies	12 Months Ended
	Dec. 31, 2023
Significant accounting policies
Significant accounting policies	3. Material accounting policies Our material accounting policies are summarized below. BASIS OF PREPARATION AND GOING CONCERN ASSUMPTION The consolidated financial statements are prepared in accordance with the International Financial Reporting Standards (IFRS), issued by the International Accounting Standards Board (IASB) and the interpretations issued by the IASB’s International Financial Reporting Interpretation Committee. The consolidated financial statements provide a general overview of our activities and the results achieved. They give a true and fair view of our financial position, our financial performance and cash flows, on a going concern basis. The consolidated financial statements are presented in Euros, which is also our functional currency. Amounts are rounded to the nearest thousand, unless otherwise stated. RECLASSIFICATION OF ACCRUED INTERESTS ON FINANCIAL INVESTMENTS – COMPARATIVE PERIODS NOT RESTATED Accrued interests on financial assets were in the past recorded on the “current financial investments” line for treasury bills while reported on a separate current assets/current liabilities line for the other financial investments measured at amortized cost (mainly term deposits). During the third quarter of 2023 we decided to align the presentation of all our financial investments at amortized cost and present all accrued interests as part of the amortized cost measurement on the “current financial investments” / “cash and cash equivalents” line. As the impact of this classification misstatement on the prior period comparative numbers was deemed immaterial for all comparative periods presented, we did not restate the prior period financial statements. This is in accordance with IAS 8.42 that requires to only adjust the comparatives for material prior period errors. The impact of this error on December 31, 2022 amounted to 9.9 million net positive accrued interests mainly related to accrued positive interests on current financial investments that would have increased our “current financial investments” and “cash and cash equivalents” line and decreased our “other current assets” line by the same amount. On December 31, 2021 this error amounted to 2.6 million net negative accrued interests that were mainly related to accrued negative interests on cash and cash equivalents that would have decreased our “cash and cash equivalents” and “current financial investments” line and decreased our “trade and other liabilities” line by the same amount . DISCONTINUED OPERATIONS PRESENTATION – COMPARATIVE PERIODS RESTATED Our income statement and statement of comprehensive income of the comparative periods presented in these financial statements have been restated to present the activities related to the Jyseleca® business on a separate line “Net income/loss (-) from discontinued operations, net of tax”. We refer to note 5 for more detailed information on these discontinued operations. NEW STANDARDS AND INTERPRETATIONS APPLICABLE FOR THE ANNUAL PERIOD BEGINNING ON JANUARY 1, 2023 New standards and interpretations applicable for the annual period beginning on January 1, 2023 did not have a material impact on our consolidated financial statements except for the application of the amendments made to IAS 1 Disclosure of Accounting Policies. As a result of this amendment, we reassessed our accounting policies in order to remain with only the material accounting policies. STANDARDS AND INTERPRETATIONS PUBLISHED, BUT NOT YET APPLICABLE FOR THE ANNUAL PERIOD BEGINNING ON JANUARY 1, 2023 A number of new standards are effective for annual periods beginning on or after January 1, 2024 with earlier adoption permitted. However we have not early adopted new or amended standards in preparing our consolidated financial statements. We are currently still assessing the impact of these new accounting standards and amendments that are not yet effective but we expect no standard to have a material impact on our financial statements in the period of initial application. The following amendments are effective for the period beginning January 1, 2024: ● ● ● ● ​ The following amendments are effective for the period beginning January 1, 2025: ​ ● ​ BUSINESS COMBINATIONS Business combinations are accounted for using the acquisition method. In the statement of financial position, all identifiable assets, liabilities and contingent liabilities are initially recognized at their fair value at the acquisition date. The results of acquired operations are included in our consolidated income statement from the date on which control is obtained. Any contingent consideration to be transferred by us will be recognized at fair value at the acquisition date. Subsequent changes to the fair value of the contingent consideration, which is deemed to be an asset or liability, will be recognized in our consolidated income statement. The excess of the fair value of the total purchase consideration transferred over the fair value of the acquired assets and assumed liabilities is recognized as goodwill. The valuations in support of fair value determinations are based on information available at the acquisition date. Acquisition related costs are expensed as incurred. Any contingent consideration to be transferred by us in relation to businesses acquired that are linked to milestone payments and are initially recognized at fair value as a financial liability. They are adjusted for the probability of their likelihood of payment and are appropriately discounted to reflect the impact of time. Changes in the fair value of these contingent consideration liabilities in subsequent periods are recognized in our consolidated income statement on the line “other operating income/expense”. The effect of unwinding the discount over time is recognized on the line “other financial expenses”. Contingent amounts payable or paid by us to former shareholders of acquired companies, who continue to be employed by us, but which would be automatically forfeited (or become repayable) upon termination of employment before a specific date, are classified as remuneration for post-combination services in our consolidated income statement. These cash-settled contingent amounts are recognized in accordance with IAS 19 and are recorded in the statement of financial position on the lines “other (non-) current assets” and “other non-current/trade and other liabilities” depending on the timing of the payment by us . GOODWILL Goodwill is initially measured as the excess of the total purchase consideration transferred and the fair value of the acquired assets and assumed liabilities. Subsequently, goodwill is stated at cost less impairments. As goodwill is considered to have an indefinite life, it is tested for impairment at least once a year (at each year-end), and whenever there is an indication that it may be impaired, by comparing its carrying amount with its recoverable amount. ​ Any impairment costs are recorded in our consolidated income statement on the line “Other operating income/expenses”. INTANGIBLE ASSETS OTHER THAN GOODWILL Expenditure on research activities is recognized as an expense in the period in which it is incurred. An internally generated intangible asset arising from our development activities is recognized only if all of the following conditions are met: ● Technically feasible to complete the intangible asset so that it will be available for use or sale ● We have the intention to complete the intangible assets and use or sell it ● We have the ability to use or sell the intangible assets ● The intangible asset will generate probable future economic benefits, or indicate the existence of a market ● Adequate technical, financial and other resources to complete the development are available ● We are able to measure reliably the expenditure attributable to the intangible asset during its development (i) Internally generated intangible assets The amount capitalized as internally generated intangible assets is the sum of the development costs incurred as of the date that the asset meets the conditions described above. Because of risks and uncertainties inherent to the regulatory authorizations and to the development process itself, management estimates that the conditions for capitalization are not met until we obtain regulatory approval from the competent authorities. Currently we recognize all development costs as an expense in the period in which they are incurred, even for approved products because they do not generate separately identifiable incremental future economic benefits that can be reliably measured. (ii) Licences, rights and in-process research and development Acquired in-process research and development obtained through in-licensing agreements, business combinations, collaboration agreements or separate acquisitions are capitalized as an intangible asset provided that they are separately identifiable, controlled by us and expected to provide economic benefits. As the probability criterion in IAS 38 is always considered to be satisfied for separately acquired research and development assets, upfront and milestone payments to third parties for products or compounds for which regulatory approval has not yet been obtained are recognized as intangible assets. We consider such intangible assets as not yet available for use until the moment that the underlying asset is approved and commercially launched. Amortization will commence when the underlying asset is approved for commercialization and the asset will be amortized over its useful life. Intangible assets may also consist of upfront fees paid to third party institutions in exchange for an option to negotiate a license to any of the third party’s rights in technology resulting from the collaboration. The upfront fee paid in exchange for this option is capitalized as intangible asset and amortized over the expected duration of the option. Exclusivity contracts and technology acquired through business combinations are valued independently as part of the fair value of the businesses acquired and are amortized over their estimated useful lives. The estimated useful life is based on the lower of the contract life or the economic useful life. In the event an asset has an indefinite life, this fact is disclosed along with the reasons for being deemed to have an indefinite life. Intangible assets with an indefinite useful life and intangible assets which are not yet available for use are tested for impairment annually, and whenever there is an indication that the asset might be impaired. (iii) Software and databases Acquired software is recognized at cost less accumulated amortization and any impairment loss. Amortization is recognized so as to write off the cost of assets over their useful lives (generally between 3 and 5 years), using the straight-line method. (iv) Contract costs Contract costs only include success fees that were capitalized in relation to the Gilead agreement of 2019. These costs are currently amortized on a straight-line basis over a period of 10 years, reflecting the term of our collaboration with Gilead. We review at each balance sheet date the carrying amount of our intangible assets to determine whether there is any indication that those assets have suffered an impairment generate cash flows that are independent from other assets, we estimate the recoverable PROPERTY, PLANT AND EQUIPMENT Property, plant and equipment are recognized at cost less accumulated depreciation and any impairment loss. Depreciation of an asset begins when it is available for use, ie when it is in the location and condition necessary for it to be capable of operating in the manner intended by management. Depreciation is recognized so as to write off the cost of assets over their useful lives, using the straight-line method, on the following bases: ● Buildings: 33 years ● Installation & machinery: 3 – 15 years ● Furniture, fixtures & vehicles: 4 – 10 years Leasehold improvements are depreciated 3 -10 years, being the term of the lease, unless a shorter useful life is expected. The other tangible assets category mainly consists of assets under construction. Assets under construction are not depreciated. Any gain or loss incurred at the disposal of an asset is determined as the difference between the sale proceeds and the carrying amount of the asset and is recognized in profit or loss. We review at each balance sheet date the carrying amount of our property, plant and equipment to determine whether there is any indication that those assets have suffered an impairment LEASES All leases are accounted for by recognizing a right-of-use asset and a corresponding lease liability except for: ● Leases of low value assets; and ● Leases with a duration of 12 months or less Liabilities arising from a lease are initially measured on a present value basis. Lease liabilities include the net present value of the lease payments that are not paid at the commencement date, discounted using the incremental borrowing rate. Our lease payments generally only include fixed payments and extension option payments if we are reasonably certain to exercise this option. After initial recognition, the lease liability will be measured at amortized cost using the discount rate determined at commencement and will be re-measured (with a corresponding adjustment to the related right-of-use asset) when there is a change in future lease payments, generally in case of reassessment of options. At the commencement date, the right-of-use assets are measured at cost, comprising the amount of the initial lease liability, less any lease incentives received from the lessors. After initial recognition, the right-of-use assets are measured at cost and generally depreciated over the the lease term on a straight-line basis. The right-of-use assets will be adjusted for any re-measurements of the lease liability as a result of lease modifications. The right-of-use assets are subject to impairment testing if there is an indicator for impairment, as for property, plant and equipment. The right-of-use assets are presented in the statement of financial position under the caption “property, plant and equipment” and the lease liabilities are presented as current and non-current lease liabilities. We only include extension options (or periods after termination options) in the lease term if the lease is reasonably certain to be extended (or not terminated). The assessment is reviewed if a significant event or a significant change in circumstances occurs which affects this assessment and that is within our control. ​ INVENTORIES Inventories consist of raw materials, semi-finished products and finished products. These inventories are initially recognized at cost, and subsequently at the lower of cost and net realizable value. Cost comprises all costs of purchase, conversion costs and transportation costs, and is determined using the FIFO-method. FINANCIAL INSTRUMENTS Financial assets and financial liabilities are recognized in our statement of financial position when we become a party to the contractual provisions of the instrument. (i) Financial assets Financial assets are initially recognized either at fair value or at their transaction price. All recognized financial assets will subsequently be measured at either amortized cost or fair value under IFRS 9 on the basis of both our business model for managing the financial assets and the contractual cash flow characteristics of the financial asset. ● a financial asset that (i) is held within a business model whose objective is to collect the contractual cash flows and (ii) has contractual cash flows that are solely payments of principal and interest on the principal amount outstanding is measured at amortized cost (net of any write down for impairment), unless the asset is designated at fair value through profit or loss (FVTPL) under the fair value option; ● all other financial assets are measured at FVTPL. A financial asset is classified as current when the cash flows expected to flow from the instrument mature within one year. We derecognize a financial asset when the contractual rights to the cash flows from the asset expire, or we transfer the rights to receive the contractual cash flows on the financial asset in a transaction in which substantially all the risks and rewards of ownership of the financial asset are transferred. Financial assets at fair value through profit or loss Financial assets are designated at fair value through profit or loss if we manage such investments and make purchase and sale decisions based on their fair value in accordance with the investment strategy. Attributable transaction costs are recognized in profit or loss as incurred. Financial assets at fair value through profit or loss are measured at fair value, and changes therein, which take into account any dividend income, are recognized in profit or loss. Equity instruments We hold investments in equity instruments, which based on IFRS 9, are designated as financial assets at fair value through profit or loss. The fair value of listed investments is based upon the closing price of such securities on Euronext at each reporting date. If there is no active market for an equity instrument, we establish the fair value by using valuation techniques. Current financial investments measured at fair value through profit or loss Current financial investments include financial assets measured at fair value through profit or loss and may comprise short term bond funds that have a maturity equal or less than 12 months, and money market funds. Cash equivalents measured at fair value through profit or loss Cash equivalents measured at fair value through profit or loss may comprise bonds and money market funds that are readily convertible to cash and are subject to an insignificant risk of changes in value. Financial assets at amortized cost Receivables Receivables are designated as financial assets measured at amortized cost. They are initially measured either at fair value or at transaction price, in the absence of a significant financing component. All receivables are subsequently measured in the balance sheet at amortized cost, which generally corresponds to nominal value less expected credit loss provision. Receivables mainly comprise trade and other receivables and current/non-current R&D incentives receivables. The R&D incentives receivables relate to refunds resulting from R&D incentives on research and development expenses in France and Belgium. This is a grant receivable that is based on annual declarations and is only refunded in case it cannot be offset by a tax payable. Current financial investments measured at amortized cost Current financial investments measured at amortized cost include treasury bills that have a maturity equal to or less than 12 months. We apply settlement date accounting for the recognition and de-recognition of current financial investments measured at amortized cost. Current financial investments measured at amortized cost also include term deposits with maturities exceeding three months from the acquisition date. Cash and cash equivalents measured at amortized cost Cash and cash equivalents measured at amortized cost mainly comprise of notice accounts and term deposits that are readily convertible to cash within three months or less, that are subject to an insignificant risk of changes in their value and that are held for the purpose of meeting short-term cash commitments. Cash and cash equivalents exclude restricted cash, which is presented in the line other non-current assets in the statement of financial position. Impairment The For trade receivables, in the absence of a significant financing component, the loss allowance Impairment statement. (ii) Financial liabilities Financial liabilities are initially measured either at fair value or at their transaction price. Subsequent to initial recognition, financial liabilities are measured at amortized cost or at fair value. Financial liabilities measured at amortized cost mainly comprise trade and other liabilities. Trade and other liabilities are comprised of liabilities that are due less than one year from the balance sheet date and are in general not interest bearing and settled on an ongoing basis during the financial year. They also include accrued expenses related to our research and development project costs. We derecognize a financial liability when its contractual obligations are discharged, cancelled or expire. TAXATION Income tax in the profit or loss accounts represents the sum of the current tax and deferred tax. Current tax is the expected tax payable on the taxable profit of the year. The taxable profit of the year differs from the profit as reported in the financial statements as it excludes items of income or expense that are taxable or deductible in other years and it further excludes items that are never taxable or deductible. Our liability for current tax is calculated using tax rates that have been enacted or substantively enacted by the balance sheet date. Deferred income tax is provided in full, using the liability-method, on temporary differences arising between the tax bases of assets and liabilities and their carrying amounts in the financial statements. However, the deferred income tax is not accounted for if it arises from the initial recognition of an asset or liability in a transaction other than a business combination that at the time of the transaction affects neither accounting nor taxable profit nor loss. Deferred income tax is determined using tax rates (and laws) that have been enacted or substantively enacted by the balance sheet date and are expected to apply when the related deferred income tax asset is realized or the deferred income tax liability is settled. Deferred tax assets are recognized to the extent that it is probable that future taxable profit will be available against which the temporary differences can be utilized. As such, a deferred tax asset for the carry forward of unused tax losses will be recognized to the extent that is probable that future taxable profits will be available. REVENUE RECOGNITION Revenues to date have consisted principally of collaboration revenues, which consist of milestones, license fees, non-refundable upfront fees and royalties received in connection with collaboration and license agreements. The revenue recognition policies can be summarized as follows: We recognize revenue when our customer obtains control of promised goods or services, in an amount that reflects the consideration that we expect to receive in exchange for those goods or services. To determine revenue recognition for agreements that we determine are within the scope of IFRS 15, we perform the following five steps: COLLABORATION REVENUES (i) identify the contract In our agreements with customers we are mainly transferring licenses on our IP and in some cases this is combined with access rights and/or providing research and development services and/or cost sharing mechanisms. In some cases our collaborations also include an equity subscription component. If this is the case, we analyze if the criteria to combine contracts, as set out by IFRS 15, are met. (ii) identify the performance obligations in the contract Depending on the type of the agreement, there can be one or more distinct performance obligations under IFRS 15. This is based on an assessment of whether the promises in an agreement are capable of being distinct and are distinct from the other promises to transfer goods and/or services in the context of the contract. For some of our agreements we combine the transfer of the license with the performance of research and development activities because we consider that the license is not capable of being distinct and is not distinct in the context of the contract. (iii) determine the transaction price Collaboration and license agreements with our commercial partners for research and development activities generally include non- upfront fees; milestone payments, the receipt of which is dependent upon the achievement of certain clinical, regulatory or commercial milestones; license fees, royalties on sales and sometimes reimbursement income or profits sharing arrangements. a/ License fees or upfront payments If the license to our intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, we recognize revenues from non-refundable upfront fees allocated to the license at the point in time the license is transferred to the customer and the customer has the right to use the license. For licenses that are bundled with other promises, we utilize judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time. If the performance obligation is satisfied over time, revenue is then recognized based on a pattern that best reflects the transfer of control of the service to the customer. b/ Milestone Payments other than sales based milestones A milestone payment is only included in the transaction price to the extent that it is highly probable . W we estimate the amount to be included in the transaction price using the most likely amount method. The transaction price is allocated to each performance obligation on a stand-alone selling price basis. We recognize revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, we re-evaluate the probability of achievement of such milestones and any related constraint. If necessary we adjust our estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenue and earnings in the period of adjustment. c/ Reimbursement Income for R&D Services Collaboration and license agreements may include reimbursement or cost sharing for research and development services: such as outsourcing costs and payment for FTEs at contractual rates. R&D services are performed and satisfied over time given that the customer simultaneously receives and consumes the benefits provided by us. Such costs reimbursements received are recognized in revenues when costs are incurred and agreed by the parties when we are acting as a principal in the scope of our stake of the R&D activities. If the later condition is not fulfilled, costs reimbursements are d/ Sales based milestone payment and Royalties License and collaboration agreements include sales-based royalties, including commercial milestone payments based on the level of sales, and the license has been deemed to be the predominant item to which the royalties relate. Related revenue is recognized as the subsequent underlying sales occur. (iv) allocate the transaction price to the performance obligations in the contract We allocate the transaction price to each performance obligation identified in the contract based upon the stand-alone selling price. The stand-alone selling price of each performance obligation is estimated by using one of the following methods: adjusted (v) recognize revenue when (or as) the entity satisfies a performance obligation Revenue is recognized when our customer obtains control of the goods and/or services foreseen in the contracts. The control can be transferred In case of revenue recognition over time, we use an input model that considers estimates of the percentage of total research and development costs that are completed each period compared to the total estimated costs (percentage of completion method PRODUCT NET SALES Revenue on the sale of Jyseleca is recorded as “Product net sales” on the discontinued operations line in our consolidated income statement. Product net sales is the net amount of revenue recognized resulting from transferring control over our products to our customer (for example wholesalers and hospitals). Product sales revenue is recognized at a point in time when control of the goods has transferred The amount of revenue recognized is the amount allocated to the satisfied performance obligation taking into account variable consideration. The estimated amount of variable consideration is included in the transaction price only to the extent that it is highly probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Variable consideration that is included in the transaction price is primarily composed of rebates, discounts, cash discounts and chargebacks granted to various customers that are part of commercial and governmental contractual arrangements or other reimbursement The amount of variable consideration is estimated using several elements such third-party market data, product pricing, the specific terms in the individual agreements, estimated inventory levels and the shelf life of our product. If actual results differ, these Net sales are presented COST OF SALES Cost of sales includes primarily the purchase OTHER OPERATING INCOME Grants and R&D incentives As we carry out extensive research and development activities, we benefit from various grants and R&D incentives from certain governmental agencies. These grants and R&D incentives generally aim to partly reimburse (approved) expenditures incurred in our research and development efforts and are credited to the income statement, under other income, when the relevant expenditure has been incurred and there is reasonable assurance that the grants or R&D incentives are receivable. SHARE-BASED PAYMENTS a/ Equity-settled share based payments We grant equity-settled incentives to certain employees, members of the Executive Committee and consultants in the form of subscription rights. Equity-settled subscription rights are measured at fair value at the date of acceptance. The fair value determined at the acceptance date of the subscription rights is expensed over time until the end of the vesting period, based on our estimate of subscription right warrants that are expected to be exercised. Fair value is measured by use of the Black & Scholes model. The expected life used in the model has been adjusted, based on management’s best estimate, for the effects of non-transferability, exercise restrictions, and behavioral considerations. b/ Long-term incentive plans in RSUs (Restricted Stock Units) Executive Committee members and other employees are granted RSUs. An RSU is a grant that takes the form of a promise that employees will receive Galapagos stock in the future and it will be payable, at the company’s discretion in cash or in shares, upon completion of a certain vesting period. Each RSU reflects the value of one Galapagos share. The RSUs are measured based on the average share price over the 30-calendar day period preceding the measurement date. We recognize the corresponding expense and liability over the vesting period. The fair value of the liability is re-measured at each reporting date because currently it is management’s intention to settle the RSUs in cash. ​ SEGMENT REPORTING We currently have one operating and reportable segment. ASSETS HELD FOR SALE AND DISCONTINUED OPERATIONS A discontinued operation is a component of an entity that either has been disposed of, or that is classified as held for sale. It must either: represent a major separate line of business or geographical area of operations; be part of a single coordinated disposal plan; or be a subsidiary acquired exclusively with a view to resale. Intercompany transactions between continuing and discontinued operations are eliminated against discontinuing operations. Non-current assets and disposal groups are classified as assets held for sale if their carrying amount is to be recovered principally through a sale transaction rather than through continuing use. This condition is regarded as met only when the sale is highly probable and the asset (or disposal group) is available for immediate sale in its present condition. A transaction is assumed to be highly probable if there are no significant risks of completion of the transaction, which depends on the specific circumstances but usually required at least an agreed binding term sheet. They are stated at the lower of carrying amount and fair value less costs to sell with any resulting impairment recognized. Assets related to discontinued operations and assets of disposal group held for sale are not depreciated. On November 23, 2020 we signed a share purchase agreement with Selvita S.A. in relation to the disposal of Fidelta d.o.o. (our previous fee-for-servic

Critical accounting judgments a

Critical accounting judgments and key sources of estimation uncertainty	12 Months Ended
	Dec. 31, 2023
Critical accounting judgments and key sources of estimation uncertainty
Critical accounting judgments and key sources of estimation uncertainty	4. Critical accounting judgments and key sources of estimation uncertainty In the application of the accounting policies, we are required to make judgments, estimates and assumptions about the carrying amounts of assets and liabilities that are not readily apparent from other sources. The estimates and associated assumptions are based on historical experience and other factors that are considered to be relevant. Actual results may differ from these estimates. Our estimates and assumptions are reviewed on an ongoing basis. Revisions to accounting estimates are recognized in the period in which the estimate is revised if the revision affects only that period or in the period of the revisions and future periods if the revision affects both current and future periods. The following are the critical judgments that we have made in the process of applying the accounting policies and the key sources of estimation that have the most significant effect on the amounts recognized in the consolidated financial statements presented elsewhere in this annual report. Critical judgments in applying accounting policies IFRS 15 – Revenue recognition of the collaboration with Gilead for the development of filgotinib (reported within the results from discontinued operations) ​ Our critical judgments were as follows: ​ Identification of the contract ● Despite the recent additional amendment to the collaboration with Gilead for the development of filgotinib (reference is made to note 2), management judged that all activities are still beneficial for the further development of filgotinib, for which Gilead still owns the ex-Europe rights. All contract modifications have thus been analyzed following the requirements of IFRS 15 as we concluded that Gilead is still to be considered as a customer. This is also supported by the fact that we concluded that there continues to be only one performance obligation with respect to filgotinib. Identification of the performance obligation ● The recent modifications to the collaboration with Gilead (reference is made to note 2) did not give rise to new performance obligations. There was only a change in scope and price of the existing filgotinib performance obligation, which was only partly satisfied at the time of the modification. Based on this, the contract modification has been treated on a cumulative catch-up basis under IFRS 15. Allocation of the total transaction price ● We assessed that the contract modification only changes the scope of the filgotinib performance obligation and the change in both fixed and variable consideration is reflective of the updated stand-alone selling price for the remaining activities of this performance obligation. If we would have concluded that the increased consideration was not, or only partially, related to the filgotinib performance obligation, the consideration would have been potentially allocated to other performance obligations in the contract, which would alter the timing of revenue recognition. ● The denominator used in the calculation of the percentage of completion reflects our best estimate of our total costs to complete the filgotinib performance obligation. These costs were assessed considering management’s best estimate of the design and duration of ongoing and planned clinical trials and the expected closing of the transaction with Alfasigma. As a result of this transaction, the contract with Gilead relating to filgotinib will be transferred to Alfasigma and we will be released from our performance obligation. The remaining costs per December 31, 2023 mainly reflect the costs that we still estimate to incur before the transfer to Alfasigma. IFRS 5 – Classification of group of assets/liabilities held for sale (disposal group) and discontinued operations ● Management determined that selling the Jyseleca® business represents a “discontinued operation” in accordance with IFRS 5. We assessed that the Jyseleca® business represents a component of the group for which the related operations and cashflows could be distinguished from the rest of the entity. Jyseleca® is our only commercialized product and represents a major line of business. ● Management assessed that, at the reporting date, the sale of the Jyseleca® business to Alfasigma was highly probable. A letter of intent was signed on October 30, 2023 and included a customary break-up fee in the event that the parties would not proceed with definitive agreements (share and asset purchase agreement and transition agreement). These definitive agreements were signed on December 30, 2023 and only included usual and customary closing conditions. Based on this, we assessed that the sale was highly probable and classified the disposal group as held for sale per December 31, 2023. ● Our inventories were not considered to be part of the disposal group held for sale. The inventories will not transfer to Alfasigma on closing of the sale transaction but will gradually be transferred to Alfasigma over the coming years. In the meantime, we will bear all risks related to these inventories. We refer to note 5 for more information about the discontinued operations and disposal group held for sale. ​ Key sources of estimation uncertainty The following are the key sources of estimation uncertainty that have the most significant effect on the amounts recognized in our consolidated financial statements for the year ended December 31, 2023. ​ Costs to complete the filgotinib performance obligation The denominator used in the calculation of the percentage of completion reflects our best estimate of the total costs to complete the filgotinib performance obligation (which is composed of the actual costs already incurred at reporting date and our best estimate of the remaining costs to complete the performance obligation). As our estimate of the costs is depending on the evolution of the development activities and the expected closing date of the transfer of the Jyseleca® business to Alfasigma, it may be subject to change in the future. If the outcome of certain activities would be different from the assumptions that we made, it could lead to a material adjustment to the total estimated costs, resulting in a reallocation of revenue between current and future periods. Our total deferred income balance related to this filgotinib performance obligation amounts to €26.3 million on December 31, 2023 and will be released to revenue from discontinued operations in the first quarter of 2024 as a result of the completion of the sale of the Jyseleca® business to Alfasigma on January 31, 2024. The sale to Alfasigma includes the transfer of the amended filgotinib agreement, and by consequence marks the end of our performance obligation towards Gilead . At reporting date, had our best estimate of the remaining cost to complete the filgotinib performance obligation been increased by 10%, this would have resulted in a decrease in revenue recognition in 2023 of €2.6 million and a corresponding increase in current deferred income. Had our best estimate of the remaining cost to complete the filgotinib performance obligation been decreased by 10%, this would have resulted in an increase in revenue recognition in 2023 of €2.6 million and a corresponding decrease in current deferred income. We refer to note 5 for more information on the results from discontinued operations. Goodwill impairment Determining whether goodwill is impaired requires an estimation of the recoverable amount of the cash-generating unit to which the goodwill has been allocated. The calculation of this recoverable amount includes forecasts of future cash flows of the cash-generating unit (highly dependent upon the probability of success linked to the progress of our clinical programs) that cover a period of 17 years and an appropriate discount rate is required to calculate present values, a process which involves estimates. Given that the calculation contains cashflows that go beyond the 5-years horizon it becomes less verifiable and more assumptions are used. ​ We refer to note 13 for more information about the goodwill and impairment of goodwill. ​ Contingent consideration The contingent consideration included in the consideration payable for the acquisition of CellPoint was recorded at fair value at the date of acquisition and is updated at each reporting date. The carrying amount at 31 December 2023 amounts to €21.0 million. These fair values were mainly based on our best estimate of probabilities of reaching the underlying milestones and by applying an appropriate discount rate. The fair values are reviewed at each reporting date and any changes are reflected in our consolidated income statement. ​ We refer to note 25 for more information about the contingent consideration payable for the acquisition of CellPoint. ​

Discontinued operations and ass

Discontinued operations and assets held for sale	12 Months Ended
	Dec. 31, 2023
Discontinued operations and assets held for sale
Discontinued operations and assets held for sale	5. Discontinued operations and assets held for sale TRANSFER OF JYSELECA BUSINESS TO ALFASIGMA On October 30, 2023 we announced that we had signed a letter of intent contemplating a transfer of the Jyseleca® business to Alfasigma, including the European and UK Marketing Authorizations, the commercial, medical and development activities for Jyseleca and approximately 400 positions in 14 European countries. On December 30, 2023, we signed a final share and asset purchase agreement with Alfasigma. On December 31, 2023, the transaction was still subject to certain closing conditions such as the finalization of the consultation process with the workers councils and FDI clearance in Italy and France and Denmark. The transaction was closed on January 31, 2024, upon obtaining all necessary approvals. We received a €50.0 million upfront payment in 2024, and are entitled to potential sales-based milestone payments totalling €120.0 million and mid-single to mid-double-digit royalties on European sales. We will contribute up to €40.0 million to Alfasigma by June 2025 for Jyseleca® related development activities. On January 31, 2024, we also signed a transition agreement with Alfasigma enacting the responsibilities and services that will be provided by the parties during a transition period for the transfer of the business. The gradual transfer of our remaining inventories to Alfasigma is also governed by this contract. ​ The transfer of our Jyseleca® business has been determined to meet the criteria to be classified as held for sale and discontinued operations in our financial statements for the year ended December 31, 2023. The post-tax result from discontinued operations can be disaggregated in the following items: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022 2021 ​ ​ (Euro, in thousands, except share and per share data) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Product net sales ​ € 112,339 ​ € 87,599 ​ € 14,753 Collaboration revenues ​ ​ 431,465 ​ ​ 176,432 ​ ​ 235,709 Total net revenues ​ ​ 543,804 ​ ​ 264,031 ​ ​ 250,462 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of sales ​ ​ (18,022) ​ ​ (12,079) ​ ​ (1,629) Research and development expenditure ​ ​ (190,177) ​ ​ (245,286) ​ ​ (171,205) Sales and marketing expenses ​ ​ (113,356) ​ ​ (144,075) ​ ​ (66,179) General and administrative expenses ​ ​ (17,989) ​ ​ (9,776) ​ ​ (13,155) Other operating income ​ ​ 13,003 ​ ​ 10,721 ​ ​ 7,678 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating profit/loss (-) ​ ​ 217,262 ​ ​ (136,464) ​ ​ 5,972 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value adjustments and net currency exchange differences ​ ​ (13) ​ ​ (25) ​ ​ — Other financial income ​ ​ 679 ​ ​ 15 ​ ​ 164 Other financial expenses ​ ​ (167) ​ ​ (7,825) ​ ​ (9,733) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Profit/loss (-) before tax ​ ​ 217,761 ​ ​ (144,298) ​ ​ (3,597) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income taxes ​ ​ (2,076) ​ ​ (2,272) ​ ​ (1,034) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net profit/loss (-) ​ € 215,685 ​ € (146,570) ​ € (4,631) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic and diluted earnings/loss (-) per share from discontinued operations ​ € 3.27 ​ € (2.23) ​ € (0.07) Weighted average number of shares (in thousands of shares) ​ ​ 65,884 ​ ​ 65,699 ​ ​ 65,500 Weighted average number of shares - Diluted (in thousands of shares) ​ ​ 65,933 ​ ​ 65,699 ​ ​ 65,500 ​ Jyseleca ® product net sales in Europe amounted to €112.3 million in 2023, compared to €87.6 million in 2022, of which €8.1 million realized in Belgium ( €7.3 million in 2022). Collaboration revenues in discontinued operations related to revenue recognition of the collaboration agreement with Gilead for the filgotinib development amount to €429.4 million in 2023 compared to €174.4 million last year. Effective January 31, 2024, following the closing of the transaction between us and Alfasigma S.p.A. to transfer the Jyseleca® business to Alfasigma, we assigned our rights and obligations under the filgotinib collaboration with Gilead to Alfasigma, except for our right to receive royalties from Gilead on net sales in the Gilead Territory under a separate agreement between Gilead and us entered into in October 2023. As a consequence, our performance obligation towards Gilead for the development of filgotinib will come to its end, and the total estimated remaining costs to complete the filgotinib development was substantially reduced leading to a major increase in the percentage of completion of our performance obligation (applying the “cost-to-cost” input model) and a considerable positive catch-up of revenue explaining the increase in revenue recognition for the year 2023 compared to 2022. We refer to note 2 “Summary of significant transactions” for a general description of our collaboration with Gilead. ​ On December 31, 2023, the remaining deferred income related to the filgotinib development amounts to €26.3 million, which will mainly be released in revenue in 2024. The following major classes of assets and liabilities relating to these operations have been classified as held for sale in the consolidated statement of financial position on December 31, 2023: ​ Assets and liabilities held for sale ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ (Euro, in thousands) Property, plant and equipment ​ € 4,194 Deferred tax assets ​ ​ 292 Other non-current assets ​ ​ 598 Inventories ​ ​ 737 Trade and other receivables ​ ​ 15,786 Cash and cash equivalents ​ ​ 7 Other current assets ​ ​ 471 Total assets in disposal group classified as held for sale ​ ​ 22,085 ​ ​ ​ ​ ​ ​ ​ ​ Retirement benefit liabilities ​ ​ 1,160 Non-current lease liabilities ​ ​ 2,327 Other non-current liabilities ​ ​ 329 Current lease liabilities ​ ​ 1,308 Trade and other liabilities ​ ​ 25,619 Current tax payable ​ ​ 1,242 Current deferred income ​ ​ 59 Total liabilities directly associated with assets in disposal group classified as held for sale ​ ​ 32,044 ​ ​ ​ ​ Net liability held for sale ​ € (9,959) ​ This disposal group contains all assets and liabilities of the Galapagos subsidiaries that were fully dedicated to the Jyseleca® business and that will be transferred to Alfasigma in the current transaction. The divestiture includes 100% of the shares of the following subsidiaries, including most of the employees: Galapagos Biotech Limited (UK), Galapagos Biopharma Belgium BV, Galapagos Biopharma GmbH, Galapagos Biopharma Italy S.r.l., Galapagos Biopharma Netherlands B.V., Galapagos Biopharma Spain S.L.U., Galapagos Biopharma Denmark ApS, Galapagos Biopharma Sweden AB, Galapagos Biopharma Finland Oy, Galapagos Biopharma Ireland Ltd., Galapagos Biopharma Norway AS, Galapagos Biopharma Austria GmbH. In addition, and as part of the same transaction, we will transfer all assets, liabilities and employees directly related to the Jyseleca® business but belonging to Galapagos NV or other Galapagos subsidiaries, of which the main asset is the worldwide IP relating to Jyseleca®. Our inventories were not considered as part of the disposal group as these did not transfer to Alfasigma on closing of the transaction on January 31, 2024 but will gradually transfer to Alfasigma during the coming years and we will bear the risks associated with it as long as it is not transferred. ​ Held for sale assets are stated at their carrying amount, which is lower than the fair value less costs to sell. We concluded that the expected present value of the purchase price to be obtained from Alfasigma for the sale of the Jyseleca® business approximates the fair value less costs to sell of the disposal group. ​ Cash flow ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 2021 ​ ​ ​ (Euro, in thousands) Net cash flow used in operating activities ​ € (175,627) ​ € (191,095) ​ € (119,524) Net cash flow used in investing activities ​ ​ (105) ​ ​ (136) ​ ​ (157) Net cash flow used in financing activities ​ ​ (1,928) ​ ​ (1,841) ​ ​ (872) Net cash flow used in discontinued operations ​ € (177,660) ​ € (193,072) ​ € (120,554) ​ ​ DISPOSAL OF FIDELTA On November 23, 2020 we signed a share purchase agreement with Selvita S.A. in relation to the disposal of Fidelta d.o.o. (our previous fee-for-service segment). The transaction was completed on January 4, 2021 for a total consideration of €37.1 million. Fidelta will continue performing drug discovery services for us for the next two years for which we have purchase commitments for an aggregate amount of €6.6 million on December 31, 2023. Consideration received ​ ​ ​ ​ ​ (Euro, in thousands) Cash received ​ € 37,080 Total cash received ​ € 37,080 ​ Analysis of assets and liabilities over which control was lost ​ ​ ​ ​ ​ ​ ​ ​ ​ January 4, 2021 ​ ​ ​ (Euro, in thousands) Intangible assets ​ € 21 Property, plant and equipment ​ ​ 10,050 Other non-current assets ​ ​ 160 Trade and other receivables ​ ​ 4,428 Cash and cash equivalents ​ ​ 7,884 Other current assets ​ ​ 863 Total assets ​ ​ 23,406 ​ ​ ​ ​ ​ ​ ​ ​ Non-current lease liabilities ​ ​ 4,115 Other non-current liabilities ​ ​ 70 Trade and other liabilities ​ ​ 4,479 Current lease liabilities ​ ​ 727 Income tax payable ​ ​ 356 Total liabilities ​ ​ 9,747 ​ ​ ​ ​ Net assets disposed of ​ € 13,658 ​ ​ Gain on disposal of Fidelta ​ ​ ​ ​ ​ ​ (Euro, in thousands) Cash received ​ € 37,080 Net assets disposed of ​ ​ (13,658) Effect of cumulative translation adjustment reclassified from equity on loss of control ​ ​ (731) Costs associated to the sale ​ ​ (500) Gain on disposal ​ € 22,191 ​ Net cash proceeds from the disposal of Fidelta ​ ​ ​ ​ ​ ​ (Euro, in thousands) Cash received ​ € 37,080 Less: cash and cash equivalents balances disposed of ​ ​ (7,884) Total consideration received, net of cash disposed of ​ ​ 29,196 Costs associated to the sale ​ ​ (500) Cash in from disposal of Fidelta, net of cash disposed of ​ € 28,696 ​ RESULT FROM DISCONTINUED OPERATIONS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2023 2022 ​ 2021 ​ ​ ​ (Euro, in thousands, except share and per share data) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain on disposal of subsidiaries ​ € — ​ € — ​ € 22,191 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating profit ​ ​ — ​ ​ — ​ ​ 22,191 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net profit ​ € — ​ € — ​ € 22,191 ​ Basic and diluted earnings per share from discontinued operations ​ € — ​ € — ​ € 0.34 ​ Weighted average number of shares (in thousands of shares) ​ ​ — ​ ​ — ​ ​ 65,500 ​ Weighted average number of shares - Diluted (in thousands of shares) ​ ​ — ​ ​ — ​ ​ 65,831 ​ ​ CASH FLOW FROM DISCONTINUED OPERATIONS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 2021 ​ ​ ​ (Euro, in thousands) Net cash flows generated from investing activities ​ € — ​ € — ​ € 28,696 Net cash flow from discontinued operations ​ € — ​ € — ​ € 28,696 ​

Segment information

Segment information	12 Months Ended
	Dec. 31, 2023
Segment information
Segment information	6. Segment information We currently operate as a single operating segment. GEOGRAPHICAL INFORMATION In 2021, 2022 and 2023, our continuing operations were mainly located in Belgium, France, the Netherlands, Switzerland and United States. The revenues from our collaboration partner Gilead represented nearly 100% of our total net revenues from continuing operations in 2023 (99.9% in 2022, 99.9% in 2021). Following table summarizes the net revenues by destination of customer: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022 2021 ​ ​ (Euro, in thousands) United States of America ​ € 665,174 ​ € 414,129 ​ € 467,978 Europe ​ ​ 118,354 ​ ​ 91,151 ​ ​ 16,867 Total net revenues ​ € 783,528 ​ € 505,280 ​ € 484,846 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ minus: ​ ​ ​ ​ ​ ​ ​ ​ ​ United States of America ​ € 425,466 ​ € 172,980 ​ € 233,638 Europe ​ ​ 118,338 ​ ​ 91,051 ​ ​ 16,824 Total net revenues from discontinued operations ​ € 543,804 ​ € 264,031 ​ € 250,462 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ United States of America ​ € 239,708 ​ € 241,149 ​ € 234,340 Europe ​ ​ 16 ​ ​ 100 ​ ​ 43 Total net revenues from continuing operations ​ € 239,724 ​ € 241,249 ​ € 234,384 ​ ​ As of December 31, 2023, we held €323.8 million of non-current assets (€370.4 million in 2022; €197.6 million in 2021) distributed as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 ​ ​ ​ (Euro, in thousands) Belgium ​ € 56,209 ​ € 72,087 ​ € 98,295 France ​ ​ 1,438 ​ ​ 20,397 ​ ​ 21,051 The Netherlands ​ ​ 251,230 ​ ​ 255,461 ​ ​ 66,621 Switzerland ​ ​ 3,247 ​ ​ 4,962 ​ ​ 7,181 Spain ​ ​ — ​ ​ 3,037 ​ ​ 3,029 United States of America ​ ​ 11,660 ​ ​ 12,729 ​ ​ 136 Other ​ ​ — ​ ​ 1,747 ​ ​ 1,302 Total non-current assets ​ € 323,784 ​ € 370,420 ​ € 197,615 ​

Total revenues

Total revenues	12 Months Ended
	Dec. 31, 2023
Total revenues
Total revenues	7. Total revenues COLLABORATION REVENUES The following table summarizes details of collaboration revenues for the years ended December 31, 2023, 2022 and 2021 by collaboration and by category of revenue: upfront payments and license fees, reimbursement income, and royalties. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Over time Point in time ​ 2023 ​ 2022(*) ​ 2021(*) ​ ​ ​ ​ ​ (Euro, in ​ ​ (Euro, in ​ ​ (Euro, in ​ ​ ​ ​ ​ thousands) ​ ​ thousands) ​ ​ thousands) Recognition of non-refundable upfront payments and license fees ​ ​ ​ ​ € 230,242 ​ € 230,423 ​ € 230,582 Gilead collaboration agreement for drug discovery platform Ö ​ ​ ​ ​ 230,242 ​ ​ 230,423 ​ ​ 230,582 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reimbursement income ​ ​ ​ ​ ​ - ​ ​ 56 ​ ​ - Novartis collaboration agreement for MOR106 Ö ​ ​ ​ ​ - ​ ​ 56 ​ ​ - ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Royalties ​ ​ ​ ​ ​ 9,482 ​ ​ 10,770 ​ ​ 3,801 Gilead royalties on Jyseleca ​ ​ Ö ​ ​ 9,466 ​ ​ 10,726 ​ ​ 3,757 Other royalties ​ ​ Ö ​ ​ 16 ​ ​ 44 ​ ​ 43 Total collaboration revenues ​ ​ ​ ​ € 239,724 ​ € 241,249 ​ € 234,383 (*) The 2022 and 2021 comparatives have been restated to reflect the impact of classifying the Jyseleca® business as discontinued operations in 2023. ​ We recognize recognized Since signing of the letter of intent with Alfasigma in October 2023, we classified all activities that were directly related to the Jyseleca® business, including the revenue recognition related to the filgotinib performance obligation, as discontinued operations in accordance with IFRS 5. We refer to note 5 “Discontinued Operations” for additional information. For the year ended 31 ​ ​ Collaboration with Gilead ​ We refer to note 2 of these consolidated financial statements for a general description of our collaboration with Gilead. ​ In addition, we concluded as follows for the remaining performance obligations: Access rights to the drug discovery platform, option rights and R&D activities ● ● 10 10

Operating costs and other opera

Operating costs and other operating income	12 Months Ended
	Dec. 31, 2023
Operating costs and other operating income
Operating costs and other operating income	8. Operating costs and other operating income RESEARCH AND DEVELOPMENT EXPENDITURE The following table summarizes research and development expenditure for the years ended December 31, 2023, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) Personnel costs ​ € (95,788) ​ € (115,484) ​ € (128,402) Subcontracting ​ ​ (82,997) ​ ​ (61,192) ​ ​ (126,881) Disposables and lab fees and premises costs ​ ​ (18,083) ​ ​ (19,529) ​ ​ (22,933) Depreciation ​ ​ (22,254) ​ ​ (51,493) ​ ​ (15,709) Professional fees ​ ​ (9,272) ​ ​ (9,316) ​ ​ (12,234) Other operating expenses ​ ​ (12,900) ​ ​ (12,783) ​ ​ (14,344) Total R&D expenses ​ € (241,294) ​ € (269,797) ​ € (320,503) (*) The 2022 and 2021 comparatives have been restated to reflect the impact of classifying the Jyseleca® business as discontinued operations in 2023. ​ The table below summarizes our research and development expenditure for the years ended December 31, 2023, 2022 and 2021, broken down by program. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ziritaxestat program ​ € — ​ € (1,096) ​ € (26,725) SIKi program ​ ​ (18,900) ​ ​ (47,727) ​ ​ (91,957) TYK2 program on GLPG3667 ​ ​ (31,289) ​ ​ (24,467) ​ ​ (27,141) CAR-T programs in oncology ​ ​ (82,218) ​ ​ (29,999) ​ ​ — Other programs ​ ​ (108,887) ​ ​ (166,507) ​ ​ (174,680) Total R&D expenses ​ € (241,294) ​ € (269,797) ​ € (320,503) (*) The 2022 and 2021 comparatives have been restated to reflect the impact of classifying the Jyseleca® business as discontinued operations in 2023. ​ SALES AND MARKETING EXPENSES The following table summarizes the sales and marketing expenses for the years ended December 31, 2023, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) Personnel costs ​ € (2,997) ​ € (1,693) ​ € (1,709) Depreciation ​ ​ (113) ​ ​ (59) ​ ​ (37) External outsourcing costs ​ ​ (1,776) ​ ​ (1,267) ​ ​ (1,802) Professional fees ​ ​ (131) ​ ​ (99) ​ ​ (15) Other operating expenses ​ ​ (659) ​ ​ (363) ​ ​ (214) Total sales and marketing expenses ​ € (5,676) ​ € (3,480) ​ € (3,776) (*) The 2022 and 2021 comparatives have been restated to reflect the impact of classifying the Jyseleca® business as discontinued operations in 2023. ​ GENERAL AND ADMINISTRATIVE EXPENSES The following table summarizes the general and administrative expenses for the years ended December 31, 2023, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) Personnel costs ​ € (66,098) ​ € (76,536) ​ € (60,364) Depreciation and impairment ​ ​ (15,978) ​ ​ (8,529) ​ ​ (16,338) Legal and professional fees ​ ​ (23,250) ​ ​ (23,715) ​ ​ (25,345) Other operating expenses ​ ​ (22,963) ​ ​ (26,375) ​ ​ (25,697) Total general and administrative expenses ​ € (128,289) ​ € (135,155) ​ € (127,744) ​ (*) The 2022 and 2021 comparatives have been restated to reflect the impact of classifying the Jyseleca® business as discontinued operations in 2023. ​ OTHER OPERATING INCOME The following table summarizes other operating income for the years ended December 31, 2023, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2023 ​ 2022(*) ​ 2021(*) ​ ​ ​ (Euro, in thousands) Grant income ​ € 6,618 ​ € 1,873 ​ € 7,334 R&D incentives income ​ ​ 32,968 ​ ​ 29,104 ​ ​ 37,416 Other income ​ ​ 7,686 ​ ​ 5,150 ​ ​ 1,325 Total other operating income ​ € 47,272 ​ € 36,127 ​ € 46,075 ​ (*) The 2022 and 2021 comparatives have been restated to reflect the impact of classifying the Jyseleca® business as discontinued operations in 2023. ​ The grant income in 2023, 2022 and 2021was fully related to grants from a Flemish agency and the Belgian government. In many cases these grant agreements carry clauses which require us to maintain a presence in the same region for a number of years and invest according to pre-agreed budgets. Grant income in 2023 also included a grant of €6.1 million from the National Institute for Health and Disability Insurance (2022: nil, 2021: €5.4 million). This grant aimed to incentivize innovative Belgian biotech companies who are performing research and development activities in order to identify new medicines. R&D incentives income was primarily composed of: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2023 ​ 2022(*) ​ 2021(*) ​ ​ ​ (Euro, in thousands) Income from innovation incentive system in France ​ € 5,881 ​ € 11,075 ​ € 12,245 Income from Belgian R&D incentives ​ ​ 16,535 ​ ​ 10,339 ​ ​ 14,835 Tax rebates on payroll withholding taxes of R&D personnel (Belgium & the Netherlands) ​ ​ 10,552 ​ ​ 7,689 ​ ​ 10,336 Total R&D incentives income ​ € 32,968 ​ € 29,104 ​ € 37,416 ​

Staff costs

Staff costs	12 Months Ended
	Dec. 31, 2023
Staff costs
Staff costs	9. Staff costs The continuing ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 2021 Number of employees on December 31 ​ ​ 646 ​ ​ 724 ​ ​ 772 ​ The average number of FTE’s of our continuing operations during the years 2023, 2022 and 2021 was: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022 2021 Members of the Executive Committee ​ ​ 4 ​ ​ 4 ​ ​ 5 Research and development ​ ​ 372 ​ ​ 434 ​ ​ 568 Commercial and medical affairs ​ ​ 13 ​ ​ 7 ​ ​ 6 Corporate and support ​ ​ 245 ​ ​ 250 ​ ​ 298 Total ​ ​ 634 ​ ​ 695 ​ ​ 877 ​ Their aggregate remuneration comprised: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) Wages and salaries ​ € (100,250) ​ € (99,708) ​ € (107,794) Social security costs ​ ​ (15,742) ​ ​ (16,748) ​ ​ (19,109) Pension costs ​ ​ (5,581) ​ ​ (5,583) ​ ​ (4,906) Costs related to subscription right plans ​ ​ (36,628) ​ ​ (62,003) ​ ​ (52,131) Other personnel costs ​ ​ (6,682) ​ ​ (9,670) ​ ​ (6,535) Total personnel costs ​ € (164,883) ​ € (193,712) ​ € (190,475) ​ (*) The 2022 and 2021 comparatives have been restated to reflect the impact of classifying the Jyseleca® business as discontinued operations in 2023. ​ Reference is made to note 31 “Share-based payments” for more information on our subscription right plans.

Financial result

Financial result	12 Months Ended
	Dec. 31, 2023
Financial result
Financial result	10. Financial result The following table summarizes the financial result, consisting of fair value adjustments and net currency exchange differences, other financial income and other financial expenses for the years ended December 31, 2023, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) Fair value adjustments and net currency exchange differences: ​ ​ ​ ​ ​ ​ ​ ​ ​ Net unrealized currency exchange gain/loss (-) ​ € (20,544) ​ € 41,559 ​ € 56,966 Net realized currency exchange gain/loss (-) ​ ​ (1,118) ​ ​ 2,825 ​ ​ (308) Fair value re-measurement of warrants ​ ​ 18 ​ ​ 186 ​ ​ 2,960 Fair value loss on financial assets held at fair value through profit or loss ​ ​ (390) ​ ​ — ​ ​ (4,919) Fair value gain on current financial investments ​ ​ 38,286 ​ ​ 6,929 ​ ​ 6,763 Total fair value adjustments and net currency exchange differences ​ ​ 16,252 ​ ​ 51,498 ​ ​ 61,462 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other financial income: ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest income ​ ​ 79,290 ​ ​ 18,094 ​ ​ 2,865 Discounting effect of non-current R&D incentives receivables ​ ​ 617 ​ ​ 93 ​ ​ 93 Discounting effect of other non-current liabilities ​ ​ 318 ​ ​ — ​ ​ — Other finance income ​ ​ 24 ​ ​ 376 ​ ​ 99 Total other financial income ​ ​ 80,249 ​ ​ 18,563 ​ ​ 3,057 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other financial expenses: ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest expenses ​ ​ (1,770) ​ ​ (6,884) ​ ​ (11,592) Discounting effect of other non-current liabilities ​ ​ — ​ ​ (2,271) ​ ​ — Other finance charges ​ ​ (843) ​ ​ (699) ​ ​ (761) Total other financial expense ​ ​ (2,613) ​ ​ (9,854) ​ ​ (12,353) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total net other financial income ​ € 93,888 ​ € 60,206 ​ € 52,166 ​ (*) The 2022 and 2021 comparatives have been restated to reflect the impact of classifying the Jyseleca® business as discontinued operations in 2023. ​ The net currency unrealized exchange loss of €20.5 The fair value gain on the current financial investments reflects the exchange differences booked on the money market funds, the interest on the money market funds and the effect of the re-measurement at fair value of the money market funds on December 31, 2023. These re-measurement gains are mainly the result of the positive returns on the EUR denominated money market funds. Interest income was related to interests on term deposits, notice accounts and current financial investments. Interest income increased due to increased interest rates. Interest expenses were related to interests on term deposits and treasury bills, on leases of buildings and cars. Other financial expense for 2022 also comprise the discounting effect of other non-current liabilities as deferred consideration and milestones payables related to the acquisition of subsidiaries.

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2023
Income taxes
Income taxes	11. Income taxes The following table summarizes the income taxes recognized in profit or loss for the years ended December 31, 2023, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ (Euro, in thousands) Continuing operations ​ ​ ​ ​ ​ ​ ​ ​ ​ Current tax ​ € (5,928) ​ € (1,738) ​ € (884) Deferred tax ​ ​ (3,685) ​ ​ 1,166 ​ ​ (505) Income taxes ​ € (9,613) ​ € (572) ​ € (1,389) (*) The 2022 and 2021 comparatives have been restated to reflect the impact of classifying the Jyseleca® business as discontinued operations in 2023. ​ Current tax, consisting of corporate income taxes, and deferred tax income/cost (–) related to subsidiaries of our continuing operations working on a cost plus basis. The increase in 2023 as compared to 2022 was primarily due to the re-assessment of net deferred tax liabilities and corporate income tax payables as a result of a one-off intercompany transaction. TAXES RECOGNIZED IN INCOME STATEMENT For the purpose of the disclosure below corporation tax was calculated at 25% (2022 and 2021: 25%)—which is the tax rate applied in Belgium—on the estimated assessable profit for the year. The applied tax rate for other territorial jurisdictions was the tax rate that is applicable in these respective territorial jurisdictions on the estimated taxable result of the accounting year. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Profit/loss (-) before tax ​ € 5,625 ​ € (70,849) ​ € (119,402) Income tax debit/credit (-), calculated using the Belgian statutory tax rate on the accounting income/loss (-) before tax (theoretical) ​ ​ 1,406 ​ ​ (17,712) ​ ​ (29,850) Tax expenses in income statement (effective) ​ ​ 9,613 ​ ​ 572 ​ ​ 1,389 Difference in tax expense/income to explain ​ € 8,207 ​ € 18,284 ​ € 31,239 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Effect of tax rates in other jurisdictions ​ € (94) ​ € (337) ​ € (588) Effect of non-taxable income ​ ​ (6,752) ​ ​ (5,828) ​ ​ (2,320) Effect of share based payment expenses without tax impact ​ ​ 9,157 ​ ​ 15,501 ​ ​ 13,033 Effect of expenses/income (-) not subject to tax ​ ​ (5) ​ ​ (146) ​ ​ (907) Effect of non tax-deductible expenses ​ ​ 1,549 ​ ​ 2,975 ​ ​ 3,688 Effect of recognition of previously non-recognized deferred tax assets ​ ​ (81) ​ ​ (1,677) ​ ​ (1,411) Effect of tax losses (utilized) reversed ​ ​ (267) ​ ​ — ​ ​ — Effect of under or over provision in prior periods ​ ​ (722) ​ ​ 1,101 ​ ​ (828) Effect of non-recognition of deferred tax assets ​ ​ 34,339 ​ ​ 4,819 ​ ​ 20,949 Effect of derecognition of previously recognized deferred tax assets ​ ​ 1,062 ​ ​ 1,877 ​ ​ 135 Effect of use of investment deduction ​ ​ — ​ ​ — ​ ​ (512) Effect of use of innovation income deduction ​ ​ (29,979) ​ ​ — ​ ​ — Total explanations ​ € 8,207 ​ € 18,284 ​ € 31,239 (*) The 2022 and 2021 comparatives have been restated to reflect the impact of classifying the Jyseleca® business as discontinued operations in 2023. ​ Non-taxable income for the years ended December 31, 2023, 2022 and 2021 related to non-taxable grants and tax credits.

Income_loss (-) per share

Income/loss (-) per share	12 Months Ended
	Dec. 31, 2023
Income/loss (-) per share
Income/loss (-) per share	12. Earnings/loss (-) per share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022 2021 Earnings/loss (-) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ Net profit/loss (-) attributable to owners of the parent (Euro, in thousands) ​ € 211,697 ​ € (217,991) ​ € (103,231) Number of shares (thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of shares for the purpose of basic earnings/loss (-) per share ​ ​ 65,884 ​ ​ 65,699 ​ ​ 65,500 Basic earnings/loss (-) per share (Euros) ​ € 3.21 ​ € (3.32) ​ € (1.58) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net profit/loss (-) attributable to owners of the parent (Euro, in thousands) ​ € 211,697 ​ € (217,991) ​ € (103,231) Number of shares (thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of shares for the purpose of diluted earnings/loss (-) per share ​ ​ 65,884 ​ ​ 65,699 ​ ​ 65,500 Number of dilutive potential ordinary shares ​ ​ 49 ​ ​ — ​ ​ — Diluted earnings/loss (-) per share (Euros) ​ € 3.21 ​ € (3.32) ​ € (1.58) ​ As our operations reported a net loss in 2022 and 2021, the outstanding subscription rights (specified in note Reference is also made to note 2 where an explanation is provided about the terms and conditions of the outstanding Gilead Warrant B that can, potentially, be exercised by Gilead and lead to a dilutive effect. Due to the exercise price mechanism of the Gilead Warrant B, this warrant was out-of-the-money for all years presented.

Goodwill and impairment of good

Goodwill and impairment of goodwill	12 Months Ended
	Dec. 31, 2023
Goodwill and impairment of goodwill
Goodwill and impairment of goodwill	13. Goodwill and impairment of goodwill The following table illustrates the goodwill at December 31, 2023: ​ ​ ​ ​ ​ Cost ​ (Euro, in thousands) On January 1, 2022 ​ € — Recognized on acquisition of subsidiaries ​ ​ 69,893 Exchange differences on goodwill ​ ​ (80) On December 31, 2022 ​ € 69,813 Exchange differences on goodwill ​ ​ (256) On December 31, 2023 ​ € 69,557 ​ The goodwill resulting from both the acquisition of CellPoint (€62.4 million) and AboundBio (€7.1 million) was allocated to the same cash-generating unit, “CAR-T/Cell therapy” (which was the same as “oncology” before). The intangible assets acquired as a result of both business combinations were also allocated to this cash-generating unit, together with some other (in)tangible assets related to the “CAR-T/Cell therapy” cash-generating unit. The valuation method of the recoverable amount of this cash-generating unit is based on the fair value less costs of disposal. The valuation technique that was applied to determine the fair value less costs of disposal of the cash-generating unit is a discounted cash flow method (“DCF”) with projected cash flows that cover a period of 17 years (in accordance with management's assumptions on patent protection of the underlying assets). The period considered exceeds five years because the main sales are expected for the period beyond 2029. The key assumptions used in this valuation (level 3 in the fair value hierarchy) of the recoverable amount of the underlying cash-generating unit were: ● Probability of success of our clinical programs that is based on benchmarks in combination with management estimate. Probabilities of success are continuously evaluated in light of the progress of our portfolio. ● Terminal growth rate of -50% reflecting the anticipated sales evolution beyond 2040 ● Discount rate of 13.72 % ( 12.5 % on December 31, 2022) ● Future revenue and investment assumptions are based on management estimates of the overall cell therapy market, consistent with the assumptions that a market participant would make. Estimates about sales volumes and prices were verified against several external databases. ​ No impairment was identified per December 31, 2023. ​ Reference is made to note 27 “Business combinations during the prior period” for a detailed description of both business combinations.

Intangible assets other than go

Intangible assets other than goodwill	12 Months Ended
	Dec. 31, 2023
Intangible assets other than goodwill.
Intangible assets other than goodwill	14. Intangible assets other than goodwill ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Software & databases Licenses, technology and in-process R&D ​ ​ Exclusive rights ​ Contract costs ​ Total ​ ​ (Euro, in thousands) Acquisition value ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 24,554 ​ € 39,929 ​ € — ​ € 15,384 ​ € 79,868 Impact of acquisitions of businesses ​ ​ 2,610 ​ ​ 32,240 ​ ​ 89,720 ​ ​ ​ ​ ​ 124,570 Additions ​ ​ 1,126 ​ ​ 8,423 ​ ​ ​ ​ ​ ​ ​ ​ 9,549 Sales and disposals ​ ​ (913) ​ ​ (36,298) ​ ​ ​ ​ ​ ​ ​ ​ (37,211) Translation differences ​ ​ ​ ​ ​ (36) ​ ​ ​ ​ ​ ​ ​ ​ (36) On December 31, 2022 ​ ​ 27,377 ​ ​ 44,258 ​ ​ 89,720 ​ ​ 15,384 ​ € 176,740 Additions ​ ​ 567 ​ ​ — ​ ​ — ​ ​ ​ ​ ​ 567 Sales and disposals ​ ​ (930) ​ ​ (948) ​ ​ ​ ​ ​ ​ ​ ​ (1,878) Translation differences ​ ​ ​ ​ ​ (139) ​ ​ ​ ​ ​ ​ ​ ​ (139) On December 31, 2023 ​ € 27,014 ​ € 43,171 ​ € 89,720 ​ € 15,384 ​ € 175,290 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization and impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 11,977 ​ € 4,199 ​ € — ​ € 3,588 ​ € 19,765 Amortization ​ ​ 4,146 ​ ​ 333 ​ ​ 6,154 ​ ​ 1,538 ​ ​ 12,171 Impairment ​ ​ ​ ​ ​ 35,666 ​ ​ ​ ​ ​ ​ ​ ​ 35,666 Sales and disposals ​ ​ (913) ​ ​ (36,298) ​ ​ ​ ​ ​ ​ ​ ​ (37,211) Translation differences ​ ​ ​ ​ ​ (4) ​ ​ ​ ​ ​ ​ ​ ​ (4) On December 31, 2022 ​ ​ 15,210 ​ ​ 3,896 ​ ​ 6,154 ​ ​ 5,126 ​ ​ 30,387 Amortization ​ ​ 4,291 ​ ​ 1,426 ​ ​ 11,637 ​ ​ 1,538 ​ ​ 18,892 Sales and disposals ​ ​ (927) ​ ​ (948) ​ ​ ​ ​ ​ ​ ​ ​ (1,875) Translation differences ​ ​ ​ ​ ​ (20) ​ ​ ​ ​ ​ ​ ​ ​ (20) On December 31, 2023 ​ € 18,574 ​ € 4,354 ​ € 17,791 ​ € 6,664 ​ € 47,384 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ € 12,167 ​ € 40,362 ​ € 83,566 ​ € 10,258 ​ € 146,354 On December 31, 2023 ​ € 8,440 ​ € 38,817 ​ € 71,929 ​ € 8,720 ​ € 127,906 ​ Impact of acquisition of businessess in 2022 refers to the acquisition of CellPoint and AboundBio. We refer to note 27 ‘Business combinations during the prior period’. ​ The exclusive rights refer to our exclusivity contract with Lonza and are depreciated until the beginning of March 2030, in accordance with the contract. ​ In 2022 we recorded an impairment of €26.7 million on previously capitalized upfront fees related to our collaboration with Molecure on the dual chitinase inhibitor OATD-01 (GLPG4716) in fibrosis, and impairments of €8.9 million on intangible assets related to other discontinued projects. On December 31, 2023, our statement of financial position did not hold any internally generated assets capitalized as intangible asset.

Property, plant and equipment

Property, plant and equipment	12 Months Ended
	Dec. 31, 2023
Property, plant and equipment
Property, plant and equipment	15. Property, plant and equipment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ FULLY OWNED Land, buildings & leasehold improvements Installation & machinery Furniture, fixtures & vehicles Other tangible assets Total ​ ​ (Euro, in thousands) Acquisition value ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 26,131 ​ € 46,270 ​ € 7,829 ​ € 60,324 ​ € 140,555 Impact of acquisitions of businesses ​ ​ 29 ​ ​ 2,117 ​ ​ 108 ​ ​ ​ ​ ​ 2,254 Additions ​ ​ 914 ​ ​ 5,688 ​ ​ 3,438 ​ ​ 19,296 ​ ​ 29,336 Sales and disposals ​ ​ (2,846) ​ ​ (600) ​ ​ (1,344) ​ ​ ​ ​ ​ (4,790) Reclassifications ​ ​ 64,286 ​ ​ 3,580 ​ ​ 167 ​ ​ (68,033) ​ ​ — Translation differences ​ ​ 205 ​ ​ (15) ​ ​ 43 ​ ​ ​ ​ ​ 233 On December 31, 2022 ​ ​ 88,719 ​ ​ 57,040 ​ ​ 10,241 ​ ​ 11,587 ​ ​ 167,588 Additions ​ ​ 6,754 ​ ​ 6,472 ​ ​ 268 ​ ​ 3,329 ​ ​ 16,823 Sales and disposals ​ ​ (4,403) ​ ​ (24,057) ​ ​ (1,067) ​ ​ (7,655) ​ ​ (37,182) Reclassifications ​ ​ 95 ​ ​ 272 ​ ​ 124 ​ ​ (491) ​ ​ — Reclassifications to assets in disposal group classified as held for sale ​ ​ (739) ​ ​ ​ ​ ​ (249) ​ ​ ​ ​ ​ (988) Translation differences ​ ​ 279 ​ ​ (49) ​ ​ 36 ​ ​ ​ ​ ​ 266 On December 31, 2023 ​ € 90,705 ​ € 39,678 ​ € 9,353 ​ € 6,770 ​ € 146,507 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciations and impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 5,505 ​ € 24,749 ​ € 4,582 ​ € — ​ € 34,837 Depreciation ​ ​ 4,433 ​ ​ 4,336 ​ ​ 1,265 ​ ​ ​ ​ ​ 10,034 Sales and disposals ​ ​ (2,173) ​ ​ (574) ​ ​ (1,328) ​ ​ ​ ​ ​ (4,075) Translation differences ​ ​ 49 ​ ​ (1) ​ ​ 18 ​ ​ ​ ​ ​ 66 On December 31, 2022 ​ ​ 7,814 ​ ​ 28,510 ​ ​ 4,537 ​ ​ — ​ ​ 40,862 Depreciation ​ ​ 4,603 ​ ​ 4,355 ​ ​ 1,290 ​ ​ ​ ​ ​ 10,248 Impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7,645 ​ ​ 7,645 Sales and disposals ​ ​ (1,194) ​ ​ (13,676) ​ ​ (827) ​ ​ (7,645) ​ ​ (23,342) Reclassifications to assets in disposal group classified as held for sale ​ ​ (161) ​ ​ ​ ​ ​ (129) ​ ​ ​ ​ ​ (290) Translation differences ​ ​ 156 ​ ​ (11) ​ ​ 19 ​ ​ ​ ​ ​ 164 On December 31, 2023 ​ € 11,218 ​ € 19,178 ​ € 4,891 ​ € — ​ € 35,287 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ € 80,905 ​ € 28,530 ​ € 5,704 ​ € 11,587 ​ € 126,726 On December 31, 2023 ​ € 79,487 ​ € 20,500 ​ € 4,463 ​ € 6,770 ​ € 111,220 ​ The sales and disposals of 2023 mainly relate to the transaction with NovAlix. We refer to note 28 “Details of the NovAlix transaction” for more information. The other tangible assets primarily consist of assets under construction, which are not yet available for use and therefore not yet depreciated as per December 31, 2023. In 2023 we recorded an impairment of €7.6 million on the construction project in Mechelen (Belgium), following a re-assessment of the project. During 2022, the construction of our new building in Oegstgeest (the Netherlands) was completed which explains the reclassification from “other tangible assets” to “land, building and building improvements” for €64.3 million. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ RIGHT-OF-USE Land & building Installation & machinery Furniture, fixtures & vehicles Total ​ ​ (Euro, in thousands) Acquisition value ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 37,461 ​ € 593 ​ € 10,184 ​ € 48,239 Additions ​ ​ 703 ​ ​ ​ ​ ​ 3,603 ​ ​ 4,306 Sales and disposals ​ ​ (3,554) ​ ​ (156) ​ ​ (1,274) ​ ​ (4,984) Translation differences ​ ​ 224 ​ ​ ​ ​ ​ (8) ​ ​ 216 On December 31, 2022 ​ ​ 34,834 ​ ​ 437 ​ ​ 12,505 ​ ​ 47,777 Additions ​ ​ 1,726 ​ ​ ​ ​ ​ 1,724 ​ ​ 3,450 Sales and disposals ​ ​ (11,497) ​ ​ (186) ​ ​ (1,897) ​ ​ (13,580) Reclassifications to assets in disposal group classified as held for sale ​ ​ (2,091) ​ ​ ​ ​ ​ (4,683) ​ ​ (6,774) Translation differences ​ ​ 202 ​ ​ ​ ​ ​ 3 ​ ​ 205 On December 31, 2023 ​ € 23,174 ​ € 251 ​ € 7,652 ​ € 31,078 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciations and impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 12,500 ​ € 374 ​ € 3,569 ​ € 16,444 Depreciation ​ ​ 4,421 ​ ​ 134 ​ ​ 3,141 ​ ​ 7,696 Sales and disposals ​ ​ (2,602) ​ ​ (156) ​ ​ (1,235) ​ ​ (3,993) Translation differences ​ ​ 105 ​ ​ ​ ​ ​ (2) ​ ​ 103 On December 31, 2022 ​ ​ 14,424 ​ ​ 352 ​ ​ 5,473 ​ ​ 20,250 Depreciation ​ ​ 3,342 ​ ​ 57 ​ ​ 3,450 ​ ​ 6,849 Sales and disposals ​ ​ (5,922) ​ ​ (186) ​ ​ (1,871) ​ ​ (7,979) Reclassifications to assets in disposal group classified as held for sale ​ ​ (699) ​ ​ ​ ​ ​ (2,580) ​ ​ (3,279) Translation differences ​ ​ 134 ​ ​ ​ ​ ​ 1 ​ ​ 135 On December 31, 2023 ​ € 11,279 ​ € 223 ​ € 4,473 ​ € 15,976 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ € 20,410 ​ € 85 ​ € 7,032 ​ € 27,526 On December 31, 2023 ​ € 11,895 ​ € 28 ​ € 3,179 ​ € 15,101 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 ​ ​ 2022 ​ ​ ​ ​ ​ ​ ​ ​ (Euro, in thousands) ​ ​ ​ Carrying amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Property, plant and equipment fully owned ​ ​ ​ ​ € 111,220 ​ € 126,726 ​ ​ ​ Right-of-use ​ ​ ​ ​ ​ 15,101 ​ ​ 27,526 ​ ​ ​ Total property, plant and equipment ​ ​ ​ ​ € 126,321 ​ € 154,252 ​ ​ ​ ​ The sales and disposals of 2023 mainly relate to the transaction with NovAlix. We refer to note 28 “Details of the NovAlix transaction” for more information. We refer to note 24 Lease liabilities for a detail of the lease liabilities related to these right-of-use assets. There are no pledged items of property, plant and equipment. There are also no restrictions in use on any items of property, plant and equipment.

Other non-current assets

Other non-current assets	12 Months Ended
	Dec. 31, 2023
Other non-current assets
Other non-current assets	16. Other non-current assets Other non-current assets consisted of following items: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Non-current restricted cash ​ € 5,533 ​ € 4,569 Financial assets held at fair value through profit or loss ​ ​ 13,575 ​ ​ — Non-current portion of upfront payment to NovAlix ​ ​ 4,656 ​ ​ — Non-current portion of advance related to the NovAliX transaction ​ ​ 5,563 ​ ​ — Other non-current assets ​ ​ 318 ​ ​ 1,209 Total other non-current assets ​ € 29,645 ​ € 5,778 ​ Financial assets held at fair value through profit or loss on December 31, 2023 consisted of an equity instrument of a non-listed company. We have no restrictions on the sale of this equity instrument and the asset is not pledged under any of our liabilities. We refer to note 28 “Details of the NovAlix transaction” for more information related to the upfront payment and the advance.

Research and Development incent

Research and Development incentives receivables	12 Months Ended
	Dec. 31, 2023
Research and Development incentives receivables
Research and Development incentives receivables	17. Research and Development incentives receivables The table below illustrates the R&D incentives receivables related captions in the balance sheet at December 31, 2023 and 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Non-current R&D incentives receivables ​ € 141,252 ​ € 119,941 Current R&D incentives receivables ​ ​ 37,436 ​ ​ 26,126 Total R&D incentives receivables ​ € 178,688 ​ € 146,067 ​ The table below provides detailed information on the maturity of the non-current R&D incentives receivables reported in our statement of financial position at December 31, 2023. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ ​ ​ Maturity date ​ ​ ​ ​ 2025 2026 2027 2028 2029-2033 Total ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ French non-current R&D incentives receivables - discounted value ​ € 11,495 ​ ​ 11,511 ​ ​ 5,578 ​ ​ — ​ ​ — ​ € 28,584 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Belgian non-current R&D incentives receivables - discounted value ​ ​ 17,530 ​ ​ 19,340 ​ ​ 20,202 ​ ​ 19,858 ​ ​ 35,738 ​ ​ 112,668 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total non-current R&D incentives receivables - discounted value ​ € 29,025 ​ € 30,851 ​ ​ 25,780 ​ ​ 19,858 ​ ​ 35,738 ​ € 141,252 ​

Inventories

Inventories	12 Months Ended
	Dec. 31, 2023
Inventories
Inventories	18. Inventories ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Raw materials ​ € 55,263 ​ € 39,071 Semi-finished products ​ ​ 12,598 ​ ​ 5,791 Finished products ​ ​ 6,117 ​ ​ 8,063 Total inventories ​ € 73,978 ​ € 52,925 ​ Finished goods consisted in full out of Jyseleca® finished products.

Trade and other receivables and

Trade and other receivables and other current assets	12 Months Ended
	Dec. 31, 2023
Trade and other receivables and other current assets
Trade and other receivables and other current assets	19. Trade and other receivables and other current assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Trade receivables ​ € 17,494 ​ € 28,194 Prepayments ​ ​ 738 ​ ​ 488 Other receivables ​ ​ 10,217 ​ ​ 11,747 Trade and other receivables ​ ​ 28,449 ​ ​ 40,429 Accrued income ​ ​ 508 ​ ​ 11,277 Deferred charges ​ ​ 14,632 ​ ​ 12,029 Other current assets ​ ​ 15,140 ​ ​ 23,307 Total trade and other receivables & other current assets ​ € 43,589 ​ € 63,735 ​ Trade and other receivables decreased primarily due to the classification to assets held for sale for an amount of €15.8 million related to the trade and other receivables of the commercial entities which transferred to Alfasigma on January 31, 2024. The decrease in accrued income is due to the fact that accrued interest income on current financial investments is now included in the line ‘current financial investments’. We refer to note 3 for more information about this reclass of accrued interests. On December 31, 2023, we did not have any provision for expected credit losses since we don’t have a history of credit losses and we are not aware of any forward-looking information that could materially influence the credit risk.

Current financial investments

Current financial investments	12 Months Ended
	Dec. 31, 2023
Current financial investments
Current financial investments	20. Current financial investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Money market funds ​ € 1,316,805 ​ € 1,292,514 Treasury bills ​ ​ 742,025 ​ ​ 749,835 Term deposits ​ ​ 1,458,868 ​ ​ 1,543,596 Total current financial investments ​ € 3,517,698 ​ € 3,585,945 ​ Term deposits refer to non-cancellable term deposits with a maturity exceeding three months from the acquisition date. Our portfolio of treasury bills contains only AAA rated paper, issued by Belgium, Germany, France and Europe. Our money market funds portfolio consists of AAA short-term money market funds with a diversified and highly rated underlying portfolio managed by established fund management companies with a proven track record leading to an insignificant risk of changes in value. The funds have an important daily liquidity and can be easily converted to cash. On December 31, 2023, our current financial investments included $830.9 million held in USD, which could generate a foreign currency exchange gain or loss in our financial results in accordance with the fluctuation of the EUR/USD exchange rate as our functional currency is EUR. This effect is embedded in the net exchange differences (for exchange differences on term deposits) and the fair value result of current financial investments (for exchange differences on money market funds) recognized in our consolidated income statement. We refer to note 34 for more information on these current financial investments and to note 10 for more details about the fair value re-meaurements and currency exchange gains or losses in our consolidated income statement.

Cash and cash equivalents

Cash and cash equivalents	12 Months Ended
	Dec. 31, 2023
Cash and cash equivalents
Cash and cash equivalents	21. Cash and cash equivalents ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 ​ 2022 ​ ​ (Euro, in thousands) Cash at banks ​ € 71,803 ​ € 458,117 Term deposits ​ ​ 95,000 ​ ​ 50,000 Cash and cash equivalents from continuing operations ​ € 166,803 ​ € 508,117 Cash and cash equivalents included in assets held for sale ​ ​ 7 ​ ​ — Total cash and cash equivalents ​ € 166,810 ​ € 508,117 ​ Cash and cash equivalents may comprise cash at banks, bank deposits and money market funds that are readily convertible to cash and are subject to an insignificant risk of changes in value. Cash and cash equivalents at December 31, 2023 comprised a term deposit of €50.0 million of term deposits which had an original maturity longer than three months, but was readily convertible to cash without a significant penalty, and a term deposit with an original maturity less than three months of €45 million. All cash and cash equivalents are available upon maximum three month notice period and without significant penalty. Cash at banks were mainly composed of notice accounts and current accounts. Our credit risk is mitigated by selecting a panel of highly rated financial institutions for our deposits. On December 31, 2023 our cash and cash equivalents included $34.5 million held in U.S.dollars, which could generate a foreign currency exchange gain or loss in our financial results in accordance with the fluctuation of the EUR/U.S.dollar exchange rate as our functional currency is EUR. We refer to note 10 for more details about the exchange gains/losses recognized in our consolidated income statement.

Share capital

Share capital	12 Months Ended
	Dec. 31, 2023
Share capital
Share capital	22. Share capital ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 2021 ​ ​ (Euro, in thousands) On January 1 ​ € 293,604 ​ € 292,075 ​ € 291,312 Share capital increase ​ ​ 333 ​ ​ 1,530 ​ ​ 763 Costs of capital increase ​ ​ — ​ ​ — ​ ​ — Share capital on December 31, ​ € 293,937 ​ € 293,604 ​ € 292,075 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aggregate share capital ​ € 356,445 ​ € 356,112 ​ € 354,582 Costs of capital increase (accumulated) ​ ​ (62,507) ​ ​ (62,507) ​ ​ (62,507) Share capital on December 31, ​ € 293,937 ​ € 293,604 ​ € 292,075 ​ ​ HISTORY OF SHARE CAPITAL The history of the share capital of Galapagos NV between January 1, 2021 and December 31, 2023 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Date ​ ​ Share capital increase due to exercise subscription rights (in thousands €) ​ Number of shares issued (in thousands of shares) ​ Aggregate number of shares after transaction (in thousands of shares) Aggregate share capital after transaction (in thousands €) January 1, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 65,412 ​ € 353,819 March 19, 2021 ​ ​ ​ ​ ​ ​ ​ ​ 540 ​ ​ 100 ​ ​ ​ ​ ​ ​ June 7, 2021 ​ ​ ​ ​ ​ ​ ​ ​ 59 ​ ​ 11 ​ ​ ​ ​ ​ ​ September 20, 2021 ​ ​ ​ ​ ​ ​ ​ ​ 41 ​ ​ 8 ​ ​ ​ ​ ​ ​ December 3, 2021 ​ ​ ​ ​ ​ ​ ​ ​ 123 ​ ​ 23 ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 65,553 ​ ​ 354,582 March 18, 2022 ​ ​ ​ ​ ​ ​ ​ ​ 517 ​ ​ 96 ​ ​ ​ ​ ​ ​ June 20, 2022 ​ ​ ​ ​ ​ ​ ​ ​ 434 ​ ​ 80 ​ ​ ​ ​ ​ ​ September 27, 2022 ​ ​ ​ ​ ​ ​ ​ ​ 579 ​ ​ 107 ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 65,836 ​ ​ 356,112 March 20, 2023 ​ ​ ​ ​ ​ ​ ​ ​ 333 ​ ​ 62 ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 65,897 ​ € 356,445 ​ On December 31, 2023, Galapagos NV’s share capital amounted to €356,445 thousand, represented by 65,897,071 shares. All shares were issued, fully paid up and of the same class. All of the share issuances listed above were for cash consideration. ​ The below table summarizes the capital increases for the years 2021, 2022 and 2023. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Euro, in thousands, except share data) Number of shares Share capital Share premium ​ Share capital and share premium ​ Average exercise price subscription right ​ Closing share price on date of capital increase ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ( in Euro/ subscription right) ​ ​ ( in Euro/ share) On January 1, 2021 ​ ​ 65,411,767 ​ € 291,312 ​ € 2,727,840 ​ € 3,019,153 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 19, 2021 : exercise of subscription rights ​ ​ 99,814 ​ ​ 540 ​ ​ 1,718 ​ ​ 2,258 ​ ​ 22.62 ​ ​ 68.48 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 7, 2021 : exercise of subscription rights ​ ​ 10,940 ​ ​ 59 ​ ​ 266 ​ ​ 325 ​ ​ 29.73 ​ ​ 61.78 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 20, 2021 : exercise of subscription rights ​ ​ 7,600 ​ ​ 41 ​ ​ 111 ​ ​ 152 ​ ​ 19.97 ​ ​ 46.93 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 3, 2021 : exercise of subscription rights ​ ​ 22,600 ​ ​ 123 ​ ​ 456 ​ ​ 579 ​ ​ 25.61 ​ ​ 41.72 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2021 ​ ​ 65,552,721 ​ ​ 292,075 ​ ​ 2,730,391 ​ ​ 3,022,467 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 18, 2022 : exercise of subscription rights ​ ​ 95,500 ​ ​ 517 ​ ​ 1,643 ​ ​ 2,160 ​ ​ 22.61 ​ ​ 57.38 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 20, 2022 : exercise of subscription rights ​ ​ 80,290 ​ ​ 434 ​ ​ 1,025 ​ ​ 1,460 ​ ​ 18.18 ​ ​ 53.52 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 27, 2022 : exercise of subscription rights ​ ​ 107,000 ​ ​ 579 ​ ​ 2,497 ​ ​ 3,076 ​ ​ 28.75 ​ ​ 44.49 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ ​ 65,835,511 ​ ​ 293,604 ​ ​ 2,735,557 ​ ​ 3,029,162 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 20, 2023 : exercise of subscription rights ​ ​ 61,560 ​ ​ 333 ​ ​ 1,437 ​ ​ 1,770 ​ ​ 28.75 ​ ​ 35.47 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2023 ​ ​ 65,897,071 ​ € 293,937 ​ € 2,736,994 ​ € 3,030,932 ​ ​ ​ ​ ​ ​ ​ Other information ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ordinary shares Total Par value of shares (€) ​ ​ ​ ​ ​ 5.41 ​ ​ 5.41 ​ The Board of Directors is authorized for a period of five years starting from the date of publication in the Annexes to the Belgian State Gazette of the Shareholders’ Resolution that granted the renewed authorization, to increase the share capital of Galapagos NV within the framework of the authorized capital through contributions in kind or in cash, with limitation or cancellation of the shareholders’ preferential subscription rights. Said authorization can be renewed. The authorized capital of Galapagos NV consists of two parts: ◾ A general authorization for capital increases up to 20% of the share capital at the time of convening the Shareholders’ Meeting of October 22, 2019 (i.e. €67,022,402.04 ) was renewed and is valid for a period of five years from the date of publication of this renewal in the Annexes to the Belgian State Gazette, i.e. November 13, 2019. This general authorization will expire on November 12, 2024. ◾ A specific authorization for capital increases of more than 20% and up to 33% of the share capital at the time of the convening the Shareholders' Meeting of April 25, 2017 (i.e. €82,561,764.93 ), was renewed and is valid for a period of five years from the date of publication of this renewal in the Annexes to the Belgian State Gazette, i.e. May 31, 2017. This specific part of the authorized capital can, however, only be used in a number of specific circumstances and upon a resolution of the Board of Directors that all independent members of the Board of Directors (within the meaning of article 7:87 of the Belgian Companies Code) approve. The Board of Directors is currently not authorized to increase the share capital after notification by the FSMA (Financial Services and Markets Authority) of a public takeover bid on Galapagos NV’s shares. The specific authorization expired on May 30, 2022. As of December 31, 2023, an amount of €16,566,540.17 still remained available under the general part of the authorized capital.

Deferred tax

Deferred tax	12 Months Ended
	Dec. 31, 2023
Deferred tax
Deferred tax	23. Deferred tax The following table shows the movements in deferred tax assets and deferred tax liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ DEFERRRED TAX ASSETS ​ Retirement benefit liabilities Tax loss carryforward Property, plant and equipment Other Total deferred tax assets ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 776 ​ € 3,133 ​ ​ ​ ​ € 122 ​ € 4,032 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Credited/charged (-) to profit or loss ​ ​ 17 ​ ​ (1,797) ​ ​ ​ ​ ​ 165 ​ ​ (1,615) Reclassification ​ ​ ​ ​ ​ (275) ​ ​ ​ ​ ​ ​ ​ ​ (275) Charged to other comprehensive income ​ ​ (795) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (795) Exchange differences ​ ​ 22 ​ ​ ​ ​ ​ ​ ​ ​ (6) ​ ​ 15 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ ​ 19 ​ ​ 1,061 ​ € — ​ ​ 281 ​ ​ 1,363 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Credited/charged (-) to profit or loss ​ ​ ​ ​ ​ (1,061) ​ ​ 298 ​ ​ 692 ​ ​ (72) Reclassification to assets/liabilities held for sale ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (292) ​ ​ (292) Charged to other comprehensive income ​ ​ 132 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 132 Exchange differences ​ ​ 8 ​ ​ ​ ​ ​ (6) ​ ​ (6) ​ ​ (4) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2023 ​ € 159 ​ € — ​ € 292 ​ € 675 ​ € 1,126 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ DEFERRED TAX LIABILITIES ​ ​ ​ ​ ​ ​ ​ Intangible assets other than goodwill Other Total deferred tax liabilities ​ ​ ​ ​ ​ ​ ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € — ​ ​ ​ ​ € — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Impact of acquisition of businesses ​ ​ (23,265) ​ ​ ​ ​ ​ (23,265) ​ ​ ​ ​ ​ ​ Credited/charged (-) to profit or loss ​ ​ 2,842 ​ ​ ​ ​ ​ 2,842 ​ ​ ​ ​ ​ ​ Reclassification ​ ​ 275 ​ ​ ​ ​ ​ 275 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ ​ (20,148) ​ € — ​ ​ (20,148) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Credited/charged (-) to profit or loss ​ ​ (1,458) ​ ​ (2,019) ​ ​ (3,477) ​ ​ ​ ​ ​ ​ Exchange differences ​ ​ 18 ​ ​ ​ ​ ​ 18 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2023 ​ € (21,588) ​ € (2,019) ​ € (23,607) ​ ​ ​ ​ ​ ​ ​ The unrecognized deferred tax assets on December 31, 2023 amount to €326.8 million (as compared to €460.1 million on December 31, 2022). The total amount of tax attributes and deductible temporary differences at December 31, 2023 amounted to €1,722.2 million (2022: €1,882.5 million, 2021: €1,653.7 million). This is composed of i) consolidated tax losses carried forward and deductible temporary differences at December 31, 2023 amounting to €1,312.2 million (2022: €1,516.6 million; 2021: €1,343.2 million), and (ii) innovation income deduction, dividend received deduction and investment deduction carried forward at December 31, 2023 amounting to €410.0 million (2022: €365.9 million; 2021: €310.5 million). The available tax losses carried forward that can be offset against possible future taxable profits amounted to €798.7 million on December 31,2023 and can be carried forward for an indefinite period except for an amount of €2.2 million in the United States with expiry date between 2028 and 2034. On December 31, 2023, the available tax losses carried forward in Galapagos NV (Belgium) amounted to €757.9 million. In addition to the latter, Galapagos NV (Belgium) also benefits from the Belgian innovation income deduction regime which led to report, on December 31, 2023, a carried forward tax deduction of €390.3 million (2022: €346.2 million; 2021: €301.3 million) that can also be offset against possible future taxable results. In addition, Galapagos NV (Belgium) also has available investment deduction carried forward of €1 million (2022 and 2021: €1 million) and a dividend received deduction carryforward of €18.7 million (2022: €18.7 million, 2021: €8.2 million) that can be offset against possible future taxable profits. There is no limit in time for the innovation income deduction, the dividend received deduction carryforward and investment deduction carried forward. With the exception of 2019 and 2023, we have a history of losses. We forecast to continue incurring taxable losses in the foreseeable future as we continue to invest in clinical and preclinical development programs and discovery platforms. Consequently, no net deferred tax asset was recognized as at December 31, 2023, except for our subsidiaries operating on a cost plus basis for which deferred tax assets were recognized for €1.1 million (2022: €1.1 million and 2021: €4.0 million). ​ Net deferred tax liabilities were initially calculated based on the fair value of the intangible assets identified from the acquisition of CellPoint and AboundBio, adjusted by considering the related recognizable deferred tax assets. We refer to note 27 for more information on the purchase price allocation of the business combinations.

Lease liabilities

Lease liabilities	12 Months Ended
	Dec. 31, 2023
Lease liabilities.
Lease liabilities	24. Lease liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ 2023 2022 ​ 2023 2022 ​ ​ (Euro, in thousands) ​ (Euro, in thousands) ​ Lease payments Present value of lease payments Lease liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Within one year ​ € 4,779 ​ € 7,507 ​ € 4,652 ​ € 7,209 In the second to fifth years inclusive ​ ​ 5,031 ​ ​ 14,401 ​ ​ 4,944 ​ ​ 14,100 After five years ​ ​ — ​ ​ 609 ​ ​ — ​ ​ 592 ​ ​ € 9,810 ​ € 22,517 ​ € 9,596 ​ € 21,901 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less future finance charges ​ ​ 214 ​ ​ 616 ​ ​ ​ ​ ​ ​ Present value of lease liabilities ​ € 9,596 ​ € 21,901 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less amount due for settlement within 12 months ​ ​ 4,652 ​ ​ 7,209 ​ ​ 4,652 ​ ​ 7,209 Amount due for settlement after 12 months ​ € 4,944 ​ € 14,692 ​ € 4,944 ​ € 14,692 ​

Trade and other liabilities and

Trade and other liabilities and other non-current liabilities	12 Months Ended
	Dec. 31, 2023
Trade and other liabilities and other non-current liabilities
Trade and other liabilities and other non-current liabilities	25. Trade and other liabilities and other non-current liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Trade and other liabilities ​ € 134,653 ​ € 133,298 Current contingent consideration related to milestones CellPoint ​ ​ — ​ ​ 8,485 Current deferred consideration payable CellPoint ​ ​ — ​ ​ 6,222 Current financial instruments ​ ​ — ​ ​ 19 Accrued charges ​ ​ 548 ​ ​ 651 Total trade and other liabilities ​ € 135,201 ​ € 148,675 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-current contingent consideration related to milestones CellPoint ​ € 20,972 ​ € 13,582 Other non-current liabilities ​ ​ 10,598 ​ ​ 8,226 Total other non-current liabilities ​ € 31,570 ​ € 21,808 ​ ​ The decrease in total trade and other liabilities can be largely explained by the payment of deferred consideration related to the acquisition of CellPoint. The contingent consideration arrangement relating to the acquisition of CellPoint requires us to pay the former owners of CellPoint additional considerations up to €100.0 million. This amount is due when certain sequential development (€20.0 million), regulatory (€30.0 million) and sales-based (€50.0 million) milestones would be achieved. Total fair value at acquisition date of these milestones amounted to €20.2 million at acquisition date. The fair value measurement is based on significant inputs that are not observable in the market, which are classified as Level 3 inputs. Key assumptions in the valuation at December 31, 2022 included a discount rate of 12.5%, an appropriate probability of success of reaching these milestones and expected timing of these milestones, in line with the timelines and probabilities used in our impairment test of the CAR-T business. As per December 31, 2023 changes were made to the discount rate (13.72%) and the timing of the milestones. The only impact that was recognized compared to the date of acquisition is the discounting effect. This is recognized on the line “other financial income”. A change in probabilities of success by 5 percentage points would result in a change of €3.0 million in the total contingent consideration liability on December 31, 2023.

Deferred income

Deferred income	12 Months Ended
	Dec. 31, 2023
Deferred income
Deferred income	26. Deferred income The movement in the non-current and current deferred income is detailed in the table below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gilead collaboration agreement for filgotinib Gilead collaboration agreement for drug discovery platform (1) Other deferred income Total ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 604,875 ​ € 1,759,828 ​ € — ​ € 2,364,701 Of which current portion : ​ ​ 190,018 ​ ​ 229,848 ​ ​ — ​ ​ 419,866 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Upfront received ​ ​ 18,238 ​ ​ ​ ​ ​ ​ ​ ​ 18,238 Significant financing component (2) ​ ​ 7,672 ​ ​ ​ ​ ​ ​ ​ ​ 7,672 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue recognition of upfront ​ ​ (139,655) ​ ​ (230,423) ​ ​ ​ ​ ​ (370,078) Revenue recognition of milestones ​ ​ (34,777) ​ ​ ​ ​ ​ ​ ​ ​ (34,777) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other movements ​ ​ ​ ​ ​ ​ ​ ​ 3,474 ​ ​ 3,474 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ € 456,352 ​ € 1,529,405 ​ € 3,474 ​ ​ 1,989,230 Of which current portion : ​ ​ 133,470 ​ ​ 230,022 ​ ​ 2,139 ​ ​ 365,631 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reclassification to liabilities directly associated with assets in disposal group classified as held for sale ​ ​ ​ ​ ​ ​ ​ ​ (60) ​ ​ (60) Significant financing component (2) ​ ​ (645) ​ ​ ​ ​ ​ ​ ​ ​ (645) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue recognition of upfront ​ ​ (361,412) ​ ​ (230,242) ​ ​ ​ ​ ​ (591,654) Revenue recognition of milestones ​ ​ (68,027) ​ ​ ​ ​ ​ ​ ​ ​ (68,027) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other movements ​ ​ ​ ​ ​ ​ ​ ​ (1,382) ​ ​ (1,382) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2023 ​ € 26,268 ​ € 1,299,163 ​ € 2,032 ​ € 1,327,463 Of which current portion : ​ ​ 25,054 ​ ​ 230,070 ​ ​ 1,146 ​ ​ 256,270 (1) The upfront received and the outstanding balance comprise the issuance liabilities for the warrants and the upfront payment allocated to the drug discovery platform. (2) With regard to the additional consideration received for the extended cost sharing for filgotinib, we assume the existence of a sigificant financing component reflecting the time value of money on the estimated recognition period We refer to note 2 for a detail of the allocation of the transaction price received from Gilead and to note 5 and note 7 for a description of our revenue recognition.

Business combinations during th

Business combinations during the period.	12 Months Ended
	Dec. 31, 2023
Business combinations during the period.
Business combinations during the period.	27. Business combinations during the prior period On June 21, 2022 we acquired, in an all-cash transaction, 100% of the shares and voting interests of CellPoint for a total agreed payment at completion of €125 million, including consideration for other liabilities associated with the transaction amounting to €10.3 million. Additional contingent consideration up to €100.0 million is due when certain milestones would be achieved. ​ On the same date we acquired all of the outstanding capital of AboundBio, for a total agreed price of $14 million, including consideration for other liabilities associated with the transaction. ​ The main reason for these acquisitions was to position ourselves in next-generation cancer therapy market and to significantly broaden our portfolio and capabilities. The goal is to expand the current market for CAR-T therapies and have an important impact on patients in need of additional and improved treatment options. ​ Details of the fair value of identifiable assets and liabilities acquired in both transactions, the purchase consideration, the goodwill at the acquisition date and the net cash outflow arising on acquisition are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 21, 2022 ​ ​ ​ ​ ​ (Euro, in thousands) ​ ​ CellPoint ​ AboundBio ​ Total ​ Book value Adjustment Fair value Book value Adjustment Fair value ​ ​ Intangible assets other than goodwill ​ ​ ​ ​ € 120,517 ​ € 120,517 ​ ​ ​ ​ € 4,053 ​ € 4,053 ​ ​ ​ Property, plant and equipment ​ € 1,289 ​ ​ ​ ​ ​ 1,289 ​ € 965 ​ ​ ​ ​ ​ 965 ​ ​ ​ Other non-current assets ​ ​ 81 ​ ​ ​ ​ ​ 81 ​ ​ 4 ​ ​ ​ ​ ​ 4 ​ ​ ​ Trade and other receivables ​ ​ 162 ​ ​ ​ ​ ​ 162 ​ ​ - ​ ​ ​ ​ ​ - ​ ​ ​ Cash and cash equivalents ​ ​ 3,179 ​ ​ ​ ​ ​ 3,179 ​ ​ 4,279 ​ ​ ​ ​ ​ 4,279 ​ ​ ​ Other current assets ​ ​ 1,254 ​ ​ ​ ​ ​ 1,254 ​ ​ 536 ​ ​ ​ ​ ​ 536 ​ ​ ​ Deferred tax liabilities ​ ​ - ​ ​ (22,368) ​ ​ (22,368) ​ ​ - ​ ​ (907) ​ ​ (907) ​ ​ ​ Trade and other liabilities ​ ​ (32,789) ​ ​ ​ ​ ​ (32,789) ​ ​ (587) ​ ​ ​ ​ ​ (587) ​ ​ ​ Current deferred income ​ ​ - ​ ​ ​ ​ ​ - ​ ​ (474) ​ ​ ​ ​ ​ (474) ​ ​ ​ Net assets acquired ​ ​ (26,824) ​ ​ 98,149 ​ ​ 71,325 ​ ​ 4,723 ​ ​ 3,146 ​ ​ 7,869 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Consideration paid in cash ​ ​ ​ ​ ​ ​ ​ ​ 107,750 ​ ​ ​ ​ ​ ​ ​ ​ 14,976 ​ ​ ​ Fair value re-measurement of previously held equity investment ​ ​ ​ ​ ​ ​ ​ ​ - ​ ​ ​ ​ ​ ​ ​ ​ 342 ​ ​ ​ Deferred consideration ​ ​ ​ ​ ​ ​ ​ ​ 5,808 ​ ​ ​ ​ ​ ​ ​ ​ - ​ ​ ​ Fair value of contingent consideration ​ ​ ​ ​ ​ ​ ​ ​ 20,211 ​ ​ ​ ​ ​ ​ ​ ​ - ​ ​ ​ Fair value of total consideration ​ ​ ​ ​ ​ ​ ​ ​ 133,769 ​ ​ ​ ​ ​ ​ ​ ​ 15,318 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Goodwill ​ ​ ​ ​ ​ ​ ​ ​ 62,444 ​ ​ ​ ​ ​ ​ ​ ​ 7,449 ​ ​ ​ Exchange differences on goodwill ​ ​ ​ ​ ​ ​ ​ ​ - ​ ​ ​ ​ ​ ​ ​ ​ (80) ​ ​ ​ Goodwill in the balance sheet at December 31, 2022 ​ ​ ​ ​ ​ ​ ​ € 62,444 ​ ​ ​ ​ ​ ​ ​ € 7,369 ​ € 69,813 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net cash outflow arising on acquisition (2022) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Consideration paid in cash ​ ​ ​ ​ ​ ​ ​ ​ 107,750 ​ ​ ​ ​ ​ ​ ​ ​ 14,976 ​ ​ ​ Less: cash and cash equivalents balances acquired ​ ​ ​ ​ ​ ​ ​ ​ (3,179) ​ ​ ​ ​ ​ ​ ​ ​ (4,279) ​ ​ ​ Cash out from acquisition of subsidiaries, net of cash acquired (paid in 2022) ​ ​ ​ ​ ​ ​ ​ € 104,571 ​ ​ ​ ​ ​ ​ ​ ​ 10,698 ​ € 115,270 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash used in operating activities for other liabilities related to the acquisition of subsidiaries (2022) ​ ​ ​ ​ ​ ​ ​ € 28,164 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ € 28,164 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash out from acquisition of subsidiaries (payment of deferred consideration in 2023) ​ ​ ​ ​ ​ ​ ​ € 7,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ € 7,000 ​ As part of the acquisitions, we identified the following acquired intangible assets: ● IPR&D: in-process research and development related to two CD19 CAR-T product candidates in Phase 1/2a clinical studies. The fair value at acquisition date ( €28.2 million) was based on the relief from royalty method. ● Exclusive rights: through the acquisition of Cellpoint we acquired on the one hand a collaboration agreement between Cellpoint and Lonza providing the exclusive right to use the automated Lonza Cocoon® Platform in the development and commercialization of CAR-T cell products, and secondly, a collaboration agreement between Cellpoint and Hypertrust providing exclusivity to use the jointly developed XCellit ® software for workflow management and monitoring for the manufacturing of the CAR-T cells using the Lonza Cocoons® Platform. The fair values at acquisition date amounted to €89.7 million and €2.6 million respectively. A with and without method was retained to value the exclusivity with Lonza and the XCellit ® software was valued based on the applicable royalty rate in the contract. ● Technology: through the acquisition of AboundBio, we acquired a fully human antibody-based therapeutics platform which was valued at €4.1 million at the time of acquisition. We assessed that the carrying value of all other acquired assets and assumed liabilities approximate their fair value at acquisition date. The goodwill arising from both transactions totaling €69.8 million was attributable to buyer specific synergies, the value of the assembled workforce and the accounting for net deferred tax liabilities for a total amount of €23.3 million, consisting of deferred tax liabilities on the acquired intangible assets of €32.3 million less recognized deferred tax assets of €9.0 million. The acquisition costs related to both transactions were considered not to be material and were recognized in our consolidated income statement on the line "general & administrative expenses”.

Details of the NovAlix transact

Details of the NovAlix transaction	12 Months Ended
	Dec. 31, 2023
Details of the NovAlix transaction
Details of the NovAlix transaction	28. Details of the NovAlix transaction We completed the integrated drug discovery collaboration transaction with NovAliX on June 30, 2023, effective as from July 1, 2023. Under the terms of the agreement, Galapagos’ drug discovery and research activities conducted in Romainville, France, and Galapagos’ employees in Romainville, which are exclusively dedicated to the operation of these activities, were transferred to NovAliX who will assume all ongoing research and discovery activities in Romainville, and this for no consideration. In return, Galapagos is committed to utilizing the research capabilities and expertise of NovAliX through a five year -collaboration and within the context of the company’s R&D portfolio, resulting in a total commitment of €73.8 million on June 30, 2023 ( €63.9 million on December 31, 2023). The collaboration agreement and sale and purchase agreement were negotiated as a package with one single commercial objective and with an agreed consideration for the transaction as a whole. The impact of the transfer of activities and personnel (reference is made to the table below) was treated as an advance for future services to be obtained from NovaliX throughout the five years collaboration. This advance will gradually be released through profit or loss, in line with the purchase commitment towards NovAliX over the five year period of the collaboration between us and NovAliX. The part still to be released on December 31, 2023 has been presented in the statement of financial position as other current asset ( €2.7 million) and other non-current asset ( €5.6 million). ​ ​ ​ ​ ​ ​ June 30, ​ 2023 ​ ​ (Euro, in thousands) ​ ​ ​ ​ Loss on sale of fixed assets ​ € 12,506 Result of transfer of retirement benefit liability ​ ​ (3,022) Result of transfer of right-of-use asset ​ ​ 174 Advance related to the NovAliX transaction ​ € 9,658 ​ Furthermore we made an upfront payment to NovAliX of €8.3 million on closing of the transaction which is a prepayment for the future purchase commitment for the following five years . The remaining part has been presented in our statement of financial position on December 31, 2023 as other current asset ( €2.4 million) and other non-current asset ( €4.7 million).

Note to the cash flow statement

Note to the cash flow statement	12 Months Ended
	Dec. 31, 2023
Consolidated Statement of Cash Flows
Note to the cash flow statement	29. Note to the cash flow statement The following table details the adjustments related to the operating cash flow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 ​ ​ (Euro, in thousands) Adjustment for non-cash transactions ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and impairment ​ € 43,642 ​ € 65,566 ​ € 34,636 Share-based compensation expenses ​ ​ 56,718 ​ ​ 88,506 ​ ​ 70,726 Increase/decrease (-) in retirement benefit obligations and provisions ​ ​ 11 ​ ​ 136 ​ ​ (2,347) Unrealized exchange losses/gains (-) and non-cash other financial result ​ ​ 19,908 ​ ​ (41,970) ​ ​ (57,073) Discounting effect of non-current deferred income ​ ​ (645) ​ ​ 7,672 ​ ​ 9,289 Discounting effect of other non-current liabilities ​ ​ (318) ​ ​ 2,271 ​ ​ — Fair value re-measurement of warrants ​ ​ (18) ​ ​ (186) ​ ​ (2,960) Net change in fair value of current financial investments ​ ​ (22,690) ​ ​ (6,929) ​ ​ (119) Fair value adjustment financial assets held at fair value through profit or loss ​ ​ 390 ​ ​ — ​ ​ 4,919 Other non-cash expenses ​ ​ 2,292 ​ ​ 2,229 ​ ​ 648 Total adjustment for non-cash transactions ​ € 99,291 ​ € 117,296 ​ € 57,718 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Adjustment for items to disclose separately under operating cash flow ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest expense ​ € 1,867 ​ € 6,967 ​ € 11,656 Interest income ​ ​ (79,319) ​ ​ (14,344) ​ ​ (2,853) Tax expense ​ ​ 11,689 ​ ​ 2,844 ​ ​ 2,423 Total adjustment for items to disclose separately under operating cash flow ​ € (65,763) ​ € (4,533) ​ € 11,227 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Adjustment for items to disclose under investing and financing cash flows ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain on disposal of subsidiaries ​ € — ​ € — ​ € (22,191) Gain on sale of fixed assets ​ ​ (1,091) ​ ​ (23) ​ ​ — Realized exchange gain on sale of current financial investments ​ ​ — ​ ​ — ​ ​ (6,645) Investment income related to current financial investments ​ ​ (15,597) ​ ​ (3,766) ​ ​ (12) Total adjustment for items to disclose separately under investing and financing cash flow ​ € (16,688) ​ € (3,789) ​ € (28,847) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Change in working capital other than deferred income ​ ​ ​ ​ ​ ​ ​ ​ ​ Increase in inventories ​ € (24,076) ​ € (34,588) ​ € (21,168) Increase (-)/ decrease in receivables ​ ​ (39,114) ​ ​ 68,984 ​ ​ 79,859 Increase/decrease (-) in liabilities ​ ​ 31,817 ​ ​ (2,083) ​ ​ (35,353) Total change in working capital other than deferred income ​ € (31,373) ​ € 32,313 ​ € 23,337 ​

Off-balance sheet arrangements

Off-balance sheet arrangements	12 Months Ended
	Dec. 31, 2023
Off-balance sheet arrangements
Off-balance sheet arrangements	30. Off-balance sheet arrangements CONTRACTUAL OBLIGATIONS AND COMMITMENTS On December 31, 2023, we had outstanding obligations for future purchase commitments, which become due as ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years ​ ​ ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Purchase commitments ​ € 408,521 ​ € 237,495 ​ ​ 143,532 ​ ​ 25,768 ​ ​ 1,727 ​ ​ On December 31, 2022, we had outstanding obligations for future purchase commitments, which become due as ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years ​ ​ ​ ​ (Euro, in thousands) ​ ​ Purchase commitments ​ € 398,627 ​ € 240,237 ​ € 136,560 ​ € 20,797 ​ € 1,032 ​ Our purchase commitments at the end of the year 2023 included €239.6 million related to projects in development phase (2022: €243.6 million), €79.0 million for projects in discovery research phase (2022: €20.9 million), €45.9 million for shared services (2022: €49.4 million), €29.9 million for commercial and medical affairs (2022: €36.0 million), and €14.2 million related to Jyseleca® product supply chain (2022: €48.8 million). At year end 2023, our purchase commitments towards NovAliX amounted to €63.9 million and were included in the €79.0 million related to discovery research. We refer to notes 2 and 28 for more information about the transaction with NovAliX. At the end of the year 2023, €139.1 million of our purchase commitments related to the Jyseleca® discontinued operations transferred to Alfasigma on January 31, 2024, in which €110.8 million related to the filgotinib clinical development and €21.2 million related to commercial and medical affairs activities. At the end of the year 2023, we have remaining short-term contractual cost sharing obligations related to the termination of our collaboration agreement with Gilead for filgotinib, before its transfer to Alfasigma, amounting to €12.3 million. We entered into a license agreement with another pharmaceutical company. Under the terms of this agreement we have the obligation to pay potential milestones, which are dependent on successful completion of certain development and commercial milestones, as detailed in the agreement. At December 31, 2023 this commitment amounts to €243.5 million on an undiscounted and non-risk adjusted basis. This amount represents the maximum amount that would be paid if all milestones would be achieved but excludes variable royalty payments based on unit sales.

Share based payments

Share based payments	12 Months Ended
	Dec. 31, 2023
Share based payments
Share based payments	31. Share based payments SUBSCRIPTION RIGHT PLANS Presented below is a summary of subscription right activities for the reported periods. Various subscription right plans were approved for the benefit of our employees, and for members of the Executive Committee and of the Board of Directors and independent consultants of Galapagos NV. The subscription rights offered to members of the Board of Directors vest over a period of 36 months at a rate of 1/36 th On May 5, 2023 the Board of Directors issued “Subscription Right Plan 2023 BE”, “Subscription Right Plan 2023 RMV” and “Subscription Right Plan 2032 ROW”, for a total of 1,538,400 subscription rights (after acceptance by the beneficiaries), within the framework of the authorized capital. Following table shows when a subscription right becomes exercisable, per issued plan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Subscription right exercisable as from: ​ Cliff vesting ​ Graded vesting ​ ​ ​ First tranche of 25% ​ Second tranche of 25% ​ Third tranche of 50% Subscription right plans before 2021 ​ First day after end of third calenderyear following the grant ​ — ​ — ​ — Subscription right plan 2021BE ​ First day after end of third calenderyear following the grant ​ — ​ — ​ — Subscription right plan 2021RMV and ROW ​ — ​ January 1, 2023 ​ January 1, 2024 ​ January 1, 2025 Subscription right plan 2022 (A) ​ — ​ January 1, 2023 ​ January 1, 2024 ​ January 1, 2025 Subscription right plan 2022 (B) ​ January 1, 2026 ​ — ​ — ​ — Subscription right plan 2022BE ​ January 1, 2026 ​ — ​ — ​ — Subscription right plan 2022RMV and ROW ​ — ​ January 1, 2024 ​ January 1, 2025 ​ January 1, 2026 Subscription right plan 2023BE ​ January 1, 2027 ​ — ​ — ​ — Subscription right plan 2023RMV and ROW ​ — ​ January 1, 2025 ​ January 1, 2026 ​ January 1, 2027 ​ In the event of a change of control over Galapagos NV, all outstanding subscription rights vest immediately and will be immediately exercisable. The table below sets forth a summary of subscription rights outstanding and exercisable at December 31, 2023, per subscription right plan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding ​ ​ ​ ​ Outstanding Exercisable ​ ​ ​ ​ ​ ​ ​ ​ per ​ Granted ​ Exercised ​ Forfeited ​ Expired ​ per ​ per ​ ​ Allocation ​ Expiry ​ Exercise ​ January 1, ​ during ​ during ​ during ​ during ​ December 31, ​ December 31, Subscription right plan ​ date ​ date ​ price (€) ​ 2023 ​ year ​ year ​ year ​ year ​ 2023 ​ 2023 2015 ​ 04/30/2015 ​ 04/29/2023 ​ 28.75 ​ 63,223 ​ ​ ​ (61,560) ​ (1,663) ​ ​ ​ — ​ — 2015 (B) ​ 12/22/2015 ​ 12/21/2023 ​ 49.00 ​ 241,500 ​ ​ ​ ​ ​ ​ ​ (241,500) ​ — ​ — 2015 RMV ​ 12/22/2015 ​ 12/21/2023 ​ 49.00 ​ 35,000 ​ ​ ​ ​ ​ ​ ​ (35,000) ​ — ​ — 2016 ​ 1/6/2016 ​ 05/31/2024 ​ 46.10 ​ 325,500 ​ ​ ​ ​ ​ ​ ​ ​ ​ 325,500 ​ 325,500 2016 RMV ​ 1/6/2016 ​ 05/31/2024 ​ 46.10 ​ 69,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 69,000 ​ 69,000 2016 (B) ​ 01/20/2017 ​ 01/19/2025 ​ 62.50 ​ 10,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 10,000 ​ 10,000 2017 ​ 05/17/2017 ​ 05/16/2025 ​ 80.57 ​ 590,000 ​ ​ ​ ​ ​ (5,000) ​ ​ ​ 585,000 ​ 585,000 2017 RMV ​ 05/17/2017 ​ 05/16/2025 ​ 80.57 ​ 127,500 ​ ​ ​ ​ ​ (5,000) ​ ​ ​ 122,500 ​ 122,500 2018 ​ 04/19/2018 ​ 04/18/2026 ​ 79.88 ​ 974,995 ​ ​ ​ ​ ​ (10,000) ​ ​ ​ 964,995 ​ 964,995 2018 RMV ​ 04/19/2018 ​ 04/18/2026 ​ 79.88 ​ 137,500 ​ ​ ​ ​ ​ (5,000) ​ ​ ​ 132,500 ​ 132,500 2019 ​ 10/4/2019 ​ 9/4/2027 ​ 95.11 ​ 1,216,990 ​ ​ ​ ​ ​ (8,750) ​ ​ ​ 1,208,240 ​ 1,208,240 2019 RMV ​ 10/4/2019 ​ 9/4/2027 ​ 95.11 ​ 186,000 ​ ​ ​ ​ ​ (8,750) ​ ​ ​ 177,250 ​ 177,250 2020 ​ 04/17/2020 ​ 04/16/2028 ​ 168.42 ​ 1,458,244 ​ ​ ​ ​ ​ (88,627) ​ ​ ​ 1,369,617 ​ 1,317,779 2020RMV ​ 04/17/2020 ​ 04/16/2028 ​ 168.42 ​ 209,075 ​ ​ ​ ​ ​ (15,775) ​ ​ ​ 193,300 ​ 193,300 2021BE ​ 04/30/2021 ​ 04/29/2029 ​ 64.76 ​ 1,041,148 ​ ​ ​ ​ ​ (8,542) ​ ​ ​ 1,032,606 ​ ​ 2021RMV ​ 04/30/2021 ​ 04/29/2029 ​ 64.76 ​ 257,700 ​ ​ ​ ​ ​ (31,404) ​ ​ ​ 226,296 ​ 117,030 2021ROW ​ 04/30/2021 ​ 04/29/2029 ​ 64.76 ​ 783,375 ​ ​ ​ ​ ​ (115,879) ​ ​ ​ 667,496 ​ 356,418 2022 (A) ​ 01/13/2022 ​ 12/1/2030 ​ 46.18 ​ 30,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 30,000 ​ 15,000 2022 (B) ​ 01/26/2022 ​ 01/25/2030 ​ 50.00 ​ 1,000,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 1,000,000 ​ ​ 2022BE ​ 6/5/2022 ​ 5/5/2030 ​ 57.46 ​ 831,542 ​ ​ ​ ​ ​ (13,714) ​ ​ ​ 817,828 ​ ​ 2022BE ​ 5/8/2022 ​ 5/5/2030 ​ 51.58 ​ 78,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 78,000 ​ ​ 2022RMV ​ 6/5/2022 ​ 5/5/2030 ​ 57.46 ​ 242,714 ​ ​ ​ ​ ​ (39,250) ​ ​ ​ 203,464 ​ 50,770 2022ROW ​ 6/5/2022 ​ 5/5/2030 ​ 57.46 ​ 847,850 ​ ​ ​ ​ ​ (142,350) ​ ​ ​ 705,500 ​ 176,256 2022ROW ​ 5/8/2022 ​ 4/8/2030 ​ 51.58 ​ 60,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 60,000 ​ 15,000 2023BE ​ 5/5/2023 ​ 4/5/2031 ​ 35.11 ​ — ​ 611,000 ​ ​ ​ (1,972) ​ ​ ​ 609,028 ​ ​ 2023RMV ​ 5/5/2023 ​ 4/5/2031 ​ 35.11 ​ — ​ 110,000 ​ ​ ​ (7,500) ​ ​ ​ 102,500 ​ ​ 2023ROW ​ 5/5/2023 ​ 4/5/2031 ​ 35.11 ​ — ​ 597,400 ​ ​ ​ (35,500) ​ ​ ​ 561,900 ​ ​ 2023BE ​ 06/15/2023 ​ 06/14/2031 ​ 38.58 ​ — ​ 200,000 ​ ​ ​ ​ ​ ​ ​ 200,000 ​ ​ 2023ROW ​ 11/17/2023 ​ 4/5/2031 ​ 32.99 ​ — ​ 20,000 ​ ​ ​ ​ ​ ​ ​ 20,000 ​ ​ Total ​ ​ ​ ​ ​ ​ ​ 10,816,856 ​ 1,538,400 ​ (61,560) ​ (544,676) ​ (276,500) ​ 11,472,520 ​ 5,836,538 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ average ​ ​ ​ ​ ​ exercise ​ ​ ​ Subscription rights ​ price (Euro) Outstanding on January 1, 2021 ​ ​ 6,929,111 ​ € 103.95 Exercisable on December 31, 2020 ​ ​ 1,168,967 ​ ​ 37.84 ​ ​ ​ ​ ​ ​ ​ Granted during the period ​ ​ 2,493,433 ​ ​ 64.76 Forfeited during the year ​ ​ (701,753) ​ ​ 118.53 Exercised during the period ​ ​ (140,954) ​ ​ 23.51 Expired during the year ​ ​ — ​ ​ — Outstanding on December 31, 2021 ​ ​ 8,579,837 ​ € 92.69 Exercisable on December 31, 2021 ​ ​ 1,751,013 ​ ​ 56.64 ​ ​ ​ ​ ​ ​ ​ Granted during the period ​ ​ 3,127,239 ​ ​ 54.71 Forfeited during the year ​ ​ (607,430) ​ ​ 100.00 Exercised during the period ​ ​ (282,790) ​ ​ 23.68 Expired during the year ​ ​ — ​ ​ — Outstanding on December 31, 2022 ​ ​ 10,816,856 ​ € 83.12 Exercisable on December 31, 2022 ​ ​ 2,574,218 ​ ​ 70.26 ​ ​ ​ ​ ​ ​ ​ Granted during the period ​ ​ 1,538,400 ​ ​ 35.53 Forfeited during the year ​ ​ (544,676) ​ ​ 80.31 Exercised during the period ​ ​ (61,560) ​ ​ 28.75 Expired during the year ​ ​ (276,500) ​ ​ 49.00 Outstanding on December 31, 2023 ​ ​ 11,472,520 ​ € 77.93 Exercisable on December 31, 2023 ​ ​ 5,836,538 ​ ​ 101.93 ​ The table below sets forth the inputs into the valuation of the subscription rights. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023BE 2023RMV/ROW ​ ​ 2022 (A) 2022 (B) ​ ​ ​ ​ ​ ​ ​ May 5 & June 15 ​ May 5 & November 17 ​ ​ ​ January 13 ​ January 26 ​ ​ ​ ​ ​ ​ Weighted average exercise price (€) ​ € 35.97 ​ € 35.05 ​ ​ ​ ​ € 46.18 ​ € 50.00 ​ ​ ​ ​ ​ ​ Weighted average share price at acceptance date (€) ​ € 38.53 ​ € 38.63 ​ ​ ​ ​ € 46.21 ​ € 56.67 ​ ​ ​ ​ ​ ​ Weighted average fair value at the acceptance date (€) ​ € 16.61 ​ € 15.96 ​ ​ ​ ​ € 16.10 ​ € 24.53 ​ ​ ​ ​ ​ ​ Weighted average estimated volatility (%) ​ ​ 36.89 ​ ​ 36.67 ​ ​ ​ ​ ​ 41.80 ​ ​ 40.80 ​ ​ ​ ​ ​ ​ Weighted average expected life of the subscription rights (years) ​ ​ 6.14 ​ ​ 5.38 ​ ​ ​ ​ ​ 4.72 ​ ​ 5.95 ​ ​ ​ ​ ​ ​ Weighted average risk free rate (%) ​ ​ 2.77 ​ ​ 2.74 ​ ​ ​ ​ ​ (0.13) ​ ​ 0.67 ​ ​ ​ ​ ​ ​ Expected dividends ​ ​ None ​ ​ None ​ ​ ​ ​ ​ None ​ ​ None ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022BE ​ 2022 RMV/ROW ​ 2022BE/ROW ​ 2021 ​ 2021 RMV/ROW ​ ​ ​ ​ ​ ​ ​ ​ May 6 ​ May 6 ​ August 6 April 30 ​ April 30 ​ ​ ​ ​ ​ ​ Exercise Price (€) ​ € 57.46 ​ € 57.46 ​ € 51.58 ​ € 64.76 ​ € 64.76 ​ ​ ​ ​ ​ ​ Weighted average share price at acceptance date (€) ​ € 51.64 ​ € 51.64 ​ € 44.55 ​ € 61.10 ​ € 61.10 ​ ​ ​ ​ ​ ​ Weighted average fair value at the acceptance date (€) ​ € 20.73 ​ € 18.92 ​ € 17.07 ​ € 22.72 ​ € 20.68 ​ ​ ​ ​ ​ ​ Weighted average estimated volatility (%) ​ ​ 42.59 ​ ​ 42.65 ​ ​ 41.75 ​ ​ 40.73 ​ ​ 40.61 ​ ​ ​ ​ ​ ​ Weighted average expected life of the subscription rights (years) ​ ​ 6.37 ​ ​ 5.36 ​ ​ 5.68 ​ ​ 6.43 ​ ​ 5.36 ​ ​ ​ ​ ​ ​ Weighted average risk free rate (%) ​ ​ 1.33 ​ ​ 1.26 ​ ​ 2.70 ​ ​ (0.21) ​ ​ (0.29) ​ ​ ​ ​ ​ ​ Expected dividends ​ ​ None ​ ​ None ​ ​ None ​ ​ None ​ ​ None ​ ​ ​ ​ ​ ​ ​ Subscription right Plans The exercise price of the subscription rights is determined pursuant to the applicable provisions of the Belgian Law of March 26, 1999. The weighted average estimated volatility is calculated on the basis of the implied volatility of the share price over the weighted average expected life of the subscription rights. The weighted average expected life of the subscription right is calculated as the estimated duration until exercise, taking into account the specific features of the plans. Our share based compensation expense in 2023 in relation to subscription right plans amounted to €56,718 thousand (2022: €88,506 thousand; 2021: €70,726 thousand), of which €36.628 €62.003 €52.131 €20.090 €26.503 €18.595 The following table provides an overview of the outstanding subscription rights per category of subscription right holders at December 31, 2023, 2022 and 2021. Category ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 (1) ​ ​ (in number of subscription rights) Members of the Board of Directors ​ ​ 7,500 ​ ​ 75,000 ​ ​ 157,560 Members of the Executive Committee ​ ​ 1,670,500 ​ ​ 1,864,000 ​ ​ 1,965,000 Personnel ​ ​ 9,794,520 ​ ​ 8,877,856 ​ ​ 6,457,277 Total subscription rights outstanding ​ ​ 11,472,520 ​ ​ 10,816,856 ​ ​ 8,579,837 ​ The outstanding subscription rights at the end of the accounting period have an average exercise price of €77.93 (2022: €83.10; 2021: €92.69) and a weighted average remaining expected life of 1,728 days 1,914 days 1,955 days RESTRICTED STOCK UNITS RSUs Each RSU represents the right to receive, at Galapagos’ discretion, one Galapagos share or a payment in cash of an amount equivalent to the volume-weighted average price of the Galapagos share on Euronext Brussels over the 30-calendar day period preceding the relevant vesting date, in accordance with the terms and conditions of the relevant RSU program. We currently have the following restricted stock unit (RSU) programs: ● Plan 2020.I, Plan 2021.I and Plan 2022.I and Plan 2023.1: these plans are intended to provide a long-term incentive to certain of our employees and members of the Executive Committee; ● Plan 2020.II, Plan 2021.II, Plan 2021.IV, Plan 2022.II and Plan 2023.II: these plans are designed with the aim to retain a specific group of our key employees and members of the Executive Committee whose retention is considered so important for our future performance that an additional incentive is desired. The beneficiaries are nominated by the Remuneration Committee and the Board of Directors approves the list of beneficiaries. The four-year vesting period is designed to be aligned with long-term shareholder interests; ● Plan 2021.III and Plan 2022.III: these plans are intended to compensate employees who transferred from Gilead to us in the framework of the transfer of European commercialization rights for the long-term incentive plans within Gilead under which unvested RSU awards lapsed upon transfer out of the Gilead group. These employees received a one-time Restricted Stock Units grant from us. The main characteristics of all these plans are as follows: ● the RSUs are offered for no consideration; ● generally four-year vesting period, with 25% vesting each year, except for some plans or some beneficiaries for which the RSUs will all vest at the same time three years after the offer date (bullet vesting); vest 50% after two years and 50% after three years or vest over three years with 34% vesting the first year and 33% in each of the remaining two years ; ● payout will be in cash or shares, at Galapagos’ discretion, it being understood that in respect of members of the Executive Committee, any vesting prior to the third anniversary of the offer date will always give rise to a payment in cash rather than a delivery of shares as an incentive; ● any unvested RSUs are forfeited upon termination of service before the vesting date . The table below sets forth a summary of RSUs outstanding at December 31, 2023, per RSU plan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding ​ ​ ​ Outstanding ​ ​ ​ ​ per ​ Granted ​ Forfeited ​ Paid in cash ​ per ​ ​ Offer ​ January 1, ​ during ​ during ​ during ​ December 31, RSU plan ​ date ​ 2023 ​ year ​ year ​ year ​ 2023 Plan 2019.II. ​ 10/16/2019 ​ 12,931 ​ ​ ​ (768) ​ (12,163) ​ — Plan 2020.I. ​ 06/05/2020 ​ 17,110 ​ ​ ​ (2,558) ​ (9,361) ​ 5,191 Plan 2020.II. ​ 07/05/2020 ​ 17,626 ​ ​ ​ (6,530) ​ (8,335) ​ 2,761 Plan 2021.I. ​ 05/05/2021 ​ 92,600 ​ ​ ​ (23,150) ​ (26,621) ​ 42,829 Plan 2021.II. ​ 05/06/2021 ​ 22,341 ​ ​ ​ (7,447) ​ (5,416) ​ 9,478 Plan 2021.III. ​ 06/03/2021 ​ 16,259 ​ ​ ​ (2,636) ​ (8,207) ​ 5,416 Plan 2021.IV. ​ 09/24/2021 ​ 101,838 ​ ​ ​ (52,462) ​ (33,946) ​ 15,430 Plan 2022.I. ​ 03/05/2022 ​ 194,638 ​ ​ ​ (49,844) ​ (41,486) ​ 103,308 Plan 2022.II. ​ 5/05/2022 - 5/08/2022 ​ 249,000 ​ ​ ​ (83,602) ​ (59,270) ​ 106,128 Plan 2022.III. ​ 07/06/2022 ​ 11,752 ​ ​ ​ (349) ​ (5,873) ​ 5,530 Plan 2023.I. ​ 08/05/2023 ​ ​ ​ 401,962 ​ (35,380) ​ ​ ​ 366,582 Plan 2023.II. ​ 9/05/2023 - 15/06/2023 - 17/11/2023 ​ ​ ​ 518,548 ​ (5,748) ​ ​ ​ 512,800 Total ​ ​ ​ 736,095 ​ 920,510 ​ (270,474) ​ (210,678) ​ 1,175,453 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 ​ 2021 ​ ​ ​ (in number of RSUs) Outstanding on January 1, ​ ​ 736,095 ​ ​ 657,803 ​ ​ 313,596 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Granted during the year ​ ​ 920,510 ​ ​ 470,273 ​ ​ 511,518 Forfeited during the year ​ ​ (270,474) ​ ​ (172,885) ​ ​ (74,873) Paid in cash during the year ​ ​ (210,678) ​ ​ (219,096) ​ ​ (92,438) Outstanding on December 31, ​ ​ 1,175,453 ​ ​ 736,095 ​ ​ 657,803 ​ The RSUs are measured based on the volume-weighted average price of the Galapagos share on Euronext Brussels over the 30-calendar day period preceding the reporting period and they are re-measured at each reporting date. We recognize the corresponding expense and liability over the vesting period. The total liability relating to outstanding RSUs on December 31, 2023 amounted to €13.8 million (2022: €12.9 million, 2021: €11.3 million). The following table provides an overview of the outstanding RSUs per category of RSU holders on December 31, 2023, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 ​ ​ (in number of RSUs) Members of the Executive Committee ​ ​ 438,738 ​ ​ 332,038 ​ ​ 384,340 Personnel ​ ​ 736,715 ​ ​ 404,057 ​ ​ 273,463 Total outstanding RSUs ​ ​ 1,175,453 ​ ​ 736,095 ​ ​ 657,803 ​

Related parties

Related parties	12 Months Ended
	Dec. 31, 2023
Related parties
Related parties	32. Related parties Relationship and transactions with entities with control of, or significant influence over, Galapagos Gilead Gilead exercises significant influence over Galapagos as from the equity subscription on August 23, 2019. As a result of the equity subscription we received a transparency notification from Gilead on August 28, 2019 confirming they held 22.04% of the then issued and outstanding shares of Galapagos. By exercising Warrant A on November 6, 2019 Gilead increased its ownership in Galapagos to 25.10% of the then outstanding shares. Gilead further increased its ownership to 25.84% at December 31, 2019. Gilead’s ownership then diluted to 25.38% at December 31, 2022 and to 25.35% at December 31, 2023, due to four capital increases resulting from the exercise of subscription rights under employee subscription right plans in the course of respectively 2022 (three capital increases) and 2023 (one capital increase). The presumption of significant influence is also confirmed by the fact that Gilead has the right, for as long as it holds more than 20% of Galapagos’ share capital, to appoint two Investor Board Designees to Galapagos’ Board of Directors, out of a total of nine. The following table details our relation with Gilead: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 2022 ​ 2021 ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Trade and other receivables (1) ​ € 5,198 ​ € 7,877 ​ € 88,246 Trade and other payables ​ ​ 585 ​ ​ ​ ​ € 11,580 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2023 2022 ​ 2021 ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues recognized related to the performance obligation for the drug discovery platform ​ € 230,242 ​ € 230,423 ​ € 230,582 Revenues recognized related to the filgotinib performance obligation (2) ​ ​ 429,439 ​ ​ 174,432 ​ ​ 235,709 Royalty income related to the commercialization of filgotinib ​ ​ 9,466 ​ ​ 10,726 ​ ​ 3,757 Cost reimbursements related to the development of GLPG1690 (3) ​ ​ 299 ​ ​ 411 ​ ​ 18,055 Cross charges from and to Gilead relating to filgotinib (4) ​ ​ 3,643 ​ ​ (2,374) ​ ​ (81,334) Costs (-)/deduction of costs relating to our 50/50 profit/(cost) share mechanism (5) ​ ​ ​ ​ ​ ​ ​ ​ ​ included in sales and marketing expenses ​ ​ — ​ ​ 31 ​ ​ 59,699 included in research and development expenditure ​ ​ — ​ ​ (31) ​ ​ 7,026 Purchase of raw materials, semi-finished products and finished products of Jyseleca ​ € — ​ € 13,539 ​ € 24,867 ​ (1) Consisting on December 31, 2023 of filgotinib development cost sharing receivables of €2.5 million and royalties receivables of €2.4 million, consisting on December 31, 2022 of filgotinib development cost sharing receivables of €5.1 million and royalties receivables of €2.6 million, consisting on December 31, 2021 of €50 million receivables relating to the in 2020 modified collaboration for filgotinib, €12.6 million related to the transfer of the DIVERSITY trial from Gilead to us, and €23.8 million of filgotinib profit and cost sharing receivables (all paid in 2022). (2) Upfront and milestone payments recognized in accordance with the percentage of completion of the underlying obligation. (3) Shown as decrease of research and development expenditure. (4) Net amount shown as an (increase)/decrease of research and development expenditure (5) Profit/cost share mechanism came to an end beginning of 2022. As at December 31, 2023 we have two outstanding performance obligations under IFRS 15 towards Gilead, being the performance obligation related to our drug discovery platform and the performance obligation relating to filgotinib before its transfer to Alfasigma on January 31, 2024, following the closing of the transaction for the transfer of the Jyseleca® business. This results in an outstanding deferred income balance of €1.3 billion for the drug discovery platform (including the warrant issuance liability relating to subsequent warrant B) and €26.3 million for the performance obligation relating to filgotinib. A detailed explanation of our transactions with Gilead in 2021, 2022 and 2023 can be found in the section titled Agreements with major Galapagos NV shareholders. There are no other shareholders or other entities who, solely or jointly, control Galapagos or exercise significant influence over Galapagos. Relationship and transactions with subsidiaries Please see note 33 for an overview of the consolidated companies of the group, which are all wholly-owned subsidiaries of Galapagos NV. Relationship and transactions with key management personnel Our key management personnel consists of the members of the Executive Committee and members of the Board of Directors. All amounts mentioned in this section are based on expenses recognized in the financial statements for the relevant financial year. Remuneration of key management personnel On December 31, 2023, our Board of Directors consisted of nine members: Stoffels IMC BV (permanently represented by Dr. Paul Stoffels), Mr. Simon Sturge, Dr. Susanne Schaffert, , Mr. Peter Guenter, Mr. Daniel O’Day, Dr. Linda Higgins, Dr. Elisabeth Svanberg, Mr. Jérôme Contamine and Dr. Dan Baker. During its meeting of June 12, 2023, the Board of Directors appointed Dr. Susanne Schaffert by cooptation as a non-executive independent Director, replacing Dr. Rajesh Parekh who stepped down on June 10, 2023. During its meeting of September 19, 2023, the Board of Directors appointed Mr. Simon Sturge by cooptation as a non-executive independent Director, replacing Dr. Mary Kerr who stepped down on September 18, 2023. Dr. Susanne Schaffert’s and Mr. Simon Sturge’s appointments will be submitted for confirmation to the Company’s Annual Shareholders’ Meeting which will be held on April 30, 2024. Effective from January 1, 2020, Galapagos no longer grants any subscription rights to members of the Board of Directors, taking into account the stricter rules of the Belgian Companies Code. Prior to 2020, Board members were granted subscription rights. Effective from April 26, 2022, our new CEO, Stoffels IMC BV, permanently represented by Dr. Paul Stoffels, has been appointed as the Chair of the Board of Directors of Galapagos. The CEO will only be remunerated for the performance of its executive functions as CEO and is not entitled to any additional remuneration for its mandates of Chair of the Board of Directors or of any Committee. The remuneration package of the members of key management personnel comprises: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022 2021 Remuneration of key management personnel: ​ ​ ​ ​ ​ ​ Euro, in thousands (except for the number of subscription rights and RSUs) ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term benefits to executive Committee members as a group (1) ​ € 3,902 ​ € 3,444 ​ € 4,264 Board fees for members of the Board of Directors ​ ​ 749 ​ ​ 740 ​ ​ 750 Post-employment benefits (2) ​ ​ 209 ​ ​ 240 ​ ​ 399 Severance package (3) ​ ​ 3,150 ​ ​ — ​ ​ 802 Subscription rights granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of subscription rights granted in the year to Executive Committee members as a group ​ ​ 325,000 ​ ​ 1,124,000 ​ ​ 275,000 Total cost of subscription rights granted in the year under IFRS 2 ​ € 5,163 ​ € 27,010 ​ € 5,629 Number of RSUs granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Total number of RSUs granted in the year to Executive Committee members as a group (1)(4) ​ ​ 331,066 ​ ​ 200,478 ​ ​ 254,560 (1) Dr. Wigerinck was a member of the Executive Committee (formerly Management Board) until November 30, 2021. His remuneration and benefits are included in the overview for the financial year 2021. Mr. Onno Van de Stolpe was our CEO and Executive Committee member until March 31, 2022, Dr. Andre Hoekema was our CBO and Executive Committee member until October 31, 2022 and Dr. Walid Abi-Saab was our CMO and Executive Committee member until December 31, 2022. Their (prorated) remuneration and benefits are included in the overview for the financial years 2021 and 2022. Effective as of April 1, 2022, Stoffels IMC BV, permanently represented by Dr. Paul Stoffels, is our CEO and Chair of the Executive Committee. His (prorated) remuneration is included in the overview for the financial years 2022 and 2023. Mr. Bart Filius was a member of the Executive Committee until June 30, 2023 and Mr. Michele Manto was a member of the Executive Committee until December 31, 2023. Their (prorated) remuneration and benefits are included in the overview for the financial years 2021, 2022 and 2023. Ms. Valeria Cnossen and Ms. Annelies Missotten were members of the Executive Committee as of January 1, 2023. Mr. Thad Huston was a member of the Executive Committee as of July 1, 2023. Their (prorated) remuneration and benefits are included in the overview for the financial year 2023. (2) (3) (4) ​ OTHER No loans, quasi-loans or other guarantees were given by Galapagos NV or any of its subsidiaries to members of the Board of Directors and of the Executive Committee. We have not entered into transactions with our key management personnel, other than as described above with respect to remuneration arrangements relating to the exercise or termination of their mandates as members of the Executive Committee and the Board of Directors.

Consolidated companies as of De

Consolidated companies as of December 31, 2023	12 Months Ended
	Dec. 31, 2023
Consolidated companies as of December 31, 2023
Consolidated companies as of December 31, 2023	33. Consolidated companies as of December 31, 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ ​ ​ 2023 ​ 2022 ​ 2021 Name of the subsidiary Country % voting right Galapagos NV (directly or indirectly through subsidiaries) Change in % voting right previous period (2023 vs 2022) % voting right Galapagos NV (directly or indirectly through subsidiaries) % voting right Galapagos NV (directly or indirectly through subsidiaries) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CONTINUING OPERATIONS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Glpg US Inc. (formerly AboundBio Inc.) ​ United States ​ 100% ​ ​ ​ 100% ​ 0% CellPoint B.V. (till 30/11/2023) ​ The Netherlands ​ 100% ​ ​ ​ 100% ​ 0% Galapagos B.V. (merged with CellPoint B.V.) ​ The Netherlands ​ 100% ​ ​ ​ 100% ​ 100% Galapagos GmbH ​ Switzerland ​ 100% ​ ​ ​ 100% ​ 100% Glpg US Holding Inc. (formerly Galapagos, Inc.) ​ United States ​ 100% ​ ​ ​ 100% ​ 100% Galapagos NV ​ Belgium ​ Parent company ​ ​ ​ Parent company ​ Parent company Galapagos Real Estate Belgium BV (former Galapagos Real Estate 1 BV) ​ Belgium ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Real Estate Netherlands B.V. ​ The Netherlands ​ 100% ​ ​ ​ 100% ​ 100% Galapagos SASU ​ France ​ 100% ​ ​ ​ 100% ​ 100% Xenometrix, Inc. in liquidation ​ United States ​ 100% ​ ​ ​ 100% ​ 100% ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ DISCONTINUED OPERATIONS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Galapagos Biopharma Belgium BV ​ Belgium ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Netherlands B.V. ​ The Netherlands ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Spain S.L.U. ​ Spain ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Italy S.r.l. ​ Italy ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Germany GmbH ​ Germany ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Sweden AB ​ Sweden ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Norway AS ​ Norway ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Finland Oy ​ Finland ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Denmark ApS ​ Denmark ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Austria GmbH ​ Austria ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Ireland Ltd ​ Ireland ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biotech Ltd (formerly Inpharmatica Ltd.) ​ United Kingdom ​ 100% ​ ​ ​ 100% ​ 100% ​ There are no significant restrictions on the group’s ability to access or use assets and settle liabilities of one of the group’s subsidiaries.

Financial risk management

Financial risk management	12 Months Ended
	Dec. 31, 2023
Financial risk management
Financial risk management	34. Financial risk management Financial risk factors Our financial risks are managed centrally. Our finance department coordinates the access to national and international financial markets and considers and manages continuously the financial risks concerning our activities. These relate to the following financial markets risks: credit risk, liquidity risk, currency risk and interest rate risk. Our interest rate risk is limited because we have no financial debt. In case of decreasing interest rates we will face a reinvestment risk on our strong cash and cash equivalents and current financial investments balance. We do not buy or trade financial instruments for speculative purposes. Categories of financial assets and liabilities (the below table does not contain the financial assets and liabilities included in the disposal group held for sale – reference is made to note 5 for more information): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 2022 2021 Notes ​ ​ (Euro, in thousands) ​ Financial assets held at fair value through profit or loss ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Equity instruments ​ € 13,575 ​ ​ — ​ ​ — 16 Current financial investments ​ ​ 1,316,805 ​ ​ 1,292,514 ​ ​ 1,317,460 20 Financial assets at amortized cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current financial investments ​ ​ 2,200,893 ​ ​ 2,293,431 ​ ​ 1,152,349 20 Cash and cash equivalents ​ ​ 166,803 ​ ​ 508,117 ​ ​ 2,233,368 21 Restricted cash (current and non-current) ​ ​ 5,533 ​ ​ 4,569 ​ ​ 1,425 16 Other non-current assets ​ ​ 318 ​ ​ 1,209 ​ ​ 1,048 16 Trade receivables ​ ​ 17,494 ​ ​ 28,194 ​ ​ 91,786 19 Total financial assets ​ € 3,721,421 ​ € 4,128,033 ​ € 4,797,436 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Financial liabilities held at fair value through profit or loss ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current financial instruments ​ € — ​ € 19 ​ € 204 25 Current contingent consideration related to milestones CellPoint ​ ​ — ​ ​ 8,485 ​ ​ — 25 Non-current contingent consideration related to milestones CellPoint ​ ​ 20,972 ​ ​ 13,582 ​ ​ — 25 Financial liabilities at amortized cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Trade liabilities ​ ​ 87,966 ​ ​ 68,928 ​ ​ 84,519 25 Lease liabilities ​ ​ 9,596 ​ ​ 21,901 ​ ​ 26,859 24 Current deferred consideration payable CellPoint ​ ​ — ​ ​ 6,222 ​ ​ — 25 Total financial liabilities ​ € 118,534 ​ € 119,137 ​ € 111,582 ​ ​ The carrying amounts of trade and other payables and trade and other receivables are considered to be the same as their fair values, due to their short-term nature. Financial assets held at fair value through profit or loss Financial assets held at fair value through profit or loss consisted of an equity instrument of a non-listed companies and current financial investments . We have no restrictions on the sale of this equity instrument and the asset is not pledged under any of our liabilities. The fair value of the equity instrument in the non-listed company has been determined mainly by reference to the initial transaction price (classified as level 3 in the fair value hierarchy). Current financial investments include money market funds in EUR and USD, which all classify for level 1 fair value measurement. Liquidity risk Current financial investments and cash and cash equivalents amounted to €3,684.5 million on December 31, 2023. Management forecasts our liquidity requirements to ensure that we have sufficient cash to meet operational needs. We have no credit lines. Such forecasting is based on realistic assumptions with regards to product sales, royalties, milestone and upfront payments to be received, taking into account our past track record, including the assumption that not all new projects that are being planned will be realized. All our and cash and cash equivalents have only an insignificant liquidity risk as they are all convertible upon a maximum three month notice period and without incurring a significant penalty in normal market circumstances. Credit risk The term “credit risk” refers to the risk that counterparty will default on its contractual obligations resulting in financial loss for us. We grant credit to our clients in the framework of our normal business activities. Usually, we require no pledge or other collateral to cover the amounts due. All our receivables are considered collectable. We did not account for a provision for expected credit losses relating to our trade and other receivables given that there is no history of material credit losses, nor does forward looking information reveals any potential risks and due to the high quality nature of our customers. Aging balance of receivables that are due, but that are still considered collectable: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 ​ ​ (Euro, in thousands) 60 - 90 days ​ € 3 ​ € 424 ​ € 141 90 - 120 days ​ ​ 3 ​ ​ 208 ​ ​ 92 more than 120 days ​ € 117 ​ € 473 ​ € 113 ​ Our cash and cash equivalents are invested primarily in current, notice and term accounts. For banks and financial institutions, only independently rated parties with a minimum rating of ‘A’ are accepted at the beginning of the term. Our current financial investments are also kept within different financial institutions and include term deposits, money market funds and treasury bills with an AAA rating. Interest rate risk The only variable interest-bearing financial instruments are cash and cash equivalents and current financial investments. Changes in interest rates may cause variations in interest income and expenses resulting from short term interest-bearing assets. Management does not expect the short term interest rates to decrease significantly in the immediate foreseeable future, which limits the interest exposure on our cash and cash equivalents and current financial investments. Effect of interest rate fluctuation A 100 basis point increase in interest rates at balance sheet date would have increased profit or loss, and equity, by approximately €36.8 million (2022: €40.9 million; 2021: €47.0 million); a 100 basis point decrease in interest rates would have decreased profit or loss, and equity, by approximately €36.8 million (2022: €40.9 million; 2021: €47.0 million). Foreign exchange risk We are exposed to foreign exchange risk arising from various currency exposures. Our principal functional currency is euro, but we receive payments from our main collaboration partner Gilead in U.S. dollars and acquire some consumables and materials in U.S. dollars, Swiss Francs and GB Pounds. To limit this risk, we attempt to align incoming and outgoing cash flows in currencies other than EUR. In addition, contracts closed by our different entities are mainly in the functional currencies of that entity, except for the collaboration agreement signed with Gilead for which payments are denominated in U.S. dollars. The exchange rate risk in case of a 10% change in the exchange rate amounts to: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 Net book value ​ (Euro, in thousands) Increase in Euros - U.S. Dollars ​ € (78,013) ​ € (85,140) ​ € (83,996) Increase in Euros - GB Pounds ​ ​ 666 ​ ​ 960 ​ ​ 1,093 Increase in Euros - CH Francs ​ ​ 385 ​ ​ 557 ​ ​ 233 ​ The exchange rate risk on the U.S. dollar is primarily related to our cash and cash equivalents and current financial investments held in U.S dollars. Capital risk factors We manage our capital to safeguard that we will be able to continue as a going concern. At the same time, we want to ensure the return to our shareholders through the results from our research and development activities. Our capital structure consists of current financial investments, cash and cash equivalents, and equity attributed to the holders of our equity instruments, such as capital, reserves and results carried forward, as mentioned in the consolidated statement of changes in equity. We manage our capital structure and make the necessary adjustments in the light of changes of economic circumstances, the risk characteristics of underlying assets and the projected cash needs of the current research and development activities. The adequacy of the capital structure will depend on many factors, including scientific progress in the research and development programs, the magnitude of those programs, the commitments to existing and new clinical CROs, the ability to establish new alliance or collaboration agreements, the capital expenditures, the new commercial activities, market developments and any future acquisition. Neither Galapagos NV nor any of its subsidiaries are subject to any externally imposed capital requirements, other than those imposed by generally applicable company law requirements.

Auditor's remuneration

Auditor's remuneration	12 Months Ended
	Dec. 31, 2023
Auditor's remuneration
Auditor's remuneration	35. Auditor’s remuneration BDO Bedrijfsrevisoren BV (BDO) was appointed as statutory auditor by the Shareholders’ Meeting held on April 25, 2023, for a term of three years expiring immediately after the Annual Shareholders’ meeting to be held in 2026 which will have decided upon the annual accounts for the financial year to be ended on December 31, 2025. Deloitte Bedrijfsrevisoren BV (Deloitte) ceased to be our statutory auditor as of the date of the Annual Shareholders’ Meeting held on April 25, 2023. Our principal accountants billed the following fees to us for professional services rendered in 2023 (BDO) and 2022 (Deloitte). The statutory auditor’s fees for carrying out its mandate at group level amounted to €1,124.0 thousand in 2023 (2022: €1,127.1 thousand). The 2023 audit fee was €191.3 thousand higher compared to the fee that was approved by the Shareholders’ Meeting held on April 25, 2023 due to exceptional audit activities and special assignments performed by the statutory auditor. Audit-related fees, which generally the auditor provides, amounted to €20.2 thousand in 2023 (2022: €26.9 thousand). Other fees related to non-audit services executed by the statutory auditor amounted to €6.6 thousand in 2023 (2022: €nil) and related to ESG reporting. Other fees related to non-audit services executed by persons related to the statutory auditor amounted to €nil in 2023 (2022: €429.5 thousand and related to advisory services in relation to IT and quality management). Tax fees amounted to €68.0 thousand in 2023 (2022: €nil) and related to tax assistance relating to personal payroll taxes related to prior year filings. The Audit Committee and the Board of Directors are of the opinion that these non-audit services do not affect the independence of the statutory auditor in the performance of his audit. The abovementioned additional fees were fully approved by the Audit Committee in accordance with article 3:64 of the Belgian Code of Companies and Associations.

Events after balance sheet date

Events after balance sheet date	12 Months Ended
	Dec. 31, 2023
Events after balance sheet date
Events after balance sheet date	36. Events after balance sheet date On January 3, 2024, we signed a strategic collaboration and license agreement with BridGene Biosciences to further strengthen our growing early-stage oncology precision medicine pipeline. Under the terms of the agreement, BridGene will receive from us up to $27 million in upfront and preclinical research milestone payments and potentially over $700 million in clinical and commercial milestones, assuming success of the programs. In addition, BridGene will be entitled to receive single-digit tiered royalties on net sales of each product resulting from the collaboration. ​ On January 4, 2024, we announced that we entered into a strategic collaboration agreement with Thermo Fisher Scientific for CAR-T manufacturing and kitting services for our point-of-care CAR-T product candidate in the San Francisco area. Under the terms of the agreement, Thermo Fisher will provide GMP manufacturing as well as BioServices and Specialty Logistics for our CAR-T hemato-oncology clinical program in the San Francisco area, effective January 2024. We will initiate the technology transfer to enable Thermo Fisher’s manufacturing activities. ​ On January 31, 2024, we successfully completed the transaction with Alfasigma for the transfer of the Jyseleca® business after having met all closing conditions. As part of the transaction, the amended Filgotinib Agreement between us and Gilead has been assigned by us to Alfasigma. Alfasigma paid us an upfront payment of €50.0 million plus €13.2 million for cash and working capital subject to final settlement based on completion accounts. We are entitled to potential future sales-based milestone payments totaling €120 million and mid-single to mid-double-digit royalties on European sales. We will contribute up to €40 million to Alfasigma by June 2025 for Jyseleca® related development activities. ​ On January 31, 2024 we participated for $40.0 million in Series C financing round of Frontier Medicines, a pioneer in precision oncology with a unique technology platform and a pipeline of potential best-in-class assets that fit with our precision oncology R&D approach. The investment aligns with our innovation acceleration strategy to bring transformational medicines to patients around the world. ​ ​ ​

Significant accounting polici_2

Significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2023
Notes and other explanatory information [abstract]
Basis Of Presentation And Going Concern Assumption	BASIS OF PREPARATION AND GOING CONCERN ASSUMPTION The consolidated financial statements are prepared in accordance with the International Financial Reporting Standards (IFRS), issued by the International Accounting Standards Board (IASB) and the interpretations issued by the IASB’s International Financial Reporting Interpretation Committee. The consolidated financial statements provide a general overview of our activities and the results achieved. They give a true and fair view of our financial position, our financial performance and cash flows, on a going concern basis. The consolidated financial statements are presented in Euros, which is also our functional currency. Amounts are rounded to the nearest thousand, unless otherwise stated.
New Standards and Interpretations Applicable for the Annual Period	NEW STANDARDS AND INTERPRETATIONS APPLICABLE FOR THE ANNUAL PERIOD BEGINNING ON JANUARY 1, 2023 New standards and interpretations applicable for the annual period beginning on January 1, 2023 did not have a material impact on our consolidated financial statements except for the application of the amendments made to IAS 1 Disclosure of Accounting Policies. As a result of this amendment, we reassessed our accounting policies in order to remain with only the material accounting policies.
Business Combinations	BUSINESS COMBINATIONS Business combinations are accounted for using the acquisition method. In the statement of financial position, all identifiable assets, liabilities and contingent liabilities are initially recognized at their fair value at the acquisition date. The results of acquired operations are included in our consolidated income statement from the date on which control is obtained. Any contingent consideration to be transferred by us will be recognized at fair value at the acquisition date. Subsequent changes to the fair value of the contingent consideration, which is deemed to be an asset or liability, will be recognized in our consolidated income statement. The excess of the fair value of the total purchase consideration transferred over the fair value of the acquired assets and assumed liabilities is recognized as goodwill. The valuations in support of fair value determinations are based on information available at the acquisition date. Acquisition related costs are expensed as incurred. Any contingent consideration to be transferred by us in relation to businesses acquired that are linked to milestone payments and are initially recognized at fair value as a financial liability. They are adjusted for the probability of their likelihood of payment and are appropriately discounted to reflect the impact of time. Changes in the fair value of these contingent consideration liabilities in subsequent periods are recognized in our consolidated income statement on the line “other operating income/expense”. The effect of unwinding the discount over time is recognized on the line “other financial expenses”. Contingent amounts payable or paid by us to former shareholders of acquired companies, who continue to be employed by us, but which would be automatically forfeited (or become repayable) upon termination of employment before a specific date, are classified as remuneration for post-combination services in our consolidated income statement. These cash-settled contingent amounts are recognized in accordance with IAS 19 and are recorded in the statement of financial position on the lines “other (non-) current assets” and “other non-current/trade and other liabilities” depending on the timing of the payment by us .
Goodwill	GOODWILL Goodwill is initially measured as the excess of the total purchase consideration transferred and the fair value of the acquired assets and assumed liabilities. Subsequently, goodwill is stated at cost less impairments. As goodwill is considered to have an indefinite life, it is tested for impairment at least once a year (at each year-end), and whenever there is an indication that it may be impaired, by comparing its carrying amount with its recoverable amount. ​ Any impairment costs are recorded in our consolidated income statement on the line “Other operating income/expenses”.
Intangible Assets Other Than Goodwill	INTANGIBLE ASSETS OTHER THAN GOODWILL Expenditure on research activities is recognized as an expense in the period in which it is incurred. An internally generated intangible asset arising from our development activities is recognized only if all of the following conditions are met: ● Technically feasible to complete the intangible asset so that it will be available for use or sale ● We have the intention to complete the intangible assets and use or sell it ● We have the ability to use or sell the intangible assets ● The intangible asset will generate probable future economic benefits, or indicate the existence of a market ● Adequate technical, financial and other resources to complete the development are available ● We are able to measure reliably the expenditure attributable to the intangible asset during its development (i) Internally generated intangible assets The amount capitalized as internally generated intangible assets is the sum of the development costs incurred as of the date that the asset meets the conditions described above. Because of risks and uncertainties inherent to the regulatory authorizations and to the development process itself, management estimates that the conditions for capitalization are not met until we obtain regulatory approval from the competent authorities. Currently we recognize all development costs as an expense in the period in which they are incurred, even for approved products because they do not generate separately identifiable incremental future economic benefits that can be reliably measured. (ii) Licences, rights and in-process research and development Acquired in-process research and development obtained through in-licensing agreements, business combinations, collaboration agreements or separate acquisitions are capitalized as an intangible asset provided that they are separately identifiable, controlled by us and expected to provide economic benefits. As the probability criterion in IAS 38 is always considered to be satisfied for separately acquired research and development assets, upfront and milestone payments to third parties for products or compounds for which regulatory approval has not yet been obtained are recognized as intangible assets. We consider such intangible assets as not yet available for use until the moment that the underlying asset is approved and commercially launched. Amortization will commence when the underlying asset is approved for commercialization and the asset will be amortized over its useful life. Intangible assets may also consist of upfront fees paid to third party institutions in exchange for an option to negotiate a license to any of the third party’s rights in technology resulting from the collaboration. The upfront fee paid in exchange for this option is capitalized as intangible asset and amortized over the expected duration of the option. Exclusivity contracts and technology acquired through business combinations are valued independently as part of the fair value of the businesses acquired and are amortized over their estimated useful lives. The estimated useful life is based on the lower of the contract life or the economic useful life. In the event an asset has an indefinite life, this fact is disclosed along with the reasons for being deemed to have an indefinite life. Intangible assets with an indefinite useful life and intangible assets which are not yet available for use are tested for impairment annually, and whenever there is an indication that the asset might be impaired. (iii) Software and databases Acquired software is recognized at cost less accumulated amortization and any impairment loss. Amortization is recognized so as to write off the cost of assets over their useful lives (generally between 3 and 5 years), using the straight-line method. (iv) Contract costs Contract costs only include success fees that were capitalized in relation to the Gilead agreement of 2019. These costs are currently amortized on a straight-line basis over a period of 10 years, reflecting the term of our collaboration with Gilead. We review at each balance sheet date the carrying amount of our intangible assets to determine whether there is any indication that those assets have suffered an impairment generate cash flows that are independent from other assets, we estimate the recoverable
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENT Property, plant and equipment are recognized at cost less accumulated depreciation and any impairment loss. Depreciation of an asset begins when it is available for use, ie when it is in the location and condition necessary for it to be capable of operating in the manner intended by management. Depreciation is recognized so as to write off the cost of assets over their useful lives, using the straight-line method, on the following bases: ● Buildings: 33 years ● Installation & machinery: 3 – 15 years ● Furniture, fixtures & vehicles: 4 – 10 years Leasehold improvements are depreciated 3 -10 years, being the term of the lease, unless a shorter useful life is expected. The other tangible assets category mainly consists of assets under construction. Assets under construction are not depreciated. Any gain or loss incurred at the disposal of an asset is determined as the difference between the sale proceeds and the carrying amount of the asset and is recognized in profit or loss. We review at each balance sheet date the carrying amount of our property, plant and equipment to determine whether there is any indication that those assets have suffered an impairment
Leases	LEASES All leases are accounted for by recognizing a right-of-use asset and a corresponding lease liability except for: ● Leases of low value assets; and ● Leases with a duration of 12 months or less Liabilities arising from a lease are initially measured on a present value basis. Lease liabilities include the net present value of the lease payments that are not paid at the commencement date, discounted using the incremental borrowing rate. Our lease payments generally only include fixed payments and extension option payments if we are reasonably certain to exercise this option. After initial recognition, the lease liability will be measured at amortized cost using the discount rate determined at commencement and will be re-measured (with a corresponding adjustment to the related right-of-use asset) when there is a change in future lease payments, generally in case of reassessment of options. At the commencement date, the right-of-use assets are measured at cost, comprising the amount of the initial lease liability, less any lease incentives received from the lessors. After initial recognition, the right-of-use assets are measured at cost and generally depreciated over the the lease term on a straight-line basis. The right-of-use assets will be adjusted for any re-measurements of the lease liability as a result of lease modifications. The right-of-use assets are subject to impairment testing if there is an indicator for impairment, as for property, plant and equipment. The right-of-use assets are presented in the statement of financial position under the caption “property, plant and equipment” and the lease liabilities are presented as current and non-current lease liabilities. We only include extension options (or periods after termination options) in the lease term if the lease is reasonably certain to be extended (or not terminated). The assessment is reviewed if a significant event or a significant change in circumstances occurs which affects this assessment and that is within our control.
Inventories	​ INVENTORIES Inventories consist of raw materials, semi-finished products and finished products. These inventories are initially recognized at cost, and subsequently at the lower of cost and net realizable value. Cost comprises all costs of purchase, conversion costs and transportation costs, and is determined using the FIFO-method.
Financial Instruments	FINANCIAL INSTRUMENTS Financial assets and financial liabilities are recognized in our statement of financial position when we become a party to the contractual provisions of the instrument. (i) Financial assets Financial assets are initially recognized either at fair value or at their transaction price. All recognized financial assets will subsequently be measured at either amortized cost or fair value under IFRS 9 on the basis of both our business model for managing the financial assets and the contractual cash flow characteristics of the financial asset. ● a financial asset that (i) is held within a business model whose objective is to collect the contractual cash flows and (ii) has contractual cash flows that are solely payments of principal and interest on the principal amount outstanding is measured at amortized cost (net of any write down for impairment), unless the asset is designated at fair value through profit or loss (FVTPL) under the fair value option; ● all other financial assets are measured at FVTPL. A financial asset is classified as current when the cash flows expected to flow from the instrument mature within one year. We derecognize a financial asset when the contractual rights to the cash flows from the asset expire, or we transfer the rights to receive the contractual cash flows on the financial asset in a transaction in which substantially all the risks and rewards of ownership of the financial asset are transferred. Financial assets at fair value through profit or loss Financial assets are designated at fair value through profit or loss if we manage such investments and make purchase and sale decisions based on their fair value in accordance with the investment strategy. Attributable transaction costs are recognized in profit or loss as incurred. Financial assets at fair value through profit or loss are measured at fair value, and changes therein, which take into account any dividend income, are recognized in profit or loss. Equity instruments We hold investments in equity instruments, which based on IFRS 9, are designated as financial assets at fair value through profit or loss. The fair value of listed investments is based upon the closing price of such securities on Euronext at each reporting date. If there is no active market for an equity instrument, we establish the fair value by using valuation techniques. Current financial investments measured at fair value through profit or loss Current financial investments include financial assets measured at fair value through profit or loss and may comprise short term bond funds that have a maturity equal or less than 12 months, and money market funds. Cash equivalents measured at fair value through profit or loss Cash equivalents measured at fair value through profit or loss may comprise bonds and money market funds that are readily convertible to cash and are subject to an insignificant risk of changes in value. Financial assets at amortized cost Receivables Receivables are designated as financial assets measured at amortized cost. They are initially measured either at fair value or at transaction price, in the absence of a significant financing component. All receivables are subsequently measured in the balance sheet at amortized cost, which generally corresponds to nominal value less expected credit loss provision. Receivables mainly comprise trade and other receivables and current/non-current R&D incentives receivables. The R&D incentives receivables relate to refunds resulting from R&D incentives on research and development expenses in France and Belgium. This is a grant receivable that is based on annual declarations and is only refunded in case it cannot be offset by a tax payable. Current financial investments measured at amortized cost Current financial investments measured at amortized cost include treasury bills that have a maturity equal to or less than 12 months. We apply settlement date accounting for the recognition and de-recognition of current financial investments measured at amortized cost. Current financial investments measured at amortized cost also include term deposits with maturities exceeding three months from the acquisition date. Cash and cash equivalents measured at amortized cost Cash and cash equivalents measured at amortized cost mainly comprise of notice accounts and term deposits that are readily convertible to cash within three months or less, that are subject to an insignificant risk of changes in their value and that are held for the purpose of meeting short-term cash commitments. Cash and cash equivalents exclude restricted cash, which is presented in the line other non-current assets in the statement of financial position. Impairment The For trade receivables, in the absence of a significant financing component, the loss allowance Impairment statement. (ii) Financial liabilities Financial liabilities are initially measured either at fair value or at their transaction price. Subsequent to initial recognition, financial liabilities are measured at amortized cost or at fair value. Financial liabilities measured at amortized cost mainly comprise trade and other liabilities. Trade and other liabilities are comprised of liabilities that are due less than one year from the balance sheet date and are in general not interest bearing and settled on an ongoing basis during the financial year. They also include accrued expenses related to our research and development project costs. We derecognize a financial liability when its contractual obligations are discharged, cancelled or expire.
Taxation	TAXATION Income tax in the profit or loss accounts represents the sum of the current tax and deferred tax. Current tax is the expected tax payable on the taxable profit of the year. The taxable profit of the year differs from the profit as reported in the financial statements as it excludes items of income or expense that are taxable or deductible in other years and it further excludes items that are never taxable or deductible. Our liability for current tax is calculated using tax rates that have been enacted or substantively enacted by the balance sheet date. Deferred income tax is provided in full, using the liability-method, on temporary differences arising between the tax bases of assets and liabilities and their carrying amounts in the financial statements. However, the deferred income tax is not accounted for if it arises from the initial recognition of an asset or liability in a transaction other than a business combination that at the time of the transaction affects neither accounting nor taxable profit nor loss. Deferred income tax is determined using tax rates (and laws) that have been enacted or substantively enacted by the balance sheet date and are expected to apply when the related deferred income tax asset is realized or the deferred income tax liability is settled. Deferred tax assets are recognized to the extent that it is probable that future taxable profit will be available against which the temporary differences can be utilized. As such, a deferred tax asset for the carry forward of unused tax losses will be recognized to the extent that is probable that future taxable profits will be available.
Revenue Recognition	REVENUE RECOGNITION Revenues to date have consisted principally of collaboration revenues, which consist of milestones, license fees, non-refundable upfront fees and royalties received in connection with collaboration and license agreements. The revenue recognition policies can be summarized as follows: We recognize revenue when our customer obtains control of promised goods or services, in an amount that reflects the consideration that we expect to receive in exchange for those goods or services. To determine revenue recognition for agreements that we determine are within the scope of IFRS 15, we perform the following five steps: COLLABORATION REVENUES (i) identify the contract In our agreements with customers we are mainly transferring licenses on our IP and in some cases this is combined with access rights and/or providing research and development services and/or cost sharing mechanisms. In some cases our collaborations also include an equity subscription component. If this is the case, we analyze if the criteria to combine contracts, as set out by IFRS 15, are met. (ii) identify the performance obligations in the contract Depending on the type of the agreement, there can be one or more distinct performance obligations under IFRS 15. This is based on an assessment of whether the promises in an agreement are capable of being distinct and are distinct from the other promises to transfer goods and/or services in the context of the contract. For some of our agreements we combine the transfer of the license with the performance of research and development activities because we consider that the license is not capable of being distinct and is not distinct in the context of the contract. (iii) determine the transaction price Collaboration and license agreements with our commercial partners for research and development activities generally include non- upfront fees; milestone payments, the receipt of which is dependent upon the achievement of certain clinical, regulatory or commercial milestones; license fees, royalties on sales and sometimes reimbursement income or profits sharing arrangements. a/ License fees or upfront payments If the license to our intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, we recognize revenues from non-refundable upfront fees allocated to the license at the point in time the license is transferred to the customer and the customer has the right to use the license. For licenses that are bundled with other promises, we utilize judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time. If the performance obligation is satisfied over time, revenue is then recognized based on a pattern that best reflects the transfer of control of the service to the customer. b/ Milestone Payments other than sales based milestones A milestone payment is only included in the transaction price to the extent that it is highly probable . W we estimate the amount to be included in the transaction price using the most likely amount method. The transaction price is allocated to each performance obligation on a stand-alone selling price basis. We recognize revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, we re-evaluate the probability of achievement of such milestones and any related constraint. If necessary we adjust our estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenue and earnings in the period of adjustment. c/ Reimbursement Income for R&D Services Collaboration and license agreements may include reimbursement or cost sharing for research and development services: such as outsourcing costs and payment for FTEs at contractual rates. R&D services are performed and satisfied over time given that the customer simultaneously receives and consumes the benefits provided by us. Such costs reimbursements received are recognized in revenues when costs are incurred and agreed by the parties when we are acting as a principal in the scope of our stake of the R&D activities. If the later condition is not fulfilled, costs reimbursements are d/ Sales based milestone payment and Royalties License and collaboration agreements include sales-based royalties, including commercial milestone payments based on the level of sales, and the license has been deemed to be the predominant item to which the royalties relate. Related revenue is recognized as the subsequent underlying sales occur. (iv) allocate the transaction price to the performance obligations in the contract We allocate the transaction price to each performance obligation identified in the contract based upon the stand-alone selling price. The stand-alone selling price of each performance obligation is estimated by using one of the following methods: adjusted (v) recognize revenue when (or as) the entity satisfies a performance obligation Revenue is recognized when our customer obtains control of the goods and/or services foreseen in the contracts. The control can be transferred In case of revenue recognition over time, we use an input model that considers estimates of the percentage of total research and development costs that are completed each period compared to the total estimated costs (percentage of completion method PRODUCT NET SALES Revenue on the sale of Jyseleca is recorded as “Product net sales” on the discontinued operations line in our consolidated income statement. Product net sales is the net amount of revenue recognized resulting from transferring control over our products to our customer (for example wholesalers and hospitals). Product sales revenue is recognized at a point in time when control of the goods has transferred The amount of revenue recognized is the amount allocated to the satisfied performance obligation taking into account variable consideration. The estimated amount of variable consideration is included in the transaction price only to the extent that it is highly probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Variable consideration that is included in the transaction price is primarily composed of rebates, discounts, cash discounts and chargebacks granted to various customers that are part of commercial and governmental contractual arrangements or other reimbursement The amount of variable consideration is estimated using several elements such third-party market data, product pricing, the specific terms in the individual agreements, estimated inventory levels and the shelf life of our product. If actual results differ, these Net sales are presented COST OF SALES Cost of sales includes primarily the purchase OTHER OPERATING INCOME Grants and R&D incentives As we carry out extensive research and development activities, we benefit from various grants and R&D incentives from certain governmental agencies. These grants and R&D incentives generally aim to partly reimburse (approved) expenditures incurred in our research and development efforts and are credited to the income statement, under other income, when the relevant expenditure has been incurred and there is reasonable assurance that the grants or R&D incentives are receivable.
Share-Based Payments	SHARE-BASED PAYMENTS a/ Equity-settled share based payments We grant equity-settled incentives to certain employees, members of the Executive Committee and consultants in the form of subscription rights. Equity-settled subscription rights are measured at fair value at the date of acceptance. The fair value determined at the acceptance date of the subscription rights is expensed over time until the end of the vesting period, based on our estimate of subscription right warrants that are expected to be exercised. Fair value is measured by use of the Black & Scholes model. The expected life used in the model has been adjusted, based on management’s best estimate, for the effects of non-transferability, exercise restrictions, and behavioral considerations. b/ Long-term incentive plans in RSUs (Restricted Stock Units) Executive Committee members and other employees are granted RSUs. An RSU is a grant that takes the form of a promise that employees will receive Galapagos stock in the future and it will be payable, at the company’s discretion in cash or in shares, upon completion of a certain vesting period. Each RSU reflects the value of one Galapagos share. The RSUs are measured based on the average share price over the 30-calendar day period preceding the measurement date. We recognize the corresponding expense and liability over the vesting period. The fair value of the liability is re-measured at each reporting date because currently it is management’s intention to settle the RSUs in cash.
Discontinued Operations	DISCONTINUED OPERATIONS PRESENTATION – COMPARATIVE PERIODS RESTATED Our income statement and statement of comprehensive income of the comparative periods presented in these financial statements have been restated to present the activities related to the Jyseleca® business on a separate line “Net income/loss (-) from discontinued operations, net of tax”. We refer to note 5 for more detailed information on these discontinued operations.
Segment Reporting	SEGMENT REPORTING We currently have one operating and reportable segment.
Assets held for sale and discontinued operations	ASSETS HELD FOR SALE AND DISCONTINUED OPERATIONS A discontinued operation is a component of an entity that either has been disposed of, or that is classified as held for sale. It must either: represent a major separate line of business or geographical area of operations; be part of a single coordinated disposal plan; or be a subsidiary acquired exclusively with a view to resale. Intercompany transactions between continuing and discontinued operations are eliminated against discontinuing operations. Non-current assets and disposal groups are classified as assets held for sale if their carrying amount is to be recovered principally through a sale transaction rather than through continuing use. This condition is regarded as met only when the sale is highly probable and the asset (or disposal group) is available for immediate sale in its present condition. A transaction is assumed to be highly probable if there are no significant risks of completion of the transaction, which depends on the specific circumstances but usually required at least an agreed binding term sheet. They are stated at the lower of carrying amount and fair value less costs to sell with any resulting impairment recognized. Assets related to discontinued operations and assets of disposal group held for sale are not depreciated. On November 23, 2020 we signed a share purchase agreement with Selvita S.A. in relation to the disposal of Fidelta d.o.o. (our previous fee-for-service segment). The transaction was completed on January 4, 2021 for a total consideration of €37.1 million. Fidelta will continue performing drug discovery services for us for the next three years. On October 30, 2023, we signed a letter of intent to transfer our Jyseleca® business to Alfasigma and the final agreement was signed on December 30, 2023. We classified the assets and the associated liabilities of the Jyseleca® business as held for sale in our financial statements for the year ended December 31, 2023. The transaction was closed on January 31, 2024. Where applicable and in accordance with IFRS 5, we have restated the 2022 and 2021 comparatives in the consolidated income statement and in the notes to consider the impact of classifying the business as discontinued operations in 2023. We refer to note 5 of our consolidated financial statements. ​
Description Of Accounting Policy For Reclassification Of Accrued Interest On Financial Investments	RECLASSIFICATION OF ACCRUED INTERESTS ON FINANCIAL INVESTMENTS – COMPARATIVE PERIODS NOT RESTATED Accrued interests on financial assets were in the past recorded on the “current financial investments” line for treasury bills while reported on a separate current assets/current liabilities line for the other financial investments measured at amortized cost (mainly term deposits). During the third quarter of 2023 we decided to align the presentation of all our financial investments at amortized cost and present all accrued interests as part of the amortized cost measurement on the “current financial investments” / “cash and cash equivalents” line. As the impact of this classification misstatement on the prior period comparative numbers was deemed immaterial for all comparative periods presented, we did not restate the prior period financial statements. This is in accordance with IAS 8.42 that requires to only adjust the comparatives for material prior period errors. The impact of this error on December 31, 2022 amounted to 9.9 million net positive accrued interests mainly related to accrued positive interests on current financial investments that would have increased our “current financial investments” and “cash and cash equivalents” line and decreased our “other current assets” line by the same amount. On December 31, 2021 this error amounted to 2.6 million net negative accrued interests that were mainly related to accrued negative interests on cash and cash equivalents that would have decreased our “cash and cash equivalents” and “current financial investments” line and decreased our “trade and other liabilities” line by the same amount .
Description Of Accounting Policy For Standards And Interpretations Published But Not Yet Applicable	STANDARDS AND INTERPRETATIONS PUBLISHED, BUT NOT YET APPLICABLE FOR THE ANNUAL PERIOD BEGINNING ON JANUARY 1, 2023 A number of new standards are effective for annual periods beginning on or after January 1, 2024 with earlier adoption permitted. However we have not early adopted new or amended standards in preparing our consolidated financial statements. We are currently still assessing the impact of these new accounting standards and amendments that are not yet effective but we expect no standard to have a material impact on our financial statements in the period of initial application. The following amendments are effective for the period beginning January 1, 2024: ● ● ● ● ​ The following amendments are effective for the period beginning January 1, 2025: ​ ●

Discontinued operations and a_2

Discontinued operations and assets held for sale (Tables)		12 Months Ended
	Jan. 04, 2021	Dec. 31, 2023
Jyseleca business, classified as held for sale
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Schedule of financial statements in relation to the discontinued operations		​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022 2021 ​ ​ (Euro, in thousands, except share and per share data) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Product net sales ​ € 112,339 ​ € 87,599 ​ € 14,753 Collaboration revenues ​ ​ 431,465 ​ ​ 176,432 ​ ​ 235,709 Total net revenues ​ ​ 543,804 ​ ​ 264,031 ​ ​ 250,462 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of sales ​ ​ (18,022) ​ ​ (12,079) ​ ​ (1,629) Research and development expenditure ​ ​ (190,177) ​ ​ (245,286) ​ ​ (171,205) Sales and marketing expenses ​ ​ (113,356) ​ ​ (144,075) ​ ​ (66,179) General and administrative expenses ​ ​ (17,989) ​ ​ (9,776) ​ ​ (13,155) Other operating income ​ ​ 13,003 ​ ​ 10,721 ​ ​ 7,678 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating profit/loss (-) ​ ​ 217,262 ​ ​ (136,464) ​ ​ 5,972 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value adjustments and net currency exchange differences ​ ​ (13) ​ ​ (25) ​ ​ — Other financial income ​ ​ 679 ​ ​ 15 ​ ​ 164 Other financial expenses ​ ​ (167) ​ ​ (7,825) ​ ​ (9,733) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Profit/loss (-) before tax ​ ​ 217,761 ​ ​ (144,298) ​ ​ (3,597) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income taxes ​ ​ (2,076) ​ ​ (2,272) ​ ​ (1,034) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net profit/loss (-) ​ € 215,685 ​ € (146,570) ​ € (4,631) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic and diluted earnings/loss (-) per share from discontinued operations ​ € 3.27 ​ € (2.23) ​ € (0.07) Weighted average number of shares (in thousands of shares) ​ ​ 65,884 ​ ​ 65,699 ​ ​ 65,500 Weighted average number of shares - Diluted (in thousands of shares) ​ ​ 65,933 ​ ​ 65,699 ​ ​ 65,500 ​ Jyseleca ® product net sales in Europe amounted to €112.3 million in 2023, compared to €87.6 million in 2022, of which €8.1 million realized in Belgium ( €7.3 million in 2022). Collaboration revenues in discontinued operations related to revenue recognition of the collaboration agreement with Gilead for the filgotinib development amount to €429.4 million in 2023 compared to €174.4 million last year. Effective January 31, 2024, following the closing of the transaction between us and Alfasigma S.p.A. to transfer the Jyseleca® business to Alfasigma, we assigned our rights and obligations under the filgotinib collaboration with Gilead to Alfasigma, except for our right to receive royalties from Gilead on net sales in the Gilead Territory under a separate agreement between Gilead and us entered into in October 2023. As a consequence, our performance obligation towards Gilead for the development of filgotinib will come to its end, and the total estimated remaining costs to complete the filgotinib development was substantially reduced leading to a major increase in the percentage of completion of our performance obligation (applying the “cost-to-cost” input model) and a considerable positive catch-up of revenue explaining the increase in revenue recognition for the year 2023 compared to 2022. We refer to note 2 “Summary of significant transactions” for a general description of our collaboration with Gilead. ​ On December 31, 2023, the remaining deferred income related to the filgotinib development amounts to €26.3 million, which will mainly be released in revenue in 2024. The following major classes of assets and liabilities relating to these operations have been classified as held for sale in the consolidated statement of financial position on December 31, 2023: ​ Assets and liabilities held for sale ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ (Euro, in thousands) Property, plant and equipment ​ € 4,194 Deferred tax assets ​ ​ 292 Other non-current assets ​ ​ 598 Inventories ​ ​ 737 Trade and other receivables ​ ​ 15,786 Cash and cash equivalents ​ ​ 7 Other current assets ​ ​ 471 Total assets in disposal group classified as held for sale ​ ​ 22,085 ​ ​ ​ ​ ​ ​ ​ ​ Retirement benefit liabilities ​ ​ 1,160 Non-current lease liabilities ​ ​ 2,327 Other non-current liabilities ​ ​ 329 Current lease liabilities ​ ​ 1,308 Trade and other liabilities ​ ​ 25,619 Current tax payable ​ ​ 1,242 Current deferred income ​ ​ 59 Total liabilities directly associated with assets in disposal group classified as held for sale ​ ​ 32,044 ​ ​ ​ ​ Net liability held for sale ​ € (9,959) ​ This disposal group contains all assets and liabilities of the Galapagos subsidiaries that were fully dedicated to the Jyseleca® business and that will be transferred to Alfasigma in the current transaction. The divestiture includes 100% of the shares of the following subsidiaries, including most of the employees: Galapagos Biotech Limited (UK), Galapagos Biopharma Belgium BV, Galapagos Biopharma GmbH, Galapagos Biopharma Italy S.r.l., Galapagos Biopharma Netherlands B.V., Galapagos Biopharma Spain S.L.U., Galapagos Biopharma Denmark ApS, Galapagos Biopharma Sweden AB, Galapagos Biopharma Finland Oy, Galapagos Biopharma Ireland Ltd., Galapagos Biopharma Norway AS, Galapagos Biopharma Austria GmbH. In addition, and as part of the same transaction, we will transfer all assets, liabilities and employees directly related to the Jyseleca® business but belonging to Galapagos NV or other Galapagos subsidiaries, of which the main asset is the worldwide IP relating to Jyseleca®. Our inventories were not considered as part of the disposal group as these did not transfer to Alfasigma on closing of the transaction on January 31, 2024 but will gradually transfer to Alfasigma during the coming years and we will bear the risks associated with it as long as it is not transferred. ​ Held for sale assets are stated at their carrying amount, which is lower than the fair value less costs to sell. We concluded that the expected present value of the purchase price to be obtained from Alfasigma for the sale of the Jyseleca® business approximates the fair value less costs to sell of the disposal group. ​ Cash flow ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 2021 ​ ​ ​ (Euro, in thousands) Net cash flow used in operating activities ​ € (175,627) ​ € (191,095) ​ € (119,524) Net cash flow used in investing activities ​ ​ (105) ​ ​ (136) ​ ​ (157) Net cash flow used in financing activities ​ ​ (1,928) ​ ​ (1,841) ​ ​ (872) Net cash flow used in discontinued operations ​ € (177,660) ​ € (193,072) ​ € (120,554)
Fidelta
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Schedule of financial statements in relation to the discontinued operations	Consideration received ​ ​ ​ ​ ​ (Euro, in thousands) Cash received ​ € 37,080 Total cash received ​ € 37,080 ​ Analysis of assets and liabilities over which control was lost ​ ​ ​ ​ ​ ​ ​ ​ ​ January 4, 2021 ​ ​ ​ (Euro, in thousands) Intangible assets ​ € 21 Property, plant and equipment ​ ​ 10,050 Other non-current assets ​ ​ 160 Trade and other receivables ​ ​ 4,428 Cash and cash equivalents ​ ​ 7,884 Other current assets ​ ​ 863 Total assets ​ ​ 23,406 ​ ​ ​ ​ ​ ​ ​ ​ Non-current lease liabilities ​ ​ 4,115 Other non-current liabilities ​ ​ 70 Trade and other liabilities ​ ​ 4,479 Current lease liabilities ​ ​ 727 Income tax payable ​ ​ 356 Total liabilities ​ ​ 9,747 ​ ​ ​ ​ Net assets disposed of ​ € 13,658 ​ ​ Gain on disposal of Fidelta ​ ​ ​ ​ ​ ​ (Euro, in thousands) Cash received ​ € 37,080 Net assets disposed of ​ ​ (13,658) Effect of cumulative translation adjustment reclassified from equity on loss of control ​ ​ (731) Costs associated to the sale ​ ​ (500) Gain on disposal ​ € 22,191 ​ Net cash proceeds from the disposal of Fidelta ​ ​ ​ ​ ​ ​ (Euro, in thousands) Cash received ​ € 37,080 Less: cash and cash equivalents balances disposed of ​ ​ (7,884) Total consideration received, net of cash disposed of ​ ​ 29,196 Costs associated to the sale ​ ​ (500) Cash in from disposal of Fidelta, net of cash disposed of ​ € 28,696 ​ RESULT FROM DISCONTINUED OPERATIONS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2023 2022 ​ 2021 ​ ​ ​ (Euro, in thousands, except share and per share data) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain on disposal of subsidiaries ​ € — ​ € — ​ € 22,191 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating profit ​ ​ — ​ ​ — ​ ​ 22,191 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net profit ​ € — ​ € — ​ € 22,191 ​ Basic and diluted earnings per share from discontinued operations ​ € — ​ € — ​ € 0.34 ​ Weighted average number of shares (in thousands of shares) ​ ​ — ​ ​ — ​ ​ 65,500 ​ Weighted average number of shares - Diluted (in thousands of shares) ​ ​ — ​ ​ — ​ ​ 65,831 ​ ​ CASH FLOW FROM DISCONTINUED OPERATIONS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 2021 ​ ​ ​ (Euro, in thousands) Net cash flows generated from investing activities ​ € — ​ € — ​ € 28,696 Net cash flow from discontinued operations ​ € — ​ € — ​ € 28,696 ​

Segment information (Tables)

Segment information (Tables)	12 Months Ended
	Dec. 31, 2023
Segment information
Summary of collaboration revenues by destination	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022 2021 ​ ​ (Euro, in thousands) United States of America ​ € 665,174 ​ € 414,129 ​ € 467,978 Europe ​ ​ 118,354 ​ ​ 91,151 ​ ​ 16,867 Total net revenues ​ € 783,528 ​ € 505,280 ​ € 484,846 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ minus: ​ ​ ​ ​ ​ ​ ​ ​ ​ United States of America ​ € 425,466 ​ € 172,980 ​ € 233,638 Europe ​ ​ 118,338 ​ ​ 91,051 ​ ​ 16,824 Total net revenues from discontinued operations ​ € 543,804 ​ € 264,031 ​ € 250,462 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ United States of America ​ € 239,708 ​ € 241,149 ​ € 234,340 Europe ​ ​ 16 ​ ​ 100 ​ ​ 43 Total net revenues from continuing operations ​ € 239,724 ​ € 241,249 ​ € 234,384
Summary of revenues by major customers	​
Schedule of non-current assets other than financial instruments, deferred tax assets, post-employment benefit assets, and rights arising under insurance contracts by location	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 ​ ​ ​ (Euro, in thousands) Belgium ​ € 56,209 ​ € 72,087 ​ € 98,295 France ​ ​ 1,438 ​ ​ 20,397 ​ ​ 21,051 The Netherlands ​ ​ 251,230 ​ ​ 255,461 ​ ​ 66,621 Switzerland ​ ​ 3,247 ​ ​ 4,962 ​ ​ 7,181 Spain ​ ​ — ​ ​ 3,037 ​ ​ 3,029 United States of America ​ ​ 11,660 ​ ​ 12,729 ​ ​ 136 Other ​ ​ — ​ ​ 1,747 ​ ​ 1,302 Total non-current assets ​ € 323,784 ​ € 370,420 ​ € 197,615 ​

Total revenues (Tables)

Total revenues (Tables)	12 Months Ended
	Dec. 31, 2023
Total revenues
Revenue by collaboration and by category of revenue	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Over time Point in time ​ 2023 ​ 2022(*) ​ 2021(*) ​ ​ ​ ​ ​ (Euro, in ​ ​ (Euro, in ​ ​ (Euro, in ​ ​ ​ ​ ​ thousands) ​ ​ thousands) ​ ​ thousands) Recognition of non-refundable upfront payments and license fees ​ ​ ​ ​ € 230,242 ​ € 230,423 ​ € 230,582 Gilead collaboration agreement for drug discovery platform Ö ​ ​ ​ ​ 230,242 ​ ​ 230,423 ​ ​ 230,582 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reimbursement income ​ ​ ​ ​ ​ - ​ ​ 56 ​ ​ - Novartis collaboration agreement for MOR106 Ö ​ ​ ​ ​ - ​ ​ 56 ​ ​ - ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Royalties ​ ​ ​ ​ ​ 9,482 ​ ​ 10,770 ​ ​ 3,801 Gilead royalties on Jyseleca ​ ​ Ö ​ ​ 9,466 ​ ​ 10,726 ​ ​ 3,757 Other royalties ​ ​ Ö ​ ​ 16 ​ ​ 44 ​ ​ 43 Total collaboration revenues ​ ​ ​ ​ € 239,724 ​ € 241,249 ​ € 234,383

Operating costs and other ope_2

Operating costs and other operating income (Tables)	12 Months Ended
	Dec. 31, 2023
Operating costs and other operating income
Summary of research and development expenditure	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) Personnel costs ​ € (95,788) ​ € (115,484) ​ € (128,402) Subcontracting ​ ​ (82,997) ​ ​ (61,192) ​ ​ (126,881) Disposables and lab fees and premises costs ​ ​ (18,083) ​ ​ (19,529) ​ ​ (22,933) Depreciation ​ ​ (22,254) ​ ​ (51,493) ​ ​ (15,709) Professional fees ​ ​ (9,272) ​ ​ (9,316) ​ ​ (12,234) Other operating expenses ​ ​ (12,900) ​ ​ (12,783) ​ ​ (14,344) Total R&D expenses ​ € (241,294) ​ € (269,797) ​ € (320,503)
Summary of R&D expenditure by program	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ziritaxestat program ​ € — ​ € (1,096) ​ € (26,725) SIKi program ​ ​ (18,900) ​ ​ (47,727) ​ ​ (91,957) TYK2 program on GLPG3667 ​ ​ (31,289) ​ ​ (24,467) ​ ​ (27,141) CAR-T programs in oncology ​ ​ (82,218) ​ ​ (29,999) ​ ​ — Other programs ​ ​ (108,887) ​ ​ (166,507) ​ ​ (174,680) Total R&D expenses ​ € (241,294) ​ € (269,797) ​ € (320,503)
Summary of sales and marketing expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) Personnel costs ​ € (2,997) ​ € (1,693) ​ € (1,709) Depreciation ​ ​ (113) ​ ​ (59) ​ ​ (37) External outsourcing costs ​ ​ (1,776) ​ ​ (1,267) ​ ​ (1,802) Professional fees ​ ​ (131) ​ ​ (99) ​ ​ (15) Other operating expenses ​ ​ (659) ​ ​ (363) ​ ​ (214) Total sales and marketing expenses ​ € (5,676) ​ € (3,480) ​ € (3,776)
Summary of general and administrative expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) Personnel costs ​ € (66,098) ​ € (76,536) ​ € (60,364) Depreciation and impairment ​ ​ (15,978) ​ ​ (8,529) ​ ​ (16,338) Legal and professional fees ​ ​ (23,250) ​ ​ (23,715) ​ ​ (25,345) Other operating expenses ​ ​ (22,963) ​ ​ (26,375) ​ ​ (25,697) Total general and administrative expenses ​ € (128,289) ​ € (135,155) ​ € (127,744)
Schedule of other income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2023 ​ 2022(*) ​ 2021(*) ​ ​ ​ (Euro, in thousands) Grant income ​ € 6,618 ​ € 1,873 ​ € 7,334 R&D incentives income ​ ​ 32,968 ​ ​ 29,104 ​ ​ 37,416 Other income ​ ​ 7,686 ​ ​ 5,150 ​ ​ 1,325 Total other operating income ​ € 47,272 ​ € 36,127 ​ € 46,075
Schedule of R&D incentives income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2023 ​ 2022(*) ​ 2021(*) ​ ​ ​ (Euro, in thousands) Income from innovation incentive system in France ​ € 5,881 ​ € 11,075 ​ € 12,245 Income from Belgian R&D incentives ​ ​ 16,535 ​ ​ 10,339 ​ ​ 14,835 Tax rebates on payroll withholding taxes of R&D personnel (Belgium & the Netherlands) ​ ​ 10,552 ​ ​ 7,689 ​ ​ 10,336 Total R&D incentives income ​ € 32,968 ​ € 29,104 ​ € 37,416 ​

Staff costs (Tables)

Staff costs (Tables)	12 Months Ended
	Dec. 31, 2023
Staff costs
Summary of Staff costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) Wages and salaries ​ € (100,250) ​ € (99,708) ​ € (107,794) Social security costs ​ ​ (15,742) ​ ​ (16,748) ​ ​ (19,109) Pension costs ​ ​ (5,581) ​ ​ (5,583) ​ ​ (4,906) Costs related to subscription right plans ​ ​ (36,628) ​ ​ (62,003) ​ ​ (52,131) Other personnel costs ​ ​ (6,682) ​ ​ (9,670) ​ ​ (6,535) Total personnel costs ​ € (164,883) ​ € (193,712) ​ € (190,475)
Summary of average number of FTE's	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022 2021 Members of the Executive Committee ​ ​ 4 ​ ​ 4 ​ ​ 5 Research and development ​ ​ 372 ​ ​ 434 ​ ​ 568 Commercial and medical affairs ​ ​ 13 ​ ​ 7 ​ ​ 6 Corporate and support ​ ​ 245 ​ ​ 250 ​ ​ 298 Total ​ ​ 634 ​ ​ 695 ​ ​ 877
Summary of number of employees	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 2021 Number of employees on December 31 ​ ​ 646 ​ ​ 724 ​ ​ 772

Financial result (Tables)

Financial result (Tables)	12 Months Ended
	Dec. 31, 2023
Financial result
Schedule of other financial income and expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ ​ (Euro, in thousands) Fair value adjustments and net currency exchange differences: ​ ​ ​ ​ ​ ​ ​ ​ ​ Net unrealized currency exchange gain/loss (-) ​ € (20,544) ​ € 41,559 ​ € 56,966 Net realized currency exchange gain/loss (-) ​ ​ (1,118) ​ ​ 2,825 ​ ​ (308) Fair value re-measurement of warrants ​ ​ 18 ​ ​ 186 ​ ​ 2,960 Fair value loss on financial assets held at fair value through profit or loss ​ ​ (390) ​ ​ — ​ ​ (4,919) Fair value gain on current financial investments ​ ​ 38,286 ​ ​ 6,929 ​ ​ 6,763 Total fair value adjustments and net currency exchange differences ​ ​ 16,252 ​ ​ 51,498 ​ ​ 61,462 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other financial income: ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest income ​ ​ 79,290 ​ ​ 18,094 ​ ​ 2,865 Discounting effect of non-current R&D incentives receivables ​ ​ 617 ​ ​ 93 ​ ​ 93 Discounting effect of other non-current liabilities ​ ​ 318 ​ ​ — ​ ​ — Other finance income ​ ​ 24 ​ ​ 376 ​ ​ 99 Total other financial income ​ ​ 80,249 ​ ​ 18,563 ​ ​ 3,057 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other financial expenses: ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest expenses ​ ​ (1,770) ​ ​ (6,884) ​ ​ (11,592) Discounting effect of other non-current liabilities ​ ​ — ​ ​ (2,271) ​ ​ — Other finance charges ​ ​ (843) ​ ​ (699) ​ ​ (761) Total other financial expense ​ ​ (2,613) ​ ​ (9,854) ​ ​ (12,353) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total net other financial income ​ € 93,888 ​ € 60,206 ​ € 52,166

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income taxes
Income tax recognized in profit or loss	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ (Euro, in thousands) Continuing operations ​ ​ ​ ​ ​ ​ ​ ​ ​ Current tax ​ € (5,928) ​ € (1,738) ​ € (884) Deferred tax ​ ​ (3,685) ​ ​ 1,166 ​ ​ (505) Income taxes ​ € (9,613) ​ € (572) ​ € (1,389)
Tax reconciled to the accounting result	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022(*) 2021(*) ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Profit/loss (-) before tax ​ € 5,625 ​ € (70,849) ​ € (119,402) Income tax debit/credit (-), calculated using the Belgian statutory tax rate on the accounting income/loss (-) before tax (theoretical) ​ ​ 1,406 ​ ​ (17,712) ​ ​ (29,850) Tax expenses in income statement (effective) ​ ​ 9,613 ​ ​ 572 ​ ​ 1,389 Difference in tax expense/income to explain ​ € 8,207 ​ € 18,284 ​ € 31,239 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Effect of tax rates in other jurisdictions ​ € (94) ​ € (337) ​ € (588) Effect of non-taxable income ​ ​ (6,752) ​ ​ (5,828) ​ ​ (2,320) Effect of share based payment expenses without tax impact ​ ​ 9,157 ​ ​ 15,501 ​ ​ 13,033 Effect of expenses/income (-) not subject to tax ​ ​ (5) ​ ​ (146) ​ ​ (907) Effect of non tax-deductible expenses ​ ​ 1,549 ​ ​ 2,975 ​ ​ 3,688 Effect of recognition of previously non-recognized deferred tax assets ​ ​ (81) ​ ​ (1,677) ​ ​ (1,411) Effect of tax losses (utilized) reversed ​ ​ (267) ​ ​ — ​ ​ — Effect of under or over provision in prior periods ​ ​ (722) ​ ​ 1,101 ​ ​ (828) Effect of non-recognition of deferred tax assets ​ ​ 34,339 ​ ​ 4,819 ​ ​ 20,949 Effect of derecognition of previously recognized deferred tax assets ​ ​ 1,062 ​ ​ 1,877 ​ ​ 135 Effect of use of investment deduction ​ ​ — ​ ​ — ​ ​ (512) Effect of use of innovation income deduction ​ ​ (29,979) ​ ​ — ​ ​ — Total explanations ​ € 8,207 ​ € 18,284 ​ € 31,239

Income_loss (-) per share (Tabl

Income/loss (-) per share (Tables)	12 Months Ended
	Dec. 31, 2023
Income/loss (-) per share
Schedule of income/loss per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022 2021 Earnings/loss (-) per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ Net profit/loss (-) attributable to owners of the parent (Euro, in thousands) ​ € 211,697 ​ € (217,991) ​ € (103,231) Number of shares (thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of shares for the purpose of basic earnings/loss (-) per share ​ ​ 65,884 ​ ​ 65,699 ​ ​ 65,500 Basic earnings/loss (-) per share (Euros) ​ € 3.21 ​ € (3.32) ​ € (1.58) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net profit/loss (-) attributable to owners of the parent (Euro, in thousands) ​ € 211,697 ​ € (217,991) ​ € (103,231) Number of shares (thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of shares for the purpose of diluted earnings/loss (-) per share ​ ​ 65,884 ​ ​ 65,699 ​ ​ 65,500 Number of dilutive potential ordinary shares ​ ​ 49 ​ ​ — ​ ​ — Diluted earnings/loss (-) per share (Euros) ​ € 3.21 ​ € (3.32) ​ € (1.58)

Goodwill and impairment of go_2

Goodwill and impairment of goodwill (Tables)	12 Months Ended
	Dec. 31, 2023
Goodwill and impairment of goodwill
Schedule of Goodwill	​ ​ ​ ​ ​ Cost ​ (Euro, in thousands) On January 1, 2022 ​ € — Recognized on acquisition of subsidiaries ​ ​ 69,893 Exchange differences on goodwill ​ ​ (80) On December 31, 2022 ​ € 69,813 Exchange differences on goodwill ​ ​ (256) On December 31, 2023 ​ € 69,557

Intangible assets other than _2

Intangible assets other than goodwill (Tables)	12 Months Ended
	Dec. 31, 2023
Intangible assets other than goodwill.
Schedule of intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Software & databases Licenses, technology and in-process R&D ​ ​ Exclusive rights ​ Contract costs ​ Total ​ ​ (Euro, in thousands) Acquisition value ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 24,554 ​ € 39,929 ​ € — ​ € 15,384 ​ € 79,868 Impact of acquisitions of businesses ​ ​ 2,610 ​ ​ 32,240 ​ ​ 89,720 ​ ​ ​ ​ ​ 124,570 Additions ​ ​ 1,126 ​ ​ 8,423 ​ ​ ​ ​ ​ ​ ​ ​ 9,549 Sales and disposals ​ ​ (913) ​ ​ (36,298) ​ ​ ​ ​ ​ ​ ​ ​ (37,211) Translation differences ​ ​ ​ ​ ​ (36) ​ ​ ​ ​ ​ ​ ​ ​ (36) On December 31, 2022 ​ ​ 27,377 ​ ​ 44,258 ​ ​ 89,720 ​ ​ 15,384 ​ € 176,740 Additions ​ ​ 567 ​ ​ — ​ ​ — ​ ​ ​ ​ ​ 567 Sales and disposals ​ ​ (930) ​ ​ (948) ​ ​ ​ ​ ​ ​ ​ ​ (1,878) Translation differences ​ ​ ​ ​ ​ (139) ​ ​ ​ ​ ​ ​ ​ ​ (139) On December 31, 2023 ​ € 27,014 ​ € 43,171 ​ € 89,720 ​ € 15,384 ​ € 175,290 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization and impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 11,977 ​ € 4,199 ​ € — ​ € 3,588 ​ € 19,765 Amortization ​ ​ 4,146 ​ ​ 333 ​ ​ 6,154 ​ ​ 1,538 ​ ​ 12,171 Impairment ​ ​ ​ ​ ​ 35,666 ​ ​ ​ ​ ​ ​ ​ ​ 35,666 Sales and disposals ​ ​ (913) ​ ​ (36,298) ​ ​ ​ ​ ​ ​ ​ ​ (37,211) Translation differences ​ ​ ​ ​ ​ (4) ​ ​ ​ ​ ​ ​ ​ ​ (4) On December 31, 2022 ​ ​ 15,210 ​ ​ 3,896 ​ ​ 6,154 ​ ​ 5,126 ​ ​ 30,387 Amortization ​ ​ 4,291 ​ ​ 1,426 ​ ​ 11,637 ​ ​ 1,538 ​ ​ 18,892 Sales and disposals ​ ​ (927) ​ ​ (948) ​ ​ ​ ​ ​ ​ ​ ​ (1,875) Translation differences ​ ​ ​ ​ ​ (20) ​ ​ ​ ​ ​ ​ ​ ​ (20) On December 31, 2023 ​ € 18,574 ​ € 4,354 ​ € 17,791 ​ € 6,664 ​ € 47,384 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ € 12,167 ​ € 40,362 ​ € 83,566 ​ € 10,258 ​ € 146,354 On December 31, 2023 ​ € 8,440 ​ € 38,817 ​ € 71,929 ​ € 8,720 ​ € 127,906

Property, plant and equipment (

Property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2023
Property, plant and equipment
Schedule of property, plant and equipment - Fully owned	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ FULLY OWNED Land, buildings & leasehold improvements Installation & machinery Furniture, fixtures & vehicles Other tangible assets Total ​ ​ (Euro, in thousands) Acquisition value ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 26,131 ​ € 46,270 ​ € 7,829 ​ € 60,324 ​ € 140,555 Impact of acquisitions of businesses ​ ​ 29 ​ ​ 2,117 ​ ​ 108 ​ ​ ​ ​ ​ 2,254 Additions ​ ​ 914 ​ ​ 5,688 ​ ​ 3,438 ​ ​ 19,296 ​ ​ 29,336 Sales and disposals ​ ​ (2,846) ​ ​ (600) ​ ​ (1,344) ​ ​ ​ ​ ​ (4,790) Reclassifications ​ ​ 64,286 ​ ​ 3,580 ​ ​ 167 ​ ​ (68,033) ​ ​ — Translation differences ​ ​ 205 ​ ​ (15) ​ ​ 43 ​ ​ ​ ​ ​ 233 On December 31, 2022 ​ ​ 88,719 ​ ​ 57,040 ​ ​ 10,241 ​ ​ 11,587 ​ ​ 167,588 Additions ​ ​ 6,754 ​ ​ 6,472 ​ ​ 268 ​ ​ 3,329 ​ ​ 16,823 Sales and disposals ​ ​ (4,403) ​ ​ (24,057) ​ ​ (1,067) ​ ​ (7,655) ​ ​ (37,182) Reclassifications ​ ​ 95 ​ ​ 272 ​ ​ 124 ​ ​ (491) ​ ​ — Reclassifications to assets in disposal group classified as held for sale ​ ​ (739) ​ ​ ​ ​ ​ (249) ​ ​ ​ ​ ​ (988) Translation differences ​ ​ 279 ​ ​ (49) ​ ​ 36 ​ ​ ​ ​ ​ 266 On December 31, 2023 ​ € 90,705 ​ € 39,678 ​ € 9,353 ​ € 6,770 ​ € 146,507 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciations and impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 5,505 ​ € 24,749 ​ € 4,582 ​ € — ​ € 34,837 Depreciation ​ ​ 4,433 ​ ​ 4,336 ​ ​ 1,265 ​ ​ ​ ​ ​ 10,034 Sales and disposals ​ ​ (2,173) ​ ​ (574) ​ ​ (1,328) ​ ​ ​ ​ ​ (4,075) Translation differences ​ ​ 49 ​ ​ (1) ​ ​ 18 ​ ​ ​ ​ ​ 66 On December 31, 2022 ​ ​ 7,814 ​ ​ 28,510 ​ ​ 4,537 ​ ​ — ​ ​ 40,862 Depreciation ​ ​ 4,603 ​ ​ 4,355 ​ ​ 1,290 ​ ​ ​ ​ ​ 10,248 Impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7,645 ​ ​ 7,645 Sales and disposals ​ ​ (1,194) ​ ​ (13,676) ​ ​ (827) ​ ​ (7,645) ​ ​ (23,342) Reclassifications to assets in disposal group classified as held for sale ​ ​ (161) ​ ​ ​ ​ ​ (129) ​ ​ ​ ​ ​ (290) Translation differences ​ ​ 156 ​ ​ (11) ​ ​ 19 ​ ​ ​ ​ ​ 164 On December 31, 2023 ​ € 11,218 ​ € 19,178 ​ € 4,891 ​ € — ​ € 35,287 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ € 80,905 ​ € 28,530 ​ € 5,704 ​ € 11,587 ​ € 126,726 On December 31, 2023 ​ € 79,487 ​ € 20,500 ​ € 4,463 ​ € 6,770 ​ € 111,220
Schedule of property, plant and equipment - Right of use	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ RIGHT-OF-USE Land & building Installation & machinery Furniture, fixtures & vehicles Total ​ ​ (Euro, in thousands) Acquisition value ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 37,461 ​ € 593 ​ € 10,184 ​ € 48,239 Additions ​ ​ 703 ​ ​ ​ ​ ​ 3,603 ​ ​ 4,306 Sales and disposals ​ ​ (3,554) ​ ​ (156) ​ ​ (1,274) ​ ​ (4,984) Translation differences ​ ​ 224 ​ ​ ​ ​ ​ (8) ​ ​ 216 On December 31, 2022 ​ ​ 34,834 ​ ​ 437 ​ ​ 12,505 ​ ​ 47,777 Additions ​ ​ 1,726 ​ ​ ​ ​ ​ 1,724 ​ ​ 3,450 Sales and disposals ​ ​ (11,497) ​ ​ (186) ​ ​ (1,897) ​ ​ (13,580) Reclassifications to assets in disposal group classified as held for sale ​ ​ (2,091) ​ ​ ​ ​ ​ (4,683) ​ ​ (6,774) Translation differences ​ ​ 202 ​ ​ ​ ​ ​ 3 ​ ​ 205 On December 31, 2023 ​ € 23,174 ​ € 251 ​ € 7,652 ​ € 31,078 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciations and impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 12,500 ​ € 374 ​ € 3,569 ​ € 16,444 Depreciation ​ ​ 4,421 ​ ​ 134 ​ ​ 3,141 ​ ​ 7,696 Sales and disposals ​ ​ (2,602) ​ ​ (156) ​ ​ (1,235) ​ ​ (3,993) Translation differences ​ ​ 105 ​ ​ ​ ​ ​ (2) ​ ​ 103 On December 31, 2022 ​ ​ 14,424 ​ ​ 352 ​ ​ 5,473 ​ ​ 20,250 Depreciation ​ ​ 3,342 ​ ​ 57 ​ ​ 3,450 ​ ​ 6,849 Sales and disposals ​ ​ (5,922) ​ ​ (186) ​ ​ (1,871) ​ ​ (7,979) Reclassifications to assets in disposal group classified as held for sale ​ ​ (699) ​ ​ ​ ​ ​ (2,580) ​ ​ (3,279) Translation differences ​ ​ 134 ​ ​ ​ ​ ​ 1 ​ ​ 135 On December 31, 2023 ​ € 11,279 ​ € 223 ​ € 4,473 ​ € 15,976 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ € 20,410 ​ € 85 ​ € 7,032 ​ € 27,526 On December 31, 2023 ​ € 11,895 ​ € 28 ​ € 3,179 ​ € 15,101 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 ​ ​ 2022 ​ ​ ​ ​ ​ ​ ​ ​ (Euro, in thousands) ​ ​ ​ Carrying amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Property, plant and equipment fully owned ​ ​ ​ ​ € 111,220 ​ € 126,726 ​ ​ ​ Right-of-use ​ ​ ​ ​ ​ 15,101 ​ ​ 27,526 ​ ​ ​ Total property, plant and equipment ​ ​ ​ ​ € 126,321 ​ € 154,252 ​ ​ ​

Other non-current assets (Table

Other non-current assets (Tables)	12 Months Ended
	Dec. 31, 2023
Other non-current assets
Schedule of other non-current assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Non-current restricted cash ​ € 5,533 ​ € 4,569 Financial assets held at fair value through profit or loss ​ ​ 13,575 ​ ​ — Non-current portion of upfront payment to NovAlix ​ ​ 4,656 ​ ​ — Non-current portion of advance related to the NovAliX transaction ​ ​ 5,563 ​ ​ — Other non-current assets ​ ​ 318 ​ ​ 1,209 Total other non-current assets ​ € 29,645 ​ € 5,778

Research and Development ince_2

Research and Development incentives receivables (Tables)	12 Months Ended
	Dec. 31, 2023
Research and Development incentives receivables
Schedule of the classifications of R&D incentives receivables	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Non-current R&D incentives receivables ​ € 141,252 ​ € 119,941 Current R&D incentives receivables ​ ​ 37,436 ​ ​ 26,126 Total R&D incentives receivables ​ € 178,688 ​ € 146,067
Schedule of maturities of non-current R&D incentives receivables	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ ​ ​ Maturity date ​ ​ ​ ​ 2025 2026 2027 2028 2029-2033 Total ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ French non-current R&D incentives receivables - discounted value ​ € 11,495 ​ ​ 11,511 ​ ​ 5,578 ​ ​ — ​ ​ — ​ € 28,584 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Belgian non-current R&D incentives receivables - discounted value ​ ​ 17,530 ​ ​ 19,340 ​ ​ 20,202 ​ ​ 19,858 ​ ​ 35,738 ​ ​ 112,668 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total non-current R&D incentives receivables - discounted value ​ € 29,025 ​ € 30,851 ​ ​ 25,780 ​ ​ 19,858 ​ ​ 35,738 ​ € 141,252 ​

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2023
Inventories
Schedule of inventories	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Raw materials ​ € 55,263 ​ € 39,071 Semi-finished products ​ ​ 12,598 ​ ​ 5,791 Finished products ​ ​ 6,117 ​ ​ 8,063 Total inventories ​ € 73,978 ​ € 52,925

Trade and other receivables a_2

Trade and other receivables and other current assets (Tables)	12 Months Ended
	Dec. 31, 2023
Trade and other receivables and other current assets
Schedule of trade and other receivables and other current assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Trade receivables ​ € 17,494 ​ € 28,194 Prepayments ​ ​ 738 ​ ​ 488 Other receivables ​ ​ 10,217 ​ ​ 11,747 Trade and other receivables ​ ​ 28,449 ​ ​ 40,429 Accrued income ​ ​ 508 ​ ​ 11,277 Deferred charges ​ ​ 14,632 ​ ​ 12,029 Other current assets ​ ​ 15,140 ​ ​ 23,307 Total trade and other receivables & other current assets ​ € 43,589 ​ € 63,735

Current financial investments (

Current financial investments (Tables)	12 Months Ended
	Dec. 31, 2023
Current financial investments
Schedule of current financial investments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Money market funds ​ € 1,316,805 ​ € 1,292,514 Treasury bills ​ ​ 742,025 ​ ​ 749,835 Term deposits ​ ​ 1,458,868 ​ ​ 1,543,596 Total current financial investments ​ € 3,517,698 ​ € 3,585,945

Cash and cash equivalents (Tabl

Cash and cash equivalents (Tables)	12 Months Ended
	Dec. 31, 2023
Cash and cash equivalents
Schedule of cash and cash equivalents	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 ​ 2022 ​ ​ (Euro, in thousands) Cash at banks ​ € 71,803 ​ € 458,117 Term deposits ​ ​ 95,000 ​ ​ 50,000 Cash and cash equivalents from continuing operations ​ € 166,803 ​ € 508,117 Cash and cash equivalents included in assets held for sale ​ ​ 7 ​ ​ — Total cash and cash equivalents ​ € 166,810 ​ € 508,117

Share capital (Tables)

Share capital (Tables)	12 Months Ended
	Dec. 31, 2023
Share capital
Schedule of reconciliation of share capital	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 2021 ​ ​ (Euro, in thousands) On January 1 ​ € 293,604 ​ € 292,075 ​ € 291,312 Share capital increase ​ ​ 333 ​ ​ 1,530 ​ ​ 763 Costs of capital increase ​ ​ — ​ ​ — ​ ​ — Share capital on December 31, ​ € 293,937 ​ € 293,604 ​ € 292,075 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Aggregate share capital ​ € 356,445 ​ € 356,112 ​ € 354,582 Costs of capital increase (accumulated) ​ ​ (62,507) ​ ​ (62,507) ​ ​ (62,507) Share capital on December 31, ​ € 293,937 ​ € 293,604 ​ € 292,075
Schedule of history of the share capital	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Date ​ ​ Share capital increase due to exercise subscription rights (in thousands €) ​ Number of shares issued (in thousands of shares) ​ Aggregate number of shares after transaction (in thousands of shares) Aggregate share capital after transaction (in thousands €) January 1, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 65,412 ​ € 353,819 March 19, 2021 ​ ​ ​ ​ ​ ​ ​ ​ 540 ​ ​ 100 ​ ​ ​ ​ ​ ​ June 7, 2021 ​ ​ ​ ​ ​ ​ ​ ​ 59 ​ ​ 11 ​ ​ ​ ​ ​ ​ September 20, 2021 ​ ​ ​ ​ ​ ​ ​ ​ 41 ​ ​ 8 ​ ​ ​ ​ ​ ​ December 3, 2021 ​ ​ ​ ​ ​ ​ ​ ​ 123 ​ ​ 23 ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 65,553 ​ ​ 354,582 March 18, 2022 ​ ​ ​ ​ ​ ​ ​ ​ 517 ​ ​ 96 ​ ​ ​ ​ ​ ​ June 20, 2022 ​ ​ ​ ​ ​ ​ ​ ​ 434 ​ ​ 80 ​ ​ ​ ​ ​ ​ September 27, 2022 ​ ​ ​ ​ ​ ​ ​ ​ 579 ​ ​ 107 ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 65,836 ​ ​ 356,112 March 20, 2023 ​ ​ ​ ​ ​ ​ ​ ​ 333 ​ ​ 62 ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 65,897 ​ € 356,445
Summary of capital increases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (Euro, in thousands, except share data) Number of shares Share capital Share premium ​ Share capital and share premium ​ Average exercise price subscription right ​ Closing share price on date of capital increase ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ( in Euro/ subscription right) ​ ​ ( in Euro/ share) On January 1, 2021 ​ ​ 65,411,767 ​ € 291,312 ​ € 2,727,840 ​ € 3,019,153 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 19, 2021 : exercise of subscription rights ​ ​ 99,814 ​ ​ 540 ​ ​ 1,718 ​ ​ 2,258 ​ ​ 22.62 ​ ​ 68.48 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 7, 2021 : exercise of subscription rights ​ ​ 10,940 ​ ​ 59 ​ ​ 266 ​ ​ 325 ​ ​ 29.73 ​ ​ 61.78 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 20, 2021 : exercise of subscription rights ​ ​ 7,600 ​ ​ 41 ​ ​ 111 ​ ​ 152 ​ ​ 19.97 ​ ​ 46.93 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 3, 2021 : exercise of subscription rights ​ ​ 22,600 ​ ​ 123 ​ ​ 456 ​ ​ 579 ​ ​ 25.61 ​ ​ 41.72 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2021 ​ ​ 65,552,721 ​ ​ 292,075 ​ ​ 2,730,391 ​ ​ 3,022,467 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 18, 2022 : exercise of subscription rights ​ ​ 95,500 ​ ​ 517 ​ ​ 1,643 ​ ​ 2,160 ​ ​ 22.61 ​ ​ 57.38 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 20, 2022 : exercise of subscription rights ​ ​ 80,290 ​ ​ 434 ​ ​ 1,025 ​ ​ 1,460 ​ ​ 18.18 ​ ​ 53.52 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 27, 2022 : exercise of subscription rights ​ ​ 107,000 ​ ​ 579 ​ ​ 2,497 ​ ​ 3,076 ​ ​ 28.75 ​ ​ 44.49 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ ​ 65,835,511 ​ ​ 293,604 ​ ​ 2,735,557 ​ ​ 3,029,162 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 20, 2023 : exercise of subscription rights ​ ​ 61,560 ​ ​ 333 ​ ​ 1,437 ​ ​ 1,770 ​ ​ 28.75 ​ ​ 35.47 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2023 ​ ​ 65,897,071 ​ € 293,937 ​ € 2,736,994 ​ € 3,030,932 ​ ​ ​ ​ ​ ​
Summary of other information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ordinary shares Total Par value of shares (€) ​ ​ ​ ​ ​ 5.41 ​ ​ 5.41

Deferred tax (Tables)

Deferred tax (Tables)	12 Months Ended
	Dec. 31, 2023
Deferred tax
Movements in deferred tax assets and deferred tax liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ DEFERRRED TAX ASSETS ​ Retirement benefit liabilities Tax loss carryforward Property, plant and equipment Other Total deferred tax assets ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 776 ​ € 3,133 ​ ​ ​ ​ € 122 ​ € 4,032 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Credited/charged (-) to profit or loss ​ ​ 17 ​ ​ (1,797) ​ ​ ​ ​ ​ 165 ​ ​ (1,615) Reclassification ​ ​ ​ ​ ​ (275) ​ ​ ​ ​ ​ ​ ​ ​ (275) Charged to other comprehensive income ​ ​ (795) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (795) Exchange differences ​ ​ 22 ​ ​ ​ ​ ​ ​ ​ ​ (6) ​ ​ 15 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ ​ 19 ​ ​ 1,061 ​ € — ​ ​ 281 ​ ​ 1,363 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Credited/charged (-) to profit or loss ​ ​ ​ ​ ​ (1,061) ​ ​ 298 ​ ​ 692 ​ ​ (72) Reclassification to assets/liabilities held for sale ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (292) ​ ​ (292) Charged to other comprehensive income ​ ​ 132 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 132 Exchange differences ​ ​ 8 ​ ​ ​ ​ ​ (6) ​ ​ (6) ​ ​ (4) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2023 ​ € 159 ​ € — ​ € 292 ​ € 675 ​ € 1,126 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ DEFERRED TAX LIABILITIES ​ ​ ​ ​ ​ ​ ​ Intangible assets other than goodwill Other Total deferred tax liabilities ​ ​ ​ ​ ​ ​ ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € — ​ ​ ​ ​ € — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Impact of acquisition of businesses ​ ​ (23,265) ​ ​ ​ ​ ​ (23,265) ​ ​ ​ ​ ​ ​ Credited/charged (-) to profit or loss ​ ​ 2,842 ​ ​ ​ ​ ​ 2,842 ​ ​ ​ ​ ​ ​ Reclassification ​ ​ 275 ​ ​ ​ ​ ​ 275 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ ​ (20,148) ​ € — ​ ​ (20,148) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Credited/charged (-) to profit or loss ​ ​ (1,458) ​ ​ (2,019) ​ ​ (3,477) ​ ​ ​ ​ ​ ​ Exchange differences ​ ​ 18 ​ ​ ​ ​ ​ 18 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2023 ​ € (21,588) ​ € (2,019) ​ € (23,607) ​ ​ ​ ​ ​ ​ ​

Lease liabilities (Tables)

Lease liabilities (Tables)	12 Months Ended
	Dec. 31, 2023
Lease liabilities.
Schedule of lease liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ 2023 2022 ​ 2023 2022 ​ ​ (Euro, in thousands) ​ (Euro, in thousands) ​ Lease payments Present value of lease payments Lease liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Within one year ​ € 4,779 ​ € 7,507 ​ € 4,652 ​ € 7,209 In the second to fifth years inclusive ​ ​ 5,031 ​ ​ 14,401 ​ ​ 4,944 ​ ​ 14,100 After five years ​ ​ — ​ ​ 609 ​ ​ — ​ ​ 592 ​ ​ € 9,810 ​ € 22,517 ​ € 9,596 ​ € 21,901 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less future finance charges ​ ​ 214 ​ ​ 616 ​ ​ ​ ​ ​ ​ Present value of lease liabilities ​ € 9,596 ​ € 21,901 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less amount due for settlement within 12 months ​ ​ 4,652 ​ ​ 7,209 ​ ​ 4,652 ​ ​ 7,209 Amount due for settlement after 12 months ​ € 4,944 ​ € 14,692 ​ € 4,944 ​ € 14,692 ​

Trade and other liabilities a_2

Trade and other liabilities and other non-current liabilities (Tables)	12 Months Ended
	Dec. 31, 2023
Trade and other liabilities and other non-current liabilities
Schedule of trade and other liabilities and other non-current liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 ​ ​ (Euro, in thousands) Trade and other liabilities ​ € 134,653 ​ € 133,298 Current contingent consideration related to milestones CellPoint ​ ​ — ​ ​ 8,485 Current deferred consideration payable CellPoint ​ ​ — ​ ​ 6,222 Current financial instruments ​ ​ — ​ ​ 19 Accrued charges ​ ​ 548 ​ ​ 651 Total trade and other liabilities ​ € 135,201 ​ € 148,675 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-current contingent consideration related to milestones CellPoint ​ € 20,972 ​ € 13,582 Other non-current liabilities ​ ​ 10,598 ​ ​ 8,226 Total other non-current liabilities ​ € 31,570 ​ € 21,808

Deferred income (Tables)

Deferred income (Tables)	12 Months Ended
	Dec. 31, 2023
Deferred income
Schedule of movement in the non-current and current deferred income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gilead collaboration agreement for filgotinib Gilead collaboration agreement for drug discovery platform (1) Other deferred income Total ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2022 ​ € 604,875 ​ € 1,759,828 ​ € — ​ € 2,364,701 Of which current portion : ​ ​ 190,018 ​ ​ 229,848 ​ ​ — ​ ​ 419,866 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Upfront received ​ ​ 18,238 ​ ​ ​ ​ ​ ​ ​ ​ 18,238 Significant financing component (2) ​ ​ 7,672 ​ ​ ​ ​ ​ ​ ​ ​ 7,672 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue recognition of upfront ​ ​ (139,655) ​ ​ (230,423) ​ ​ ​ ​ ​ (370,078) Revenue recognition of milestones ​ ​ (34,777) ​ ​ ​ ​ ​ ​ ​ ​ (34,777) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other movements ​ ​ ​ ​ ​ ​ ​ ​ 3,474 ​ ​ 3,474 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2022 ​ € 456,352 ​ € 1,529,405 ​ € 3,474 ​ ​ 1,989,230 Of which current portion : ​ ​ 133,470 ​ ​ 230,022 ​ ​ 2,139 ​ ​ 365,631 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reclassification to liabilities directly associated with assets in disposal group classified as held for sale ​ ​ ​ ​ ​ ​ ​ ​ (60) ​ ​ (60) Significant financing component (2) ​ ​ (645) ​ ​ ​ ​ ​ ​ ​ ​ (645) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenue recognition of upfront ​ ​ (361,412) ​ ​ (230,242) ​ ​ ​ ​ ​ (591,654) Revenue recognition of milestones ​ ​ (68,027) ​ ​ ​ ​ ​ ​ ​ ​ (68,027) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other movements ​ ​ ​ ​ ​ ​ ​ ​ (1,382) ​ ​ (1,382) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2023 ​ € 26,268 ​ € 1,299,163 ​ € 2,032 ​ € 1,327,463 Of which current portion : ​ ​ 25,054 ​ ​ 230,070 ​ ​ 1,146 ​ ​ 256,270 (1) The upfront received and the outstanding balance comprise the issuance liabilities for the warrants and the upfront payment allocated to the drug discovery platform. (2) With regard to the additional consideration received for the extended cost sharing for filgotinib, we assume the existence of a sigificant financing component reflecting the time value of money on the estimated recognition period

Business combinations during _2

Business combinations during the period. (Tables)	12 Months Ended
	Dec. 31, 2023
Business combinations during the period.
Schedule of fair value of identifiable assets and liabilities acquired	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 21, 2022 ​ ​ ​ ​ ​ (Euro, in thousands) ​ ​ CellPoint ​ AboundBio ​ Total ​ Book value Adjustment Fair value Book value Adjustment Fair value ​ ​ Intangible assets other than goodwill ​ ​ ​ ​ € 120,517 ​ € 120,517 ​ ​ ​ ​ € 4,053 ​ € 4,053 ​ ​ ​ Property, plant and equipment ​ € 1,289 ​ ​ ​ ​ ​ 1,289 ​ € 965 ​ ​ ​ ​ ​ 965 ​ ​ ​ Other non-current assets ​ ​ 81 ​ ​ ​ ​ ​ 81 ​ ​ 4 ​ ​ ​ ​ ​ 4 ​ ​ ​ Trade and other receivables ​ ​ 162 ​ ​ ​ ​ ​ 162 ​ ​ - ​ ​ ​ ​ ​ - ​ ​ ​ Cash and cash equivalents ​ ​ 3,179 ​ ​ ​ ​ ​ 3,179 ​ ​ 4,279 ​ ​ ​ ​ ​ 4,279 ​ ​ ​ Other current assets ​ ​ 1,254 ​ ​ ​ ​ ​ 1,254 ​ ​ 536 ​ ​ ​ ​ ​ 536 ​ ​ ​ Deferred tax liabilities ​ ​ - ​ ​ (22,368) ​ ​ (22,368) ​ ​ - ​ ​ (907) ​ ​ (907) ​ ​ ​ Trade and other liabilities ​ ​ (32,789) ​ ​ ​ ​ ​ (32,789) ​ ​ (587) ​ ​ ​ ​ ​ (587) ​ ​ ​ Current deferred income ​ ​ - ​ ​ ​ ​ ​ - ​ ​ (474) ​ ​ ​ ​ ​ (474) ​ ​ ​ Net assets acquired ​ ​ (26,824) ​ ​ 98,149 ​ ​ 71,325 ​ ​ 4,723 ​ ​ 3,146 ​ ​ 7,869 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Consideration paid in cash ​ ​ ​ ​ ​ ​ ​ ​ 107,750 ​ ​ ​ ​ ​ ​ ​ ​ 14,976 ​ ​ ​ Fair value re-measurement of previously held equity investment ​ ​ ​ ​ ​ ​ ​ ​ - ​ ​ ​ ​ ​ ​ ​ ​ 342 ​ ​ ​ Deferred consideration ​ ​ ​ ​ ​ ​ ​ ​ 5,808 ​ ​ ​ ​ ​ ​ ​ ​ - ​ ​ ​ Fair value of contingent consideration ​ ​ ​ ​ ​ ​ ​ ​ 20,211 ​ ​ ​ ​ ​ ​ ​ ​ - ​ ​ ​ Fair value of total consideration ​ ​ ​ ​ ​ ​ ​ ​ 133,769 ​ ​ ​ ​ ​ ​ ​ ​ 15,318 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Goodwill ​ ​ ​ ​ ​ ​ ​ ​ 62,444 ​ ​ ​ ​ ​ ​ ​ ​ 7,449 ​ ​ ​ Exchange differences on goodwill ​ ​ ​ ​ ​ ​ ​ ​ - ​ ​ ​ ​ ​ ​ ​ ​ (80) ​ ​ ​ Goodwill in the balance sheet at December 31, 2022 ​ ​ ​ ​ ​ ​ ​ € 62,444 ​ ​ ​ ​ ​ ​ ​ € 7,369 ​ € 69,813 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net cash outflow arising on acquisition (2022) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Consideration paid in cash ​ ​ ​ ​ ​ ​ ​ ​ 107,750 ​ ​ ​ ​ ​ ​ ​ ​ 14,976 ​ ​ ​ Less: cash and cash equivalents balances acquired ​ ​ ​ ​ ​ ​ ​ ​ (3,179) ​ ​ ​ ​ ​ ​ ​ ​ (4,279) ​ ​ ​ Cash out from acquisition of subsidiaries, net of cash acquired (paid in 2022) ​ ​ ​ ​ ​ ​ ​ € 104,571 ​ ​ ​ ​ ​ ​ ​ ​ 10,698 ​ € 115,270 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash used in operating activities for other liabilities related to the acquisition of subsidiaries (2022) ​ ​ ​ ​ ​ ​ ​ € 28,164 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ € 28,164 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash out from acquisition of subsidiaries (payment of deferred consideration in 2023) ​ ​ ​ ​ ​ ​ ​ € 7,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ € 7,000

Details of the NovAlix transa_2

Details of the NovAlix transaction (Tables)	12 Months Ended
	Dec. 31, 2023
Details of the NovAlix transaction
Schedule of advances	​ ​ ​ ​ ​ ​ June 30, ​ 2023 ​ ​ (Euro, in thousands) ​ ​ ​ ​ Loss on sale of fixed assets ​ € 12,506 Result of transfer of retirement benefit liability ​ ​ (3,022) Result of transfer of right-of-use asset ​ ​ 174 Advance related to the NovAliX transaction ​ € 9,658

Note to the cash flow stateme_2

Note to the cash flow statement (Tables)	12 Months Ended
	Dec. 31, 2023
Consolidated Statement of Cash Flows
Adjustments related to operating cash flow	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 ​ ​ (Euro, in thousands) Adjustment for non-cash transactions ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and impairment ​ € 43,642 ​ € 65,566 ​ € 34,636 Share-based compensation expenses ​ ​ 56,718 ​ ​ 88,506 ​ ​ 70,726 Increase/decrease (-) in retirement benefit obligations and provisions ​ ​ 11 ​ ​ 136 ​ ​ (2,347) Unrealized exchange losses/gains (-) and non-cash other financial result ​ ​ 19,908 ​ ​ (41,970) ​ ​ (57,073) Discounting effect of non-current deferred income ​ ​ (645) ​ ​ 7,672 ​ ​ 9,289 Discounting effect of other non-current liabilities ​ ​ (318) ​ ​ 2,271 ​ ​ — Fair value re-measurement of warrants ​ ​ (18) ​ ​ (186) ​ ​ (2,960) Net change in fair value of current financial investments ​ ​ (22,690) ​ ​ (6,929) ​ ​ (119) Fair value adjustment financial assets held at fair value through profit or loss ​ ​ 390 ​ ​ — ​ ​ 4,919 Other non-cash expenses ​ ​ 2,292 ​ ​ 2,229 ​ ​ 648 Total adjustment for non-cash transactions ​ € 99,291 ​ € 117,296 ​ € 57,718 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Adjustment for items to disclose separately under operating cash flow ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest expense ​ € 1,867 ​ € 6,967 ​ € 11,656 Interest income ​ ​ (79,319) ​ ​ (14,344) ​ ​ (2,853) Tax expense ​ ​ 11,689 ​ ​ 2,844 ​ ​ 2,423 Total adjustment for items to disclose separately under operating cash flow ​ € (65,763) ​ € (4,533) ​ € 11,227 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Adjustment for items to disclose under investing and financing cash flows ​ ​ ​ ​ ​ ​ ​ ​ ​ Gain on disposal of subsidiaries ​ € — ​ € — ​ € (22,191) Gain on sale of fixed assets ​ ​ (1,091) ​ ​ (23) ​ ​ — Realized exchange gain on sale of current financial investments ​ ​ — ​ ​ — ​ ​ (6,645) Investment income related to current financial investments ​ ​ (15,597) ​ ​ (3,766) ​ ​ (12) Total adjustment for items to disclose separately under investing and financing cash flow ​ € (16,688) ​ € (3,789) ​ € (28,847) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Change in working capital other than deferred income ​ ​ ​ ​ ​ ​ ​ ​ ​ Increase in inventories ​ € (24,076) ​ € (34,588) ​ € (21,168) Increase (-)/ decrease in receivables ​ ​ (39,114) ​ ​ 68,984 ​ ​ 79,859 Increase/decrease (-) in liabilities ​ ​ 31,817 ​ ​ (2,083) ​ ​ (35,353) Total change in working capital other than deferred income ​ € (31,373) ​ € 32,313 ​ € 23,337 ​

Off-balance sheet arrangements

Off-balance sheet arrangements (Tables)	12 Months Ended
	Dec. 31, 2023
Off-balance sheet arrangements
Schedule of outstanding obligation for future lease and purchase commitments	On December 31, 2023, we had outstanding obligations for future purchase commitments, which become due as ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years ​ ​ ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Purchase commitments ​ € 408,521 ​ € 237,495 ​ ​ 143,532 ​ ​ 25,768 ​ ​ 1,727 ​ ​ On December 31, 2022, we had outstanding obligations for future purchase commitments, which become due as ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years ​ ​ ​ ​ (Euro, in thousands) ​ ​ Purchase commitments ​ € 398,627 ​ € 240,237 ​ € 136,560 ​ € 20,797 ​ € 1,032 ​

Share based payments (Tables)

Share based payments (Tables)	12 Months Ended
	Dec. 31, 2023
Disclosure of terms and conditions of share-based payment arrangement [line items]
RSUs outstanding	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 2022 ​ 2021 ​ ​ ​ (in number of RSUs) Outstanding on January 1, ​ ​ 736,095 ​ ​ 657,803 ​ ​ 313,596 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Granted during the year ​ ​ 920,510 ​ ​ 470,273 ​ ​ 511,518 Forfeited during the year ​ ​ (270,474) ​ ​ (172,885) ​ ​ (74,873) Paid in cash during the year ​ ​ (210,678) ​ ​ (219,096) ​ ​ (92,438) Outstanding on December 31, ​ ​ 1,175,453 ​ ​ 736,095 ​ ​ 657,803
Subscription rights
Disclosure of terms and conditions of share-based payment arrangement [line items]
Schedule of Subscription Rights exercisable	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Subscription right exercisable as from: ​ Cliff vesting ​ Graded vesting ​ ​ ​ First tranche of 25% ​ Second tranche of 25% ​ Third tranche of 50% Subscription right plans before 2021 ​ First day after end of third calenderyear following the grant ​ — ​ — ​ — Subscription right plan 2021BE ​ First day after end of third calenderyear following the grant ​ — ​ — ​ — Subscription right plan 2021RMV and ROW ​ — ​ January 1, 2023 ​ January 1, 2024 ​ January 1, 2025 Subscription right plan 2022 (A) ​ — ​ January 1, 2023 ​ January 1, 2024 ​ January 1, 2025 Subscription right plan 2022 (B) ​ January 1, 2026 ​ — ​ — ​ — Subscription right plan 2022BE ​ January 1, 2026 ​ — ​ — ​ — Subscription right plan 2022RMV and ROW ​ — ​ January 1, 2024 ​ January 1, 2025 ​ January 1, 2026 Subscription right plan 2023BE ​ January 1, 2027 ​ — ​ — ​ — Subscription right plan 2023RMV and ROW ​ — ​ January 1, 2025 ​ January 1, 2026 ​ January 1, 2027
Schedule of summary of other equity instruments outstanding and exercisable per plan	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding ​ ​ ​ ​ Outstanding Exercisable ​ ​ ​ ​ ​ ​ ​ ​ per ​ Granted ​ Exercised ​ Forfeited ​ Expired ​ per ​ per ​ ​ Allocation ​ Expiry ​ Exercise ​ January 1, ​ during ​ during ​ during ​ during ​ December 31, ​ December 31, Subscription right plan ​ date ​ date ​ price (€) ​ 2023 ​ year ​ year ​ year ​ year ​ 2023 ​ 2023 2015 ​ 04/30/2015 ​ 04/29/2023 ​ 28.75 ​ 63,223 ​ ​ ​ (61,560) ​ (1,663) ​ ​ ​ — ​ — 2015 (B) ​ 12/22/2015 ​ 12/21/2023 ​ 49.00 ​ 241,500 ​ ​ ​ ​ ​ ​ ​ (241,500) ​ — ​ — 2015 RMV ​ 12/22/2015 ​ 12/21/2023 ​ 49.00 ​ 35,000 ​ ​ ​ ​ ​ ​ ​ (35,000) ​ — ​ — 2016 ​ 1/6/2016 ​ 05/31/2024 ​ 46.10 ​ 325,500 ​ ​ ​ ​ ​ ​ ​ ​ ​ 325,500 ​ 325,500 2016 RMV ​ 1/6/2016 ​ 05/31/2024 ​ 46.10 ​ 69,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 69,000 ​ 69,000 2016 (B) ​ 01/20/2017 ​ 01/19/2025 ​ 62.50 ​ 10,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 10,000 ​ 10,000 2017 ​ 05/17/2017 ​ 05/16/2025 ​ 80.57 ​ 590,000 ​ ​ ​ ​ ​ (5,000) ​ ​ ​ 585,000 ​ 585,000 2017 RMV ​ 05/17/2017 ​ 05/16/2025 ​ 80.57 ​ 127,500 ​ ​ ​ ​ ​ (5,000) ​ ​ ​ 122,500 ​ 122,500 2018 ​ 04/19/2018 ​ 04/18/2026 ​ 79.88 ​ 974,995 ​ ​ ​ ​ ​ (10,000) ​ ​ ​ 964,995 ​ 964,995 2018 RMV ​ 04/19/2018 ​ 04/18/2026 ​ 79.88 ​ 137,500 ​ ​ ​ ​ ​ (5,000) ​ ​ ​ 132,500 ​ 132,500 2019 ​ 10/4/2019 ​ 9/4/2027 ​ 95.11 ​ 1,216,990 ​ ​ ​ ​ ​ (8,750) ​ ​ ​ 1,208,240 ​ 1,208,240 2019 RMV ​ 10/4/2019 ​ 9/4/2027 ​ 95.11 ​ 186,000 ​ ​ ​ ​ ​ (8,750) ​ ​ ​ 177,250 ​ 177,250 2020 ​ 04/17/2020 ​ 04/16/2028 ​ 168.42 ​ 1,458,244 ​ ​ ​ ​ ​ (88,627) ​ ​ ​ 1,369,617 ​ 1,317,779 2020RMV ​ 04/17/2020 ​ 04/16/2028 ​ 168.42 ​ 209,075 ​ ​ ​ ​ ​ (15,775) ​ ​ ​ 193,300 ​ 193,300 2021BE ​ 04/30/2021 ​ 04/29/2029 ​ 64.76 ​ 1,041,148 ​ ​ ​ ​ ​ (8,542) ​ ​ ​ 1,032,606 ​ ​ 2021RMV ​ 04/30/2021 ​ 04/29/2029 ​ 64.76 ​ 257,700 ​ ​ ​ ​ ​ (31,404) ​ ​ ​ 226,296 ​ 117,030 2021ROW ​ 04/30/2021 ​ 04/29/2029 ​ 64.76 ​ 783,375 ​ ​ ​ ​ ​ (115,879) ​ ​ ​ 667,496 ​ 356,418 2022 (A) ​ 01/13/2022 ​ 12/1/2030 ​ 46.18 ​ 30,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 30,000 ​ 15,000 2022 (B) ​ 01/26/2022 ​ 01/25/2030 ​ 50.00 ​ 1,000,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 1,000,000 ​ ​ 2022BE ​ 6/5/2022 ​ 5/5/2030 ​ 57.46 ​ 831,542 ​ ​ ​ ​ ​ (13,714) ​ ​ ​ 817,828 ​ ​ 2022BE ​ 5/8/2022 ​ 5/5/2030 ​ 51.58 ​ 78,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 78,000 ​ ​ 2022RMV ​ 6/5/2022 ​ 5/5/2030 ​ 57.46 ​ 242,714 ​ ​ ​ ​ ​ (39,250) ​ ​ ​ 203,464 ​ 50,770 2022ROW ​ 6/5/2022 ​ 5/5/2030 ​ 57.46 ​ 847,850 ​ ​ ​ ​ ​ (142,350) ​ ​ ​ 705,500 ​ 176,256 2022ROW ​ 5/8/2022 ​ 4/8/2030 ​ 51.58 ​ 60,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ 60,000 ​ 15,000 2023BE ​ 5/5/2023 ​ 4/5/2031 ​ 35.11 ​ — ​ 611,000 ​ ​ ​ (1,972) ​ ​ ​ 609,028 ​ ​ 2023RMV ​ 5/5/2023 ​ 4/5/2031 ​ 35.11 ​ — ​ 110,000 ​ ​ ​ (7,500) ​ ​ ​ 102,500 ​ ​ 2023ROW ​ 5/5/2023 ​ 4/5/2031 ​ 35.11 ​ — ​ 597,400 ​ ​ ​ (35,500) ​ ​ ​ 561,900 ​ ​ 2023BE ​ 06/15/2023 ​ 06/14/2031 ​ 38.58 ​ — ​ 200,000 ​ ​ ​ ​ ​ ​ ​ 200,000 ​ ​ 2023ROW ​ 11/17/2023 ​ 4/5/2031 ​ 32.99 ​ — ​ 20,000 ​ ​ ​ ​ ​ ​ ​ 20,000 ​ ​ Total ​ ​ ​ ​ ​ ​ ​ 10,816,856 ​ 1,538,400 ​ (61,560) ​ (544,676) ​ (276,500) ​ 11,472,520 ​ 5,836,538 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ average ​ ​ ​ ​ ​ exercise ​ ​ ​ Subscription rights ​ price (Euro) Outstanding on January 1, 2021 ​ ​ 6,929,111 ​ € 103.95 Exercisable on December 31, 2020 ​ ​ 1,168,967 ​ ​ 37.84 ​ ​ ​ ​ ​ ​ ​ Granted during the period ​ ​ 2,493,433 ​ ​ 64.76 Forfeited during the year ​ ​ (701,753) ​ ​ 118.53 Exercised during the period ​ ​ (140,954) ​ ​ 23.51 Expired during the year ​ ​ — ​ ​ — Outstanding on December 31, 2021 ​ ​ 8,579,837 ​ € 92.69 Exercisable on December 31, 2021 ​ ​ 1,751,013 ​ ​ 56.64 ​ ​ ​ ​ ​ ​ ​ Granted during the period ​ ​ 3,127,239 ​ ​ 54.71 Forfeited during the year ​ ​ (607,430) ​ ​ 100.00 Exercised during the period ​ ​ (282,790) ​ ​ 23.68 Expired during the year ​ ​ — ​ ​ — Outstanding on December 31, 2022 ​ ​ 10,816,856 ​ € 83.12 Exercisable on December 31, 2022 ​ ​ 2,574,218 ​ ​ 70.26 ​ ​ ​ ​ ​ ​ ​ Granted during the period ​ ​ 1,538,400 ​ ​ 35.53 Forfeited during the year ​ ​ (544,676) ​ ​ 80.31 Exercised during the period ​ ​ (61,560) ​ ​ 28.75 Expired during the year ​ ​ (276,500) ​ ​ 49.00 Outstanding on December 31, 2023 ​ ​ 11,472,520 ​ € 77.93 Exercisable on December 31, 2023 ​ ​ 5,836,538 ​ ​ 101.93
Schedule of inputs into the valuation of the other equity instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023BE 2023RMV/ROW ​ ​ 2022 (A) 2022 (B) ​ ​ ​ ​ ​ ​ ​ May 5 & June 15 ​ May 5 & November 17 ​ ​ ​ January 13 ​ January 26 ​ ​ ​ ​ ​ ​ Weighted average exercise price (€) ​ € 35.97 ​ € 35.05 ​ ​ ​ ​ € 46.18 ​ € 50.00 ​ ​ ​ ​ ​ ​ Weighted average share price at acceptance date (€) ​ € 38.53 ​ € 38.63 ​ ​ ​ ​ € 46.21 ​ € 56.67 ​ ​ ​ ​ ​ ​ Weighted average fair value at the acceptance date (€) ​ € 16.61 ​ € 15.96 ​ ​ ​ ​ € 16.10 ​ € 24.53 ​ ​ ​ ​ ​ ​ Weighted average estimated volatility (%) ​ ​ 36.89 ​ ​ 36.67 ​ ​ ​ ​ ​ 41.80 ​ ​ 40.80 ​ ​ ​ ​ ​ ​ Weighted average expected life of the subscription rights (years) ​ ​ 6.14 ​ ​ 5.38 ​ ​ ​ ​ ​ 4.72 ​ ​ 5.95 ​ ​ ​ ​ ​ ​ Weighted average risk free rate (%) ​ ​ 2.77 ​ ​ 2.74 ​ ​ ​ ​ ​ (0.13) ​ ​ 0.67 ​ ​ ​ ​ ​ ​ Expected dividends ​ ​ None ​ ​ None ​ ​ ​ ​ ​ None ​ ​ None ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022BE ​ 2022 RMV/ROW ​ 2022BE/ROW ​ 2021 ​ 2021 RMV/ROW ​ ​ ​ ​ ​ ​ ​ ​ May 6 ​ May 6 ​ August 6 April 30 ​ April 30 ​ ​ ​ ​ ​ ​ Exercise Price (€) ​ € 57.46 ​ € 57.46 ​ € 51.58 ​ € 64.76 ​ € 64.76 ​ ​ ​ ​ ​ ​ Weighted average share price at acceptance date (€) ​ € 51.64 ​ € 51.64 ​ € 44.55 ​ € 61.10 ​ € 61.10 ​ ​ ​ ​ ​ ​ Weighted average fair value at the acceptance date (€) ​ € 20.73 ​ € 18.92 ​ € 17.07 ​ € 22.72 ​ € 20.68 ​ ​ ​ ​ ​ ​ Weighted average estimated volatility (%) ​ ​ 42.59 ​ ​ 42.65 ​ ​ 41.75 ​ ​ 40.73 ​ ​ 40.61 ​ ​ ​ ​ ​ ​ Weighted average expected life of the subscription rights (years) ​ ​ 6.37 ​ ​ 5.36 ​ ​ 5.68 ​ ​ 6.43 ​ ​ 5.36 ​ ​ ​ ​ ​ ​ Weighted average risk free rate (%) ​ ​ 1.33 ​ ​ 1.26 ​ ​ 2.70 ​ ​ (0.21) ​ ​ (0.29) ​ ​ ​ ​ ​ ​ Expected dividends ​ ​ None ​ ​ None ​ ​ None ​ ​ None ​ ​ None ​ ​ ​ ​ ​ ​
Schedule of summary of other equity instruments outstanding by category	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 (1) ​ ​ (in number of subscription rights) Members of the Board of Directors ​ ​ 7,500 ​ ​ 75,000 ​ ​ 157,560 Members of the Executive Committee ​ ​ 1,670,500 ​ ​ 1,864,000 ​ ​ 1,965,000 Personnel ​ ​ 9,794,520 ​ ​ 8,877,856 ​ ​ 6,457,277 Total subscription rights outstanding ​ ​ 11,472,520 ​ ​ 10,816,856 ​ ​ 8,579,837 ​
Restricted Stock Units (RSUs)
Disclosure of terms and conditions of share-based payment arrangement [line items]
Schedule of summary of other equity instruments outstanding and exercisable per plan	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding ​ ​ ​ Outstanding ​ ​ ​ ​ per ​ Granted ​ Forfeited ​ Paid in cash ​ per ​ ​ Offer ​ January 1, ​ during ​ during ​ during ​ December 31, RSU plan ​ date ​ 2023 ​ year ​ year ​ year ​ 2023 Plan 2019.II. ​ 10/16/2019 ​ 12,931 ​ ​ ​ (768) ​ (12,163) ​ — Plan 2020.I. ​ 06/05/2020 ​ 17,110 ​ ​ ​ (2,558) ​ (9,361) ​ 5,191 Plan 2020.II. ​ 07/05/2020 ​ 17,626 ​ ​ ​ (6,530) ​ (8,335) ​ 2,761 Plan 2021.I. ​ 05/05/2021 ​ 92,600 ​ ​ ​ (23,150) ​ (26,621) ​ 42,829 Plan 2021.II. ​ 05/06/2021 ​ 22,341 ​ ​ ​ (7,447) ​ (5,416) ​ 9,478 Plan 2021.III. ​ 06/03/2021 ​ 16,259 ​ ​ ​ (2,636) ​ (8,207) ​ 5,416 Plan 2021.IV. ​ 09/24/2021 ​ 101,838 ​ ​ ​ (52,462) ​ (33,946) ​ 15,430 Plan 2022.I. ​ 03/05/2022 ​ 194,638 ​ ​ ​ (49,844) ​ (41,486) ​ 103,308 Plan 2022.II. ​ 5/05/2022 - 5/08/2022 ​ 249,000 ​ ​ ​ (83,602) ​ (59,270) ​ 106,128 Plan 2022.III. ​ 07/06/2022 ​ 11,752 ​ ​ ​ (349) ​ (5,873) ​ 5,530 Plan 2023.I. ​ 08/05/2023 ​ ​ ​ 401,962 ​ (35,380) ​ ​ ​ 366,582 Plan 2023.II. ​ 9/05/2023 - 15/06/2023 - 17/11/2023 ​ ​ ​ 518,548 ​ (5,748) ​ ​ ​ 512,800 Total ​ ​ ​ 736,095 ​ 920,510 ​ (270,474) ​ (210,678) ​ 1,175,453
Schedule of summary of other equity instruments outstanding by category	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 ​ ​ (in number of RSUs) Members of the Executive Committee ​ ​ 438,738 ​ ​ 332,038 ​ ​ 384,340 Personnel ​ ​ 736,715 ​ ​ 404,057 ​ ​ 273,463 Total outstanding RSUs ​ ​ 1,175,453 ​ ​ 736,095 ​ ​ 657,803 ​

Related parties (Tables)

Related parties (Tables)	12 Months Ended
	Dec. 31, 2023
Related parties
Summary of transactions with related party	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 2022 ​ 2021 ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Trade and other receivables (1) ​ € 5,198 ​ € 7,877 ​ € 88,246 Trade and other payables ​ ​ 585 ​ ​ ​ ​ € 11,580 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2023 2022 ​ 2021 ​ ​ (Euro, in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues recognized related to the performance obligation for the drug discovery platform ​ € 230,242 ​ € 230,423 ​ € 230,582 Revenues recognized related to the filgotinib performance obligation (2) ​ ​ 429,439 ​ ​ 174,432 ​ ​ 235,709 Royalty income related to the commercialization of filgotinib ​ ​ 9,466 ​ ​ 10,726 ​ ​ 3,757 Cost reimbursements related to the development of GLPG1690 (3) ​ ​ 299 ​ ​ 411 ​ ​ 18,055 Cross charges from and to Gilead relating to filgotinib (4) ​ ​ 3,643 ​ ​ (2,374) ​ ​ (81,334) Costs (-)/deduction of costs relating to our 50/50 profit/(cost) share mechanism (5) ​ ​ ​ ​ ​ ​ ​ ​ ​ included in sales and marketing expenses ​ ​ — ​ ​ 31 ​ ​ 59,699 included in research and development expenditure ​ ​ — ​ ​ (31) ​ ​ 7,026 Purchase of raw materials, semi-finished products and finished products of Jyseleca ​ € — ​ € 13,539 ​ € 24,867
Summary of remuneration package of the members of key management personnel	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2023 2022 2021 Remuneration of key management personnel: ​ ​ ​ ​ ​ ​ Euro, in thousands (except for the number of subscription rights and RSUs) ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term benefits to executive Committee members as a group (1) ​ € 3,902 ​ € 3,444 ​ € 4,264 Board fees for members of the Board of Directors ​ ​ 749 ​ ​ 740 ​ ​ 750 Post-employment benefits (2) ​ ​ 209 ​ ​ 240 ​ ​ 399 Severance package (3) ​ ​ 3,150 ​ ​ — ​ ​ 802 Subscription rights granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of subscription rights granted in the year to Executive Committee members as a group ​ ​ 325,000 ​ ​ 1,124,000 ​ ​ 275,000 Total cost of subscription rights granted in the year under IFRS 2 ​ € 5,163 ​ € 27,010 ​ € 5,629 Number of RSUs granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Total number of RSUs granted in the year to Executive Committee members as a group (1)(4) ​ ​ 331,066 ​ ​ 200,478 ​ ​ 254,560 (1) Dr. Wigerinck was a member of the Executive Committee (formerly Management Board) until November 30, 2021. His remuneration and benefits are included in the overview for the financial year 2021. Mr. Onno Van de Stolpe was our CEO and Executive Committee member until March 31, 2022, Dr. Andre Hoekema was our CBO and Executive Committee member until October 31, 2022 and Dr. Walid Abi-Saab was our CMO and Executive Committee member until December 31, 2022. Their (prorated) remuneration and benefits are included in the overview for the financial years 2021 and 2022. Effective as of April 1, 2022, Stoffels IMC BV, permanently represented by Dr. Paul Stoffels, is our CEO and Chair of the Executive Committee. His (prorated) remuneration is included in the overview for the financial years 2022 and 2023. Mr. Bart Filius was a member of the Executive Committee until June 30, 2023 and Mr. Michele Manto was a member of the Executive Committee until December 31, 2023. Their (prorated) remuneration and benefits are included in the overview for the financial years 2021, 2022 and 2023. Ms. Valeria Cnossen and Ms. Annelies Missotten were members of the Executive Committee as of January 1, 2023. Mr. Thad Huston was a member of the Executive Committee as of July 1, 2023. Their (prorated) remuneration and benefits are included in the overview for the financial year 2023. (2) (3) (4) ​

Consolidated companies as of _2

Consolidated companies as of December 31, 2023 (Tables)	12 Months Ended
	Dec. 31, 2023
Consolidated companies as of December 31, 2023
Disclosure of voting rights in consolidated companies	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ ​ ​ 2023 ​ 2022 ​ 2021 Name of the subsidiary Country % voting right Galapagos NV (directly or indirectly through subsidiaries) Change in % voting right previous period (2023 vs 2022) % voting right Galapagos NV (directly or indirectly through subsidiaries) % voting right Galapagos NV (directly or indirectly through subsidiaries) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CONTINUING OPERATIONS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Glpg US Inc. (formerly AboundBio Inc.) ​ United States ​ 100% ​ ​ ​ 100% ​ 0% CellPoint B.V. (till 30/11/2023) ​ The Netherlands ​ 100% ​ ​ ​ 100% ​ 0% Galapagos B.V. (merged with CellPoint B.V.) ​ The Netherlands ​ 100% ​ ​ ​ 100% ​ 100% Galapagos GmbH ​ Switzerland ​ 100% ​ ​ ​ 100% ​ 100% Glpg US Holding Inc. (formerly Galapagos, Inc.) ​ United States ​ 100% ​ ​ ​ 100% ​ 100% Galapagos NV ​ Belgium ​ Parent company ​ ​ ​ Parent company ​ Parent company Galapagos Real Estate Belgium BV (former Galapagos Real Estate 1 BV) ​ Belgium ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Real Estate Netherlands B.V. ​ The Netherlands ​ 100% ​ ​ ​ 100% ​ 100% Galapagos SASU ​ France ​ 100% ​ ​ ​ 100% ​ 100% Xenometrix, Inc. in liquidation ​ United States ​ 100% ​ ​ ​ 100% ​ 100% ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ DISCONTINUED OPERATIONS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Galapagos Biopharma Belgium BV ​ Belgium ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Netherlands B.V. ​ The Netherlands ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Spain S.L.U. ​ Spain ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Italy S.r.l. ​ Italy ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Germany GmbH ​ Germany ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Sweden AB ​ Sweden ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Norway AS ​ Norway ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Finland Oy ​ Finland ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Denmark ApS ​ Denmark ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Austria GmbH ​ Austria ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biopharma Ireland Ltd ​ Ireland ​ 100% ​ ​ ​ 100% ​ 100% Galapagos Biotech Ltd (formerly Inpharmatica Ltd.) ​ United Kingdom ​ 100% ​ ​ ​ 100% ​ 100%

Financial risk management (Tabl

Financial risk management (Tables)	12 Months Ended
	Dec. 31, 2023
Financial risk management
Disclosure of categories of material financial assets and liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2023 2022 2021 Notes ​ ​ (Euro, in thousands) ​ Financial assets held at fair value through profit or loss ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Equity instruments ​ € 13,575 ​ ​ — ​ ​ — 16 Current financial investments ​ ​ 1,316,805 ​ ​ 1,292,514 ​ ​ 1,317,460 20 Financial assets at amortized cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current financial investments ​ ​ 2,200,893 ​ ​ 2,293,431 ​ ​ 1,152,349 20 Cash and cash equivalents ​ ​ 166,803 ​ ​ 508,117 ​ ​ 2,233,368 21 Restricted cash (current and non-current) ​ ​ 5,533 ​ ​ 4,569 ​ ​ 1,425 16 Other non-current assets ​ ​ 318 ​ ​ 1,209 ​ ​ 1,048 16 Trade receivables ​ ​ 17,494 ​ ​ 28,194 ​ ​ 91,786 19 Total financial assets ​ € 3,721,421 ​ € 4,128,033 ​ € 4,797,436 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Financial liabilities held at fair value through profit or loss ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current financial instruments ​ € — ​ € 19 ​ € 204 25 Current contingent consideration related to milestones CellPoint ​ ​ — ​ ​ 8,485 ​ ​ — 25 Non-current contingent consideration related to milestones CellPoint ​ ​ 20,972 ​ ​ 13,582 ​ ​ — 25 Financial liabilities at amortized cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Trade liabilities ​ ​ 87,966 ​ ​ 68,928 ​ ​ 84,519 25 Lease liabilities ​ ​ 9,596 ​ ​ 21,901 ​ ​ 26,859 24 Current deferred consideration payable CellPoint ​ ​ — ​ ​ 6,222 ​ ​ — 25 Total financial liabilities ​ € 118,534 ​ € 119,137 ​ € 111,582 ​
Disclosure of aging balance of receivables	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 ​ ​ (Euro, in thousands) 60 - 90 days ​ € 3 ​ € 424 ​ € 141 90 - 120 days ​ ​ 3 ​ ​ 208 ​ ​ 92 more than 120 days ​ € 117 ​ € 473 ​ € 113
Foreign exchange risk
Financial risk management
Disclosure of sensitivity of exchange rate risk	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2023 2022 2021 Net book value ​ (Euro, in thousands) Increase in Euros - U.S. Dollars ​ € (78,013) ​ € (85,140) ​ € (83,996) Increase in Euros - GB Pounds ​ ​ 666 ​ ​ 960 ​ ​ 1,093 Increase in Euros - CH Francs ​ ​ 385 ​ ​ 557 ​ ​ 233

General information (Details)

General information (Details)	Dec. 30, 2023 country item	Oct. 30, 2023 country position	Dec. 31, 2023 employee	Jul. 01, 2023 employee	Dec. 31, 2022 employee
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Number of employees			1,123		1,338
Number of European countries in which positions has been agreed to transfer | country		14
Number of employees related to continuing operations			646		724
Drug discovery collaboration transaction with NovAliX
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Number of employees				121
Jyseleca business, classified as held for sale
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Number of positions in European countries agreed to transfer	400	400
Number of European countries in which positions has been agreed to transfer | country	14	14

Summary of significant transa_2

Summary of significant transactions (Details) € / shares in Units, $ in Millions

3 Months Ended

12 Months Ended

Dec. 30, 2023 EUR (€) country item

Oct. 30, 2023 country position

Nov. 06, 2019

Oct. 22, 2019 € / shares

Aug. 23, 2019 EUR (€)

Aug. 23, 2019 USD ($)

Jul. 17, 2019

Jul. 14, 2019 USD ($)

Jul. 13, 2019

Dec. 31, 2023 EUR (€)

Dec. 31, 2023 EUR (€) item € / shares

Dec. 31, 2022 EUR (€) € / shares

Dec. 31, 2021 EUR (€) € / shares

Jan. 31, 2024 EUR (€)

Jan. 31, 2021

Aug. 23, 2019 USD ($)

Summary of significant transaction

Number of European countries in which positions has been agreed to transfer | country

14

Global research and development collaboration term

10 years

Upfront payment to receive.

€ 3,569,800,000

$ 3,950

Equity investment received

€ 960,100,000

$ 1,100

Additional equity investment from warrant exercise

€ 1,770,000

€ 6,695,000

€ 3,314,000

Option rights period

10 years

Amount received till 31/12/2022.

€ 12,600,000

Extension option rights period

3 years

Opt-in payments to be received for each program | $

$ 150

Average exercise price warrants | € / shares

€ 28.75

€ 23.68

€ 23.51

Commitments Related To Development Activities.

€ 40,000,000

Jyseleca business, classified as held for sale

Summary of significant transaction

Number of positions in European countries agreed to transfer

400

400

Number of European countries in which positions has been agreed to transfer | country

14

14

Upfront payment to receive.

€ 50,000,000

€ 50,000,000

Potential Milestone Payments to receive

120,000,000

€ 120,000,000

120,000,000

Commitments Related To Development Activities.

€ 40,000,000

40,000,000

€ 40,000,000

Number Of Reduction In Positions | item

100

Gilead

Summary of significant transaction

Number of directors represented as board members | item

2

Percentage of stake

25.10%

22.04%

12.30%

25.35%

Restricting Gilead's ability to seek to acquire

10 years

Maximum share holding percentage

29.90%

Warrant Value

€ 50,000

€ 50,000

Gilead | Filgotinib drug license

Summary of significant transaction

Cost share for global development activities

50%

50%

Amount received till 31/12/2022.

€ 172,600,000

Gilead | Filgotinib drug license | Original Agreement

Summary of significant transaction

Cost share for global development activities

25%

Future global development cost sharing ratio before predetermined level

25%

Gilead | Filgotinib drug license | Group B activities [Member]

Summary of significant transaction

Cost share for global development activities

50%

Minimum | Outside Europe

Summary of significant transaction

Tiered royalty Percentage deduction

20%

Minimum | Gilead

Summary of significant transaction

EGM Conducted period

57 months

Minimum | Gilead | Filgotinib drug license

Summary of significant transaction

Future global development cost sharing ratio before predetermined level

50%

Minimum | Gilead | Europe | Filgotinib drug license

Summary of significant transaction

Percentage of future net sales from 2024, royalties as percentage of sales

8

Maximum | Outside Europe

Summary of significant transaction

Tiered royalty Percentage deduction

24%

Maximum | Gilead

Summary of significant transaction

Percentage of stake

29.90%

EGM Conducted period

59 months

Maximum | Gilead | Filgotinib drug license

Summary of significant transaction

Future global development cost sharing ratio before predetermined level

100%

100%

Maximum | Gilead | Europe | Filgotinib drug license

Summary of significant transaction

Percentage of future net sales from 2024, royalties as percentage of sales

15

Warrant B

Summary of significant transaction

Multiplier used to calculate exercise price per share

120%

Initial term of the warrant

5 years

Average exercise price warrants | € / shares

€ 140.59

Volume of days

30 days

Summary of significant transa_3

Summary of significant transactions - Evolution of the total transaction price (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Jun. 30, 2023	Jan. 07, 2023	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2015
Summary Of Significant Transaction [line items]
Cumulative deferred income	€ 1,327,463,000	€ 1,989,230,000			€ 2,364,701,000
Purchase Commitment Related To Services From Novalix.	63,900,000
Gilead
Summary Of Significant Transaction [line items]
Upfront Consideration	4,018,016,000	4,018,016,000			4,018,016,000
Milestones achieved, balance	212,601,000	212,601,000			194,363,000
Royalties, balance	40,176,000	30,710,000			19,984,000
Impact initial valuation of share subscription	124,604,000	124,604,000			124,604,000
Allocation to performance obligations	4,395,397,000	4,385,931,000			4,356,967,000
Cumulative deferred income	4,349,487,000	4,339,347,000			4,308,669,000
Other movements in 2023 | Gilead
Summary Of Significant Transaction [line items]
Royalties	9,466,000
Cumulative deferred income	10,140,000
Total transaction price, movements	9,466,000
Other Movements In 2022 Member | Gilead
Summary Of Significant Transaction [line items]
Milestones achieved		18,238,000
Royalties		10,726,000
Cumulative deferred income		30,678,000
Total transaction price, movements		28,964,000
Warrant A | Gilead
Summary Of Significant Transaction [line items]
Less : Warrants issuance liabilities	(43,311,000)	(43,311,000)			(43,311,000)
Initial Warrant B | Gilead
Summary Of Significant Transaction [line items]
Less : Warrants issuance liabilities	(2,545,000)	(2,545,000)			(2,545,000)
Subsequent warrant B | Gilead
Summary Of Significant Transaction [line items]
Less : Warrants issuance liabilities	(54,000)	(728,000)			(2,442,000)
Subsequent warrant B | Other movements in 2023 | Gilead
Summary Of Significant Transaction [line items]
Less : Warrants issuance liabilities	674,000
Subsequent warrant B | Other Movements In 2022 Member | Gilead
Summary Of Significant Transaction [line items]
Less : Warrants issuance liabilities		1,714,000
Filgotinib Performance Obligation Member | Gilead
Summary Of Significant Transaction [line items]
Upfront Consideration						€ 160,000,000		€ 275,600,000
Allocation to performance obligations	1,381,644,000	1,372,178,000			1,343,214,000
Estimated significant financing component	39,800,000	58,700,000			57,300,000		€ 44,500,000
Filgotinib Performance Obligation Member | Gilead | Original Agreement
Summary Of Significant Transaction [line items]
Upfront Consideration					4,000,000,000
Filgotinib Performance Obligation Member | Gilead | First Revised Agreement
Summary Of Significant Transaction [line items]
Upfront Consideration							€ 3,600,000,000
Filgotinib Performance Obligation Member | Gilead | Second Revised Agreement
Summary Of Significant Transaction [line items]
Upfront Consideration						€ 172,600,000
Filgotinib Performance Obligation Member | Gilead | Amendments Relating To The Diversity Study [member]
Summary Of Significant Transaction [line items]
Upfront Consideration					12,600,000
Filgotinib Performance Obligation Member | Other movements in 2023 | Gilead
Summary Of Significant Transaction [line items]
Allocation to performance obligations	9,466,000
Filgotinib Performance Obligation Member | Other Movements In 2022 Member | Gilead
Summary Of Significant Transaction [line items]
Allocation to performance obligations		28,964,000
Gilead collaboration agreement for ziritaxestat | Gilead
Summary Of Significant Transaction [line items]
Allocation to performance obligations	666,967,000	666,967,000			666,967,000
Collaboration agreement for filgotinib
Summary Of Significant Transaction [line items]
Cumulative deferred income	26,300,000
Collaboration agreement for drug discovery platform | Gilead
Summary Of Significant Transaction [line items]
Allocation to performance obligations	2,300,876,000	2,300,203,000			€ 2,298,489,000
Collaboration agreement for drug discovery platform | Other movements in 2023 | Gilead
Summary Of Significant Transaction [line items]
Allocation to performance obligations	€ 674,000
Collaboration agreement for drug discovery platform | Other Movements In 2022 Member | Gilead
Summary Of Significant Transaction [line items]
Allocation to performance obligations		€ 1,714,000
Drug discovery collaboration transaction with NovAliX
Summary Of Significant Transaction [line items]
Purchase Commitment Related To Services From Novalix.				€ 73,800,000
Collaboration Agreement Upfront Payment			€ (8,300,000)	€ (8,300,000)

Significant accounting polici_3

Significant accounting policies - Intangible Assets (Details) - Software and databases	12 Months Ended
	Dec. 31, 2023
Minimum
Disclosure of detailed information about intangible assets
Useful lives	3 years
Maximum
Disclosure of detailed information about intangible assets
Useful lives	5 years

Significant accounting polici_4

Significant accounting policies - Property, Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2023
Buildings
Disclosure of detailed information about property, plant and equipment
Useful lives	33 years
Minimum | Installation and machinery
Disclosure of detailed information about property, plant and equipment
Useful lives	3 years
Minimum | Furniture, fixtures & vehicles
Disclosure of detailed information about property, plant and equipment
Useful lives	4 years
Minimum | Leasehold
Disclosure of detailed information about property, plant and equipment
Useful lives	3 years
Maximum | Installation and machinery
Disclosure of detailed information about property, plant and equipment
Useful lives	15 years
Maximum | Furniture, fixtures & vehicles
Disclosure of detailed information about property, plant and equipment
Useful lives	10 years
Maximum | Leasehold
Disclosure of detailed information about property, plant and equipment
Useful lives	10 years

Significant accounting polici_5

Significant accounting policies - Segment Reporting (Details)	12 Months Ended
	Dec. 31, 2023 segment
Significant accounting policies
Operating and reportable segment	1

Significant accounting polici_6

Significant accounting policies - Restatement Made To The Comparative (Details) - EUR (€)	Dec. 31, 2022	Dec. 31, 2021
Significant accounting policies
Financial Impact Of Reclassification Of Accrued Interests On Financial Investments	€ 9,900,000	€ (2,600,000)

Significant accounting polici_7

Significant accounting policies - Assets Held For Sale And Discontinued Operations (Details) - Fidelta - EUR (€)	Apr. 01, 2021	Jan. 04, 2021
Assets Held For Sale And Discontinued Operations Accounting Policies
Total Consideration		€ 37,100,000
Purchase Commitments Term	3 years

Critical accounting judgments_2

Critical accounting judgments and key sources of estimation uncertainty - IFRS 15 - Revenue recognition Gilead (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Jun. 21, 2022	Dec. 31, 2021
Critical accounting estimates and judgments
Deferred income	€ 1,327,463,000	€ 1,989,230,000		€ 2,364,701,000
Goodwill	69,557,000	69,813,000	€ 69,800,000
Contingent consideration.	1,561,830,000	2,208,325,000
Cell Point Acquisition
Critical accounting estimates and judgments
Goodwill	62,400,000	62,444,000
Contingent consideration [member] | Cell Point Acquisition
Critical accounting estimates and judgments
Contingent consideration.	21,000,000
Collaboration agreement for filgotinib
Critical accounting estimates and judgments
Deferred income	26,300,000
Gilead | Collaboration agreement for filgotinib
Critical accounting estimates and judgments
Deferred income	€ 26,268,000	€ 456,352,000		€ 604,875,000
Scenario | Collaboration agreement for filgotinib
Critical accounting estimates and judgments
Increase (decrease) in remaining cost to complete filgotinib performance obligation	10%
(Decrease) increase in revenue recognition and corresponding increase (decrease) in current and non-current deferred income	€ (2,600,000)
Scenario 2 | Collaboration agreement for filgotinib
Critical accounting estimates and judgments
Increase (decrease) in remaining cost to complete filgotinib performance obligation	(10.00%)
(Decrease) increase in revenue recognition and corresponding increase (decrease) in current and non-current deferred income	€ 2,600,000

Discontinued operations and a_3

Discontinued operations and assets held for sale - Result from discontinued operations (Details) - EUR (€) € / shares in Units, shares in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Collaboration revenues	€ 239,724,000	€ 241,249,000	€ 234,384,000
Revenues	239,724,000	241,249,000	234,384,000
Research and development expenses	(241,294,000)	(269,797,000)	(320,503,000)
Sales and marketing expenses	(5,676,000)	(3,480,000)	(3,776,000)
General and administrative expenses	(128,289,000)	(135,155,000)	(127,744,000)
Other operating income	47,272,000	36,127,000	46,071,000
Other income	47,272,000	36,127,000	46,075,000
Operating loss	(88,263,000)	(131,056,000)	(171,568,000)
Fair value adjustments and net currency exchange differences	16,252,000	51,498,000	61,462,000
Other financial income	80,249,000	18,563,000	3,057,000
Other financial expenses	(2,613,000)	(9,854,000)	(12,353,000)
Income/loss before tax	5,625,000	(70,849,000)	(119,402,000)
Income taxes	9,613,000	572,000	1,389,000
Net income	€ 215,685,000	€ (146,570,000)	€ 17,560,000
Basic income per share	€ 3.21	€ (3.32)	€ (1.58)
Diluted income per share	€ 3.21	€ (3.32)	€ (1.58)
Weighted average number of shares - Basic	65,884	65,699	65,500
Europe
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Collaboration revenues	€ 16,000	€ 100,000	€ 43,000
Jyseleca business, classified as held for sale
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Product net sales	112,339,000	87,599,000	14,753,000
Collaboration revenues	431,465,000	176,432,000	235,709,000
Revenues	543,804,000	264,031,000	250,462,000
Cost of sales	(18,022,000)	(12,079,000)	(1,629,000)
Research and development expenses	(190,177,000)	(245,286,000)	(171,205,000)
Sales and marketing expenses	(113,356,000)	(144,075,000)	(66,179,000)
General and administrative expenses	(17,989,000)	(9,776,000)	(13,155,000)
Other operating income	13,003,000	10,721,000	7,678,000
Operating loss	217,262,000	(136,464,000)	5,972,000
Fair value adjustments and net currency exchange differences	(13,000)	(25,000)
Other financial income	679,000	15,000	164,000
Other financial expenses	(167,000)	(7,825,000)	(9,733,000)
Income/loss before tax	217,761,000	(144,298,000)	(3,597,000)
Income taxes	2,076,000	2,272,000	1,034,000
Net income	€ 215,685,000	€ (146,570,000)	€ (4,631,000)
Basic income per share	€ 3.27	€ (2.23)	€ (0.07)
Weighted average number of shares - Basic	65,884	65,699	65,500
Weighted average number of shares - Diluted	65,933	65,699	65,500
Jyseleca business, classified as held for sale | Europe
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Product net sales	€ 112,300,000	€ 87,600,000
Jyseleca business, classified as held for sale | BE
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Product net sales	8,100,000	7,300,000
Fidelta
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Operating loss			€ 22,191,000
Net income			€ 22,191,000
Basic income per share			€ 0.34
Weighted average number of shares - Basic			65,500
Weighted average number of shares - Diluted			65,831
Collaboration agreement for filgotinib
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Collaboration revenues	429,400,000	€ 174,400,000
Deferred Income	€ 26,300,000

Discontinued operations and a_4

Discontinued operations and assets held for sale - Assets and liabilities (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 04, 2021
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Intangible assets	€ 127,906	€ 146,354
Deferred tax assets included in Held for sale (HFS).	1,126	1,363
Other non-current assets included in held for sale (HFS)	29,645	5,778
Inventories included in held for sale (HFS)	73,978	52,925
Trade and other receivables included in held for sale (HFS)	28,449	40,429
Cash and cash equivalents included in assets held for sale (HFS)	7
Other current assets included in held for sale (HFS)	15,140	23,307
Total assets in disposal group classified as held for sale (HFS)	4,357,396	4,734,351
Retirement benefit liabilities held for sale (HFS).	2,293	5,540
Non current lease liabilities held for sale (HFS)	23,607	20,148
Non-current lease liabilities held for sale (HFS).	4,944	14,692
Other non-current liabilities held for sale (HFS).	10,598	8,226
Non current deferred income held for sale (HFS)	1,071,193	1,623,599
Current lease liabilities held for sale (HFS)	4,652	7,209
Trade and other liabilities held for sale (HFS)	135,201	148,675
Current deferred income held for sale (HFS)	256,270	€ 365,631	€ 419,866
Total liabilities directly associated with assets in disposal group classified as held for sale	€ 32,044
Proportion Of Ownership Interest In Subsidiary Sold	100%
Jyseleca business, classified as held for sale
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Property, plant and equipment	€ 4,194
Deferred tax assets included in Held for sale (HFS).	292
Other non-current assets included in held for sale (HFS)	598
Inventories included in held for sale (HFS)	737
Trade and other receivables included in held for sale (HFS)	15,786
Cash and cash equivalents included in assets held for sale (HFS)	7
Other current assets included in held for sale (HFS)	471
Total assets in disposal group classified as held for sale (HFS)	22,085
Retirement benefit liabilities held for sale (HFS).	1,160
Non-current lease liabilities held for sale (HFS).	2,327
Other non-current liabilities held for sale (HFS).	329
Current lease liabilities held for sale (HFS)	1,308
Trade and other liabilities held for sale (HFS)	25,619
Income tax payable held for sale (HFS)	1,242
Current deferred income held for sale (HFS)	59
Total liabilities directly associated with assets in disposal group classified as held for sale	32,044
Net assets disposed of (HFS)	€ (9,959)
Fidelta
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Intangible assets				€ 21
Property, plant and equipment				10,050
Other non-current assets included in held for sale (HFS)				160
Trade and other receivables included in held for sale (HFS)				4,428
Cash and cash equivalents included in assets held for sale (HFS)				7,884
Other current assets included in held for sale (HFS)				863
Total assets in disposal group classified as held for sale (HFS)				23,406
Non-current lease liabilities held for sale (HFS).				4,115
Other non-current liabilities held for sale (HFS).				70
Current lease liabilities held for sale (HFS)				727
Trade and other liabilities held for sale (HFS)				4,479
Income tax payable held for sale (HFS)				356
Total liabilities directly associated with assets in disposal group classified as held for sale				9,747
Net assets disposed of (HFS)				€ 13,658

Discontinued operations and a_5

Discontinued operations and assets held for sale - Cash flows (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Jyseleca business, classified as held for sale
Cash flows from discontinued operations
Net cash flow used in operating activities	€ (175,627)	€ (191,095)	€ (119,524)
Net cash flow used in investing activities	(105)	(136)	(157)
Net cash flow used in financing activities	(1,928)	(1,841)	(872)
Net cash flow from discontinued operations	€ (177,660)	€ (193,072)	(120,554)
Fidelta
Cash flows from discontinued operations
Net cash flow used in investing activities			28,696
Net cash flow from discontinued operations			€ 28,696

Discontinued operations and a_6

Discontinued operations and assets held for sale - Disposal of Fidelta (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Jan. 04, 2021
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Purchase commitments	€ 408,521	€ 398,627
Fee for service business, held for sale
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Total Consideration On The Disposal Of Fidelta			€ 37,100
Purchase commitments	€ 6,600
Purchase commitments term	2 years

Discontinued operations and a_7

Discontinued operations and assets held for sale - Fidelta, Consideration received (Details) - Fidelta € in Thousands	Jan. 04, 2021 EUR (€)
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Cash received	€ 37,080
Total consideration	€ 37,080

Discontinued operations and a_8

Discontinued operations and assets held for sale - Fidelta, Gain on disposal of subsidiaries (Details) - EUR (€) € in Thousands		12 Months Ended
	Jan. 04, 2021	Dec. 31, 2021
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Gain on disposal		€ 22,191
Fidelta
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Cash received	€ 37,080
Net assets disposed of	(13,658)
Effect of cumulative translation adjustments reclassified from equity on loss of control	(731)
Costs associated to the sale	(500)
Gain on disposal	€ 22,191	€ 22,191

Discontinued operations and a_9

Discontinued operations and assets held for sale - Fidelta, Net cash inflow on disposal of subsidiaries (Details) - Fidelta € in Thousands	Jan. 04, 2021 EUR (€)
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Cash received	€ 37,080
Less: cash and cash equivalents balances disposed of	(7,884)
Total consideration received, net of cash disposed of	29,196
Costs associated to the sale	(500)
Cash in from disposal of subsidiaries, net of cash disposed of	€ 28,696

Discontinued operations and _10

Discontinued operations and assets held for sale - Transfer of Jyseleca Business to Alfasigma (Details) $ in Millions					12 Months Ended
	Dec. 30, 2023 EUR (€) country item	Oct. 30, 2023 country position	Aug. 23, 2019 EUR (€)	Aug. 23, 2019 USD ($)	Dec. 31, 2023 EUR (€)	Jan. 31, 2024 EUR (€)
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Number of European countries in which positions has been agreed to transfer | country		14
Upfront payment to be received at 12/31/2023.			€ 3,569,800,000	$ 3,950
Commitments Related To Development Activities.						€ 40,000,000
Jyseleca business, classified as held for sale
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Number of positions in European countries agreed to transfer	400	400
Number of European countries in which positions has been agreed to transfer | country	14	14
Upfront payment to be received at 12/31/2023.	€ 50,000,000				€ 50,000,000
Potential Sales Based Milestones To Receive.	120,000,000				120,000,000
Commitments Related To Development Activities.	€ 40,000,000				€ 40,000,000

Segment information - Geographi

Segment information - Geographical information (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disclosure of operating segments [line items]
Net revenue.	€ 239,724	€ 241,249	€ 234,384
Net revenue.	783,528	505,280	484,846
Discontinued Operations [Member]
Disclosure of operating segments [line items]
Net revenue - discontinued operations	€ 543,804	€ 264,031	€ 250,462
Gilead [member]
Disclosure of operating segments [line items]
Percentage of collaboration revenue over total revenue	100%	99.90%	99.90%
United States of America
Disclosure of operating segments [line items]
Net revenue.	€ 239,708	€ 241,149	€ 234,340
Net revenue.	665,174	414,129	467,978
United States of America | Discontinued Operations [Member]
Disclosure of operating segments [line items]
Net revenue - discontinued operations	425,466	172,980	233,638
Europe
Disclosure of operating segments [line items]
Net revenue.	16	100	43
Net revenue.	118,354	91,151	16,867
Europe | Discontinued Operations [Member]
Disclosure of operating segments [line items]
Net revenue - discontinued operations	€ 118,338	€ 91,051	€ 16,824

Segment information - Major cus

Segment information - Major customers (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disclosure of major customers [line items]
Collaboration revenues	€ 239,724	€ 241,249	€ 234,384
United States of America
Disclosure of major customers [line items]
Collaboration revenues	239,708	241,149	234,340
Europe
Disclosure of major customers [line items]
Collaboration revenues	€ 16	€ 100	€ 43

Segment information - Non-curre

Segment information - Non-current assets by location (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disclosure of geographical areas [line items]
Non-current assets	€ 495,807	€ 497,501
Property, Plant and Equipment and Intangible Assets
Disclosure of geographical areas [line items]
Non-current assets	323,784	370,420	€ 197,615
Property, Plant and Equipment and Intangible Assets | Belgium
Disclosure of geographical areas [line items]
Non-current assets	56,209	72,087	98,295
Property, Plant and Equipment and Intangible Assets | France
Disclosure of geographical areas [line items]
Non-current assets	1,438	20,397	21,051
Property, Plant and Equipment and Intangible Assets | The Netherlands
Disclosure of geographical areas [line items]
Non-current assets	251,230	255,461	66,621
Property, Plant and Equipment and Intangible Assets | Switzerland
Disclosure of geographical areas [line items]
Non-current assets	3,247	4,962	7,181
Property, Plant and Equipment and Intangible Assets | Spain
Disclosure of geographical areas [line items]
Non-current assets		3,037	3,029
Property, Plant and Equipment and Intangible Assets | United States of America
Disclosure of geographical areas [line items]
Non-current assets	€ 11,660	12,729	136
Property, Plant and Equipment and Intangible Assets | Other Countries
Disclosure of geographical areas [line items]
Non-current assets		€ 1,747	€ 1,302

Total revenues - Revenue by col

Total revenues - Revenue by collaboration and by category of revenue (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disclosure of disaggregation of revenue from contracts with customers [line items]
Total collaboration revenues	€ 239,724,000	€ 241,249,000	€ 234,384,000
Total net revenues	239,724,000	241,249,000	234,384,000
Collaboration revenues
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees	230,242,000	230,423,000	230,582,000
Reimbursement income		56,000
Royalties	9,482,000	10,770,000	3,801,000
Gilead collaboration agreement for drug discovery platform
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees	230,200,000
Royalties	9,500,000
Gilead collaboration agreement for drug discovery platform | Gilead
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees	230,242,000	230,423,000	230,582,000
Novartis collaboration agreement for MOR106 | Novartis
Disclosure of disaggregation of revenue from contracts with customers [line items]
Reimbursement income		56,000
Gilead royalties on Jyseleca | Gilead
Disclosure of disaggregation of revenue from contracts with customers [line items]
Royalties	9,466,000	10,726,000	3,757,000
Other royalties | Other segments
Disclosure of disaggregation of revenue from contracts with customers [line items]
Royalties	€ 16,000	€ 44,000	€ 43,000

Total revenues - Summary of our

Total revenues - Summary of our main contracts (Details)	12 Months Ended
	Dec. 31, 2023
Disclosure of disaggregation of revenue from contracts with customers [line items]
Period over which to recognize the drug discovery platform revenue	10 years
Maximum Extension Period For Specific Program	3 years

Operating costs and other ope_3

Operating costs and other operating income - Summary of research and development expenditure (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating costs and other operating income
Personnel costs	€ (95,788)	€ (115,484)	€ (128,402)
Subcontracting	(82,997)	(61,192)	(126,881)
Disposables and lab fees and premises costs	(18,083)	(19,529)	(22,933)
Depreciation	(22,254)	(51,493)	(15,709)
Professional fees	(9,272)	(9,316)	(12,234)
Other operating expenses	(12,900)	(12,783)	(14,344)
Total R&D expenses	€ (241,294)	€ (269,797)	€ (320,503)

Operating costs and other ope_4

Operating costs and other operating income - Summary of R&D expenditure by program (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating costs and other operating income
Total R&D expenses	€ (241,294)	€ (269,797)	€ (320,503)
Ziritaxestat program
Operating costs and other operating income
Total R&D expenses		(1,096)	(26,725)
SIKi program
Operating costs and other operating income
Total R&D expenses	(18,900)	(47,727)	(91,957)
TYK2 program on GLPG3667
Operating costs and other operating income
Total R&D expenses	(31,289)	(24,467)	(27,141)
CAR-T programs in oncology
Operating costs and other operating income
Total R&D expenses	(82,218)	(29,999)
Other programs
Operating costs and other operating income
Total R&D expenses	€ (108,887)	€ (166,507)	€ (174,680)

Operating costs and other ope_5

Operating costs and other operating income - Summary of sales and marketing expenses (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating costs and other operating income
Personnel costs	€ (2,997)	€ (1,693)	€ (1,709)
Depreciation	(113)	(59)	(37)
External outsourcing costs	(1,776)	(1,267)	(1,802)
Professional fees	(131)	(99)	(15)
Other operating expenses	(659)	(363)	(214)
Total sales and marketing expenses	€ (5,676)	€ (3,480)	€ (3,776)

Operating costs and other ope_6

Operating costs and other operating income - Summary of general and administrative expenses (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating costs and other operating income
Personnel costs	€ (66,098)	€ (76,536)	€ (60,364)
Depreciation and impairment	(15,978)	(8,529)	(16,338)
Legal and professional fees	(23,250)	(23,715)	(25,345)
Other operating expenses	(22,963)	(26,375)	(25,697)
Total general and administrative expenses	€ (128,289)	€ (135,155)	€ (127,744)

Operating costs and other ope_7

Operating costs and other operating income - Other Income (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating costs and other operating incomes
Grant income	€ 6,618,000	€ 1,873,000	€ 7,334,000
R&D incentives	32,968,000	29,104,000	37,416,000
Other income	7,686,000	5,150,000	1,325,000
Total other operating income	47,272,000	36,127,000	46,075,000
Total R&D Incentive Income	32,968,000	29,104,000	37,416,000
Income From Innovation Incentive System In France	5,881,000	11,075,000	12,245,000
Income From Belgian R&D Incentives.	16,535,000	10,339,000	14,835,000
Tax Rebates On Payroll Withholding Taxes Of R&D Personnel	10,552,000	7,689,000	10,336,000
National Institute For Health [member]
Operating costs and other operating incomes
Grant income	€ 6,100,000	€ 0	€ 5,400,000

Staff costs (Details)

Staff costs (Details) € in Thousands	12 Months Ended
	Dec. 31, 2023 EUR (€) employee	Dec. 31, 2022 EUR (€) employee	Dec. 31, 2021 EUR (€) employee
Staff cost and number of employees
Wages and salaries | €	€ (100,250)	€ (99,708)	€ (107,794)
Social security costs | €	(15,742)	(16,748)	(19,109)
Pension costs | €	(5,581)	(5,583)	(4,906)
Costs related to subscription right plans | €	(36,628)	(62,003)	(52,131)
Other personnel costs | €	(6,682)	(9,670)	(6,535)
Total personnel costs | €	€ (164,883)	€ (193,712)	€ (190,475)
Number of employees | employee	646	724	772
Average number of employees | employee	634	695	877
Members of Executive Committee
Staff cost and number of employees
Average number of employees | employee	4	4	5
Research and development [Member]
Staff cost and number of employees
Average number of employees | employee	372	434	568
Commercial and medical affairs [Member]
Staff cost and number of employees
Average number of employees | employee	13	7	6
Corporate and support [Member]
Staff cost and number of employees
Average number of employees | employee	245	250	298

Financial result (Details)

Financial result (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financial result
Net Unrealized currency exchange gain/loss (-)	€ (20,544,000)	€ 41,559,000	€ 56,966,000
Net realized currency exchange gain/loss (-)	(1,118,000)	2,825,000	(308,000)
Fair value re-measurement of warrants	18,000	186,000	2,960,000
Fair value loss on financial assets held at fair value through profit or loss	(390,000)		(4,919,000)
Fair value gain on current financial investments	38,286,000	6,929,000	6,763,000
Fair value adjustments and net currency exchange differences	16,252,000	51,498,000	61,462,000
Other financial income:
Interest on bank deposit	79,290,000	18,094,000	2,865,000
Discounting effect of non-current R&D incentives receivables	617,000	93,000	93,000
Discounting effect of other non-current liabilities.	318,000
Other finance income	24,000	376,000	99,000
Total other financial income	80,249,000	18,563,000	3,057,000
Other financial expenses:
Interest expenses	(1,770,000)	(6,884,000)	(11,592,000)
Discounting effect of non-current deferred income	645,000	(7,672,000)	(9,289,000)
Discounting effect of other non-current liabilities	318,000	(2,271,000)
Other finance charges	(843,000)	(699,000)	(761,000)
Total other financial expense	(2,613,000)	(9,854,000)	(12,353,000)
Total net other financial income	93,888,000	60,206,000	52,166,000
Cash and cash equivalents and current financial investments [member] | At amortized cost [member]
Financial result
Net Unrealized currency exchange gain/loss (-)	€ (20,400,000)	€ 41,300,000	€ 56,600,000

Income taxes - Summary of incom

Income taxes - Summary of income tax recognized (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income taxes
Current tax	€ (5,928)	€ (1,738)	€ (884)
Deferred tax	(3,685)	1,166	(505)
Income taxes	€ (9,613)	€ (572)	€ (1,389)

Income taxes - Summary of inc_2

Income taxes - Summary of income tax reconciliation (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income taxes
Income/loss (-) before tax	€ 5,625	€ (70,849)	€ (119,402)
Income tax debit/credit (-), calculated using the Belgian statutory tax rate on the accounting income/loss (-) before tax (theoretical)	1,406	(17,712)	(29,850)
Tax expenses in statement of operations (effective)	9,613	572	1,389
Difference in tax expense/income to explain	8,207	18,284	31,239
Effect of tax rates in other jurisdictions	(94)	(337)	(588)
Effect of non-taxable revenues	(6,752)	(5,828)	(2,320)
Effect of share based payment expenses without tax impact	9,157	15,501	13,033
Effect of expenses/income (-) not subject to tax	(5)	(146)	(907)
Effect of non tax-deductible expenses	1,549	2,975	3,688
Effect of recognition of previously non-recognized deferred tax assets	(81)	(1,677)	(1,411)
Effect of tax losses (utilized) reversed	(267)
Effect of under or over provision in prior periods	(722)	1,101	(828)
Effect of non-recognition of deferred tax assets	34,339	4,819	20,949
Effect of derecognition of previously recognized deferred tax assets	1,062	1,877	135
Effect of use of investment deduction			(512)
Effect of use of IID	(29,979)
Total explanations	€ 8,207	€ 18,284	€ 31,239

Income taxes - Narrative (Detai

Income taxes - Narrative (Details)	12 Months Ended	24 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Belgium
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Applicable tax rate	25%	25%

Income_loss (-) per share (Deta

Income/loss (-) per share (Details) - EUR (€) € / shares in Units, € in Thousands, shares in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income/loss (-) per share: Basic
Net loss attributable to owners of the parent (Euro, in thousands)	€ 211,697	€ (217,991)	€ (103,231)
Weighted average number of shares - Basic	65,884	65,699	65,500
Basic loss per share (in EUR per share)	€ 3.21	€ (3.32)	€ (1.58)
Income/loss per share: Diluted
Net loss attributable to owners of the parent (Euro, in thousands)	€ 211,697	€ (217,991)	€ (103,231)
Weighted average number of shares - Basic	65,884	65,699	65,500
Number of dilutive potential ordinary shares	49
Diluted loss per share (in EUR per share)	€ 3.21	€ (3.32)	€ (1.58)

Goodwill and impairment of go_3

Goodwill and impairment of goodwill - Roll-forward (Details) - EUR (€) € in Thousands		12 Months Ended
	Jun. 21, 2022	Dec. 31, 2023
Goodwill and impairment of goodwill
Goodwill at beginning of period		€ 69,813
Recognized on acquisition of subsidiaries	€ 69,893
Exchange differences on goodwill	(80)	(256)
Goodwill at end of period	€ 69,800	€ 69,557

Goodwill and impairment of go_4

Goodwill and impairment of goodwill (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Jun. 21, 2022
Disclosure of detailed information about intangible assets [line items]
Goodwill	€ 69,557,000	€ 69,813,000	€ 69,800,000
Period of projected cash flow	P17Y
Terminal growth rate	(50.00%)
Discount rate	13.72%	12.50%
Goodwill impairment	€ 0
Cell Point Acquisition
Disclosure of detailed information about intangible assets [line items]
Goodwill	62,400,000	€ 62,444,000
AboundBio
Disclosure of detailed information about intangible assets [line items]
Goodwill	€ 7,100,000	€ 7,369,000

Intangible assets other than _3

Intangible assets other than goodwill (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disclosure of detailed information about intangible assets [line items]
Beginning balance	€ 146,354
Ending balance	127,906	€ 146,354
Acquisition value
Disclosure of detailed information about intangible assets [line items]
Beginning balance	176,740	79,868
Impact of acquisitions of businesses		124,570
Additions	567	9,549
Sales and disposals	(1,878)	(37,211)
Translation differences	(139)	(36)
Ending balance	175,290	176,740
Amortization and impairment
Disclosure of detailed information about intangible assets [line items]
Beginning balance	30,387	19,765
Amortization	18,892	12,171
Impairment		35,666
Sales and disposals	(1,875)	(37,211)
Translation differences	(20)	(4)
Ending balance	47,384	30,387
Software and databases
Disclosure of detailed information about intangible assets [line items]
Beginning balance	12,167
Ending balance	8,440	12,167
Software and databases | Acquisition value
Disclosure of detailed information about intangible assets [line items]
Beginning balance	27,377	24,554
Impact of acquisitions of businesses		2,610
Additions	567	1,126
Sales and disposals	(930)	(913)
Ending balance	27,014	27,377
Software and databases | Amortization and impairment
Disclosure of detailed information about intangible assets [line items]
Beginning balance	15,210	11,977
Amortization	4,291	4,146
Sales and disposals	(927)	(913)
Ending balance	18,574	15,210
Licenses, rights, technology and in process R&D
Disclosure of detailed information about intangible assets [line items]
Beginning balance	40,362
Ending balance	38,817	40,362
Licenses, rights, technology and in process R&D | Acquisition value
Disclosure of detailed information about intangible assets [line items]
Beginning balance	44,258	39,929
Impact of acquisitions of businesses		32,240
Additions		8,423
Sales and disposals	(948)	(36,298)
Translation differences	(139)	(36)
Ending balance	43,171	44,258
Licenses, rights, technology and in process R&D | Amortization and impairment
Disclosure of detailed information about intangible assets [line items]
Beginning balance	3,896	4,199
Amortization	1,426	333
Impairment		35,666
Sales and disposals	(948)	(36,298)
Translation differences	(20)	(4)
Ending balance	4,354	3,896
Intangible assets related discontinued project, Molecure
Disclosure of detailed information about intangible assets [line items]
Impairment		26,700
Intangible assets related discontinued project, others
Disclosure of detailed information about intangible assets [line items]
Impairment		8,900
Exclusive rights
Disclosure of detailed information about intangible assets [line items]
Beginning balance	83,566
Ending balance	71,929	83,566
Exclusive rights | Acquisition value
Disclosure of detailed information about intangible assets [line items]
Beginning balance	89,720
Impact of acquisitions of businesses		89,720
Ending balance	89,720	89,720
Exclusive rights | Amortization and impairment
Disclosure of detailed information about intangible assets [line items]
Beginning balance	6,154
Amortization	11,637	6,154
Ending balance	17,791	6,154
Contract costs
Disclosure of detailed information about intangible assets [line items]
Beginning balance	10,258
Ending balance	8,720	10,258
Contract costs | Acquisition value
Disclosure of detailed information about intangible assets [line items]
Beginning balance	15,384	15,384
Ending balance	15,384	15,384
Contract costs | Amortization and impairment
Disclosure of detailed information about intangible assets [line items]
Beginning balance	5,126	3,588
Amortization	1,538	1,538
Ending balance	€ 6,664	€ 5,126

Property, plant and equipment -

Property, plant and equipment - Fully Owned (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	€ 126,726
Ending balance	111,220	€ 126,726
Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	167,588	140,555
Impact of acquisitions of businesses		2,254
Additions	16,823	29,336
Sales and disposals	(37,182)	(4,790)
Reclassifications to assets held for sale	(988)
Translation differences	266	233
Ending balance	146,507	167,588
Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	40,862	34,837
Sales and disposals	(23,342)	(4,075)
Reclassifications to assets held for sale	(290)
Translation differences	164	66
Depreciation	10,248	10,034
Impairment	7,645
Ending balance	35,287	40,862
Land, buildings and leasehold improvements
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	80,905
Ending balance	79,487	80,905
Land, buildings and leasehold improvements | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	88,719	26,131
Impact of acquisitions of businesses		29
Additions	6,754	914
Sales and disposals	(4,403)	(2,846)
Reclassifications	95	64,286
Reclassifications to assets held for sale	(739)
Translation differences	279	205
Ending balance	90,705	88,719
Land, buildings and leasehold improvements | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	7,814	5,505
Sales and disposals	(1,194)	(2,173)
Reclassifications to assets held for sale	(161)
Translation differences	156	49
Depreciation	4,603	4,433
Ending balance	11,218	7,814
New Building, Oegstgeest, Netherlands
Disclosure of detailed information about property, plant and equipment [line items]
Reclassifications		64,300
Installation and machinery
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	28,530
Ending balance	20,500	28,530
Installation and machinery | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	57,040	46,270
Impact of acquisitions of businesses		2,117
Additions	6,472	5,688
Sales and disposals	(24,057)	(600)
Reclassifications	272	3,580
Translation differences	(49)	(15)
Ending balance	39,678	57,040
Installation and machinery | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	28,510	24,749
Sales and disposals	(13,676)	(574)
Translation differences	(11)	(1)
Depreciation	4,355	4,336
Ending balance	19,178	28,510
Furniture, fixtures & vehicles
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	5,704
Ending balance	4,463	5,704
Furniture, fixtures & vehicles | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	10,241	7,829
Impact of acquisitions of businesses		108
Additions	268	3,438
Sales and disposals	(1,067)	(1,344)
Reclassifications	124	167
Reclassifications to assets held for sale	(249)
Translation differences	36	43
Ending balance	9,353	10,241
Furniture, fixtures & vehicles | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	4,537	4,582
Sales and disposals	(827)	(1,328)
Reclassifications to assets held for sale	(129)
Translation differences	19	18
Depreciation	1,290	1,265
Ending balance	4,891	4,537
Other tangible assets
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	11,587
Impairment	7,600
Ending balance	6,770	11,587
Other tangible assets | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	11,587	60,324
Additions	3,329	19,296
Sales and disposals	(7,655)
Reclassifications	(491)	(68,033)
Ending balance	6,770	€ 11,587
Other tangible assets | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Sales and disposals	(7,645)
Impairment	€ 7,645

Property, plant and equipment_2

Property, plant and equipment - Right of Use (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	€ 126,726
Ending balance	111,220	€ 126,726
RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	27,526
Ending balance	15,101	27,526
Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	167,588	140,555
Additions	16,823	29,336
Sales and disposals	(37,182)	(4,790)
Reclassifications to assets held for sale	(988)
Translation differences	266	233
Ending balance	146,507	167,588
Acquisition value | RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	47,777	48,239
Additions	3,450	4,306
Sales and disposals	(13,580)	(4,984)
Reclassifications to assets held for sale	(6,774)
Translation differences	205	216
Ending balance	31,078	47,777
Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	40,862	34,837
Sales and disposals	(23,342)	(4,075)
Reclassifications to assets held for sale	(290)
Translation differences	164	66
Depreciation	10,248	10,034
Ending balance	35,287	40,862
Depreciations and impairment | RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	20,250	16,444
Sales and disposals	(7,979)	(3,993)
Reclassifications to assets held for sale	(3,279)
Translation differences	(135)	(103)
Depreciation	6,849	7,696
Ending balance	15,976	20,250
Land and building | RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	20,410
Ending balance	11,895	20,410
Land and building | Acquisition value | RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	34,834	37,461
Additions	1,726	703
Sales and disposals	(11,497)	(3,554)
Reclassifications to assets held for sale	(2,091)
Translation differences	202	224
Ending balance	23,174	34,834
Land and building | Depreciations and impairment | RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	14,424	12,500
Sales and disposals	(5,922)	(2,602)
Reclassifications to assets held for sale	(699)
Translation differences	(134)	(105)
Depreciation	3,342	4,421
Ending balance	11,279	14,424
Installation and machinery
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	28,530
Ending balance	20,500	28,530
Installation and machinery | RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	85
Ending balance	28	85
Installation and machinery | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	57,040	46,270
Additions	6,472	5,688
Sales and disposals	(24,057)	(600)
Reclassifications	272	3,580
Translation differences	(49)	(15)
Ending balance	39,678	57,040
Installation and machinery | Acquisition value | RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	437	593
Sales and disposals	(186)	(156)
Ending balance	251	437
Installation and machinery | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	28,510	24,749
Sales and disposals	(13,676)	(574)
Translation differences	(11)	(1)
Depreciation	4,355	4,336
Ending balance	19,178	28,510
Installation and machinery | Depreciations and impairment | RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	352	374
Sales and disposals	(186)	(156)
Depreciation	57	134
Ending balance	223	352
Furniture, fixtures & vehicles
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	5,704
Ending balance	4,463	5,704
Furniture, fixtures & vehicles | RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	7,032
Ending balance	3,179	7,032
Furniture, fixtures & vehicles | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	10,241	7,829
Additions	268	3,438
Sales and disposals	(1,067)	(1,344)
Reclassifications	124	167
Reclassifications to assets held for sale	(249)
Translation differences	36	43
Ending balance	9,353	10,241
Furniture, fixtures & vehicles | Acquisition value | RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	12,505	10,184
Additions	1,724	3,603
Sales and disposals	(1,897)	(1,274)
Reclassifications to assets held for sale	(4,683)
Translation differences	3	(8)
Ending balance	7,652	12,505
Furniture, fixtures & vehicles | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	4,537	4,582
Sales and disposals	(827)	(1,328)
Reclassifications to assets held for sale	(129)
Translation differences	19	18
Depreciation	1,290	1,265
Ending balance	4,891	4,537
Furniture, fixtures & vehicles | Depreciations and impairment | RIGHT OF USE
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	5,473	3,569
Sales and disposals	(1,871)	(1,235)
Reclassifications to assets held for sale	(2,580)
Translation differences	(1)	2
Depreciation	3,450	3,141
Ending balance	€ 4,473	€ 5,473

Property, plant and equipment_3

Property, plant and equipment - Carrying Amount (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022
Disclosure of detailed information about property, plant and equipment [line items]
Total property, plant and equipment	€ 126,321	€ 154,252
Installation and machinery
Disclosure of detailed information about property, plant and equipment [line items]
Property, Plant And Equipment Fully Owned	111,220
Right-of-use assets	15,101
Total property, plant and equipment	€ 126,321
Furniture, fixtures & vehicles
Disclosure of detailed information about property, plant and equipment [line items]
Property, Plant And Equipment Fully Owned		126,726
Right-of-use assets		27,526
Total property, plant and equipment		€ 154,252

Other non-current assets - Summ

Other non-current assets - Summary (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022
Other non-current assets
Non-current restricted cash	€ 5,533	€ 4,569
Non-current portion of upfront payment to NovAlix	4,656
Non-current portion of advance related to the NovAliX transaction	5,563
Financial assets held at fair value through profit or loss	13,575
Other non-current assets	318	1,209
Total other non-current assets	€ 29,645	€ 5,778

Other non-current assets - Fina

Other non-current assets - Financial assets held at fair value through profit or loss (Details) € in Thousands	Dec. 31, 2023 EUR (€)
Reconciliation of fair value remeasurement
Net book value at December 31,	€ 13,575

Research and Development ince_3

Research and Development incentives receivables - Current and non-current (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022
Research and Development incentives receivables
Non-current R&D incentives receivables	€ 141,252	€ 119,941
Current R&D incentives receivables	37,436	26,126
Total R&D incentives receivables	€ 178,688	€ 146,067

Research and Development ince_4

Research and Development incentives receivables - Maturities (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	€ 141,252	€ 119,941
France
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	28,584
Belgium
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	112,668
Later than one year and not later than two years [member]
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	29,025
Later than one year and not later than two years [member] | France
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	11,495
Later than one year and not later than two years [member] | Belgium
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	17,530
Later than two years and not later than three years [member]
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	30,851
Later than two years and not later than three years [member] | France
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	11,511
Later than two years and not later than three years [member] | Belgium
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	19,340
Later than three years and not later than four years [member]
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	25,780
Later than three years and not later than four years [member] | France
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	5,578
Later than three years and not later than four years [member] | Belgium
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	20,202
Later than four years and not later than five years [member]
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	19,858
Later than four years and not later than five years [member] | Belgium
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	19,858
Later than five years and not later than ten years [member]
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	35,738
Later than five years and not later than ten years [member] | Belgium
Disclosure of financial assets [line items]
Total non-current R&D incentives receivables-discounted value	€ 35,738

Inventories (Details)

Inventories (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022
Inventories
Raw materials	€ 55,263	€ 39,071
Semi-finished products	12,598	5,791
Finished goods	6,117	8,063
Total inventories	€ 73,978	€ 52,925

Trade and other receivables a_3

Trade and other receivables and other current assets (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022
Trade and other receivables and other current assets
Trade receivables	€ 17,494	€ 28,194
Prepayments	738	488
Other receivables	10,217	11,747
Trade and other receivables	28,449	40,429
Accrued income	508	11,277
Deferred Charges	14,632	12,029
Other current assets	15,140	23,307
Total trade and other receivables & other current assets	43,589	€ 63,735
Assets and liabilities classified as held for sale [member]
Trade and other receivables and other current assets
Trade and other receivables	€ 15,800

Current financial investments_2

Current financial investments (Details) € in Thousands, $ in Millions	Dec. 31, 2023 EUR (€)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 EUR (€)
Current financial investments
Money market funds	€ 1,316,805		€ 1,292,514
Treasury bills	742,025		749,835
Term deposits	1,458,868		1,543,596
Total current financial investments	€ 3,517,698		€ 3,585,945
Current financial investments held in USD | $		$ 830.9

Cash and cash equivalents (Deta

Cash and cash equivalents (Details) € in Thousands, $ in Millions	Dec. 31, 2023 EUR (€)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 EUR (€)	Dec. 31, 2021 EUR (€)	Dec. 31, 2020 EUR (€)
Cash and cash equivalents
Cash at banks	€ 71,803		€ 458,117
Term deposits	95,000		50,000
Cash and cash equivalents from continuing operations	166,803	$ 34.5	508,117
Cash and cash equivalents included in assets held for sale (HFS)	7
Total cash and cash equivalents	€ 166,810		€ 508,117	€ 2,233,368	€ 2,143,071

Cash and cash equivalents - Nar

Cash and cash equivalents - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 EUR (€)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 EUR (€)
Cash and cash equivalents
Term deposits	€ 95,000,000		€ 50,000,000
Cash and cash equivalents	€ 166,803,000	$ 34.5	€ 508,117,000
Maturity Period	3 months
Short Term Deposit Longer Than Three Months	€ 50,000,000
Short Term Deposit Less Than Three Months	€ 45,000,000

Share capital - Reconciliation

Share capital - Reconciliation (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Aggregate share capital	€ 356,445	€ 356,112	€ 354,582	€ 353,819
Share capital.
Balance at beginning of year, amount.	293,604	292,075	291,312
Share capital increase	333	1,530	763
Aggregate share capital	356,445	356,112	354,582
Costs of capital increase (accumulated)	(62,507)	(62,507)	(62,507)
Balance at end of year, amount	€ 293,937	€ 293,604	€ 292,075	€ 291,312

Share capital - History (Detail

Share capital - History (Details) - EUR (€) € in Thousands, shares in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
History of the share capital
Aggregate number of shares after transaction	65,897	65,836	65,553	65,412
Aggregate share capital after transaction	€ 356,445	€ 356,112	€ 354,582	€ 353,819
March 19, 2021
History of the share capital
Share capital increase warrants			€ 540
Number of shares issued			100
June 7, 2021
History of the share capital
Share capital increase warrants			€ 59
Number of shares issued			11
September 20, 2021
History of the share capital
Share capital increase warrants			€ 41
Number of shares issued			8
December 3, 2021
History of the share capital
Share capital increase warrants			€ 123
Number of shares issued			23
March 18, 2022
History of the share capital
Share capital increase warrants		€ 517
Number of shares issued		96
June 20, 2022
History of the share capital
Share capital increase warrants		€ 434
Number of shares issued		80
September 27, 2022
History of the share capital
Share capital increase warrants		€ 579
Number of shares issued		107
March 20, 2023
History of the share capital
Share capital increase warrants	€ 333
Number of shares issued	62

Share capital - History - Narra

Share capital - History - Narrative (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share capital
Aggregate share capital	€ 356,445	€ 356,112	€ 354,582	€ 353,819
Number of shares	65,897,071	65,835,511	65,552,721	65,411,767

Share capital - Capital increas

Share capital - Capital increases (Details) € / shares in Units, € in Thousands	12 Months Ended
	Dec. 31, 2023 EUR (€) shares € / shares	Dec. 31, 2022 EUR (€) shares € / shares	Dec. 31, 2021 EUR (€) shares € / shares	Dec. 31, 2020 EUR (€)
Disclosure of classes of share capital [line items]
Balance at beginning of year, shares | shares	65,835,511	65,552,721	65,411,767
Share capital	€ 293,937	€ 293,604
Share premium	2,736,994	2,735,557
Exercise of warrant/ subscription rights	€ 1,770	€ 6,695	€ 3,314
Average exercise price warrants | € / shares	€ 28.75	€ 23.68	€ 23.51
Balance at end of year, shares | shares	65,897,071	65,835,511	65,552,721
Par value of shares | € / shares	€ 5.41
Ordinary Shares
Disclosure of classes of share capital [line items]
Par value of shares | € / shares	€ 5.41
Share capital.
Disclosure of classes of share capital [line items]
Share capital	€ 293,937	€ 293,604	€ 292,075	€ 291,312
Exercise of warrant/ subscription rights	333	1,530	763
Share premium account
Disclosure of classes of share capital [line items]
Share premium	2,736,994	2,735,557	2,730,391	2,727,840
Exercise of warrant/ subscription rights	1,437	5,166	2,551
Share capital and share premium
Disclosure of classes of share capital [line items]
Balance at beginning of year, amount	3,029,162	3,022,467
Share capital and share premium				€ 3,019,153
Balance at end of year, amount	€ 3,030,932	€ 3,029,162	€ 3,022,467
December 3, 2021 : exercise of subscription rights
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares			22,600
Average exercise price warrants | € / shares			€ 25.61
Closing share price on date of capital increase | € / shares			€ 41.72
December 3, 2021 : exercise of subscription rights | Share capital.
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			€ 123
December 3, 2021 : exercise of subscription rights | Share premium account
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			456
December 3, 2021 : exercise of subscription rights | Share capital and share premium
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			€ 579
March 19, 2021 : exercise of subscription rights
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares			99,814
Average exercise price warrants | € / shares			€ 22.62
Closing share price on date of capital increase | € / shares			€ 68.48
March 19, 2021 : exercise of subscription rights | Share capital.
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			€ 540
March 19, 2021 : exercise of subscription rights | Share premium account
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			1,718
March 19, 2021 : exercise of subscription rights | Share capital and share premium
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			€ 2,258
June 7, 2021 : exercise of subscription rights
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares			10,940
Average exercise price warrants | € / shares			€ 29.73
Closing share price on date of capital increase | € / shares			€ 61.78
June 7, 2021 : exercise of subscription rights | Share capital.
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			€ 59
June 7, 2021 : exercise of subscription rights | Share premium account
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			266
June 7, 2021 : exercise of subscription rights | Share capital and share premium
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			€ 325
September 20, 2021 : exercise of subscription rights
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares			7,600
Average exercise price warrants | € / shares			€ 19.97
Closing share price on date of capital increase | € / shares			€ 46.93
September 20, 2021 : exercise of subscription rights | Share capital.
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			€ 41
September 20, 2021 : exercise of subscription rights | Share premium account
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			111
September 20, 2021 : exercise of subscription rights | Share capital and share premium
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights			€ 152
March 18, 2022 : exercise of subscription rights
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares		95,500
Average exercise price warrants | € / shares		€ 22.61
Closing share price on date of capital increase | € / shares		€ 57.38
March 18, 2022 : exercise of subscription rights | Share capital.
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights		€ 517
March 18, 2022 : exercise of subscription rights | Share premium account
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights		1,643
March 18, 2022 : exercise of subscription rights | Share capital and share premium
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights		€ 2,160
June 20, 2022 : exercise of subscription rights
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares		80,290
Average exercise price warrants | € / shares		€ 18.18
Closing share price on date of capital increase | € / shares		€ 53.52
June 20, 2022 : exercise of subscription rights | Share capital.
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights		€ 434
June 20, 2022 : exercise of subscription rights | Share premium account
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights		1,025
June 20, 2022 : exercise of subscription rights | Share capital and share premium
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights		€ 1,460
September 27, 2022 : exercise of subscription rights
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares		107,000
Average exercise price warrants | € / shares		€ 28.75
Closing share price on date of capital increase | € / shares		€ 44.49
September 27, 2022 : exercise of subscription rights | Share capital.
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights		€ 579
September 27, 2022 : exercise of subscription rights | Share premium account
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights		2,497
September 27, 2022 : exercise of subscription rights | Share capital and share premium
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights		€ 3,076
March 20, 2023 : exercise of subscription rights
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares	61,560
Average exercise price warrants | € / shares	€ 28.75
Closing share price on date of capital increase | € / shares	€ 35.47
March 20, 2023 : exercise of subscription rights | Share capital.
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights	€ 333
March 20, 2023 : exercise of subscription rights | Share premium account
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights	1,437
March 20, 2023 : exercise of subscription rights | Share capital and share premium
Disclosure of classes of share capital [line items]
Exercise of warrant/ subscription rights	€ 1,770

Share capital - Other informati

Share capital - Other information (Details) - EUR (€)			12 Months Ended
	Oct. 22, 2019	Apr. 25, 2017	Dec. 31, 2023
Disclosure of classes of share capital [line items]
Authorization period			5 years
Ordinary Shares
Disclosure of classes of share capital [line items]
Authorized capital, remained available under the general part			€ 16,566,540.17
General authorization of share capital
Disclosure of classes of share capital [line items]
Authorization period	5 years
Authorized capital, approved	€ 67,022,402.04
Percentage of share capital	20%
Specific authorization of share capital
Disclosure of classes of share capital [line items]
Authorization period		5 years
Authorized capital, approved		€ 82,561,764.93
Specific authorization of share capital | Minimum
Disclosure of classes of share capital [line items]
Percentage of share capital		20%
Specific authorization of share capital | Maximum
Disclosure of classes of share capital [line items]
Percentage of share capital		33%

Deferred tax - Changes in defer

Deferred tax - Changes in deferred taxes (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax, beginning balance	€ 1,363	€ 4,032
Credited/charged (-) to profit or loss	(72)	(1,615)
Reclassification		(275)
Reclassification to assets/liabilities held for sale	(292)
Charged to other comprehensive income	132	(795)
Exchange differences	(4)	15
Deferred tax, ending balance	1,126	1,363
Deferred tax liabilities
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax, beginning balance	(20,148)
Impact of acquisition of businesses		(23,265)
Credited/charged (-) to profit or loss	(3,477)	2,842
Reclassification		275
Exchange differences	18
Deferred tax, ending balance	(23,607)	(20,148)
Intangible assets other than goodwill | Deferred tax liabilities
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax, beginning balance	(20,148)
Impact of acquisition of businesses		(23,265)
Credited/charged (-) to profit or loss	(1,458)	2,842
Reclassification		275
Exchange differences	18
Deferred tax, ending balance	(21,588)	(20,148)
Retirement benefit liabilities | Deferred tax assets
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax, beginning balance	19	776
Credited/charged (-) to profit or loss		17
Charged to other comprehensive income	132	(795)
Exchange differences	8	22
Deferred tax, ending balance	159	19
Tax loss carryforward | Deferred tax assets
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax, beginning balance	1,061	3,133
Credited/charged (-) to profit or loss	(1,061)	(1,797)
Reclassification		(275)
Deferred tax, ending balance		1,061
Property, plant and equipment | Deferred tax assets
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Credited/charged (-) to profit or loss	298
Exchange differences	(6)
Deferred tax, ending balance	292
Other | Deferred tax assets
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax, beginning balance	281	122
Credited/charged (-) to profit or loss	692	165
Reclassification to assets/liabilities held for sale	(292)
Exchange differences	(6)	(6)
Deferred tax, ending balance	675	€ 281
Other | Deferred tax liabilities
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Credited/charged (-) to profit or loss	(2,019)
Deferred tax, ending balance	€ (2,019)

Deferred tax - Narrative (Detai

Deferred tax - Narrative (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Total amount of tax attributes and deductible temporary differences	€ 1,722,200,000	€ 1,882,500,000	€ 1,653,700,000
Tax losses carried forward and deductible temporary differences	1,312,200,000	1,516,600,000	1,343,200,000
Amount of statutory tax losses carried forward in Galapagos NV for offset against future profits	798,700,000
Deferred tax assets	1,126,000	1,363,000
Unrecognized Deferred Tax Assets	326,800,000	460,100,000
Expiry between 2028 and 2034
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Amount of statutory tax losses carried forward in Galapagos NV for offset against future profits	2,200,000
Belgium.
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Amount of statutory tax losses carried forward in Galapagos NV for offset against future profits	757,900,000
For one subsidiary company
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax assets	1,100,000	1,100,000
For several subsidiary companies
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Deferred tax assets			4,000,000
Investment Deduction
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Innovation income deduction, dividend received deduction and investment deduction	1,000,000	1,000,000
Innovation Income Deduction And Investment Deduction
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Innovation income deduction, dividend received deduction and investment deduction	410,000,000	365,900,000	310,500,000
Due to innovation income deduction | Galapagos NV
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Carried forward innovation income to be offset against future income	390,300,000	346,200,000	301,300,000
Dividend received deduction carried forward to be offset against future income Screen reader support enabled. | Galapagos NV
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Innovation income deduction, dividend received deduction and investment deduction	€ 18,700,000	€ 18,700,000	€ 8,200,000

Lease liabilities (Details)

Lease liabilities (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022
Lease liabilities
Current lease liabilities held for sale (HFS)	€ 4,652	€ 7,209
Non-current lease liabilities held for sale (HFS).	4,944	14,692
IFRS 16
Lease liabilities
Lease payments	9,810	22,517
Present value of lease payments	9,596	21,901
Less future finance charges	214	616
Lease liability	9,596	21,901
Current lease liabilities held for sale (HFS)	4,652	7,209
Non-current lease liabilities held for sale (HFS).	4,944	14,692
IFRS 16 | Less than 1 year
Lease liabilities
Lease payments	4,779	7,507
Present value of lease payments	4,652	7,209
IFRS 16 | In the second to fifth years inclusive
Lease liabilities
Lease payments	5,031	14,401
Present value of lease payments	€ 4,944	14,100
IFRS 16 | More than 5 years
Lease liabilities
Lease payments		609
Present value of lease payments		€ 592

Trade and other liabilities a_3

Trade and other liabilities and other non-current liabilities (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022
Trade and other liabilities and other non-current liabilities
Trade and other liabilities.	€ 134,653	€ 133,298
Current contingent consideration related to milestones CellPoint		8,485
Current deferred consideration payable CellPoint		6,222
Current financial instruments		19
Accrued charges	548	651
Total trade and other liabilities	135,201	148,675
Non-current contingent consideration related to milestones CellPoint	20,972	13,582
Other non-current liabilities	10,598	8,226
Total other non-current liabilities	€ 31,570	€ 21,808

Trade and other liabilities a_4

Trade and other liabilities and other non-current liabilities - Narrative (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Jun. 21, 2022
Business combinations during the period
Current contingent consideration related to milestones CellPoint		€ 8,485
Non-current contingent consideration related to milestones CellPoint	€ 20,972	€ 13,582
Cell Point Acquisition
Business combinations during the period
Fair value of contingent consideration			€ 20,211
Contingent consideration on certain development milestone			20,000
Contingent consideration on regulatory milestone			30,000
Contingent consideration on sales based milestone			50,000
Discount rate	13.72%	12.50%
Probability, success, percentage	5%
Impact on contingent consideration liability of change in probability of success	€ 3,000
Cell Point Acquisition | Maximum
Business combinations during the period
Additional contingent consideration			€ 100,000

Deferred income (Details)

Deferred income (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Deferred income related to contracts
Deferred income	€ 1,327,463	€ 1,989,230	€ 2,364,701
Non-current deferred income	1,071,193	1,623,599
Other.
Deferred income related to contracts
Deferred income	2,032	3,474
Collaboration agreement for filgotinib
Deferred income related to contracts
Deferred income	26,300
Gilead [member] | Collaboration agreement for filgotinib
Deferred income related to contracts
Deferred income	26,268	456,352	604,875
Gilead [member] | Gilead collaboration agreement for drug discovery platform
Deferred income related to contracts
Deferred income	€ 1,299,163	€ 1,529,405	€ 1,759,828

Deferred income - Movement in t

Deferred income - Movement in the non-current and current deferred income (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance	€ 1,989,230	€ 2,364,701
Of which current portion :	365,631	419,866
Upfront received		18,238
Reclassifications to liabilities related to assets held for sale	(60)
Significant financing component	(645)	7,672
Revenue recognition of upfront	(591,654)	(370,078)
Revenue recognition of milestones	(68,027)	(34,777)
Other movements	(1,382)	3,474
Deferred income, ending balance	1,327,463	1,989,230
Of which current portion :	256,270	365,631
Other.
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance	3,474
Of which current portion :	2,139
Reclassifications to liabilities related to assets held for sale	(60)
Other movements	(1,382)	3,474
Deferred income, ending balance	2,032	3,474
Of which current portion :	1,146	2,139
Collaboration agreement for filgotinib
Disclosure of Deferred Income [Line Items]
Deferred income, ending balance	26,300
Collaboration agreement for filgotinib | Gilead [member]
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance	456,352	604,875
Of which current portion :	133,470	190,018
Upfront received		18,238
Significant financing component	(645)	7,672
Revenue recognition of upfront	(361,412)	(139,655)
Revenue recognition of milestones	(68,027)	(34,777)
Deferred income, ending balance	26,268	456,352
Of which current portion :	25,054	133,470
Gilead collaboration agreement for drug discovery platform | Gilead [member]
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance	1,529,405	1,759,828
Of which current portion :	230,022	229,848
Revenue recognition of upfront	(230,242)	(230,423)
Deferred income, ending balance	1,299,163	1,529,405
Of which current portion :	€ 230,070	€ 230,022

Business combinations during _3

Business combinations during the period. - Narrative (Details) € in Thousands, $ in Millions	Jun. 21, 2022 EUR (€)	Jun. 21, 2022 USD ($)
Cell Point Acquisition
Business combinations during the period
Shares and voting interest (as a percent)	100%	100%
Total consideration	€ 125,000
Consideration for other liabilities	10,300
Fair value of contingent consideration	20,211
Total consideration	133,769
Cell Point Acquisition | Maximum
Business combinations during the period
Additional contingent consideration	100,000
AboundBio
Business combinations during the period
Total consideration | $		$ 14
Total consideration	€ 15,318

Business combinations during _4

Business combinations during the period. - Price allocations (Details) - EUR (€) € in Thousands		12 Months Ended
	Jun. 21, 2022	Dec. 31, 2023	Dec. 31, 2022
Business combinations during the period
Exchange differences on goodwill	€ (80)	€ (256)
Goodwill on 12/31/2022	69,800	69,557	€ 69,813
Net cash outflow arising on acquisition (2022)
Cash out from acquisition of subsidiaries, net of cash acquired	115,270	7,000	115,270
Cash used in operating activities for other liabilities related to the acquisition of subsidiaries (2022)	28,164		28,164
Cash used in operating activities for other liabilities related to the acquisition of subsidiaries (2023) - Payment of deferred consideration		7,000
Cell Point Acquisition
Business combinations during the period
Intangible assets other than goodwill	120,517
Property, plant and equipment	1,289
Other non-current assets	81
Trade and other receivables	162
Cash and cash equivalents	3,179
Other current assets	1,254
Deferred tax liabilities	(22,368)
Trade and other liabilities	(32,789)
Net assets acquired	71,325
Consideration paid in cash	107,750
Deferred consideration	5,808
Fair value of contingent consideration	20,211
Fair value of total consideration	133,769
Goodwill on 6/21/2022.	62,444
Goodwill on 12/31/2022		62,400	62,444
Net cash outflow arising on acquisition (2022)
Consideration paid in cash	107,750
Less: cash and cash equivalents balances acquired	3,179
Cash out from acquisition of subsidiaries, net of cash acquired	104,571
Cash used in operating activities for other liabilities related to the acquisition of subsidiaries (2022)	28,164
Cash used in operating activities for other liabilities related to the acquisition of subsidiaries (2023) - Payment of deferred consideration		7,000
Cell Point Acquisition | Book value
Business combinations during the period
Property, plant and equipment	1,289
Other non-current assets	81
Trade and other receivables	162
Cash and cash equivalents	3,179
Other current assets	1,254
Trade and other liabilities	(32,789)
Net assets acquired	(26,824)
Net cash outflow arising on acquisition (2022)
Less: cash and cash equivalents balances acquired	3,179
Cell Point Acquisition | Adjustment
Business combinations during the period
Intangible assets other than goodwill	120,517
Deferred tax liabilities	(22,368)
Net assets acquired	98,149
AboundBio
Business combinations during the period
Intangible assets other than goodwill	4,053
Property, plant and equipment	965
Other non-current assets	4
Cash and cash equivalents	4,279
Other current assets	536
Deferred tax liabilities	(907)
Trade and other liabilities	(587)
Current deferred income	(474)
Net assets acquired	7,869
Consideration paid in cash	14,976
Fair value re-measurement of previously held equity investment	342
Fair value of total consideration	15,318
Goodwill on 6/21/2022.	7,449
Exchange differences on goodwill	(80)
Goodwill on 12/31/2022		€ 7,100	€ 7,369
Net cash outflow arising on acquisition (2022)
Consideration paid in cash	14,976
Less: cash and cash equivalents balances acquired	4,279
Cash out from acquisition of subsidiaries, net of cash acquired	10,698
AboundBio | Book value
Business combinations during the period
Property, plant and equipment	965
Other non-current assets	4
Cash and cash equivalents	4,279
Other current assets	536
Trade and other liabilities	(587)
Current deferred income	(474)
Net assets acquired	4,723
Net cash outflow arising on acquisition (2022)
Less: cash and cash equivalents balances acquired	4,279
AboundBio | Adjustment
Business combinations during the period
Intangible assets other than goodwill	4,053
Deferred tax liabilities	(907)
Net assets acquired	€ 3,146

Business combinations during _5

Business combinations during the period. - Intangible asset (Details) € in Thousands	12 Months Ended
	Dec. 31, 2023 EUR (€) item	Dec. 31, 2022 EUR (€)	Jun. 21, 2022 EUR (€)
Business combinations during the period
Number of CD19- CAR-T | item	2
Goodwill	€ 69,557	€ 69,813	€ 69,800
Net deferred tax liabilities related to intangible assets			23,300
Deferred tax liabilities, intangible assets			32,300
Deferred tax assets, intangible assets	9,000
Cell Point Acquisition
Business combinations during the period
Fair value at acquisition date			120,517
Goodwill	62,400	62,444
Cell Point Acquisition | Licenses, rights, technology and in process R&D | Lonza
Business combinations during the period
Fair value at acquisition date			89,700
Cell Point Acquisition | Licenses, rights, technology and in process R&D | Hypertrust
Business combinations during the period
Fair value at acquisition date			2,600
Cell Point Acquisition | CD19 CAR-T
Business combinations during the period
Fair value at acquisition date			28,200
AboundBio
Business combinations during the period
Fair value at acquisition date			4,053
Goodwill	€ 7,100	€ 7,369
AboundBio | Licenses, rights, technology and in process R&D
Business combinations during the period
Fair value at acquisition date			€ 4,100

Details of the NovAlix transa_3

Details of the NovAlix transaction - Narrative (Details) - Drug discovery collaboration transaction with NovAliX - EUR (€)	Jun. 30, 2023	Dec. 31, 2023	Jan. 07, 2023
Ifrs Collaborative Arrangement And Arrangements Other Than Collaborative [Line Items]
Consideration	€ 0
Term of collaboration agreement	5 years
Total commitment	€ 73,800,000	€ 63,900,000
Other current asset		2,700,000
Other non-current asset		5,600,000
Upfront payment made.	€ (8,300,000)		€ (8,300,000)
Remaining part of upfront payment to be released - current		2,400,000
Remaining part of upfront payment to be released - Noncurrent		€ 4,700,000

Details of the NovAlix transa_4

Details of the NovAlix transaction - Advance (Details) - Drug discovery collaboration transaction with NovAliX € in Thousands	1 Months Ended
	Jun. 30, 2023 EUR (€)
Ifrs Collaborative Arrangement And Arrangements Other Than Collaborative [Line Items]
Loss on sale of fixed assets	€ 12,506
Result of transfer of retirement benefit liability	(3,022)
Result of transfer of right-of-use asset	174
Advance related to the NovAliX transaction	€ 9,658

Note to the cash flow stateme_3

Note to the cash flow statement (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Adjustment for non-cash transactions
Depreciation and impairment	€ 43,642	€ 65,566	€ 34,636
Share-based compensation expenses	56,718	88,506	70,726
Increase/decrease (-) in retirement benefit obligations and provisions	11	136	(2,347)
Unrealized exchange losses/gains (-) and non-cash other financial result	19,908	(41,970)	(57,073)
Discounting effect of non-current deferred income	(645)	7,672	9,289
Discounting effect of other non-current liabilities	(318)	2,271
Fair value re-measurement of warrants	(18)	(186)	(2,960)
Net change in fair value of current financial investments	(22,690)	(6,929)	(119)
Fair value adjustment financial assets held at fair value through profit or loss	390		4,919
Other non-cash expenses	2,292	2,229	648
Total adjustment for non-cash transactions	99,291	117,296	57,718
Interest expense	1,867	6,967	11,656
Interest income	(79,319)	(14,344)	(2,853)
Tax expense	11,689	2,844	2,423
Total adjustment for items to disclose separately under operating cash flow	(65,763)	(4,533)	11,227
Gain on disposal of subsidiaries			(22,191)
Gain (-)/loss on sale of fixed assets	(1,091)	(23)
Realized exchange gain on sale of current financial investments			(6,645)
interest income related to current financial investments	(15,597)	(3,766)	(12)
Total adjustment for items to disclose separately under investing and financing cash flow	(16,688)	(3,789)	(28,847)
Increase in inventories	(24,076)	(34,588)	(21,168)
Increase (-)/ decrease in receivables	(39,114)	68,984	79,859
Increase/decrease (-) in liabilities	31,817	(2,083)	(35,353)
Total change in working capital other than deferred income	€ (31,373)	€ 32,313	€ 23,337

Off-balance sheet arrangement_2

Off-balance sheet arrangements (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022
Off-balance sheet arrangements
Purchase commitments	€ 408,521	€ 398,627
Less than 1 year
Off-balance sheet arrangements
Purchase commitments	237,495	240,237
1-3 years
Off-balance sheet arrangements
Purchase commitments	143,532	136,560
3-5 years
Off-balance sheet arrangements
Purchase commitments	25,768	20,797
More than 5 years
Off-balance sheet arrangements
Purchase commitments	€ 1,727	€ 1,032

Off-balance sheet arrangement_3

Off-balance sheet arrangements narrative (Details) - EUR (€)	Dec. 31, 2023	Dec. 31, 2022
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Purchase Commitments Related To Projects In Development Phase	€ 239,600,000	€ 243,600,000
Purchase Commitment Related to Shared Services	45,900,000	49,400,000
Purchase Commitment Related to Jyseleca Product Supply Chain	14,200,000	48,800,000
Purchase Commitment Related to Commercial And Medical Affairs	29,900,000	36,000,000
Purchase Commitment Related To Project In Discovery Research Phase	79,000,000	20,900,000
Purchase Commitment Related To Services From Novalix.	63,900,000
Purchase Commitment Related To Short Term Contractual Cost Sharing Obligations	12,300,000
Purchase commitments	408,521,000	€ 398,627,000
Commitments With Pregene	243,500,000
Jyseleca discontinued operations [Member]
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Purchase commitments	139,100,000
Filgotinib clinical development [Member]
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Purchase commitments	110,800,000
Commercial and medical affairs activities [Member]
Disclosure of analysis of single amount of off-balance sheet arrangements [line items]
Purchase commitments	€ 21,200,000

Share based payments - Subscrip

Share based payments - Subscription right plans (Textual) (Details) - EUR (€) € / shares in Units, € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	May 05, 2023	Dec. 31, 2020
Subscription rights plans
Average exercise price	€ 77.93	€ 83.12	€ 92.69		€ 103.95
Number of subscription rights issued.				1,538,400
Subscription rights
Subscription rights plans
Share based compensation expense	€ 56,718	€ 88,506	€ 70,726
Average exercise price	€ 77.93	€ 83.1	€ 92.69
Weighted average remaining expected life	1913 days	1955 days	1955 days
Subscription rights | Members of the Board of Directors
Subscription rights plans
Vesting period	36 months
Percentage vested	0.027%
Twenty Twenty Three Plan ROW And RMV [Member] | Vesting tranche one
Subscription rights plans
Percentage vested	25%
Twenty Twenty Three Plan ROW And RMV [Member] | Vesting tranche two
Subscription rights plans
Percentage vested	25%
Twenty Twenty Three Plan ROW And RMV [Member] | Vesting tranche three
Subscription rights plans
Percentage vested	50%

Share based payments - Summary

Share based payments - Summary of subscription rights outstanding and exercisable (Details)	12 Months Ended
	Dec. 31, 2023 EquityInstruments € / shares	Dec. 31, 2022 EquityInstruments € / shares	Dec. 31, 2021 EquityInstruments € / shares	Dec. 31, 2020 EquityInstruments € / shares
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 77.93	€ 83.12	€ 92.69	€ 103.95
Outstanding at the beginning of the year	10,816,856	8,579,837	6,929,111
Granted during the year	1,538,400	3,127,239	2,493,433
Exercised during the year	(61,560)	(282,790)	(140,954)
Forfeited during the year	(544,676)	(607,430)	(701,753)
Expired during the year	(276,500)
Outstanding at the end of the year	11,472,520	10,816,856	8,579,837
Exercisable	5,836,538	2,574,218	1,751,013	1,168,967
Subscription rights
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 77.93	€ 83.1	€ 92.69
Outstanding at the beginning of the year	10,816,856
Granted during the year	1,538,400
Exercised during the year	(61,560)
Forfeited during the year	(544,676)
Expired during the year	(276,500)
Outstanding at the end of the year	11,472,520	10,816,856
Exercisable	5,836,538
2015 allocated on April 2015
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 28.75
Outstanding at the beginning of the year	63,223
Exercised during the year	(61,560)
Forfeited during the year	(1,663)
Outstanding at the end of the year		63,223
2015 (B) allocated on December 2015
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 49
Outstanding at the beginning of the year	241,500
Expired during the year	(241,500)
Outstanding at the end of the year		241,500
2015 RMV allocated on December 2015
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 49
Outstanding at the beginning of the year	35,000
Expired during the year	(35,000)
Outstanding at the end of the year		35,000
2016 allocated on June 2016
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 46.10
Outstanding at the beginning of the year	325,500
Outstanding at the end of the year	325,500	325,500
Exercisable	325,500
2016 RMV allocated on June 2016
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 46.10
Outstanding at the beginning of the year	69,000
Outstanding at the end of the year	69,000	69,000
Exercisable	69,000
2016 (B) allocated on January 2017
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 62.50
Outstanding at the beginning of the year	10,000
Outstanding at the end of the year	10,000	10,000
Exercisable	10,000
2017 allocated on May 2017
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 80.57
Outstanding at the beginning of the year	590,000
Forfeited during the year	(5,000)
Outstanding at the end of the year	585,000	590,000
Exercisable	585,000
2017 RMV allocated on May 2017
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 80.57
Outstanding at the beginning of the year	127,500
Forfeited during the year	(5,000)
Outstanding at the end of the year	122,500	127,500
Exercisable	122,500
2018 allocated on April 2018
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 79.88
Outstanding at the beginning of the year	974,995
Forfeited during the year	(10,000)
Outstanding at the end of the year	964,995	974,995
Exercisable	964,995
2018 RMV allocated on April 2018
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 79.88
Outstanding at the beginning of the year	137,500
Forfeited during the year	(5,000)
Outstanding at the end of the year	132,500	137,500
Exercisable	132,500
2019 allocated on April 2019
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 95.11
Outstanding at the beginning of the year	1,216,990
Forfeited during the year	(8,750)
Outstanding at the end of the year	1,208,240	1,216,990
Exercisable	1,208,240
2019 RMV allocated on April 2019
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 95.11
Outstanding at the beginning of the year	186,000
Forfeited during the year	(8,750)
Outstanding at the end of the year	177,250	186,000
Exercisable	177,250
2020 allocated on April 2020
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 168.42
Outstanding at the beginning of the year	1,458,244
Forfeited during the year	(88,627)
Outstanding at the end of the year	1,369,617	1,458,244
Exercisable	1,317,779
2020 RMV allocated on April 2020
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 168.42
Outstanding at the beginning of the year	209,075
Forfeited during the year	(15,775)
Outstanding at the end of the year	193,300	209,075
Exercisable	193,300
2021 BE allocated on April 2021
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 64.76
Outstanding at the beginning of the year	1,041,148
Forfeited during the year	(8,542)
Outstanding at the end of the year	1,032,606	1,041,148
2021 RMV allocated on April 2021
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 64.76
Outstanding at the beginning of the year	257,700
Forfeited during the year	(31,404)
Outstanding at the end of the year	226,296	257,700
Exercisable	117,030
2021 ROW allocated on April 2021
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 64.76
Outstanding at the beginning of the year	783,375
Forfeited during the year	(115,879)
Outstanding at the end of the year	667,496	783,375
Exercisable	356,418
2022 (A) allocated on January 2022
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 46.18
Outstanding at the beginning of the year	30,000
Outstanding at the end of the year	30,000	30,000
Exercisable	15,000
2022 (B) allocated on January 2022
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 50
Outstanding at the beginning of the year	1,000,000
Outstanding at the end of the year	1,000,000	1,000,000
2022 BE allocated on May 2022
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 57.46
Outstanding at the beginning of the year	831,542
Forfeited during the year	(13,714)
Outstanding at the end of the year	817,828	831,542
2022 BE allocated on August 2022
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 51.58
Outstanding at the beginning of the year	78,000
Outstanding at the end of the year	78,000	78,000
2022 RMV allocated on May 2022
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 57.46
Outstanding at the beginning of the year	242,714
Forfeited during the year	(39,250)
Outstanding at the end of the year	203,464	242,714
Exercisable	50,770
2022 ROW allocated on May 2022
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 57.46
Outstanding at the beginning of the year	847,850
Forfeited during the year	(142,350)
Outstanding at the end of the year	705,500	847,850
Exercisable	176,256
2022 BE/ROW allocated on August 2022
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 51.58
Outstanding at the beginning of the year	60,000
Outstanding at the end of the year	60,000	60,000
Exercisable	15,000
2023 BE allocated on May 2023
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 35.11
Granted during the year	611,000
Forfeited during the year	(1,972)
Outstanding at the end of the year	609,028
2023 RMV allocated on May 2023
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 35.11
Granted during the year	110,000
Forfeited during the year	(7,500)
Outstanding at the end of the year	102,500
2023 ROW allocated on May 2023
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 35.11
Granted during the year	597,400
Forfeited during the year	(35,500)
Outstanding at the end of the year	561,900
2023 BE allocated on June 2023
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 38.58
Granted during the year	200,000
Outstanding at the end of the year	200,000
2023 ROW allocated on November 2023
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise Price | € / shares	€ 32.99
Granted during the year	20,000
Outstanding at the end of the year	20,000

Share based payments - Rollforw

Share based payments - Rollforward (Details)	12 Months Ended
	Dec. 31, 2023 EquityInstruments € / shares	Dec. 31, 2022 EquityInstruments € / shares	Dec. 31, 2021 EquityInstruments € / shares	Dec. 31, 2020 EquityInstruments € / shares
Share based payments
Outstanding at the beginning of the year | EquityInstruments	10,816,856	8,579,837	6,929,111
Granted during the year | EquityInstruments	1,538,400	3,127,239	2,493,433
Forfeited during the year | EquityInstruments	(544,676)	(607,430)	(701,753)
Exercised during the year | EquityInstruments	(61,560)	(282,790)	(140,954)
Expired during the year | EquityInstruments	(276,500)
Outstanding at the end of the year | EquityInstruments	11,472,520	10,816,856	8,579,837
Exercisable | EquityInstruments	5,836,538	2,574,218	1,751,013	1,168,967
Weighted average exercise price at beginning of the year | € / shares	€ 83.12	€ 92.69	€ 103.95
Granted during the period | € / shares	35.53	54.71	64.76
Forfeited during the year | € / shares	80.31	100	118.53
Exercised during the period | € / shares	28.75	23.68	23.51
Expired during the year | € / shares	49
Weighted average exercise price at end of the year | € / shares	77.93	83.12	92.69
Exercisable | € / shares	€ 101.93	€ 70.26	€ 56.64	€ 37.84

Share based payments - Valuatio

Share based payments - Valuation (Details) - EUR (€) € / shares in Units, € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Subscription rights plans
Share-based compensation expenses for continuing operations.	€ 36,628	€ 62,003	€ 52,131
Discontinued Operations [Member]
Subscription rights plans
Share based compensation expense	€ 20,090	€ 26,503	€ 18,595
2023 BE allocated on May 2023
Subscription rights plans
Exercise Price	€ 35.97
Weighted average share price at acceptance date	38.53
Weighted average fair value at acceptance date	€ 16.61
Weighted average estimated volatility	36.89%
Weighted average expected life of the subscription rights (years)	6 years 1 month 20 days
Weighted average risk free rate (%)	2.77%
2023 RMV/ROW
Subscription rights plans
Exercise Price	€ 35.05
Weighted average share price at acceptance date	38.63
Weighted average fair value at acceptance date	€ 15.96
Weighted average estimated volatility	36.67%
Weighted average expected life of the subscription rights (years)	5 years 4 months 17 days
Weighted average risk free rate (%)	2.74%
2021 BE allocated on April 2021
Subscription rights plans
Exercise Price	€ 64.76
Weighted average share price at acceptance date	61.10
Weighted average fair value at acceptance date	€ 22.72
Weighted average estimated volatility	40.73%
Weighted average expected life of the subscription rights (years)	6 years 5 months 4 days
Weighted average risk free rate (%)	(0.21%)
2021 RMV/ROW allocated on April 2021
Subscription rights plans
Exercise Price	€ 64.76
Weighted average share price at acceptance date	61.10
Weighted average fair value at acceptance date	€ 20.68
Weighted average estimated volatility	40.61%
Weighted average expected life of the subscription rights (years)	5 years 4 months 9 days
Weighted average risk free rate (%)	(0.29%)
2022 (A) allocated on January 2022
Subscription rights plans
Exercise Price	€ 46.18
Weighted average share price at acceptance date	46.21
Weighted average fair value at acceptance date	€ 16.10
Weighted average estimated volatility	41.80%
Weighted average expected life of the subscription rights (years)	4 years 8 months 19 days
Weighted average risk free rate (%)	(0.13%)
2022 (B) allocated on January 2022
Subscription rights plans
Exercise Price	€ 50
Weighted average share price at acceptance date	56.67
Weighted average fair value at acceptance date	€ 24.53
Weighted average estimated volatility	40.80%
Weighted average expected life of the subscription rights (years)	5 years 11 months 12 days
Weighted average risk free rate (%)	0.67%
2022 BE allocated on May 2022
Subscription rights plans
Exercise Price	€ 57.46
Weighted average share price at acceptance date	51.64
Weighted average fair value at acceptance date	€ 20.73
Weighted average estimated volatility	42.59%
Weighted average expected life of the subscription rights (years)	6 years 4 months 13 days
Weighted average risk free rate (%)	1.33%
2022 RMV/ROW on May 2022
Subscription rights plans
Exercise Price	€ 57.46
Weighted average share price at acceptance date	51.64
Weighted average fair value at acceptance date	€ 18.92
Weighted average estimated volatility	42.65%
Weighted average expected life of the subscription rights (years)	5 years 4 months 9 days
Weighted average risk free rate (%)	1.26%
2022 BE/ROW allocated on August 2022
Subscription rights plans
Exercise Price	€ 51.58
Weighted average share price at acceptance date	44.55
Weighted average fair value at acceptance date	€ 17.07
Weighted average estimated volatility	41.75%
Weighted average expected life of the subscription rights (years)	5 years 8 months 4 days
Weighted average risk free rate (%)	2.70%

Share based payments - Category

Share based payments - Category (Details) - EquityInstruments	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Subscription rights plans
Total rights outstanding	11,472,520	10,816,856	8,579,837	6,929,111
Members of the Board of Directors
Subscription rights plans
Total rights outstanding	7,500	75,000	157,560
Members of the Executive Committee
Subscription rights plans
Total rights outstanding	1,670,500	1,864,000	1,965,000
Personnel
Subscription rights plans
Total rights outstanding	9,794,520	8,877,856	6,457,277

Share based payments - Summar_2

Share based payments - Summary of RSU's outstanding (Details) - EquityInstruments	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share based payments
Outstanding at the beginning of the year	10,816,856	8,579,837	6,929,111
Granted during the year	1,538,400	3,127,239	2,493,433
Forfeited during the year	(544,676)	(607,430)	(701,753)
Outstanding at the end of the year	11,472,520	10,816,856	8,579,837
Restricted Stock Units (RSUs)
Share based payments
Outstanding at the beginning of the year	736,095	657,803	313,596
Granted during the year	920,510	470,273	511,518
Forfeited during the year	(270,474)	(172,885)	(74,873)
Paid in cash during the year	(210,678)	(219,096)	(92,438)
Outstanding at the end of the year	1,175,453	736,095	657,803
Plan 2019.II
Share based payments
Outstanding at the beginning of the year	12,931
Forfeited during the year	(768)
Paid in cash during the year	(12,163)
Outstanding at the end of the year		12,931
Plan 2020.I
Share based payments
Outstanding at the beginning of the year	17,110
Forfeited during the year	(2,558)
Paid in cash during the year	(9,361)
Outstanding at the end of the year	5,191	17,110
Plan 2020.II
Share based payments
Outstanding at the beginning of the year	17,626
Forfeited during the year	(6,530)
Paid in cash during the year	(8,335)
Outstanding at the end of the year	2,761	17,626
Plan 2021.I.
Share based payments
Outstanding at the beginning of the year	92,600
Forfeited during the year	(23,150)
Paid in cash during the year	(26,621)
Outstanding at the end of the year	42,829	92,600
Plan 2021.II.
Share based payments
Outstanding at the beginning of the year	22,341
Forfeited during the year	(7,447)
Paid in cash during the year	(5,416)
Outstanding at the end of the year	9,478	22,341
Plan 2021.III
Share based payments
Outstanding at the beginning of the year	16,259
Forfeited during the year	(2,636)
Paid in cash during the year	(8,207)
Outstanding at the end of the year	5,416	16,259
Plan 2021.IV.
Share based payments
Outstanding at the beginning of the year	101,838
Forfeited during the year	(52,462)
Paid in cash during the year	(33,946)
Outstanding at the end of the year	15,430	101,838
Plan 2022.I.
Share based payments
Outstanding at the beginning of the year	194,638
Forfeited during the year	(49,844)
Paid in cash during the year	(41,486)
Outstanding at the end of the year	103,308	194,638
Plan 2022.II.
Share based payments
Outstanding at the beginning of the year	249,000
Forfeited during the year	(83,602)
Paid in cash during the year	(59,270)
Outstanding at the end of the year	106,128	249,000
Plan 2022.III.
Share based payments
Outstanding at the beginning of the year	11,752
Forfeited during the year	(349)
Paid in cash during the year	(5,873)
Outstanding at the end of the year	5,530	11,752
Plan 2023.I.
Share based payments
Granted during the year	401,962
Forfeited during the year	(35,380)
Outstanding at the end of the year	366,582
Plan 2023.II.
Share based payments
Granted during the year	518,548
Forfeited during the year	(5,748)
Outstanding at the end of the year	512,800

Share based payments - Restrict

Share based payments - Restricted stock units - Category (Details) - EquityInstruments	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share based payments
Total outstanding	11,472,520	10,816,856	8,579,837	6,929,111
Members of the Executive Committee
Share based payments
Total outstanding	1,670,500	1,864,000	1,965,000
Personnel
Share based payments
Total outstanding	9,794,520	8,877,856	6,457,277
Restricted Stock Units (RSUs)
Share based payments
Total outstanding	1,175,453	736,095	657,803	313,596
Restricted Stock Units (RSUs) | Members of the Executive Committee
Share based payments
Total outstanding	438,738	332,038	384,340
Restricted Stock Units (RSUs) | Personnel
Share based payments
Total outstanding	736,715	404,057	273,463

Share based payments - Restri_2

Share based payments - Restricted stock units (RSU's) (Textual) (Details) € in Millions	12 Months Ended
	Dec. 31, 2023 EUR (€) D shares	Dec. 31, 2022 EUR (€)	Dec. 31, 2021 EUR (€)
Restricted Stock Units (RSUs)
Share based payments
Number of securities called by each restricted stock or right | shares	1
Number of calendar days period preceding vesting date for calculate value of weighted average price of entity share traded on stock-exchange	30
Vesting period	4 years
Percentage vested	25%
Number of calendar days period preceding reporting period for calculate value of weighted average price of entity share traded on stock-exchange	30
Liability relating to outstanding RSU | €	€ 13.8	€ 12.9	€ 11.3
RSUs, other general plans
Share based payments
Vesting period	3 years
RSUs, other general plans | Vesting percentage portion one
Share based payments
Vesting period	2 years
Share based payments, Percentage of other equity instruments vested in certain period	50%
RSUs, other general plans | Vesting percentage portion two
Share based payments
Vesting period	3 years
Share based payments, Percentage of other equity instruments vested in certain period	50%
RSUs, other general plans | Vesting tranche one | Vesting percentage portion one
Share based payments
Vesting period	3 years
Share based payments, Percentage of other equity instruments vested in certain period	34%
RSUs, other general plans | Vesting tranche two
Share based payments
Share based payments, Percentage of other equity instruments vested in certain period	33%
RSUs, other general plans | Vesting tranche two | Vesting percentage portion two
Share based payments
Vesting period	2 years

Related parties (Details)

Related parties (Details)			12 Months Ended
	Nov. 06, 2019	Aug. 28, 2019	Dec. 31, 2023 EUR (€) individual	Dec. 31, 2022 EUR (€)	Dec. 31, 2021 EUR (€)	Dec. 31, 2019
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Number of board of directors | individual			9
Amount received till 31/12/2022.					€ 12,600,000
Deferred income other than contract liabilities			€ 1,327,463,000	€ 1,989,230,000	2,364,701,000
Minimum
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Percentage of ownership interest			20%
Gilead collaboration agreement for drug discovery platform
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Royalty income related to the commercialization of filgotinib			€ 9,500,000
Gilead collaboration agreement for drug discovery platform | Gilead [member]
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Deferred income other than contract liabilities			1,299,163,000	1,529,405,000	1,759,828,000
Collaboration agreement for filgotinib
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Deferred income other than contract liabilities			26,300,000
Collaboration agreement for filgotinib | Gilead [member]
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Cross charges receivable relating to development of Filgotinib				5,100,000
Deferred income other than contract liabilities			€ 26,268,000	€ 456,352,000	604,875,000
Key management personnel of entity or parent | Gilead [member]
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Number of board of directors | individual			2
Gilead.
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Percentage of stake	25.10%	22.04%
Percentage of ownership interest			25.35%	25.38%		25.84%
Trade and other receivables			€ 5,198,000	€ 7,877,000	88,246,000
Trade and other payables			€ 585,000		11,580,000
Number of outstanding performance Obligations			2
Gilead. | Gilead [member]
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Cross charges receivable relating to development of Filgotinib			€ 2,500,000
Purchase of raw materials, semi-finished products and finished products of Jyseleca				13,539,000	24,867,000
Gilead. | Gilead collaboration agreement for drug discovery platform
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Revenues recognized related to the performance obligations			230,242,000	230,423,000	230,582,000
Deferred income other than contract liabilities			1,300,000,000
Gilead. | Collaboration agreement for filgotinib
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Trade and other receivables					50,000,000
profit and cost sharing receivables					23,800,000
Royalties receivable relating to development of Filgotinib			2,400,000	2,600,000
Total impact on revenue			429,439,000	174,432,000	235,709,000
Deferred income other than contract liabilities			26,300,000
Gilead. | GLPG 1690 License
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Cost reimbursements			299,000	411,000	18,055,000
Filgotinib drug license | Gilead.
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Royalty income related to the commercialization of filgotinib			9,466,000	10,726,000	3,757,000
Cost reimbursements			€ 3,643,000	(2,374,000)	(81,334,000)
included in sales and marketing expenses				31,000	59,699,000
Included in research and development expenditure				€ (31,000)	€ 7,026,000

Related parties - Summary of re

Related parties - Summary of remuneration package (Details) € in Thousands	12 Months Ended
	Dec. 31, 2023 EUR (€) EquityInstruments	Dec. 31, 2022 EUR (€) EquityInstruments	Dec. 31, 2021 EUR (€) EquityInstruments
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Board fees and other short-term benefits for members of the Board of Directors	€ 749	€ 740	€ 750
Post-employment benefits	209	€ 240	399
Severance package	€ 3,150		€ 802
Subscription rights offered | EquityInstruments	1,538,400	3,127,239	2,493,433
Total cost of subscription rights granted in the year	€ 5,163	€ 27,010	€ 5,629
Restricted Stock Units (RSUs)
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Subscription rights offered | EquityInstruments	920,510	470,273	511,518
Key management personnel of entity or parent | Restricted Stock Units (RSUs)
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Subscription rights offered | EquityInstruments	331,066	200,478	254,560
Executive committee members as a group
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Short-term benefits	€ 3,902	€ 3,444	€ 4,264
Executive committee members as a group | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Subscription rights offered | EquityInstruments	325,000	1,124,000	275,000
Piet Wigerinck
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Severance package			€ 802
Piet Wigerinck and Onno Van De Stolpe [member]
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Severance package		€ 689

Consolidated companies as of _3

Consolidated companies as of December 31, 2023 (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
AboundBio, Inc. | United States
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	0%
CellPoint B.V. | The Netherlands
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	0%
Galapagos Biopharma BV | The Netherlands | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Biopharma BV | Belgium | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos B.V | The Netherlands
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Biopharma Spain S.L.U | Spain | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Biopharma Italy S.r.l. | Italy | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Biopharma Germany GmbH | Germany | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Biopharma A.B. | Sweden | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Biopharma A.S. | Norway | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Biopharma Oy | Finland | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Biopharma ApS | Denmark | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos GmbH | Switzerland
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos GmbH | Austria | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Biopharma Ireland Ltd | Ireland | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Biotech Ltd. (formerly Inpharmatica Ltd.) | United Kingdom | DISCONTINUED OPERATIONS
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Real Estate 1 BV | Belgium
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos Real Estate B.V. | The Netherlands
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos SASU (France) | France
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Galapagos, Inc. (formerly Biofocus, Inc.) | United States
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%
Xenometrix, Inc. | United States
Consolidated companies as of December 31, 2022
Percentage of voting rights held directly or indirectly through subsidiaries	100%	100%	100%

Financial risk management - Fin

Financial risk management - Financial risk factors (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financial risk management
Financial assets held at fair value through profit or loss	€ 13,575
Financial assets	3,721,421	€ 4,128,033	€ 4,797,436
Financial liabilities	118,534	119,137	111,582
Liquidity risk
Current financial investments and cash and cash equivalents	3,684,500
Current financial instruments
Financial risk management
Financial liabilities		19	204
Current contingent consideration related to milestones CellPoint
Financial risk management
Financial liabilities		8,485
Non-current contingent consideration related to milestones CellPoint
Financial risk management
Financial liabilities	20,972	13,582
Trade & other liabilities
Financial risk management
Financial liabilities	87,966	68,928	84,519
Lease liabilities
Financial risk management
Financial liabilities	9,596	21,901	26,859
Current deferred consideration payable CellPoint
Financial risk management
Financial liabilities		6,222
Equity instruments
Financial risk management
Financial assets held at fair value through profit or loss	13,575
Current financial investments
Financial risk management
Financial assets held at fair value through profit or loss	1,316,805	1,292,514	1,317,460
Financial assets at amortized cost	2,200,893	2,293,431	1,152,349
Cash and cash equivalents
Financial risk management
Financial assets	166,803	508,117	2,233,368
Restricted cash (current and non-current)
Financial risk management
Financial assets	5,533	4,569	1,425
Other non-current assets.
Financial risk management
Financial assets	318	1,209	1,048
Trade receivables
Financial risk management
Financial assets	€ 17,494	€ 28,194	€ 91,786

Financial risk management - Agi

Financial risk management - Aging of Debtors (Details) - EUR (€) € in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financial risk management
Financial assets	€ 3,721,421	€ 4,128,033	€ 4,797,436
60 - 90 days | Trade receivables | Credit risk
Financial risk management
Financial assets	3	424	141
90 - 120 days | Trade receivables | Credit risk
Financial risk management
Financial assets	3	208	92
more than 120 days | Trade receivables | Credit risk
Financial risk management
Financial assets	€ 117	€ 473	€ 113

Financial risk management - Int

Financial risk management - Interest rate risk and foreign exchange risk (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest rate risk
Financial risk management
Increase in interest rates	1%
Decrease in interest rates	1%
Approximate increase in profit or loss, and equity from increase in interest rates	€ 36,800	€ 40,900	€ 47,000
Approximate decrease in profit or loss, and equity from decrease in interest rates	€ 36,800	€ 40,900	€ 47,000
Foreign exchange risk
Financial risk management
Percentage of change in risk assumption	10%	10%	10%
Euros - U.S. Dollars Exchange rate value | Foreign exchange risk
Financial risk management
Increase (Decrease) in net book value	€ (78,013)	€ (85,140)	€ (83,996)
Euros - GB Pounds Exchange rate value | Foreign exchange risk
Financial risk management
Increase (Decrease) in net book value	666	960	1,093
Euros - CH Francs Exchange rate value | Foreign exchange risk
Financial risk management
Increase (Decrease) in net book value	€ 385	€ 557	€ 233

Auditor's remuneration (Details

Auditor's remuneration (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Auditor's remuneration
Statutory auditor's fees	€ 1,124,000	€ 1,127,100
audit related fees	20,200	26,900
Other fees related to non-audit services executed by the statutory auditor	6,600
Other fees related to non-audit services executed by persons related to the statutory auditor	0	429,500
Tax Fees	68,000	€ 0
Increase In Audit Fees Compared To Approved Fees	€ 191,300

Events after balance sheet da_2

Events after balance sheet date (Details)	Jan. 03, 2024 EUR (€)	Jan. 31, 2024 EUR (€)	Jan. 31, 2024 USD ($)	Jan. 03, 2024 USD ($)
Events after balance sheet date
Upfront Payment	€ 50,000,000
Receipt Of Cash for Cash And Working Capital	€ 13,200,000
Upfront Preclinical Research Commitments Milestone Payments | $				$ 27,000,000
Potential Commitments For Clinical and Commercial Milestones Payments | $				$ 700,000,000
Potential Future Sales Based Milestone Payments Receivable		€ 120,000,000
Commitments Related To Development Activities.		€ 40,000,000
Series C Investment | $			$ 40,000,000