Galapagos (GLPG) 20-F 25 Mar 21 2020 FY Annual report (foreign) Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2020shares
Document and Entity Information [Abstract]
Document Type	20-F
Document Registration Statement	false
Document Annual Report	true
Document Transition Report	false
Document Shell Company Report	false
Document Period End Date	Dec. 31, 2020
Entity Registrant Name	GALAPAGOS NV
Entity Common Stock, Shares Outstanding	65,411,767
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
Entity Shell Company	false
Entity Central Index Key	0001421876
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity File Number	001-37384
Entity Incorporation, State or Country Code	C9
Document Accounting Standard	U.S. GAAP
Entity Addresses [Line Items]
Entity Address, Address Line One	Generaal De Wittelaan L11 A3
Entity Address, City or Town	Mechelen
Entity Address, Postal Zip Code	2800
Entity Address, Country	BE
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, Postal Zip Code	2800
Entity Address, Country	BE
Contact Personnel Fax Number	32 15 342 901
Contact Personnel Name	Onno van de Stolpe

Consolidated Statement of Finan

Consolidated Statement of Financial Position - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets
Intangible assets	€ 67,565	€ 24,927	€ 3,632
Property, plant and equipment	103,378	66,052	23,137
Deferred tax assets	4,475	4,205	2,514
Non-current trade receivables	50,000	0	0
Non-current R&D incentives receivables	111,624	93,407	73,443
Other non-current assets	11,343	14,091	7,919
Non-current assets	348,384	202,682	110,645
Trade and other receivables	148,418	54,009	18,609
Current R&D incentives receivables	24,104	21,949	11,203
Current financial investments	3,026,278	3,919,216	0
Cash and cash equivalents	2,135,187	1,861,616	1,290,796
Other current assets	11,953	9,138	8,244
Current assets from continuing operations	5,345,941	5,865,927	1,328,851
Assets classified as held for sale	23,406	0	0
Total current assets	5,369,347	5,865,927	1,328,851
Total assets	5,717,731	6,068,609	1,439,496
Equity and liabilities
Share capital	291,312	287,282	236,540
Share premium account	2,727,840	2,703,583	1,277,780
Other reserves	(10,907)	(4,842)	(735)
Translation differences	(3,189)	(1,142)	(1,557)
Accumulated losses	(334,701)	(109,223)	(297,779)
Total equity	2,670,355	2,875,658	1,214,249
Retirement benefit liabilities	14,996	8,263	3,764
Non-current lease liabilities	23,035	19,558	0
Other non-current liabilities	8,096	6,989	1,578
Non-current deferred income	2,365,974	2,586,348	0
Non-current liabilities	2,412,101	2,621,158	5,342
Current lease liabilities	6,401	5,826	0
Trade and other liabilities	172,386	143,434	68,928
Current tax payable	1,248	2,037	1,175
Current financial instruments	3,164	6,198	0
Current deferred income	443,159	414,298	149,801
Current liabilities from continuing operations	626,357	571,793	219,905
Liabilities directly associated with assets classified as held for sale	8,917	0	0
Current liabilities	635,274	571,793	219,905
Total liabilities	3,047,375	3,192,951	225,247
Total equity and liabilities	€ 5,717,731	€ 6,068,609	€ 1,439,496

Consolidated Statement of Opera

Consolidated Statement of Operations - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Consolidated Statement of Operations
Revenues	€ 478,053	€ 834,901	[1]	€ 278,666	[1]
Other income	52,207	50,896	[1]	29,000	[1]
Total revenues and other income	530,260	885,797	[1]	307,666	[1]
Research and development expenses	(523,667)	(420,090)	[1]	(316,222)	[1]
Sales and marketing expenses	(66,468)	(24,577)	[1]	(4,146)	[1]
General and administrative expenses	(118,757)	(72,382)	[1]	(34,377)	[1]
Total operating expenses	(708,892)	(517,049)	[1]	(354,746)	[1]
Operating income/loss (-)	(178,632)	368,748	[1]	(47,080)	[1]
Fair value re-measurement of share subscription agreement and warrants	3,034	(181,644)	[1]	0	[1]
Other financial income	18,667	21,389	[1]	18,264	[1]
Other financial expenses	(152,844)	(59,968)	[1]	(2,602)	[1]
Income/loss (-) before tax	(309,775)	148,525	[1]	(31,417)	[1]
Income taxes	(1,226)	165	[1]	(822)	[1]
Net income/loss (-) from continuing operations	(311,001)	148,689	[1]	(32,240)	[1]
Net income from discontinued operations, net of tax	5,565	1,156	[1]	2,981	[1]
Net income/loss (-)	(305,436)	149,845	[1],[2]	(29,259)	[1],[2]
Net income/loss (-) attributable to:
Owners of the parent	€ (305,436)	€ 149,845	[1]	€ (29,259)	[1]
Basic income/loss (-) per share	€ (4.69)	€ 2.60	[1]	€ (0.56)	[1]
Diluted income/loss (-) per share	(4.69)	2.49	[1]	(0.56)	[1]
Basic income/loss (-) per share from continuing operations	(4.78)	2.58	[1]	(0.62)	[1]
Diluted income/loss (-) per share from continuing operations	€ (4.78)	€ 2.47	[1]	€ (0.62)	[1]
Weighted average number of shares - Basic (in '000 shares)	65,075	57,614		52,113
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.
[2]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued operation

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income/Loss (-) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018	[1]
Consolidated Statement of Comprehensive Income/Loss
Net income/loss (-)	€ (305,436)	€ 149,845	[1],[2]	€ (29,259)	[2]
Items that will not be reclassified subsequently to profit or loss:
Re-measurement of defined benefit obligation	(6,065)	(4,107)	[1]	(94)
Items that may be reclassified subsequently to profit or loss:
Translation differences, arisen from translating foreign activities	(1,024)	415	[1]	197
Realization of translation differences upon liquidation of foreign operations	(1,023)	0		0
Other comprehensive income/loss (-), net of income tax	(8,112)	(3,692)	[1]	103
Total comprehensive income/loss (-) attributable to:
Owners of the parent	(313,548)	146,154	[1]	(29,155)
Total comprehensive income/loss (-) attributable to owners of the parent arises from:
Continuing operations	(318,841)	145,050	[1]	(32,159)
Discontinued operations	5,293	1,104	[1]	3,003
Owners of the parent	€ (313,548)	€ 146,154	[1]	€ (29,155)
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued operation
[2]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Consolidated Statement of Chang

Consolidated Statement of Changes in Equity - EUR (€) € in Thousands	Total		Warrant AGilead	Share capital.	Share capital.Warrant AGilead	Share premium account	Share premium accountWarrant AGilead	Translation differences	Other reserves	Accumulated losses
Balance at beginning of period (IFRS 15) at Dec. 31, 2017	€ (83,220)									€ (83,220)
Balance at beginning of period (IFRS 9) at Dec. 31, 2017	0								€ 619	(619)
Balance at beginning of period (Restated total equity at January 1) at Dec. 31, 2017	928,766			€ 233,414		€ 993,025		€ (1,754)	(641)	(295,280)
Balance at beginning of period at Dec. 31, 2017	1,011,983			233,414		993,025		(1,754)	(1,260)	(211,441)
Net income/loss (-)	(29,259)	[1],[2]								(29,259)
Other comprehensive income / loss (-)	103	[1]						197	(94)
Total comprehensive income / loss (-)	(29,155)							197	(94)	(29,259)
Share-based compensation	26,757									26,757
Issue of new shares	296,188			16,021		280,167
Share issue costs	(15,964)			(15,964)
Exercise of warrant/ subscription rights	7,657			3,069		4,588
Balance at end of period (IFRS 9) at Dec. 31, 2018	416									416
Balance at end of period (Restated total equity at January 1) at Dec. 31, 2018	1,214,665			236,540		1,277,780		(1,557)	(735)	(297,363)
Balance at end of period at Dec. 31, 2018	1,214,249			236,540		1,277,780		(1,557)	(735)	(297,779)
Net income/loss (-)	149,845	[1],[2]								149,845
Other comprehensive income / loss (-)	(3,692)	[1]						415	(4,107)
Total comprehensive income / loss (-)	146,154							415	(4,107)	149,845
Share-based compensation	38,297									38,297
Derecognition of financial liability from share subscription agreement and warrant A	135,702					135,702
Issue of new shares	960,087			36,945		923,142
Share issue costs	(4,447)			(4,447)
Exercise of warrant/ subscription rights	17,167		€ 368,035	4,082	€ 14,162	13,085	€ 353,873
Balance at end of period at Dec. 31, 2019	2,875,658			287,282		2,703,583		(1,142)	(4,842)	(109,223)
Net income/loss (-)	(305,436)									(305,436)
Other comprehensive income / loss (-)	(8,112)							(2,047)	(6,065)
Total comprehensive income / loss (-)	(313,548)							(2,047)	(6,065)	(305,436)
Share-based compensation	79,959									79,959
Share issue costs				0
Exercise of warrant/ subscription rights	28,288			4,031		24,257
Balance at end of period at Dec. 31, 2020	€ 2,670,355			€ 291,312		€ 2,727,840		€ (3,189)	€ (10,907)	€ (334,701)
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued operation
[2]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Condensed Cash Flow Statements, Captions [Line Items]
Net income/loss (-)	€ (305,436)	€ 149,845	[1],[2]	€ (29,259)	[1],[2]
Adjustment for non-cash transactions	230,723	248,027		21,753
Adjustment for items to disclose separately under operating cash flow	4,067	(7,731)		(4,389)
Adjustment for items to disclose under investing and financing cash flows	(2,472)	(5,061)		(668)
Change in working capital other than deferred income	(146,092)	12,698		19,922
Increase/decrease (-) in deferred income	(207,787)	2,804,202		(153,312)
Cash generated/used (-) in operations	(426,998)	3,201,980		(145,953)
Interest paid	(9,033)	(1,158)		(1,063)
Interest received	10,054	7,852		4,558
Income taxes paid	(1,358)	(57)		(8)
Net cash flows generated/used (-) in operating activities	(427,336)	3,208,617		(142,466)
Purchase of property, plant and equipment	(42,522)	(22,385)		(10,392)
Purchase of and expenditure in intangible fixed assets	(48,793)	(23,300)		(3,325)
Proceeds from disposal of intangible assets	0	0		1
Proceeds from disposal of property, plant and equipment	49	0		0
Purchase of current financial investments	(4,574,206)	(4,787,284)		0
Interest received related to current financial investments	3,500	5,059		0
Sale of current financial investments	5,415,316	1,063,344		0
Acquisition of financial assets	(2,681)	(177)		(4,559)
Proceeds from sale of financial assets held at fair value through profit or loss	6,626	82		2,361
Net cash flows generated/used (-) in investing activities	757,288	(3,764,660)		(15,914)
Payment of lease liabilities and other debts	(6,247)	(5,091)		(5)
Proceeds from capital and share premium increases, gross amount	0	960,087		296,188
Issue cost paid, related to capital and share premium increases	0	(4,447)		(15,964)
Proceeds from capital and share premium increases from exercise of subscription rights/warrant	28,287	17,167		7,657
Net cash flows generated in financing activities	22,040	1,335,751		287,876
Increase in cash and cash equivalents	351,994	779,708		129,497
Cash and cash equivalents at beginning of year	1,861,616	1,290,796		1,151,211
Transfer to current financial investments	0	(198,922)		0
Increase in cash and cash equivalents	351,994	779,708		129,497
Effect of exchange rate differences on cash and cash equivalents	(70,539)	(9,966)		10,089
Cash and cash equivalents at end of year	2,143,071	1,861,616		1,290,796
Warrant A | Gilead
Condensed Cash Flow Statements, Captions [Line Items]
Proceeds from capital and share premium increases from exercise of subscription rights/warrant	€ 0	€ 368,035		€ 0
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued operation
[2]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Consolidated Statement of Cas_2

Consolidated Statement of Cash Flows, Current Financial Investments - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Consolidated Statement of Cash Flows
Current financial investments.	€ 3,026,278	€ 3,919,216	€ 0
Cash and cash equivalents	2,135,187	1,861,616	1,290,796
Cash and cash equivalents classified as assets held for sale	7,884	0	0
Current financial investments and cash and cash equivalents	€ 5,169,349	€ 5,780,832	€ 1,290,796

General information

General information	12 Months Ended
	Dec. 31, 2020
General information.
General information	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. R&D The research and development (“R&D”) operations are specialized in the discovery and development of small molecules. Our ambition is to become a leading global biotechnology company focused on the development and commercialization of nove l medicines. Ou The components of the operating result presented in the financial statements include the following companies: Galapagos NV, Galapagos Biopharma Belgium BV, Galapagos Real Estate Belgium BV (Mechelen, Belgium); Galapagos SASU (Romainville, France); Galapagos B.V., Galapagos Biopharma Netherlands B.V. and Galapagos Real Estate Netherlands B.V. (Leiden, the Netherlands); Galapagos, Inc. and its subsidiary Xenometrix, Inc. (United States); Galapagos GmbH (Basel, Switzerland); Galapagos Biotech Ltd. (Cambridge, UK), Galapagos Biopharma Germany GmbH (München, Germany), Galapagos Biopharma Spain S.L.U. (Madrid, Spain) and Galapagos Biopharma Italy S.r.l. (Milan, Italy). Our c ontinuing operations had em 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 fee-for-service segment). Fidelta d.o.o. had 185 employees on December 31, 2020 working in the o tal c onsideration of € mill Impact of COVID-19 on the financial statements To date, we have experienced limited impact on our financial performance, financial position, cash flows and significant judgements and estimates, although we continue to face additional risks and challenges associated with the impact of the outbreak.

Summary of significant transact

Summary of significant transaction	12 Months Ended
	Dec. 31, 2020
Summary of significant transaction
Summary of significant transaction	2. Summary of significant transaction On July 14, 2019 we and Gilead announced that we entered in to a 10 nt collaborati on. 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 ent € million ($ billion) and a € million ($ billion) equity investment from Gilead. On November 6, 2019 Gilead exercised warrant A, which resulted in an additional equity in vestment of € mi At inception of this collaboration, we identified the following three performance obligations: (i) the transfer of an extended license on GLPG1690, (ii) the granting of exclusive 80 50 As part of the collaboration, Gilead also received option rights for GLPG1972, a Phase 2b candidate for osteoarthritis, in the United States. In November 2020, Gilead however declined to exercise its option for GLPG1972. Since October 22, 2019, Gilead has had two During Q4 2020, Gilead decided not to pursue FDA approval of the RA indication for filgotinib in the U.S. as a result of Complete Response Letter (CRL) from the Food and Drug Administration (FDA). Due to this, Gilead and we agreed to amend our existing collaboration for the commercialization and development of filgotinib. Under the new arrangement, we will assume sole responsibility in Europe for filgotinib in RA and in all other potential future indications and will fully support the costs of certain of the development activities. In connection with the changes in responsibility for the commercialization and development of filgotinib in Europe, we received a payme n t of € million ($ mil million ($ million), of which € million will be paid in 2021 and € million will be paid This modification to the collaboration with Gilead did not result in the creation of new performance obligations, and only the performance obligation related to the development activities for filgotinib has been reassessed. We retain the following three performance obligations, of which the first one was satisfied completely in 2019; (i) the transfer of an extended license on GLPG1690, (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 3 80 50 50 100 0 We refer to the critical accounting judgments and key sources of estimation uncertainty section (note 4 Terms of the collaboration 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 three years For GLPG1972, after the completion of the ongoing Phase 2b study in osteoarthritis, Gilead had the op tion to pay a $ million fee to licen would have paid would have been For all other programs resulting from the collaboration, 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 Under the revised agreement, we will assume all development, manufacturing, commercialization and certain other rights for filgotinib in Europe, providing the opportunity to build a commercial presence on an accelerated timeline. The transfer will be subject to applicable local legal, regulatory and consultation requirements. The parties intend to transfer most activities by December 31, 2021 and complete the transition by December 31, 2022. Beginning on January 1, 2021, Galapagos will bear the future development costs for certain studies (defined as “Group A activities”), in lieu of the equal cost split contemplated by the previous agreement. These studies include the DARWIN3, FINCH4, FILOSOPHY, and Phase 4 studies and registries in RA, MANTA and MANTA-RAy, the PENGUIN1 and 2 and EQUATOR2 studies in PsA, the SEALION1 and 2 studies in AS, the HUMBOLDT study in uveitis in addition to other clinical and non-clinical expenses supporting these studies and support for any investigator sponsored trials in non-IBD conditions and non-clinical costs on all current tri als. T he existing / 50 es of to % of h € 35 $295 million in development and regulatory milestones (excluding the remaining approval milestones in Europe that became forfeited), sales-based milestone payments of up to $600 million and tiered royalties rangi ng from - % pay able in territories outside Europe In addition, we achieved two regulatory approval milestones in 2020 totaling $105 million. 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 at a price of € per 30 imately % to % of the the 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. The initial warrant B has a term of five years (i) 30-day (ii) EUR . Subseq ween and months

Significant accounting policies

Significant accounting policies	12 Months Ended
	Dec. 31, 2020
Significant accounting policies
Significant accounting policies	3. Significant accounting policies Our principal 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. NEW STANDARDS AND INTERPRETATIONS APPLICABLE FOR THE ANNUAL PERIOD BEGINNING ON JANUARY 1, 2019 IFRS 16 The above new applicable standard affected the consolidated financial statements as follows: We adopted IFRS 16 on January 1, 2019, in accordance with the transitional provisions of IFRS 16, using the modified retrospective approach. Consequently, the cumulative effect of adopting IFRS 16 was recognized as an adjustment to the opening balance of retained earnings as at January 1, 2019, with no restatement of the comparative figures. On adoption of IFRS 16, we recognized lease liabilities in relation to leases which had previously been The differences between our total operating lease commitments as reported in our consolidated financial statements of December 31, 2018 and the total lease liabilities recognized in our statement of financial position as at January 1, 2019 are summarized below. (Euro, in thousands) Operating lease commitments disclosed as at December 31, 2018 € 27,704 Less : discounting effect using the lessee's incremental borrowing rate at the date of initial application (1,223) Less : other (569) Lease liability recognized as at January 1, 2019 25,912 Of which are : current lease liabilities 4,516 non-current lease liabilities € 21,396 The change in accounting policy affected the statement of financial position as at January 1, 2019 as follows: January 1, 2019 (Euro, in thousands) Property, plant and equipment (right-of-use assets) € 26,406 Ot her current assets (prepaid expenses) (494) Effect on total assets 25,912 Accumulated losses 416 Lease liabilities (current and non-current) 25,912 De ferred income (416) Effect on total equity and liabilities € 25,912 We applied the following practical expedients, as permitted by IFRS 16, on transition date: ▪ ▪ ▪ ▪ ▪ We refer to our updated accounting policy on leases as a result of the adoption of IFRS 16. Other new standards and interpretations applicable for the annual period beginning on January 1, 2019 did not have any impact on our consolidated financial statements. NEW STANDARDS AND INTERPR ETATIONS APPLICABLE FOR THE ANNUAL PERIOD BEGINNING ON JANUARY 1, 20 20 New standards and interpretations applicable for the annual period beginning on January 1, 2020 did not have any material impact on our consolidated financial statements. STANDARDS AND INTERPRETATIONS PUBLISHED, BUT NOT YET APPLICABLE FOR THE ANNUAL PERIOD BEGINNING ON JANUARY 1, 20 20 A number of new standards are effective for annual periods beginning on or after January 1, 2021 with earlier adoption permitted. However we have not early adopted new or amended standards in preparing our consolidated financial statements. Of the standards that are not yet effective, we expect no standard to have a material impact on our financial statements in the period of initial application. CONSOLIDATED REPORTING The consolidated financial statements comprise the financial statements of Galapagos NV and entities controlled by Galapagos NV. Control is achieved where Galapagos NV has the power to direct the relevant activities of another entity so as to obtain benefits from its activities. The results of subsidiaries are included in the statement of operations and statement of comprehensive income from the effective date of acquisition up to the date when control ceases to exist. Where necessary, adjustments are made to the financial statements of subsidiaries to ensure consistency with our accounting policies. All intra-group transactions, balances, income and expenses are eliminated when preparing the consolidated financial statements. INTANGIBLE ASSETS 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: ▪ ▪ ▪ ▪ ▪ ▪ 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. Licenses, patents & know-how 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. Licenses, patents and know-how will be amortized over their useful life (generally between 5 and 20 years), using the straight-line method. 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. 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. Software Acquired software is recognized at cost less accumulated amortization and any impairment loss. A mortization Contract costs Contract costs are those costs we incur to obtain a contract with a customer that we would not have incurred if the contract has not been obtained and are capitalized as intangible assets only if they are expected to be recoverable. Capitalized contract costs are amortized on a systematic basis that reflects the pattern of transfer of the related promised goods or services to the customer. Costs that we would have incurred regardless of whether the contract is obtained or those costs that are not directly related to obtaining a contract would not be capitalized. 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: ▪ ▪ Leasehold improvements are depreciated over 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. Leases As explained in the beginning of this note, we adopted IFRS 16 on January 1, 2019, resulting in a change in our accounting policy. Acc ounting policy as from January 1, 2019 All leases are accounted for by recognizing a right-of-use asset and a corresponding lease liability except for: - - 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 rate implicit in the lease. If this rate cannot be readily determined, we will apply the incremental borrowing rate. The lease payments can include fixed payments, variable payments that depend on an index or rate known at the commencement date, expected residual value guarantees, termination penalties and extension option payments or purchase options if we are reasonably certain to exercise this option. After initial recognition, the lease liability is 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 in case of renegotiation, changes of an index or rate or 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, initial direct costs and the expected dismantling and removing costs (when we incur an obligation for such costs), less any lease incentives received from the lessors. After initial recognition, the right-of-use assets are measured at cost and depreciated over the shorter of the underlying asset’s useful life and 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. In determining the lease term, we consider all facts and circumstances that create an economic incentive to exercise an extension option, or not exercise a termination option. 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. Each lease payment is allocated between the liability and financial expenses. The finance cost is charged to the statement of operations over the lease period so as to produce a constant periodic rate of interest on the remaining balance of the liability for each period. Accounting policy until January 1, 2019 Until the end of 2018, leases of property, plant and equipment were classified as either finance or operating leases. Leases were classified as finance leases whenever the terms of the lease substantially transferred all the risks and rewards of ownership to the lessee. All other leases were classified as operating leases. Assets held under finance leases were recognized as our assets at their fair value or, if lower, at the present value of the minimum lease payments, each determined at the inception of the lease. These assets held under finance leases were depreciated over their useful lives on the same bases as owned assets or, where shorter, over the term of the related lease agreement. The corresponding liability to the lessor was included in the balance sheet as a finance lease obligation. The payments were divided proportionally between the financial costs and a diminution of the outstanding balance of the obligation, so that the periodic interest rate on the outstanding balance of the obligation would be constant. Interest was recognized in the statement of operations, unless it was directly attributable to the corresponding asset, in which case it was capitalized. Rents paid on operating leases were charged to income on a straight-line basis over the term of the relevant lease. Benefits received and receivable as an incentive to enter into an operating lease were also spread on a straight-line basis over the lease term. FINANCIAL INSTRUMENTS Financial assets and financial liabilities are recognized on our balance sheet when we become a party to the contractual provisions of the instrument. We do not actively use currency derivatives to hedge planned future cash flows, nor do we make use of forward foreign exchange contracts, outside of the Gilead transaction, fully settled at December 31, 2019. Additionally, we don’t have financial debts at December 31, 2020. (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; ▪ a financial asset that (i) is held within a business model whose objective is achieved both by collecting contractual cash flows and selling financial assets and (ii) has contractual terms that give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding, is measured at fair value through other comprehensive income (FVTOCI), unless the asset is designated at 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. We classify non-derivative financial assets into the following categories: - - 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 our 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 inve stments 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 v alue through profit or loss Cash equivalents measured at fair value through profit or loss may comprise short-term deposits, 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. Research and development incentives receivables are discounted over the period until maturity date according to the appropriate discount rates. Current financial investments measured at amortized cost Current financial investments measured at amortized cost include treasury bills that have a maturity equal or less than 12 months. We apply settlement date accounting for the recognition and de-recognition of current financial investments measured at amortized cost. Cash Cash are financial assets measured at amortized cost and comprise cash balances and short-term deposits with maturities of three months or less from the acquisition date that are subject to an insignificant risk of changes in their value. Cash equivalents measured at amortized costs Cash equivalents measured at amortized cost comprise short-term deposits that are readily convertible to cash and are subject to an insignificant risk of changes in value. Cash and cash equivalents exclude restricted cash, which is presented in the line other non-current assets in the statement of financial position. (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. Financial liabilities 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 expense related to our research and development project costs. We derecognize a financial liability when its contractual obligations are discharged, cancelled or expire. (iii) Financial instruments: derivative assets/liabilities Financial assets and financial liabilities are recognized on our balance sheet when we become a party to the contractual provisions of the instrument. Derivative assets and liabilities are initially measured at fair value. After initial measurement we will measure the derivatives at fair value through profit or loss. 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. FOREIGN CURRENCIES Items included in the financial statements of each of our entities are valued using the currency of the primary economic environment in which the entity operates. The consolidated financial statements are presented in Euros, which is our presentation currency. Transactions and balances in foreign currency Foreign currency transactions are translated into the functional currency using the exchange rates prevailing at the dates of transaction. We use monthly transaction rates based on the closing exchange rates of the foreign currencies on the last business day of the month preceding the date of the transaction. Foreign currency gains and losses resulting from the settlement of such transactions and from the translation at closing rates of monetary assets and liabilities denominated in foreign currencies are recognized in the financial result in the statement of operations. Non-monetary assets and liabilities measured at historical cost that are denominated in foreign currencies are translated using the exchange rate at the date of the transaction. ▪ The results and financial position of all our entities that have a functional currency different from Euro are translated as follows: ▪ ▪ ▪ ▪ RECOGNITION OF EXPENSES LINKED TO CLINICAL TRIAL MILESTONES We recognize expenses specifically linked to clinical trial milestones with regard to patient recruitment and patient treatment (i.e. completion), incurred in carrying out clinical trials, in line with actual patient recruitment or treatment at each period end, in reference to the milestone targets for patient recruitment or treatment. This involves the calculation of clinical trial accruals at each period end, for which an estimation of the expected full clinical trial milestone cost is required, as well as the current stage of patient recruitment or treatment. Clinical trials usually take place over extended time periods and typically involve a set-up phase, a recruitment phase and a completion phase which ends upon the receipt of a final report containing full statistical analysis of trial results. Accruals for patient recruitment and patient completion are prepared separately for each clinical trial in progress and take into consideration the stage of completion of each trial including the number of patients that have entered the trial and the number of patients that have been treated in the trial. In all cases, the full cost of each trial is expensed by the time the final report is received. REVENUE RECOGNITION Revenues to date have consisted principally of milestones, license fees, non-refundable upfront fees and royalties received in connection with collaboration and license agreements. We also generate revenue from our fee-for-service activities, which is reported as discontinued operations per December 31, 2020. Th e revenue recognition policies can be summarized as follows: We recognize revenue when our cust omer 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 IF RS 15, we perform the following five steps: (i) identify the contract In our current 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 p artners for research and development activities generally include non-refundable upfront fees; milestone payments, the receipt of which is dependent upon the achievement of certain clinical, regulatory or commercial milestones; license fees, royalties on s ales and sometimes reimbursement inco me 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-refundab le 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 over time, revenue is then recognized based on a pattern that best reflects the t ransfer 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 that a significant reversal in the amount of cumulative revenue recognized wi ll not occur when the uncertainty associated with the variable consideration is subsequently resolved. We estimate the amount to be included in the transaction price using the most likely amount method, where milestone paym ents are included in the transact ion price upon achievement of the milestone event. The transaction price is then allocated to each performance obligation on a stand-alone selling price basis, for which we recognize revenue as or when the performance oblig ations under the contract are sat isfied. At the end of each subsequent reporting period, we re-evaluate the probability of achievement of such milestones and any related constraint, and if necessary, adjust our estimate of the overall transaction price. An y such adjustments are recorded o n 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 f or research and development servi ces: 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 co sts reimbursements received are r ecognized 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 ac counted for as a decrease of the related expenses. d/ Sales based milestone payment and Royalties License and collaboration agreements include sales-based royalties, including com mercial 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 t o the pe rformance 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 market assessment approach, the expected cost plus a margin approach or the residual approach. If management assesses that there is only one single performance obligation, the entire transaction price would be allocated to this performance obligation. (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 over time or at a point in time – which results in recognition of revenue over time or at a point in time. In case of revenue recognition over time, we use either 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) or we apply an output method to measure the progress of the satisfaction of the underlying performance obligation. In other cases, depending on specific circumstances, we recognize revenue on a straight-line basis over the estimated term of the performance obligation. We refer to note 6 for detailed information per agreement and to our Critical accounting judgments and key sources of estimation uncertainty for more information. OTHER 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 statement of operations, under other income, when the relevant expenditure has been incurred and there is reasonable assurance that the grants or R&D incentives are receivable. EQUITY INSTRUMENTS Equity instruments issued by us are measured by the fair value of the proceeds received, net of direct issue costs. EMPLOYEE BENEFITS a/ Defined contribution plans Contributions to defined contribution pension plans are recognized as an expense in the statement of operations as incurred. b/ D efined benefit plans For defined retirement benefit plans, the cost of providing benefits is determined using the projected unit credit method, with actuarial valuations being carried out at the end of each annual reporting period. Re-measurement, comprising actuarial gains and losses, the effect of the changes to the asset ceiling (if applicable) and the return on plan assets (excluding interest), is reflected immediately in the statement of financial position with a charge or credit recognized in other comprehensive income in the period in which they occur. Re-measurement recognized in other comprehensive income is reflected immediately in retained earnings and will not be reclassified to profit or loss. Past service cost is recognized in profit or loss in the period of a plan amendment. Net interest is calculated by applying the discount rate at the beginning of the period to the net defined benefit liability or asset. Defined benefit costs are categorized as follows: ▪ ▪ ▪ The retirement benefit obligation recognized in the consolidated statement of financial position represents the actual deficit or surplus in the defined benefit plans. Any surplus resulting from this calculation is limited to the present value of any economic benefits available in the form of refunds from the plans or a reduction in future c

Critical accounting judgments a

Critical accounting judgments and key sources of estimation uncertainty	12 Months Ended
	Dec. 31, 2020
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 uncertainty 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 Gilead Our critical judgments were as follows: Identification of the contract • Although formal executive contracts are still being finalized with Gilead, we assessed that the impact of the modification must already be accounted for in our consolidated financial statements for the year ended December 31, 2020 given the legally binding and enforceable character of the term sheet that was signed between us and Gilead on December 15, 2020 as a consequence of both parties’ decision to amend our existing agreement for the commercialization and development of filgotinib. • Despite our obligation to pay future sales-based royalties to Gilead and a change in the governance structure for the development activities, we concluded that all activities are still beneficial for the further development of filgotinib, for which Gilead still owns the ex-Europe rights. The contract modification has 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 subsequently concluded that there continues to be only one performance obligation with respect to filgotinib after the contract modification. Identification of the performance obligation • The modification 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. The Group A and Group B development activities (see note 2 for more details) still to be performed are interrelated and thus cannot be seen as separate performance obligations. Based on this, the contract modification has been treated on a cumulative catch-up basis under IFRS 15. Allocation of the total transaction price • The increased fixed consideration as result of the modification has been allocated in its entirety to the filgotinib performance obligation. 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 the total costs to complete the filgotinib performance obligation. These costs were assessed considering that all ongoing and planned clinical trials (including long term extension trials) would be completed until their final stage. 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, 2020. 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. As our estimate of the costs is depending on the evolution of the development activities, 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 €818.7 million at December 31, 2020.

Segment information

Segment information	12 Months Ended
	Dec. 31, 2020
Segment information
Segment information	5 Operational segme ntation The group had two reportable segments e-for-service GEOGRAPHICAL INFORMATION In 2018, 2019 and 2020, our continuing operations were mainly located in Belgium, France and the Netherlands. Following table summarizes the revenues by destination of customer: Year ended December 31, 2020 2019 2018 (Euro, in thousands) United States of America € 472,445 € 793,873 € 116,680 Europe 5,607 41,028 161,986 Total € 478,053 € 834,901 € 278,666 Following table summarizes the revenues by major customers: Year ended December 31, 2020 2019 2018 Spilt up of revenues by major customers (Euro, in thousands) % (Euro, in thousands) % (Euro, in thousands) % Gilead: U nited States of (1) € 472,445 99% € 793,873 95% € 116,640 42% E uro (1) 1,460 0% (4,570) -1% 7,793 3% AbbVie: Europe (52) 0% 26,356 3% 89,936 32% Novartis: Europe 4,125 1% 19,177 2% 55,218 20% Les Laboratoires Servier: Europe — 0% — 0% 9,000 3% Total revenues from major customers € 477,978 100% € 834,836 100% 278,587 100% (1) As of December 31, 2020, we held €171 f property, plant and equipment and intangible assets distributed as follows: December 31, 2020 2019 (*) 2018 (*) (Euro, in thousands) Belgium € 113,524 € 57,007 € 13,134 France 18,398 18,102 5,413 The Netherlands 28,210 7,951 3,947 Croatia — 6,182 3,661 Switzerland 7,668 1,057 519 Spain 2,755 — — Other 388 681 95 Total € 170,943 € 90,979 € 26,769 (*) In accordance with IFRS 8 we only present the total of the property, plant and equipment and intangible assets in this disclosure note. This is a change in presentation compared to the amounts that were published in the disclosure note for the years ended December 31, 2019 and December 31, 2018. We elected to adjust the historical consolidated financial information presented in this disclosure note to reflect this change in presentation. As the net assets associated with Fidelta d.o.o. (Croatia) will be recovered principally through a sale transaction rather than through continuing use, we have classified these assets and the associated liabilities as held for sale in our financial statements for the year ended December 31, 2020.

Total revenues and other income

Total revenues and other income	12 Months Ended
	Dec. 31, 2020
Total revenues and other income
Total revenues and other income	6 s and other income REVENUES The following table summarizes the revenues for the years ended December 31, 2020, 2019 and 2018. Year ended December 31, 2020 2019 2018 (Euro, in thousands) Recognition of non-refun dable upfront payments and license fees € 411,417 € 812,058 € 196,486 Milestone payments 46,261 2,878 73,394 Reimbursement income 4,073 19,900 8,722 Other revenues 70 66 63 Commercial revenues 16,232 — — Total revenues € 478,053 € 834,901 € 278,666 The following table summarizes details of revenues for the years en ded December 31, 20 and by collaboration and by cat Over time Point in time 2020 2019 (Euro, in (Euro, in thousands) thousands) Recognition of non-refundable up front payments and license fees € 411,417 € 812,058 Gilead collaboration agreement for ziritaxestat  - 666,968 Gilead collaboration agreement for filgotinib (1)  181,816 62,602 Gilead collaboration agreement for drug discovery platform  229,601 80,918 AbbVie collaboration agreement for CF  - 1,569 Milestone payments 46,261 2,878 Gilead collaboration agreement for filgotinib (1)  46,261 (21,187) AbbVie collaboration agreement for CF  - 24,065 Reimbursement income 4,073 19,900 Novartis collaboration agreement for MOR106  4,125 19,177 AbbVie collaboration agreement for CF  ( 52 723 Other revenues 70 66 Other revenues  70 66 Commercial revenues 16,232 - Sale of goods  2 Royalties  16,227 Other commercial revenues  2 Total revenues € 478,053 € 834,901 ( 1 € million, resu The below table summarizes the transaction price of our collaboration with Gilead. (Euro, in thousands) Allo cation of transac Filgotinib agreement 2015 Milestones achieved during 2015-2019 Option, License and Collaboration agreement (July 14, 2019) D ecember 31, 20 Other movements in 2020 Filgotinib amendment (December 15, 2020) D e cember 31, 20 U pf ront consider € 275,558 € 3,569,815 € 3,845,373 € 160,000 € 4,005,373 Milestones achieved € 104,171 104,171 € 90,192 194,363 Royalties — 16,227 16,227 Impa ct initial valuation of share subscription 39,003 85,601 124,604 124,604 314,561 104,171 3,655,416 4,074,148 106,419 160,000 4,340,567 Less : Warrants issuance liabilities Wa rrant A (43,311) (43,311) Initial warrant B (2,545) (2,545) Subsequent warrant B (16,184) 8,325 (7,859) 314,561 104,171 3,655,416 4,012,108 114,744 160,000 4,286,852 Allocation to performance obligations Ziritaxestat 666,967 666,967 666,967 Filgotin (1) € 314,561 € 104,171 641,663 1,060,395 106,419 160,000 1,326,814 D rug discovery platfo € 2,284,747 € 2,284,747 8,325 2,293,072 ( 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 €55.3 million as of December 31, 2020, considering the effects of the amendment of December 15, 2020. On the closing date of the transaction (August 23, 2019) we concluded that the upfront payment implicitly included a premium for the future issuance of warrant A and initial and subsequent warrant B. The expected value of the warrants to be issued is treated as a contract liability ("warrant issuance liability") and reduces the transaction price until approval date of the issuance of the underlying warrants. As from approval date, the allocation of the upfront payment to the respective warrant becomes fixed and future changes in the fair value of the respective warrant will be recognized in profit or loss. As such, the part of the upfront payment allocated to the warrant A and initial warrant B reflects the fair value of these financial liabilities at the warrant approval date (October 22, 2019). Subsequent warrant B is still subject to approval by an extraordinary general meeting of shareholders and is therefore still presented as warrant issuance liability in our deferred income (we refer to note 24 for more information). The value initially allocated to the subsequent warrant B reflects the fair value of the underlying liability on December 31, 2019. On December 31, 2020 the value of the subsequent warrant B decreased to € millio On December 15, 2020 we and Gilead signed a term sheet modifying our existing collaboration for filgotinib. As a result of this modification an additional consideration of €160.0 million was allocated to the filgonitib performance obligation. A summary of all current contracts with customers is given below: Collaboration with G ilead On July 14, 2019 we and Gilead announced that we had entered into a 10-year global research and development collaboration. Through this agreement, Gilead gained exclusive access to our innovative portfolio of compounds, clinical and preclinical programs and a proven drug discovery platform. As part of this deal, our existing license and collaboration agreement for filgotinib with Gilead was amended for the first time. Under this revised filgotinib agreement, we obtained greater involvement in filgotinib’s global strategy and participate more broadly in the commercialization of the product in Europe, providing the opportunity to build a commercial presence on an accelerated timeline. On December 15, 2020 our license and collaboration agreement for filgotinib with Gilead was amended a second time. Under the new arrangement, we will assume sole responsibility in Europe for filgotinib in RA and in all future indications. We retain the following three performance obligations, of which the first one was satisfied completely in 2019; (i) the transfer of an extended license on GLPG1690, (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 20/80 to 50/50 to 100/0 (for Group A activities only) on the global development activities of filgotinib, until we complete the remaining development activities (Group A and Group B activities). We concluded as follows: Determination of the total transaction price · g current financial a sset (deri vative) of € milli · We considered that the transaction price included a premium paid by Gilead (through the upfront payment) to acquire warrants (warrant A and warrant B) in the future, upon approval by the shareholders. We measured both warrants at fair value and recognized a warrant issuance liability at closing of the transaction for the same amount (as part of the current deferred income line). This liability is re-measured at each reporting period with a corresponding impact on the allocation of the transaction price to the performance obligation relating to the drug discovery platform as long as the warrants are not approved by the shareholders. Due to the fact that warrant A and initial warrant B were already approved in 2019, only the remeasurement of subsequent warrant B still has an impact on the transaction price considered for the revenue recognition of the performance obligation relating to the drug discovery platform. · We assessed that the contract modification of December 15, 2020 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. As a consequence, the increase in the transaction price of €160.0 million as a result of this modification has been allocated in its entirety to the filgotinib performance obligation. Financing component · There are performance obligations determined in the agreement with Gilead for which the period between the transfer of the promised goods/services to Gilead and the payment of the underlying consideration by Gilead exceeds year, being the performance obligation relating to the drug discovery platform and the performance obligation resulting from the filgotinib amendment. Although the consideration paid for the drug discovery platform will be recognized over a period of years as from receipt of the funds, management concluded not to consider any financing component for this performance obligation as the granting of an exclusive access and option rights on day is the predominant value of the drug discovery platform performance obligation. As a consequence, management has considered it is only appropriate to adjust the part of the transaction price that was allocated to the filgotinib performance obligation, for the time value of money. The additional consideration as a result of the contract modification of December 15, 2020 has also been adjusted for the time value of money. License on GLPG1690 · The transaction price allocated to this performance obligation reflects our assessment of the stand-alone selling price of this performance obligation and was valued based on a discounted cash flow approach including, amongst others, assumptions on the estimated market share and size, peak sales and probability of success. · This performance obligation was completely satisfied as at December 31, 2019. Following the very recent discontinuation of the ziritaxestat trials, we don’t expect future milestone payments or royalties. · After granting the license for GLPG1690, we shared Phase 3 costs equally with Gilead. Any cost reimbursement from Gilead was not recognized as revenue but accounted as a decrease of the related expenses. Filgotinib amendment · There is single performance obligation under IFRS : the transfer of a license combined with performance of R&D activities. This is because we considered that the license is not distinct in the context of the contract. · The standalone selling price of the filgotinib amendment was determined through the cost-plus-margin approach. Management estimated that an appropriate margin is indirectly embedded in the increased involvement in the development and global strategy of filgotinib, our sole responsibility for filgotinib in Europe and the accompanying increase in the risk . · 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. During 2020 we reported € 16.2 million of revenues from royalties from Gilead. · Revenues, excluding sales based milestones and sales based royalties, The estimated costs to complete the performance obligation have been reassessed as a result of the contract modification from 2020 leading to a small decrease in the percentage of completion. Nevertheless, we recognized higher revenues in financial year 2020 as compared to financial year 2019 for €160.0 million) and the tal am ou nt of $ mi m Access rights to the drug discovery platform, option rights and R&D activities · · three years Collaboration with Servier In 2010 we signed a license and collaboration agreement with Servier in the field of osteoarthritis. Any increase in the transaction price from future potential development and regulatory milestones, sales based milestones and royalties, will be allocated to the license and will be fully recognized as revenue at a point in time when achieved, as our performance obligation towards Servier has been fully satisfied. The contract signed with Servier on May 8, 2018 took over the terms of the previous agreement but additionally included the framework of a joint Phase 2 clinical trial program in which both parties collaborate, share costs and mutually exchange services. We concluded that this contract modification was not in the scope of IFRS 15 because there is a mutual exchange of services between Servier and Galapagos, Servier is not assessed as a customer but as a collaboration partner. Any cost reimbursement from our collaboration partner is not recognized as revenue but accounted for as a decrease of the related expenses. In December 2020, Servier decided to terminate the agreement. Such termination became effective in March 2021. As a result of such termination, rights to the GLPG1972 were returned to Galapagos, subject to payment of a regulatory milestone, a commercial milestone and a mid single digit sales-based royalty upon successful commercialization of GLPG1972 in countries outside the U.S. Collaboration with Novartis Together with our collaboration partner MorphoSys, we closed a license agreement with Novartis for MOR106 in July 2018. MorphoSys and we received an equal share of an upfront payment of €95 million and were entitled to potential future milestone payments and royalties. Novartis would bear all future research, development, manufacturing and commercialization costs related to MOR106. Costs reimbursements received from Novartis were recognized in revenues when costs were incurred and agreed by the parties as we were acting as a principal in the scope of the performance of the R&D activities. On October 28, 2019, we announced the end of the clinical development program of MOR106 in AtD. On December 17, 2019, Novartis sent us a termination notice, informing us of its decision to terminate the agreement in its entirety. The termination became effective in 2020. Collaboration with AbbVie We concluded as follows for the related revenue recognition: · There was one single performance obligation under IFRS 15: the transfer of a license combined with performance of R&D activities. This was because we considered that the license was not capable of being distinct and was not distinct in the context of the contract. · The transaction price of our agreement with AbbVie was composed of a fixed part, being upfront license fees, and a variable part, being milestone payments and cost reimbursements for R&D activities delivered. Milestone payments were only included in the transaction price to the extent that it was highly probable that a significant reversal in the amount of cumulative revenue recognized would not occur when the uncertainty associated with the variable consideration is subsequently resolved. Given the nature of our industry, we only consider this once the milestone event is achieved. Sales based milestones and sales based royalties are a part of our arrangement but are not yet included in our revenues. · The transaction price was allocated to the single performance obligation and revenues were recognized over the estimated service period based on a pattern that reflects the transfer of the license and progress to complete satisfaction of the R&D activities. This is because we considered that there is a transformational relationship between the license and the R&D activities to be delivered. · We chose an input model to measure the satisfaction of the single performance obligation that considers a percentage of costs incurred for this program that are completed each period (percentage of completion method). · Costs reimbursements received from AbbVie were recognized in revenues when costs were incurred and agreed by the parties as we were acting as a principal in the scope of our stake of the R&D activities of this license and collaboration agreements. · The second amended and restated collaboration agreement signed on October 24, 2018 was assessed to be a contract modification including a change in scope and in pricing as the remaining goods or services were not distinct and form part of the single performance obligation that was partially satisfied at the date of the contract modification. We concluded that we must account for this second amended and restated collaboration agreement as if it was part of the existing contract and recognized an adjustment to revenue to reflect the contract modification on the transaction price and on the measure of progress towards satisfaction of the performance obligation. The performance obligation related to this agreement was considered fully satisfied at December 31, 2019. For the years ended December 31, 201 9 and 201 8 The following table summarizes details of revenues for the years ended December 31, 2019 and 2018 by collaboration and by category of revenue: upfront payments and license fees, milestone payments, reimbursement income, and other revenues. Over time Point in time 2019 2018 (Euro, in (Euro, in thousands) thousands) Recognition of non-refun dable upfront paym € 812,058 € 196,486 Gilead collaboration agreement for ziritaxestat  666,968 - Gilead collaboration agreement for filgotinib (1)  62,602 96,809 Gilead collaboration agreement for drug discovery platform  80,918 - AbbVie collaboration agreement for CF  1,569 52,176 Novartis collaboration agreement for MOR106  - 47,500 Milestone payments 2,878 73,394 Gilead collaboration agreement for filgotinib (1)  (21,187) 27,623 AbbVie collaboration agreement for CF  24,065 36,771 Servier collaboration agreement for osteoarthritis  - 9,000 Reimbursement income 19,900 8,722 Novartis collaboration agreement for MOR106  19,177 7,718 AbbVie collaboration agreement for CF  723 989 Other reimbursement income - 16 Other revenues 66 63 Other revenues 66 63 Total revenues € 834,901 € 278,666 (1) Following the contract amendment, the revenue recognized for filgotinib for the year ended December 31, 2019 included a negative catch-up effect on closing date of € million OTHER INCOME The following table summarizes other income for the years ended December 31, 2020, 2019 and 2018. Year ended December 31, 2020 2019 2018 (Euro, in thousands) Grant income € 5,452 € 6,549 € 1,609 R&D incentives 45,951 43,923 26,912 Other income 804 425 479 Total other income € 52,207 € 50,896 € 29,000

Operating costs

Operating costs	12 Months Ended
	Dec. 31, 2020
Expenses by nature [abstract]
Operating costs	7. Operating costs Operating result has been calculated after charging (-) / crediting: RESEARCH AND DEVELOPMENT EXPENDITURE The following table summarizes research and development expenditure for the years ended December 31, 2020, 2019 and 2018. Year ended December 31, 2020 2019 2018 (Euro, in thousands) Personnel costs € (161,509) € (118,875) € (75,819) Subcontracting (301,841) (255,725) (203,406) Disposables and lab fees and premises costs (22,349) (19,573) (20,967) Depreciation (11,707) (9,330) (4,846) Professional fees (12,692) (1,834) (262) Other operating expenses (13,570) (14,753) (10,922) Total R&D expenses € (523,667) € (420,090) € (316,222) All research and development expenditures are tracked against detailed budgets and allocated by individual project. The table below summarizes our research and development expenditure for the years ended December 31, 2020, 2019 and 2018, broken down by program. Year ended December 31, 2020 2019 2018 (Euro, in thousands) Filgotinib program € (126,879) € (100,032) € (66,138) Ziritaxestat program (55,902) (75,951) (72,718) OA program on GLPG1972 (22,966) (19,958) (15,751) Toledo program (87,107) (47,204) (20,967) CF program (69) (3,897) (30,137) AtD program on MOR106 (7,618) (24,051) (14,999) Other programs (223,126) (148,997) (95,512) Total R&D expenses € (523,667) € (420,090) € (316,222) SALES AND MARKETING EXPENSES The following table summarizes the sales and marketing expenses for the years ended December 31, 2020, 2019 and 2018. Year ended December 31, 2020 2019 2018 (Euro, in thousands) Personnel costs € (31,727) € (7,558) € (2,282) Depreciation (140) (61) — External outsourcing costs (27,174) (15,721) (1,284) Professional fees (3,420) (459) — Other operating expenses (4,007) (777) (580) Total sales and marketing expenses € (66,468) € (24,577) € (4,146) GENERAL AND ADMINISTRATIVE EXPENSES The following table summarizes the general and administrative expenses for the years ended December 31, 2020, 2019 and 2018. Year ended December 31, 2020 2019 2018 (Euro, in thousands) Personnel costs € (70,110) € (51,204) € (24,740) Depreciation (5,147) (1,421) (449) Legal and professional fees (25,592) (11,568) (4,026) Other operating expenses (17,908) (8,190) (5,162) Total general and administrative expenses € (118,757) € (72,382) € (34,377)

Staff costs

Staff costs	12 Months Ended
	Dec. 31, 2020
Staff costs
Staff costs	8. Staff costs The following table illustrates the personnel costs for the years 2020, 2019 and 2018. Year ended December 31, 2020 2019 2018 (Euro, in thousands) Wages and salaries € (139,681) € (113,660) € (57,237) Social security costs (26,471) (14,566) (10,290) Pension costs (7,337) (4,715) (2,994) Costs related to subscription right plans (79,959) (38,297) (26,757) Other personnel costs (9,897) (6,399) (5,564) Total personnel costs € (263,345) € (177,636) € (102,842)

Fair value re-measurement of sh

Fair value re-measurement of share subscription agreement and warrants granted to Gilead	12 Months Ended
	Dec. 31, 2020
Fair value re-measurement of share subscription agreement and warrants granted to Gilead
Fair value re-measurement of share subscription agreement and warrants granted to Gilead	9 alue re-measurement for the years ended D Year ended December 31, 2020 2019 (Euro, in thousands) Fair value re-measurement of the share subscription agreement € — € (142,350) Fair value re-meas urement of warrant A — (35,642) Fair value re-measurement of initial warrant B 3,034 (3,653) Total fair value re-measurement of share subscription agreement and warrants € 3,034 € (181,644) Fair value re-measurement of the Gilead share subscription agreement (Euro, in thousands) Fair value of financial asset at signing date € 85,601 Change i n fair value recorded in prof (142,350) Fair value of financial liability at closing date (56,749) Derecognition at closing date 56,749 Fair value on December 31, 2019 € — Fair value re-measurement of the financial instrument related to the issuance of warrant A (Euro, in thousands) Fair val ue of financial liability at warrant approval date € (43,311) Change in fai r value recorded in pro (35,642) Derecognition at warrant A exercise date 78,953 Fair value on December 31, 2019 € — Fair value re-measurement of the financial instrument related to the issuance of initial warrant B 2020 2019 (Euro, in thousands) Fair value of financial liability at January 1, € (6,198) Fair value of financial liability at warrant approval date € (2,545) Change i n fair value recorded in profit or lo 3,034 (3,653) Fair value on December 31, € (3,164) € (6,198)

Other financial income _ expens

Other financial income / expenses	12 Months Ended
	Dec. 31, 2020
Other financial income / expenses
Other financial income / expenses	10 The following table summarizes other financial income and exp Year ended December 31, 2020 2019 2018 (Euro, in thousands) Other financial income: Interest income € 10,030 € 14,305 € 5,217 Effect of discounting long term R&D incentives receivables 93 93 199 Currency exchange gain 4,697 775 10,978 Fair value gain on financial assets held at fair value through profit or loss 2,397 5,355 1,203 Fair value gain on current financial investments — 611 — Gain upon sale of financial assets held at fair value through profit or loss — 2 667 Other finance income 1,450 248 — Total other financial income 18,667 21,389 18,264 Other financial expenses: Interest expenses (9,389) (1,268) (780) Effect of discounting long term deferred income (16,278) (6,900) — Currency exchange loss (110,416) (47,720) (1,057) Loss upon sale of financial assets held at fair value through profit or loss (88) — — Fair value loss on current financial investments (15,901) (3,700) — Other finance charges (773) (380) (764) Total other financial expense (152,844) (59,968) (2,602) Total net other financial expense (-)/ income € (134,177) € (38,579) € 15,663

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Taxes
Income Taxes	11 INCOME TAXES The following table summarizes the income tax recognized in profit or loss for the years ended December 31, 2020, 2019 and 2018. Year ended December 31, 2020 2019 2018 (Euro, in thousands) Current tax € (1,069) € (1,372) € (584) Deferred tax (157) 1,537 (238) Income taxes € (1,226) € 165 € (822) TAX LIABILITIES The below table illustrates the tax liabilities related captions in the consolidated statement of financial position as at December 31, 2020, 2019 and 2018. December 31, 2020 2019 2018 (Euro, in thousands) Current tax payable € 1,248 € 2,037 € 1,175 Total tax liabilities € 1,248 € 2,037 € 1,175 On December 31, 2020, the tax liabilities were primarily related to our subsidiaries operating on a cost plus basis. TAXES RECOGNIZ ED IN STATEMENT OF OPERATIONS For the purpose of the disclosure below corporation tax was calculated at 25% (2019: 29.58%, 2018: 29.58%)— 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, 2020 2019 2018 (Euro, in thousands) Income/loss (-) before tax € (309,775) € 148,525 € (31,417) Income tax debit/credit (-), calculated using the Belgian statutory tax rate on the accounting income/loss (-) before tax (theoretical) (77,444) 43,934 (9,293) Tax expenses/income (-) in statement of operations (effective) 1,226 (165) 822 Difference in tax expense/income to explain € 78,670 € (44,097) € 10,116 Effect of tax rates in other jurisdictions € 184 € 960 € 599 Effect of no n-taxable revenues (10,196) (13,079) (11,547) Effect of share based payment expenses without tax impact 19,990 10,318 7,530 Effect of expe nses/income (-) no (639) 53,394 175 Effect of non tax-deductible expenses 1,053 724 914 Effect of recognition of previously non recognized deferred tax assets (475) (2,286) (532) Effect of tax losses (utilized) reversed (150) (136) (150) Effect of under or over provision in prior periods (25) 30 — Effect of non-recognition of deferred tax assets 69,141 47,413 13,127 Effect of derecognition of previously recognized deferred tax assets 157 — — Effect of use of investment deduction (370) — — Effect of use of IID — (141,435) — Total explanations € 78,670 € (44,097) € 10,116 Non-taxable revenues for the years ended December 31, 2020, 2019 and 2018 related to non-taxable subsidies and tax credits. Expenses/income (-) not subject to tax for the years ended December 31, 2020 and December 31, 2019 . The effective tax rate can thus be

Income_loss (-) per share

Income/loss (-) per share	12 Months Ended
	Dec. 31, 2020
Income/loss (-) per share
Income/loss (-) per share	12 Basic income/loss (-) per share is calculated by dividing the net income/loss (-) attributable to shareholders by the weighted average number of ordinary shares outstanding during the year. Diluted income/loss (-) per share is calculated based on the weighted average number of shares (diluted) also considering outstanding subscription rights, for which our average share price of the year was higher than the exercise price. Income/loss (-) per share Year ended December 31, 2020 2019 2018 Net income/loss (-) attributable to owners of the parent (Euro, in thousands) € (305,436) € 149,845 € (29,259) Number of shares (thousands) Weighted average number of shares for the purpose of basic income/loss (-) per share 65,075 57,614 52,113 Basic income/loss (-) per share (Euros) € (4.69) € 2.60 € (0.56) Net income/loss (-) attributable to owners of the parent (Euro, in thousands) € (305,436) € 149,845 € (29,259) Number of shares (thousands) Weighted average number of shares for the purpose of diluted income/loss (-) per share 65,075 57,614 52,113 Number of dilutive potential ordinary shares — 2,498 — Diluted income/loss (-) per share (Euros) € (4.69) € 2.49 € (0.56) As our operations reported a net loss in 2020 and 2018, the outstanding subscription rights (specified in note 29

Intangible assets

Intangible assets	12 Months Ended
	Dec. 31, 2020
Intangible assets
Intangible assets	13. Intangible ass ets Software & databases Brands, licenses, patents & know-how Contract costs Total (Euro, in thousands) Acquisition value On January 1 , 2018 € 7,496 € 8,586 € — € 16,082 Additions 1,561 1,763 3,325 Sales and disposals (20) (7,630) (7,650) Translation differences 74 74 On December 31, 2018 9,111 2,719 — 11,832 Additions 5,463 2,453 15,384 23,300 Sales and disposals (64) (64) Translation differences 31 31 On December 31, 2019 14,541 5,172 15,384 35,099 Additions 9,494 39,299 48,793 Sales and disposals (17) (17) Reclassifications to assets held for sale (159) (38) (197) Translation differences (143) (1) (144) On December 31, 2020 € 23,717 € 44,432 € 15,384 € 83,534 Amortization and impairment On January 1 , € 6,514 € 7,070 € — € 13,587 Amortization 681 426 1,107 Impairment 1,083 1,083 Sa les and disposa (20) (7,630) (7,650) Translation differences 74 74 On December 31, 2018 7,250 949 — 8,200 Amortization 816 678 512 2,006 Sales and disposals (63) (63) Translation differences 31 31 On December 31, 2019 8,034 1,626 512 10,173 Amortization 2,303 2,289 1,538 6,130 Sales and disposals (17) (17) Reclassifications to assets held for sale (143) (33) (176) Translation differences (142) (142) On December 31, 2020 € 10,034 € 3,883 € 2,050 € 15,968 Carrying amount On December 31, 2018 € 1,862 € 1,771 € — € 3,632 On December 31, 2019 € 6,507 € 3,546 € 14,872 € 24,927 On December 31, 2020 € 13,683 € 40,549 € 13,334 € 67,565 On December 31, 2020, our balance sheet did not hold any internally generated assets capitalized as intangible asset.

Property, plant and equipment

Property, plant and equipment	12 Months Ended
	Dec. 31, 2020
Property, plant and equipment
Property, plant and equipment	14 FULLY OWNED Land & leasehold improvements Installation & machinery Furniture, fixtures & vehic les Other tangible assets Total (Euro, in thousands) Acquisition value On January 1, 2018 € 4,736 € 33,060 € 3,209 € 1,189 € 42,195 Additions 275 4,674 1,039 4,404 10,392 Sales and disposals (486) (826) (1,311) Reclassifications 753 13 (766) — Translation differences 29 16 46 On December 31, 2018 5,011 38,031 3,452 4,827 51,321 Additions 273 6,382 649 15,076 22,380 Sales and disposals (1,521) (97) (1,618) Reclassifications 1,792 3 (1,795) — Reclassifications to right of use (251) (251) Translation differences (30) 22 (8) On December 31, 2019 5,284 44,655 4,028 17,856 71,823 Additions 885 3,737 1,824 32,218 38,664 Sales and disposals (51) (1,096) (81) (1,228) Reclassifications 10,625 (623) 2,084 (12,086) — Reclassifications to assets held for sale (2) (8,938) (484) (686) (10,110) Translation differences (2) (127) (19) (30) (178) On December 31, 2020 € 16,739 € 37,607 € 7,352 € 37,273 € 98,972 Depreciations and impairment On January 1 , 2018 € 2,342 € 20,495 € 2,407 € 258 € 25,502 Depreciation 344 3,377 236 17 3,974 Sales and disposals (485) (826) (1,310) Translation differences 16 2 18 On December 31, 2018 2,686 23,403 1,819 275 28,184 Depreciation 394 4,018 399 7 4,818 Sales and disposals (1,521) (99) (1,620) Reclassifications to right of use (251) (251) Translation differences (15) (15) On December 31, 2019 3,080 25,885 2,119 31 31,117 Depreciation 654 3,587 1,418 7 5,666 Sales and disposals (51) (1,058) (77) (1,186) Reclassifications 46 (1,675) 1,629 — Reclassifications to assets held for sale (4,327) (448) (39) (4,814) Translation differences (1) (61) (13) (75) On December 31, 2020 € 3,728 € 22,350 € 4,628 € — € 30,708 Carrying amount On December 31, 2018 € 2,325 € 14,628 € 1,632 € 4,552 € 23,137 On December 31, 2019 € 2,204 € 18,770 € 1,909 € 17,825 € 40,707 On December 31, 2020 € 13,011 € 15,257 € 2,724 € 37,273 € 68,264 RIGHT-OF-USE Land & building Installation & machinery Furniture, fixtures & vehicles Total (Euro, in thousands) Acquisition value On December 31, 2018 € — € — € — € — Change in accounting policy ( modified retrospective application IFRS 16 24,056 219 2,130 26,406 Restated balance on January 1, 2019 24,056 219 2,130 26,406 Additions 3,270 84 1,176 4,530 Reclassifications to right of use 251 251 Translation differences 38 38 On December 31, 2019 27,364 554 3,307 31,225 Additions 18,341 186 2,932 21,459 Sales and disposals (6) (161) (167) Reclassifications to assets held for sale (5,940) (263) (6,202) Translation differences (88) — (3) (90) On December 31, 2020 € 39,678 € 734 € 5,812 € 46,225 Depreciations and impairment On December 31, 2018 € — € — € — € — Depreciation 4,666 91 867 5,624 Reclassifications to right of use 251 251 Translation differences 4 4 On December 31, 2019 4,670 342 867 5,879 Depreciation 5,350 128 1,405 6,883 Sales and disposal (6) (161) (167) Reclassifications to assets held for sale (1,334) (115) (1,448) Translation differences (36) (1) (36) On December 31, 2020 € 8,651 € 464 € 1,995 € 11,111 Carrying amount On December 31, 2019 € 22,694 € 212 € 2,440 € 25,345 On December 31, 2020 € 31,027 € 270 € 3,817 € 35,113 December 31, Carrying amount 2020 2019 2018 Property, plant and e quipment fully owned € 68,264 € 40,707 € 23,137 Right-of-use 35,113 25,345 — Total property, plant and equipment € 103,378 € 66,052 € 23,137 Due to adoption of IFRS 16 g balance of right-of-use asset 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, 2020
Other non-current assets
Other non-current assets	15 rent assets Other non-current assets consisted of non-current restricted cash, financial assets held at fair value through profit or loss and other non-current assets. December 31, 2020 2019 2018 (Euro, in thousands) Non-current restricted cash € 1,482 € 1,418 € 1,276 Financial assets held at fair value through profit or loss 8,951 11,275 6,000 Other non-current assets 910 1,399 643 Total other non-current assets € 11,343 € 14,091 € 7,919 Restricted cash on December 31, 2020 was composed of bank guarantees on real estate lease obligations in Belgium and in the Netherlands for €1.0 million and €0.5 m Restricted cash on December 31, 2019 was composed of bank guarantees on real estate lease obligations in Belgium and in the Netherlands for €0.9 million and €0.5 million, respectively. Financial assets held at fair value through profit or loss consisted of equity instruments of both listed and non-listed companies. We have no restrictions on the sale of these equity instruments and the assets are not pledged under any of our liabilities. These instruments are designated as financial assets held at fair value through profit or loss. The fair value of the equity instrument of the listed company is determined by reference to the closing price of such securities on Euronext at each reporting date (classified as level 1 in the fair value hierarchy). The fair value of the equity instrument of the non-listed company has been determined mainly by reference to the initial transaction price (classified as level 3 in the fair valu Fair value changes on financial assets with fair value through profit or loss are recognized in profit or loss, in other financial income/othe r financial expenses. The table below i llustrates these financial assets held at fair value through profit or loss 20 , 201 9, and 201 8 . December 31, 2020 2019 2018 (Euro, in thousands) Costs at January 1, € 4,736 € 4,818 € 2,373 Acquisitions of the year 1,994 — 4,736 Disposals of the year (2,820) (82) (2,291) Costs at December 31, 3,910 4,736 4,818 Fair value adjustment at January 1, 6,539 1,182 (619) Cancellation of fair value adjustment following disposal (3,894) 2 598 Fair value adjustment of the year 2,397 5,355 1,203 Fair value adjustment at December 31, 5,042 6,539 1,182 Net book value at December 31, € 8,951 € 11,275 € 6,000

Research and Development incent

Research and Development incentives receivables	12 Months Ended
	Dec. 31, 2020
Research and Development incentives receivables
Research and Development incentives receivables	16 Development incentives receivables The table below illustrates the R&D incentives receivables related captions in the balance sheet on December 31, 2020, 2019, and 2018: December 31, 2020 2019 2018 (Euro, in thousands) Non-current R&D incentives receivables € 111,624 € 93,407 € 73,443 Current R&D incentives receivables 24,104 21,949 11,203 Total R&D incentives receivables € 135,728 € 115,356 € 84,646 The R&D incentives receivables are future expected refunds or tax deductions resulting from R&D incentives on research and development expenses in France and Belgium. Non-current R&D incentives receivables are reported at their net present value and are therefore discounted over the period until maturity date. The table below provides detailed information on the maturity of the non-current R&D incentives receivables reported in our balance sheet on December 31, 2020. Non-current R&D incentives receivables December 31, 2020 Maturity date 2022 2023 2024 2025 2026-2030 Total (Euro, in thousands) French non-current R&D incentives receivables - discounted value € 10,223 11,911 11,722 € 33,856 Belgian non-current R&D incentives receivables - discounted value 6,647 8,429 11,078 13,716 37,898 77,768 Total non-current R&D incentives receivables - discounted value € 16,870 € 20,340 22,800 13,716 37,898 € 111,624

Trade and other receivables and

Trade and other receivables and other current assets	12 Months Ended
	Dec. 31, 2020
Trade and other receivables and other current assets
Trade and other receivables and other current assets	17 rent assets December 31, 2020 2019 2018 (Euro, in thousands) Non-current trade receivables € 50,000 € — € — Trade receivables 134,632 39,603 9,206 Prepayments 219 292 142 Other receivables 13,568 14,114 9,261 Trade and other receivables 148,418 54,009 18,609 Inventories 355 255 276 Accrued income 1,096 4,443 3,863 Deferred charges 10,502 4,439 4,104 Other current assets 11,953 9,138 8,244 Total trade and other receivables & other current assets € 210,371 € 63,147 € 26,852 The ca rrying amount of trade and other receivables approximates their fair value. Other current assets mainly included accrued income from subsidy projects and deferred charges. On December 31, 20 20 , we did not have any provision for expected credit losse s.

Current financial investments

Current financial investments	12 Months Ended
	Dec. 31, 2020
Current financial investments
Current financial investments	18 . Current financial investments On December 31, 20 20 , our current financial investments amounted to € 3,026.3 million compared to €3,919.2 million at December 31, 201 9 and nil at December 31, 201 8 . On December 31, 2019 these current financial investments included a short-term bond fund and money market funds. On December 31, 2020 these current financial investments included treasury bills (€1,454.4 million) and money market funds (€1,571.9 million). Our portfolio of treasury bills contains only AAA rated paper, issued by Germany and The Netherlands. 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 Dec ember 31, 20 20 , our current financial investments included $524.6 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. We refer to note 32 for more information on these current financial investments.

Cash and cash equivalents

Cash and cash equivalents	12 Months Ended
	Dec. 31, 2020
Cash and cash equivalents.
Cash and cash equivalents	19 December 31, 2020 2019 2018 (Euro, in thousands) Cash at banks € 1,239,993 € 907,939 € 358,016 Term deposits 895,194 953,677 733,537 Money market fund — — 199,243 Cash and cash equivalents from continuing ope 2,135,187 1,861,616 1,290,796 Cash and cash equivalents included in assets classified as held for sale 7,884 — — Total cash and cash equivalents € 2,143,071 € 1,861,616 € 1,290,796 Table of Contents Cash and cash equivalents may comprise cash at banks, short term bank deposits and money market funds that are readily convertible to cash and are subject to an insignificant risk of changes in value. Our cash management strategy monitors and optimizes our liquidity position. Our cash management strategy may allow short term deposits with an original maturity exceeding three months while monitoring all liquidity aspects. Cash and cash equivalents comprised €895.2 million of term deposits which all had an original maturity longer than three 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, 2020 our cash and cash equivalents included $894.3 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.

Share capital

Share capital	12 Months Ended
	Dec. 31, 2020
Share capital
Share capital	20 2020 2019 2018 (Euro, in thousands) On January 1 € 287,282 € 236,540 € 233,414 Share capital increase 4,031 55,189 19,090 Costs of capital increase — (4,447) (15,964) Share capital on December 31, € 291,312 € 287,282 € 236,540 Aggregate share capital € 353,819 € 349,789 € 294,600 Costs of capital increase (accumulated) (62,507) (62,507) (58,060) Share capital on December 31, € 291,312 € 287,282 € 236,540 Costs of capital increases are netted against the proceeds of capital increases, in accordance with IAS 32 HISTORY OF SHARE CAPITAL The history of the share capital of Galapagos NV between January 1, 201 8 20 Date Share capital increase new shares (in thousands €) Share capital increase due to exe rcise 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, 2018 46,256 € 250,187 March 20, 2018 1,613 298 June 20, 2018 556 103 September 17, 2018 16,021 2,961 October 3, 2018 733 135 November 23, 2018 167 31 December 31, 2018 54,466 294,600 March 20, 2019 808 149 Ju ne 20, 20 1,127 208 August 23, 2019 36,945 6,829 S eptember 19, 201 1,632 302 November 6, 2019 14,162 2,618 November 25, 2019 515 95 December 31, 2019 64,667 349,789 March 17, 2020 824 152 May 28, 2020 2,356 436 September 18, 2020 467 86 December 4, 2020 384 71 December 31, 2020 65,412 € 353,819 On December 31, 20 20 All of the share issuances listed above were for cash consideration. The below table summarizes the capital increases for the years 201 8 201 9, 20 20 (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, 2018 50,936,778 € 233,414 € 993,025 € 1,226,439 March 20, 2018 : exercise of subscription rights 298,184 1,613 2,311 3,924 13.16 83.72 June 20, 2018 : exercise of subscription rights 102,801 556 781 1,337 13.01 85.00 September 17, 2018 : U.S. public offering ADSs (fully paid) 2,961,373 16,021 280,167 296,188 Underwriter discounts and offering expenses (paid) (15,964) (15,964) Total U.S. public offering 2,961,373 57 280,167 280,224 99.68 October 3, 2018 : exercise of subscription rights 135,485 733 1,281 2,014 14.86 94.32 November 23, 2018 : exercise of subscription rights 30,800 167 215 382 12.40 88.90 On December 31, 2018 54,465,421 236,540 1,277,780 1,514,320 March 20, 2019 : exercise of subscription rights 149,370 808 2,673 3,481 23.30 90.32 June 20, 2019 : exercise of subscription rights 208,310 1,127 3,198 4,325 20.76 113.55 Aug ust 23, 2019 : share subsc Ordinary shares (fully paid) 6,828,985 36,945 923,142 960,087 148.90 Derecognition of financial liability from share subscription agreement 56,749 56,749 Underwriter discounts and offering expenses (paid) (4,447) (4,447) Total share subscription by Gilead 6,828,985 32,498 979,891 1,012,389 September 19, 2019 : exercise of subscription rights 301,745 1,632 5,043 6,675 22.12 145.25 Nove mber 6, 2019 : exercise of war Exercise of warrant A 2,617,791 14,162 353,873 368,035 Derecognition of financial liability related to warrant A 78,953 78,953 Total exercise of warrant A by Gilead 2,617,791 14,162 432,826 446,988 140.59 170.75 November 25, 2019 : exercise of subscription rights 95,180 515 2,172 2,687 28.23 172.95 On December 31, 2019 64,666,802 287,282 2,703,583 2,990,865 March 17, 2020 : exercise of subscription rights 152,220 824 4,531 5,355 35.18 141.40 May 28, 2020 : exercise of subscription rights 435,540 2,356 15,558 17,914 41.13 186.60 September 18, 2020 : exercise of subscription rights 86,280 467 1,936 2,403 27.85 117.70 December 4, 2020 : exercise of subscription rights 70,925 384 2,232 2,616 36.88 100.30 On December 31, 2020 65,411,767 € 291,312 € 2,727,840 € 3,019,153 Ordinary shares Total Accounting par value of shares (€) 5.41 5.41 The supervisory board two supervisory board members 7 87 supervisory board As of December 31, 20 20

Deferred tax

Deferred tax	12 Months Ended
	Dec. 31, 2020
Deferred tax
Deferred tax	21 December 31, 2020 2019 2018 (Euro, in thousands) Recognized deferred tax assets and liabilities Assets € 4,475 € 4,205 € 2,514 Liabilities € — € — € — Deferred tax assets unrecognized € 365,639 € 289,833 € 223,377 Deferred taxes in the consolidated statement of o € (157) € 1,537 € (238) Tax benefit arising from previously unrecognized tax assets used to reduce deferred tax expense (+) 581 1,537 528 Deferred tax expenses relating to temporary differences (44) — — Deferred tax expenses relating to use or derecognition of previously recognized deferred tax assets (695) — (766) The total amount of tax attributes and deductible temporary differences at December 31, 2020 amounted to € 1,485.8 1,229.3 tion, dividend received deduction and investmen 256.5 The available statutory tax losses carried forward that can be offset against future statutory taxable profits amount ed to € million on December 31, 20 . These statutory tax losses can be compensated with future statutory profits for an indefinite period except for an amount of € million in the United States and the Netherlands with expiry date between and . On December 31, 20 , the available tax losses carried forward in Galapagos N V (Belgium) amounted to € m ax deduction of € million ( : € million; : € million) that ca forward of € million ( and : € million) and a dividend received deduction carried forward of € million (2019 and 2018: nil) With the exception of 2019, 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 deferred tax asset was set up as at December 31, 2020, except for four subsidiaries operating on a cost plus basis for which deferred tax assets were recognized for €4.5 million (2019: €4.2 million and 2018: €2.5 million).

Lease liabilities

Lease liabilities	12 Months Ended
	Dec. 31, 2020
Lease liabilities.
Lease liabilities	22 e liabilities On adoption of IFRS 16 on January 1, 2019, we recognized lease liabilities in relation to leases, which had previously been classified as ‘operating leases’ under IAS 17. December 31, December 31, 2020 2019 2018 2020 2019 2018 (Euro, in thousands) (Euro, in thousands) Lease payments Present value of lease payments Lease liabilities Within one year € 6,772 € 6,189 € 6,401 € 5,826 In the second to fifth years inclusive 20,399 16,320 19,833 15,783 After five years 3,214 3,844 3,201 3,775 € 30,385 € 26,353 € - € 29,436 € 25,384 € - Less future finance charges 949 969 Present value of lease liabilities € 29,436 € 25,384 € - Less amount due for settlement within 12 months 6,401 5,826 Amount due for settlement after 12 months € 23,035 € 19,558 € -

Trade and other liabilities

Trade and other liabilities	12 Months Ended
	Dec. 31, 2020
Trade and other liabilities
Trade and other liabilities	23 . Trade and other liabilities December 31, 2020 2019 2018 (Euro, in thousands) Trade and other liabilities € 171,316 € 142,510 € 68,038 Other non-current liabilities 8,096 6,989 1,578 Accrued charges 1,070 923 890 Total trade and other liabilities € 180,482 € 150,422 € 70,506

Deferred income

Deferred income	12 Months Ended
	Dec. 31, 2020
Deferred income.
Deferred income	24 The movement in the non-current and current deferred income is detailed in the table below. Total Gilead collaboration agreement for filgotinib Gilead collaboration agreement for ziritaxestat Gilead collaboration agreement for drug discovery platform ( 2 AbbVie collaboration agreement for CF Servier collaboration agreement for osteoarthritis Deferred income related to contracts in our fee-for-service segment Other deferred income (grants) (Euro, in thousands) On December 31, 2017 € 219,892 € 213,981 € — € — € — € 5,362 € 248 € 300 Reclassified from equity following adoption of IFRS 15 83,220 43,832 44,749 (5,362) On Januari 1, 2018 303,112 257,814 — — 44,749 — 248 300 Upfront received 38,874 38,874 Milestones received 20,965 12,417 8,548 Revenue recognition of upfront (148,985) (96,809) (52,176) Revenue recognition of milestones (64,394) (27,623) (36,771) Other movements 229 222 7 On December 31, 2018 149,801 145,798 — — 3,224 — 471 308 Upfront received and impact of initial valuation of share subscription 3,655,416 641,663 666,967 2,346,787 Milestones received 49,727 27,317 22,410 Significant financing component ( 3 6,900 6,900 Revenue recognition of upfront (1,009,663) (260,207) (666,967) (80,918) (1,570) Revenue recognition of milestones (51,156) (27,092) (24,064) Catch-up effect on closing date ( 1 245,883 245,883 Other movements (46,262) (45,856) (109) (297) On December 31, 2019 3,000,646 780,261 — 2,220,013 — — 362 10 Upfr ont payments 160,000 160,000 Milestones received 90,192 90,192 Significant financing component ( 3 16,278 16,278 Revenue recognition of upfront (411,417) (181,816) (229,601) Revenue recognition of milestones (46,261) ( 46,261 ) Other movements (305) (362) 57 On December 31, 2020 € 2,809,133 € 818,654 € — € 1,990,412 € — € — € — € 67 (1) Following the contract amendment, the revenue recognized for filgotinib for the year ended December 31, 2019 included a negative catch-up effect resulting from the decrease in the percentage of completion applied to previously received upfront and milestones for that program. (2) The upfront received and the outstanding balance on December 31, 2020 and on December 31, 2019 comprise the issuance liabil ities for the warrants and the upfront payment allocated to the drug discovery platform. Other movements in 2019 include the derecognition of warrant issuance liabilities through the share premium account. (3) With regard to the additional consideration received for the extended cost sharing for filgotinib, we assume the existence of a significant financing component reflecting the time value of money on the estimated recognition period. The outstanding deferred income balance on December 31, 20 20 included €818.7 million related to the collaboration agreement with Gilead for filgotinib (€604.9 million classified as long term deferred income), and €1,990.4 million, including €7.9 million warrant issuance liability related to subseque nt warrant B, related to the collaboration agreement with Gilead for the drug discovery platform (€ 1,761.1 million classified as long term deferre ed to deferred The outstanding deferred income balance on December 31, 2019 included €780.3 million related to the collaboration agreement with Gilead for filgotinib (€594.7 million classified as long term deferred income), €2,220.0 million, including €16.2 million warrant issuance liability related to subseque nt warrant B, related to the collaboration agreement with Gilead for the drug discovery platform ( € million classified as long term de ca tion of the transaction price received from Gilead.

Discontinued operations

Discontinued operations	12 Months Ended
	Dec. 31, 2020
Disclosure of analysis of single amount of discontinued operations [abstract]
Discontinued operations	25 Discontinued operations On November 23, 2020 Selv ita S.A. in relation to the disposal of Fidelta d.o.o. (our fee-for-service segment). As net assets associated with our fee-for-service business will be recovered principally through a sale transaction rather than through continuing use, we have classified these assets and the associated liabilities as held for sale in our financial statements for the year ended December 31, 2020 The transaction was completed on January 4, 2021 for a total consideration of €37.1 million (including the customary adjustments for cash and working capital). Fidelta will continue performing drug discovery services for us for the next five years for which we have purchase commitments for an aggregate amount of €27.0 million. Held for sale assets are stated at their carrying amount, which is lower than the fair value less costs to sell. As we expect to continue to purchase services from Fidelta d.o.o. after the closing of the transaction, we eliminated the intragroup revenue and cost in discontinued operations. (i) Financial performance Year ended December 31, 2020 2019 2018 (Euro, in thousands, except share and per share data) Revenues € 16,140 € 10,084 € 10,170 Other income 8 9 Total revenues and other income 16,140 10,092 10,179 Research and development expenses (7,685) (7,229) (6,653) General and administrative expenses (2,000) (1,319) (1,253) Total operating expenses (9,685) (8,548) (7,906) Operating income 6,455 1,544 2,273 Other financial income 179 93 71 Other financial expenses (176) (102) (135) Income before tax 6,458 1,535 2,209 Income taxes (893) (379) 773 Net income € 5,565 € 1,156 € 2,981 Basic income per share from discontinued operations € 0.09 € 0.02 € 0.06 Diluted income per share from discontinued operations € 0.08 € 0.02 € 0.06 Weighted average number of shares (in thousands of shares) 65,075 57,614 52,113 Weighted average number of shares - Diluted (in thousands of shares) 67,572 60,112 53,922 (ii) Assets and liabilities The following assets and liabilities were classified as held for sale in relation to the discontinued op erations : 2020 (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 assets 863 Tota l assets classified as held 23,406 Non-current lease liabilities 4,115 Other non-current liabilities 70 Trade and other liabilities 3,649 Current lease liabilities 727 Income tax payable 356 Liabilities associated with assets classified as held for sale 8,917 Net assets € 14,488 (iii) Cash flow 2020 2019 2018 (Euro, in thousands) Net cash flows generated in operating activities € 7,173 € 2,911 € 3,335 Net cash flows used in investing activities (2,284) (1,350) (799) Net cash flows used in financing activities (664) (709) — Net cash flow from discontinued operations € 4,225 € 852 € 2,536

Operating Cash Flow

Operating Cash Flow	12 Months Ended
	Dec. 31, 2020
Consolidated Statement of Cash Flows
Operating Cash Flow	26 Operating Cash Flow The following table details the adjustments related to the operating cash flow: 2020 2019 2018 (Euro, in thousands) Adjustment for non-cash transactions Depreciation and amortization € 18,682 € 12,448 € 5,081 Im pairmen 1,083 Share-based compensation expenses 79,959 38,297 26,757 Decrease (-)/increase in retirement benefit obligations and provisions (260) (156) 99 Unrealized exchange losses/gains (-) and non-cash other financial result 105,055 11,169 (10,063) Discounting effect of deferred income 16,278 6,900 Fair value re-measurement of share subscription agreement and warrants (3,034) 181,644 Net change in (fair) value of current financial investments 15,900 3,081 Fair value a djustment financial assets held at fair value t (2,396) (5,355) (1,203) Other non-cash expenses 539 Total adjustment for non-cash transactions € 230,723 € 248,027 € 21,753 Adjustment for items to disclose separately under operating cash flow Interest expense € 9,424 € 1,302 € 780 Interest income (7,476) (9,247) (5,219) Tax expense 2,119 214 50 Total adjustment for items to disclose separately under operating cash flow € 4,067 € (7,731) € (4,389) Adjustment for items to disclose under investing and financing cash flows Gain ( -)/loss on sale of fixed a € 82 € (2) € (668) Interest income on current financial investments (2,554) (5,059) Total adjustment for items to disclose separately under investing and financing cash flow € ( 2,472 ) € (5,061) € (668) Change in working capital other than deferred income Increase (-)/decrease in inventories € (100) € 20 € 3 Increase in receivables (177,155) (67,263) (76) Increase in liabilities 31,163 79,940 19,996 Total change in working capital other than deferred income € (146,092) € 12,698 € 19,922

Off-balance sheet arrangements

Off-balance sheet arrangements	12 Months Ended
	Dec. 31, 2020
Off-balance sheet arrangements
Off-balance sheet arrangements	27 CONTRACTUAL OBLIGATIONS AND COMMITMENTS We entered into lease agreements for offices, labora tories and cars. As a consequence of the adoption of IFRS 16 Leases, on January 1, 2019, lease obligations in the scope of the new standard are presented as lease liabilities in the statements of financia l position and no longer disclosed separately as off -balance sheet commitments. We refer to note 22 for a breakdown of our lease liabilities. On December 31, 20 20 , we had outstanding obligations for future purchase commitments, whi ch become due as Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years (Euro, in thousands) Purchase commitments € 347,873 € 271,922 € 73,009 € 2,870 € 72 On December 31, 20 19 , we had outst anding obligations for future purchase commitments, which become due as follows: Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years (Euro, in thousands) Purchase commitments € 251,670 € 175,006 € 70,675 € 5,989 € — On December 31, 2019 we were committed to two leases which have not yet started. The total future cash outflows for leases that had not yet commenced were as follows: Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years (Euro, in thousands) Lease commitments not yet commenced € 8,986 € 5,793 € 1,502 € 1,502 € 188 On December 31, 201 8 , we had outstanding obligations for future minimum rent pa yments and purchase commitments, which become due as follows: Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years (Euro, in thousands) Operating lease obligations € 27,704 € 4,722 € 10,024 € 6,234 € 6,724 Purchase commitments (*) 222,033 121,139 81,879 19,014 — Total contractual obligations & commitments € 249,737 € 125,862 € 91,903 € 25,248 € 6,724 In addition to the tables above, we have a contractual cost sharing obligation related to our collaboration agreement with Gilead for filgotinib. The contractual cost sharing commitment amounted to € 614.1 million at December 31, 201 9 , (€ 74.0 million at December 31, 201 8 ). On December 31, 2020, after the recent renegotiation of the filgotinib collaboration, our estimate of this cost sharing commitment amounts to €493.4 million, ch we have direct purchase commitments of €18.1 million at December 31, 20 20 (€ 27.5 million at December 31, 201 9 , € 20.3 million at December 31, 201 8 ) reflected i n the tables above.

Contingent assets and liabiliti

Contingent assets and liabilities	12 Months Ended
	Dec. 31, 2020
Contingent assets and liabilities
Contingent assets and liabilities	28 On January 4, 2021, we closed the sale of our Croatian subsidiary Fidelta. Selvita acquired 100% of the outstanding shares in Fidelta for a tot al consideration of € In December 2015, we entered into a license and collaboration agreement to co-develop filgotinib with Gilead in rheumatoid arthritis, Crohn’s disease, ulcerative colitis and other indications. This agreement was revised a first time in August 2019 and in December 2020, we agreed to further revise this agreement. Under the terms of the new arrangement, we will assume all development, manufacturing, commercialization and certain other rights for filgotinib in Europe. Beginning on January 1, 2021, we will bear the future development costs for certain studies, in lieu of the equal cost split contemplated by the previous agreement. The existing 50/50 global development cost sharing arrangement will continue for certain other studies. All commercial economics on and comme rcialization responsibilities for filgotinib in Euro royalties of to % of net sales in Europe to Gilead, star 2024 . In connection with the amendments to the existing arrangement for the commercialization and development of filgotinib, Gilead has agreed to irrevocably pay us € million, subject to certain adjustments for higher than budgeted development costs. Gilead paid € million in January 2021 and will pay an additional € million in 2021 and will pay € million in 2022 . et sales of filgotinib outside of Europe a As a result of the Option, License and Collaboration agreement signed with Gilead in July 2019, we share further development costs for GLPG1690 equally with Gilead. We were also entitled to an additional milestone for GLPG1690 upon approval in the United States and we were eligible to receive tiered royalt ies ranging from - on net sales of GLPG1690 by Gilead in all countries outside Europe. In February 2021, we and Gilead announced our decision to discontinue all ongoing development activities with GLPG1690. As explained in the summary of the significant transaction in note 2

Share based payments

Share based payments	12 Months Ended
	Dec. 31, 2020
Share based payments
Share based payments	29 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 supervisory board and independent consultants of Galapagos NV. The subscription rights granted under subscription right plans created from 2011 onwards vest at the end of the third calendar year following the year of the grant, with no intermediate vesting. The subscription rights offered to members of the supervisory board vest over a period of 36 months at a rate of 1/36th per month. As of 2020, we no longer grant subscription rights to supervisory board members. Subscription rights cannot be exercised before the end of the third calendar year following the year of the grant. 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 on December 31, 2020, per subscription right plan: Outstanding Outstanding Exercisable per Granted Exercised Forfeited Expired per per Subscription Allocation Expiry Exe rcis January 1, during during during during December 31, December 31, right plan date date price (€) 2020 year year year year 2020 2020 2006 BNL 12/21/2007 12/20/2020 7.12 1,050 (1,050) — — 2007 RMV 10/25/2007 10/24/2020 8.65 14,980 (14,980) — — 2008 06/26/2008 06/25/2021 5.6 1,365 1,365 1,365 2012 09/03/2012 09/02/2020 14.19 80,040 (80,040) — — 2013 05/16/2013 05/15/2021 19.38 120,434 (64,770) 55,664 55,664 2014 07/25/2014 07/24/2022 14.54 252,340 (83,000) 169,340 169,340 2015 04/30/2015 04/29/2023 28.75 282,473 (63,000) 219,473 219,473 2015 (B) 12/22/2015 12/21/2023 49.00 329,500 (68,000) 261,500 261,500 2015 RMV 12/22/2015 12/21/2023 49.00 57,500 (17,500) 40,000 40,000 2016 06/01/2016 05/31/2024 46.10 504,250 (161,625) 342,625 342,625 2016 RMV 06/01/2016 05/31/2024 46.10 120,000 (51,000) 69,000 69,000 2016 (B) 01/20/2017 01/19/2025 62.50 150,000 (140,000) 10,000 10,000 2017 05/17/2017 05/16/2025 80.57 595,500 595,500 2017 RMV 05/17/2017 05/16/2025 80.57 127,500 127,500 2018 04/19/2018 04/18/2026 79.88 1,085,245 (2,000) 1,083,245 2018 RMV 04/19/2018 04/18/2026 79.88 137,500 137,500 2019 04/10/2019 04/09/2027 95.11 1,486,690 (8,850) 1,477,840 2019 RMV 04/10/2019 04/09/2027 95.11 194,750 (1,750) 193,000 2020 04/17/2020 04/16/2028 168.42 — 1,925,185 (19,151) 1,906,034 2020RMV 04/17/2020 04/16/2028 168.42 — 248,150 (8,625) 239,525 Total 5,541,117 2,173,335 (744,965) (40,376) — 6,929,111 1,168,967 Weighted a verag Subscription rights exercise price (Euro) Outstanding on January 1, 2018 3,970,807 € 39.3 Exercisable on December 31, 2017 763,344 13.7 Granted during the period 1,235,245 79.9 Forfeited during the year (12,000) 43.2 Exercised during the period (567,270) 13.5 Expired during the year — — Outstanding on December 31, 2018 4,626,782 € 53.3 Exercisable on December 31, 2018 882,734 14.0 Granted during the period 1,699,690 95.1 Forfeited during the year (30,750) 88.9 Exercised during the period (754,605) 22.8 Expired during the year — — Outstanding on December 31, 2019 5,541,117 € 70.1 Exercisable on December 31, 2019 1,139,682 30.2 Granted during the period 2,173,335 168.4 Forfeited during the year (40,376) 144.8 Exercised during the period (744,965) 38.0 Expired during the year — — Outstanding on December 31, 2020 6,929,111 € 104.0 Exercisable on December 31, 2020 1,168,967 37.8 The table below sets forth the inputs into the valuation of the subscription rights. 2020 2020 RMV 2019 2019 RMV 2018 2018 RMV April 17 April 17 April 19 April 19 April 18 April 18 Exercise Price (€) € 168.42 € 168.42 € 95.11 € 95.11 € 79.88 € 79.88 Weigh ted average share price at acceptance d € 178.95 € 178.95 € 107.05 € 107.45 € 84.88 € 84.88 Weight ed average fair value on the accep € 86.45 € 85.79 € 40.04 € 40.05 € 38.39 € 38.39 Weight ed average estimated vola 51.30 51.32 35.86 35.63 39.44 39.44 Weighte d average expected life of the subsc 6.00 6.00 6.02 6.00 8.00 8.00 Weigh ted average risk free ra (0.44) (0.44) (0.27) (0.28) 0.51 0.51 Expected dividends None None None None None None Subscription right Plans The exercise price of the subscription rights The weighted average estimated volatility is calculated on the basis of the implied volatility of the share price over the 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 2020 amounted to €79,959 thousand (2019: €38,297 thousand; 2018: €26,757 thousand). The following table provides an overview of the outstanding subscription rights per category of subscription right holders on December 31, 2020, 2019 and 2018. Category December 31, 2020 2019 2018 (in number of subscription rights) Supervisory board members 157,560 222,600 216,780 Management board members 2,101,874 2,171,874 2,139,374 Other 4,669,677 3,146,643 2,270,628 Total subscription rights outstanding 6,929,111 5,541,117 4,626,782 The outstanding subscription rights ted average remaining life of 2,050 days ( : 2,023 : 1,975 Restricted stock units RSUs Each RSU represents the right to receive 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 types of restricted stock unit (RSU) programs: • Plan 2020 .I, • P lan 2019 .II and Plan .II • Plan 2019 .I • Plan 2019 .III The main characteristics of all these plans are as follows: • the RSUs are offered for no consideration • four iod, w ith % ves • payout will be in cash or shares, at Galapagos’ discretion, it being understood that in respect of members of the management board, 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; • in case of termination of service before the vesting date, forfeiture rules apply. The table below sets forth a summary of RSUs outstanding at December 31, 2020, per RS Outstanding Outstanding per Granted Forfeited Paid in cash per Offer January 1, during during during December 31, RSU plan date 2020 year year year 2020 Plan 2019.I 10/16/2019 33,000 33,000 Plan 2019.II 10/16/2019 109,075 (27,268) 81,807 Plan 2019.III 10/16/2019 71,072 71,072 Plan 2020.I 6/5/2020 55,928 (1,052) 54,876 Plan 2020.II 7/5/2020 72,841 72,841 Total 213,147 128,769 (1,052) (27,268) 313,596 2020 2019 (in number of RSUs) Outstanding on January 1, 213,147 — Granted during the period 128,769 213,147 Forfeited during the year (1,052) Paid in cash during the period (27,268) Outstanding on December 31, 313,596 213,147 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 following table provides an overview of the outstanding RSUs per category of RSU holders on December 31, 2020 and December 31, 2019. December 31, Category 2020 2019 (in number of RSUs) Management board members 229,276 188,571 Other 84,320 24,576 Total outstanding RSUs 313,596 213,147

Related parties

Related parties	12 Months Ended
	Dec. 31, 2020
Related parties
Related parties	30 Relationsh ip and transactions with entities with (joint) control of, or signi nt influence over, Galapagos Gilead Gilead is exercising significant influence over Galapagos as from the equity subscription on August 23, 2019. As result of the equity subscription we received a transparency notification from Gilead on August 28, 201 9 22.04% of the then issued and outstanding shares of Galapagos. Furthermore, the extraordinary general meeting of shareholders of October 22, 2019 approved the issuance of warrant A and initial warrant B to Gilead allowing them to further increase its ownership of Galapagos to up to 29.9% of the company’s issued and outstanding shares. 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 59 tment of € milli hip to % at December 31, ownership then diluted to % hey held % of the then issued an 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’ supervisory board. The following balances are outstanding at the end of the reporting period in relation to Gilead: December 31, 2020 2019 (Euro, in thousands) Non-current trade receivables € 50,000 € — Trade and other receivables € 132,825 € 31,645 Trade and other payables € 27,074 € 39,100 The non-current trade receivables and trade and other receivables balances mainly relate to a total of €160.0 million to receive in relation to the recently modified collaboration for filgotinib of which €110.0 million will be received in 2021 and €50.0 million in 2022. Additionally, the trade and other receivables contain €22.8 million of receivables relating to our collaborations for GLPG1690 and filgotinib. 2020 Due to the approval of Jyseleca, by both the Japanese and European authorities in September 2020, we received milestone payments of respectively $30.0 million (€25.8 million) and $75.0 million (€64.4 million) from Gilead that are recognized in revenue over time until the end of the development period. During 20 20 ue € million (€ million for the relating to the performance obligation for the drug discovery platform al of € million (€ million for representing the total impact on our revenues coming from the Additionally, we recognized royalty income for an amount of €16.2 million in relation to the commercialization of Jyseleca. Furthermore, we recognized €34.1 million (€17.7 million for the year ended December 31, 2019) of cost reimbursements from Gilead related to the development of GLPG1690 as a decrease of the related expenses (on the line research and development expenditure). An amount of € million (€ million Finally, we recognized € million as a deduction of sales & marketing expenses and € million our / 50 As at December 31, 2020, 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. This results in an outstanding deferred income balance of €2.0 billion for the drug discovery platform (including the warrant issuance liability relating to subsequent warrant B) and €819 million for the performance obligation relating to filgotinib. A detailed explanation of our transactions with Gilead in 2019 and 2020 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. Relationsh ip and transactions with subsidiaries Please see Note 31 Intercompany transactions between Galapagos NV and its subsidiaries, and amongst the subsidiaries, have been eliminated in the consolidation and are not disclosed in this note. Relationship and transactions with key management personnel Our key management personnel consists of the members of our management board and the members of our supervisory board. All amounts mentioned in this section are based on expenses recognized in the financial statements for the relevant financial year. Remuneration of k ey management personnel On December 31, 2019, our management board had six members: Mr. Onno van de Stolpe, Mr. Bart Filius, Dr. Piet Wigerinck, Dr. Andre Hoekema, Dr. Walid Abi-Saab and Mr Michele Manto. They provide their services to us on a full-time basis. On December 31 2020 Howard Rowe, Ms. Katrine Bosley, Dr. Mary Kerr, Mr. Peter Guenter, Mr. Daniel O’Day, Dr. Linda Higgins and Dr Elisabeth Svanberg. Dr Elisabeth Only the CEO was, prior to the implementation of the two-tier governance structure, a member of both the executive committee and the board of directors. Our CEO did not receive any special remuneration for his board membership, as this was part of his total remuneration package in his capacity as management board member. The remuneration package of the members of key management personnel comprises: Year ended December 31, 2020 2019 2018 Remuneration of key management personnel: Euro, in thousands (except for the number of subscription rights Short-term benefits € 3,102 € 14,129 € 2,909 Management board members as a group ( 1 Gross salary 2,531 2,121 1,920 Employer social security on gross salary — 61 125 Cash bonus 433 1,230 757 Exceptional bonus — 10,500 — Employer social security on exceptional bonus — 108 — Other short-term benefits 138 109 107 Long-term benefits f or management board members as a group (2 ) — 1,874 1,812 Board fees and other short-term benefits for supervisory board members Raj Parekh 220 90 92 Harrold van Barlingen ( 3 ) — — 15 Howard Rowe 125 55 53 Werner Cautreels ( 4 ) — 15 48 Katrine Bosley 115 45 45 Christine Mummery ( 4 ) — 13 40 Mary Kerr 115 45 46 Peter ( 5 ) 115 30 — Daniel O'Day ( 6 ) — — — Linda Higgins ( 6 ) — — — Elisabeth Svanberg ( 7 ) 78 — — Post-employment benefits ( 8 ) 392 323 305 Total benefits excluding subscription rights and RSUs ( 9 ) € 4,262 € 16,618 € 5,346 Number of subscription rights granted in the year Management board members as a group 275,000 315,000 350,000 Onno van de Stolpe 85,000 100,000 Bart Filius 50,000 65,000 Andre Hoekema 30,000 50,000 Piet Wigerinck 40,000 50,000 Walid Abi-Saab 40,000 50,000 Michele Manto 30,000 40,000 Supervisory board members as a group — 45,000 52,500 Raj Parekh 15,000 15,000 Harrold van Barlingen (3) — — Howard Rowe 7,500 7,500 Werner Ca utreels ( 4 ) 7,500 Katrine Bosley 7,500 7,500 Christine Mummery ( 4 ) 7,500 Mary Kerr 7,500 7,500 Peter Guenter ( 5 ) 7,500 Daniel O'Day ( 6 ) Linda Higgins ( 6 ) Elisabeth Svanberg ( 7 Total number of subscription rights granted in the year 275,000 360,000 402,500 Total cost of subscription rights granted in the year under IFRS 2 € 22,921 € 14,236 € 15,507 Number of RSUs granted in the year (10) Onno van de Stolpe 18,317 57,528 0 Bart Filius 12,600 39,846 0 Andre Hoekema 832 19,922 0 Piet Wigerinck 12,080 33,077 0 Walid Abi-Saab 12,080 33,077 0 Michele Manto 5,920 5,121 0 Total number of RSUs granted in the year 61,829 188,571 - (1) Mr. Manto was appointed as Chief Commercial Officer and member of the management board, effective as of January 1, 2020. As a result the management board consisted of six persons in 2020. (2) Only management board members are granted long-term benefits. Pursuant to the Senior Management Bonus Scheme, these consist of the deferred part of the bonus from 3 years ago. For financial year 2020 the deferred part of the bonus was not paid out. (3) Dr. Van Barlingen's director's mandate expired on April 24, 2018 (4) Director's mandate expired on April 30, 2019 (5) Mr. Guenter's supervisory board member's mandate began on April 30, 2019 (6) Supervisory board member's (7) Supervisory board member's (8) Only management board members are granted post-employment benefits (9) For 2018, this amount excludes an amount of €20.1 thousand tax advisory services that is included in the amount of €107 thousand other short-term benefits (10) This is the sum of the RSUs awarded during the respective financial year, excluding the RSUs representing the deferred portion of the bonus for 2019 in financial year 2019 and for 2020 in financial year 2020 (each time to be granted in the following financial year). Only management board members were awarded RSUs OTHER No loans, quasi-loans or other guarantees were given by Galapagos NV or any of its subsidiaries to members of the supervisory board and of the management board. 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 of their mandates as members of the management board or supervisory board.

Consolidated companies as of De

Consolidated companies as of December 31, 2020	12 Months Ended
	Dec. 31, 2020
Consolidated companies as of December 31, 2020
Consolidated companies as of December 31, 2020	31. Consolidated companies as of December 31, 20 20 Year ended December 31, 2020 2019 2018 Name of the subsidiary Country % voting right Galapagos NV (directly or indirectly through subsidiaries) Change in % voting right previous period ( 2020 vs 2019 % voting right Galapagos NV (directly or indirectly thro ugh subsidiaries) % voting right Galapagos NV (directly or indirectly through subsidiaries) BioFocus DPI AG (liquidated) Switzerland 0% (100%) 100% 100% Galapagos Biopharma Belgium BV Belgium 100% 100% Galapagos Biopharma Netherlands B.V. The Netherlands 100% 100% Galapagos Biopharma Spain S.L.U Spain 100% 100% Galapagos Biopharma Italy S.r.l. Italy 100% 100% Galapagos Biopharma Germany GmbH Germany 100% 100% Galapagos B.V. The Netherlands 100% 100% 100% Galapagos Biotech Ltd. (formerly Inpharmatica Ltd.) United Kingdom 100% 100% 100% Galapagos GmbH Switzerland 100% 100% 100% Galapagos, Inc. (formerly Biofocus, 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 2 BV Belgium 0% (100%) 100% 100% Galapagos Real Estate Netherlands B.V. The Netherlands 100% 100% Galapagos SASU France 100% 100% 100% Fidelta d.o.o. Croatia 100% 100% 100% Xenometrix, Inc. in liquidation United States 100% 100% 100% In 2019 we incorporated the following legal entities: Galapagos Biopharma Belgium BV, Galapagos Biopharma Netherlands B.V., Galapagos Biopharma Spain S.L.U., Galapagos Biopharma Italy S.r.l., Galapagos Biopharma Germany GmbH and Galapagos Real Estate Netherlands B.V.. During 2020 we merged Galapagos Real Estate 2 BV with Galapagos Real Estate 1 BV, with the latter being the surviving entity whose company name changed into Galapagos Real Estate Belgium BV. On November 23, 2020 we signed a share purchase agreement for the sale of our subsidiary Fidelta d.o.o. (Zagreb, Croatia) Fidelta d.o.o. Selvita acquired 100% of the outstanding shares in Fidelta. one

Financial risk management

Financial risk management	12 Months Ended
	Dec. 31, 2020
Financial risk management
Financial risk management	32. 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 and interest rate risk. Our interest rate risk is limited because we have nearly 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: December 31, 2020 2019 2018 (*) (Euro, in thousands) Financial assets held at fair value through profit or loss Equity instruments € 8,951 € 11,275 € 6,000 Current financial investments 1,571,858 3,919,216 — Financial assets at amortised cost Curr ent financial i 1,454,420 — — Cash and cash equivalents 2,135,187 1,861,616 1,290,796 Restricted cash (current and non-current) 1,482 1,418 1,276 Other non-current assets 907 1,399 644 Trade receivables 184,632 39,603 9,206 Total financial assets € 5,357,438 € 5,834,526 € 1,307,922 Financial liabilities held at fair value through profit or loss Current financial instruments € 3,164 € 6,198 € — Financial liabilities at amortised cost Trade liabilities 134,905 116,749 52,466 Lease liabilities 29,436 25,384 — Total financial liabilities € 167,505 € 148,331 € 52,466 (*) The historical consolidated financial information for 2019 and 2018 presented in this disclosure note has been adjusted mainly to correct for the amounts of other receivables and other payables that are outside the scope of IFRS 9. The carrying amounts of trade payables and trade 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 F inancial assets held at fair value through profit or loss consisted of equity instruments of listed/non-listed companies and current financial investments. We have no restrictions on the sale of these equity instruments and the assets are not pledged under any of our liabilities. These instruments are classified as financial assets held at fair value adjustment through profit or loss. The equity investments in listed companies ualify 1 The market price of those shares might face fluctuations and might be affected by a variety of factors, such as the global economic situation, the business development of competitors, sector mergers and acquisitions; it is difficult to mitigate this risk. 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 Our current financial investments and cash and cash equivalents amounted to € 5,169.3 20 All our current financial investments 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. The trade receivables consist of a limited amount of creditworthy customers, many of which are large pharmaceutical companies, spread over different geographical areas. To limit the risk of financial losses, a policy of only dealing with creditworthy counterparties has been developed. 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. Management continuously evaluates the client portfolio for creditworthiness. All our receivables are considered collectable. We applied the IFRS 9 simplified approach to measuring expected credit losses, which uses a lifetime expected loss allowance for all receivables. To measure the expected credit losses, receivables have been grouped based on credit risk characteristics and the days past due. The provision for expected credit losses was not significant given that there have been no credit losses over the last three years and the high-quality nature of our customers. Aging balance of receivables that are due, but that are still considered collectable: December 31, 2020 2019 2018 (Euro, in thousands) 60 - 90 days € — € 87 € 236 90 - 120 days — — 12 more than 120 days € — € — € — 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 money market funds and treasury bills with an AAA rating. The money market funds are invested in a well-diversified portfolio of highly rated assets. Interest rate risk The only variable interest-bearing financial instruments are cash and cash equivalents and current financial investments. Our interest rate income is impacted by the negative interest rate environment in EUR, and the low interest rate environment in USD. 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 terest rates at balance sheet date would have increased profit or loss, and equity, by approximately € million ( 201 9 million; 201 8 million); a 100 basis point 201 9 201 8 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 collaboration partner Gilead in U.S. dollars and acquire some consumables and materials in U.S. dollars, Swiss Francs, GB Pounds and Croatian Kuna. 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, 2020 2019 2018 Net book value (Euro, in thousands) Increase in Euros - U.S. Dollars € (116,690) € (133,373) € (27,200) Increase in Euros - GB Pounds 303 113 100 Increase in Euros - CH Francs 2,013 538 208 Increase in Euros - HR Kunas — 650 611 Increase in U.S. Dollars - GB Pounds € — € (894) € (923) 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, financial debt (we only have leasing debts as of December 31, 20 20 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, 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, 2020
Auditor's remuneration
Auditor's remuneration	33 uditor’s rem The statutory auditor’s fees for carrying out his mandate at group level amounted to €1,202.8 thousand in 2020 ( 201 9 any’s affiliates financial stat 201 9 pany’s affiliates amo 20 20 201 9 audit-related fees, which generally the au 20 20 201 9 20 20 2019 20 20 201 9

Events after balance sheet date

Events after balance sheet date	12 Months Ended
	Dec. 31, 2020
Events after balance sheet date
Events after balance sheet date	34. Events after balance she On March 19, 2021, subscription ri other members of our management board supervisory board. mium) of € an 19 On February 10, 2021, we announced the discontinuation of all development with ziritaxestat due to an insufficient risk-benefit profile observed in the ISABELA Phase 3 program. On January 4, 2021 to Selvita S.A. for a total consideration of € 37.1 million (including the customary adjustments for cash and working capital). Fidelta will continue performing drug discovery services for us for the next five years for which €27.0 million.

Significant accounting polici_2

Significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2020
Significant accounting policies
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.
New Standards and Interpretations Applicable for the Annual Period	NEW STANDARDS AND INTERPRETATIONS APPLICABLE FOR THE ANNUAL PERIOD BEGINNING ON JANUARY 1, 2019 IFRS 16 The above new applicable standard affected the consolidated financial statements as follows: We adopted IFRS 16 on January 1, 2019, in accordance with the transitional provisions of IFRS 16, using the modified retrospective approach. Consequently, the cumulative effect of adopting IFRS 16 was recognized as an adjustment to the opening balance of retained earnings as at January 1, 2019, with no restatement of the comparative figures. On adoption of IFRS 16, we recognized lease liabilities in relation to leases which had previously been The differences between our total operating lease commitments as reported in our consolidated financial statements of December 31, 2018 and the total lease liabilities recognized in our statement of financial position as at January 1, 2019 are summarized below. (Euro, in thousands) Operating lease commitments disclosed as at December 31, 2018 € 27,704 Less : discounting effect using the lessee's incremental borrowing rate at the date of initial application (1,223) Less : other (569) Lease liability recognized as at January 1, 2019 25,912 Of which are : current lease liabilities 4,516 non-current lease liabilities € 21,396 The change in accounting policy affected the statement of financial position as at January 1, 2019 as follows: January 1, 2019 (Euro, in thousands) Property, plant and equipment (right-of-use assets) € 26,406 Ot her current assets (prepaid expenses) (494) Effect on total assets 25,912 Accumulated losses 416 Lease liabilities (current and non-current) 25,912 De ferred income (416) Effect on total equity and liabilities € 25,912 We applied the following practical expedients, as permitted by IFRS 16, on transition date: ▪ ▪ ▪ ▪ ▪ We refer to our updated accounting policy on leases as a result of the adoption of IFRS 16. Other new standards and interpretations applicable for the annual period beginning on January 1, 2019 did not have any impact on our consolidated financial statements. NEW STANDARDS AND INTERPR ETATIONS APPLICABLE FOR THE ANNUAL PERIOD BEGINNING ON JANUARY 1, 20 20 New standards and interpretations applicable for the annual period beginning on January 1, 2020 did not have any material impact on our consolidated financial statements.
Standards And Interpretations Published But Not Yet Applicable For The Annual Period	STANDARDS AND INTERPRETATIONS PUBLISHED, BUT NOT YET APPLICABLE FOR THE ANNUAL PERIOD BEGINNING ON JANUARY 1, 20 20 A number of new standards are effective for annual periods beginning on or after January 1, 2021 with earlier adoption permitted. However we have not early adopted new or amended standards in preparing our consolidated financial statements. Of the standards that are not yet effective, we expect no standard to have a material impact on our financial statements in the period of initial application.
Consolidated Reporting	CONSOLIDATED REPORTING The consolidated financial statements comprise the financial statements of Galapagos NV and entities controlled by Galapagos NV. Control is achieved where Galapagos NV has the power to direct the relevant activities of another entity so as to obtain benefits from its activities. The results of subsidiaries are included in the statement of operations and statement of comprehensive income from the effective date of acquisition up to the date when control ceases to exist. Where necessary, adjustments are made to the financial statements of subsidiaries to ensure consistency with our accounting policies. All intra-group transactions, balances, income and expenses are eliminated when preparing the consolidated financial statements.
Intangible Assets	INTANGIBLE ASSETS 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: ▪ ▪ ▪ ▪ ▪ ▪ 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. Licenses, patents & know-how 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. Licenses, patents and know-how will be amortized over their useful life (generally between 5 and 20 years), using the straight-line method. 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. 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. Software Acquired software is recognized at cost less accumulated amortization and any impairment loss. A mortization Contract costs Contract costs are those costs we incur to obtain a contract with a customer that we would not have incurred if the contract has not been obtained and are capitalized as intangible assets only if they are expected to be recoverable. Capitalized contract costs are amortized on a systematic basis that reflects the pattern of transfer of the related promised goods or services to the customer. Costs that we would have incurred regardless of whether the contract is obtained or those costs that are not directly related to obtaining a contract would not be capitalized.
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: ▪ ▪ Leasehold improvements are depreciated over 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.
Financial Instruments	FINANCIAL INSTRUMENTS Financial assets and financial liabilities are recognized on our balance sheet when we become a party to the contractual provisions of the instrument. We do not actively use currency derivatives to hedge planned future cash flows, nor do we make use of forward foreign exchange contracts, outside of the Gilead transaction, fully settled at December 31, 2019. Additionally, we don’t have financial debts at December 31, 2020. (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; ▪ a financial asset that (i) is held within a business model whose objective is achieved both by collecting contractual cash flows and selling financial assets and (ii) has contractual terms that give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding, is measured at fair value through other comprehensive income (FVTOCI), unless the asset is designated at 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. We classify non-derivative financial assets into the following categories: - - 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 our 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 inve stments 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 v alue through profit or loss Cash equivalents measured at fair value through profit or loss may comprise short-term deposits, 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. Research and development incentives receivables are discounted over the period until maturity date according to the appropriate discount rates. Current financial investments measured at amortized cost Current financial investments measured at amortized cost include treasury bills that have a maturity equal or less than 12 months. We apply settlement date accounting for the recognition and de-recognition of current financial investments measured at amortized cost. Cash Cash are financial assets measured at amortized cost and comprise cash balances and short-term deposits with maturities of three months or less from the acquisition date that are subject to an insignificant risk of changes in their value. Cash equivalents measured at amortized costs Cash equivalents measured at amortized cost comprise short-term deposits that are readily convertible to cash and are subject to an insignificant risk of changes in value. Cash and cash equivalents exclude restricted cash, which is presented in the line other non-current assets in the statement of financial position. (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. Financial liabilities 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 expense related to our research and development project costs. We derecognize a financial liability when its contractual obligations are discharged, cancelled or expire. (iii) Financial instruments: derivative assets/liabilities Financial assets and financial liabilities are recognized on our balance sheet when we become a party to the contractual provisions of the instrument. Derivative assets and liabilities are initially measured at fair value. After initial measurement we will measure the derivatives at fair value through profit or loss.
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.
Foreign Currencies	FOREIGN CURRENCIES Items included in the financial statements of each of our entities are valued using the currency of the primary economic environment in which the entity operates. The consolidated financial statements are presented in Euros, which is our presentation currency. Transactions and balances in foreign currency Foreign currency transactions are translated into the functional currency using the exchange rates prevailing at the dates of transaction. We use monthly transaction rates based on the closing exchange rates of the foreign currencies on the last business day of the month preceding the date of the transaction. Foreign currency gains and losses resulting from the settlement of such transactions and from the translation at closing rates of monetary assets and liabilities denominated in foreign currencies are recognized in the financial result in the statement of operations. Non-monetary assets and liabilities measured at historical cost that are denominated in foreign currencies are translated using the exchange rate at the date of the transaction. ▪ The results and financial position of all our entities that have a functional currency different from Euro are translated as follows: ▪ ▪ ▪ ▪
Recognition Of Expenses Linked To Clinical Trial Milestones	RECOGNITION OF EXPENSES LINKED TO CLINICAL TRIAL MILESTONES We recognize expenses specifically linked to clinical trial milestones with regard to patient recruitment and patient treatment (i.e. completion), incurred in carrying out clinical trials, in line with actual patient recruitment or treatment at each period end, in reference to the milestone targets for patient recruitment or treatment. This involves the calculation of clinical trial accruals at each period end, for which an estimation of the expected full clinical trial milestone cost is required, as well as the current stage of patient recruitment or treatment. Clinical trials usually take place over extended time periods and typically involve a set-up phase, a recruitment phase and a completion phase which ends upon the receipt of a final report containing full statistical analysis of trial results. Accruals for patient recruitment and patient completion are prepared separately for each clinical trial in progress and take into consideration the stage of completion of each trial including the number of patients that have entered the trial and the number of patients that have been treated in the trial. In all cases, the full cost of each trial is expensed by the time the final report is received.
Revenue Recognition	REVENUE RECOGNITION Revenues to date have consisted principally of milestones, license fees, non-refundable upfront fees and royalties received in connection with collaboration and license agreements. We also generate revenue from our fee-for-service activities, which is reported as discontinued operations per December 31, 2020. Th e revenue recognition policies can be summarized as follows: We recognize revenue when our cust omer 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 IF RS 15, we perform the following five steps: (i) identify the contract In our current 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 p artners for research and development activities generally include non-refundable upfront fees; milestone payments, the receipt of which is dependent upon the achievement of certain clinical, regulatory or commercial milestones; license fees, royalties on s ales and sometimes reimbursement inco me 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-refundab le 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 over time, revenue is then recognized based on a pattern that best reflects the t ransfer 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 that a significant reversal in the amount of cumulative revenue recognized wi ll not occur when the uncertainty associated with the variable consideration is subsequently resolved. We estimate the amount to be included in the transaction price using the most likely amount method, where milestone paym ents are included in the transact ion price upon achievement of the milestone event. The transaction price is then allocated to each performance obligation on a stand-alone selling price basis, for which we recognize revenue as or when the performance oblig ations under the contract are sat isfied. At the end of each subsequent reporting period, we re-evaluate the probability of achievement of such milestones and any related constraint, and if necessary, adjust our estimate of the overall transaction price. An y such adjustments are recorded o n 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 f or research and development servi ces: 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 co sts reimbursements received are r ecognized 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 ac counted for as a decrease of the related expenses. d/ Sales based milestone payment and Royalties License and collaboration agreements include sales-based royalties, including com mercial 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 t o the pe rformance 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 market assessment approach, the expected cost plus a margin approach or the residual approach. If management assesses that there is only one single performance obligation, the entire transaction price would be allocated to this performance obligation. (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 over time or at a point in time – which results in recognition of revenue over time or at a point in time. In case of revenue recognition over time, we use either 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) or we apply an output method to measure the progress of the satisfaction of the underlying performance obligation. In other cases, depending on specific circumstances, we recognize revenue on a straight-line basis over the estimated term of the performance obligation. We refer to note 6 for detailed information per agreement and to our Critical accounting judgments and key sources of estimation uncertainty for more information. OTHER 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 statement of operations, under other income, when the relevant expenditure has been incurred and there is reasonable assurance that the grants or R&D incentives are receivable.
Equity Instruments	EQUITY INSTRUMENTS Equity instruments issued by us are measured by the fair value of the proceeds received, net of direct issue costs.
Employee Benefits	EMPLOYEE BENEFITS a/ Defined contribution plans Contributions to defined contribution pension plans are recognized as an expense in the statement of operations as incurred. b/ D efined benefit plans For defined retirement benefit plans, the cost of providing benefits is determined using the projected unit credit method, with actuarial valuations being carried out at the end of each annual reporting period. Re-measurement, comprising actuarial gains and losses, the effect of the changes to the asset ceiling (if applicable) and the return on plan assets (excluding interest), is reflected immediately in the statement of financial position with a charge or credit recognized in other comprehensive income in the period in which they occur. Re-measurement recognized in other comprehensive income is reflected immediately in retained earnings and will not be reclassified to profit or loss. Past service cost is recognized in profit or loss in the period of a plan amendment. Net interest is calculated by applying the discount rate at the beginning of the period to the net defined benefit liability or asset. Defined benefit costs are categorized as follows: ▪ ▪ ▪ The retirement benefit obligation recognized in the consolidated statement of financial position represents the actual deficit or surplus in the defined benefit plans. Any surplus resulting from this calculation is limited to the present value of any economic benefits available in the form of refunds from the plans or a reduction in future contributions to the plans. A liability for a termination benefit is recognized at the earlier of when we can no longer withdraw the offer of the termination benefit and when we recognize any related restructuring costs. c/ Staff bonus plan We recognize an expense in the statement of operations for staff bonus plans. d/ Management bonus plan (I) Bonuses which were granted for performance years until 2018 The management board members, together with other senior managers, are eligible to receive bonuses under the Senior Management Bonus Scheme established in 2006. Pursuant to the rules of the Senior Management Bonus Scheme, 50% of the bonus is paid immediately around year-end and the payment of the remaining 50% is deferred for three years ▪ If the Galapagos share price change is better than or equal to the change in the Next Biotech Index, the deferred bonus will be adjusted by the share price increase/decrease percentage and paid out ▪ If the Galapagos share price change is up to 10 % worse than the change in the Next Biotech Index, 50 % of the deferred bonus will be adjusted by the share price increase/decrease percentage and paid out, and the remainder will be forfeited ▪ If the Galapagos share price change is more than 10 % worse than the change in the Next Biotech Index the deferred bonus will be forfeited We recognize the possible payment of the deferred component of the Senior Management Bonus Scheme within three years at the moment that the bonus amount is determined, based on the fair value of the liability at each reporting period. The fair value of the liability is measured by use of the Monte Carlo valuation model taking into consideration (a) (II) Bonuses which were granted for performance year 2019 and beyond The management board
Share-Based Payments	SHARE-BASED PAYMENTS a/ Equity-settled share based payments We grant equity-settled incentives to certain employees, supervisory board members 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 rights 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) Management board The RSUs are measured based on the volume weighted 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.
Provisions	PROVISIONS Provisions are recognized on the balance sheet when we have a present obligation as a result of a past event; when it is probable that an outflow of resources embodying economic benefits will be required to settle the obligations and a reliable estimate can be made of the amount of the obligations. The amount recognized as a provision is the best estimate of the expenditure required to settle the present obligation at the balance sheet date. If the effect is material, provisions are determined by discounting the expected future cash flows at a pre-tax rate that reflects current market assessments of the time value of the money and, when appropriate, the risk specific to the liability.
Leases	Leases As explained in the beginning of this note, we adopted IFRS 16 on January 1, 2019, resulting in a change in our accounting policy. Acc ounting policy as from January 1, 2019 All leases are accounted for by recognizing a right-of-use asset and a corresponding lease liability except for: - - 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 rate implicit in the lease. If this rate cannot be readily determined, we will apply the incremental borrowing rate. The lease payments can include fixed payments, variable payments that depend on an index or rate known at the commencement date, expected residual value guarantees, termination penalties and extension option payments or purchase options if we are reasonably certain to exercise this option. After initial recognition, the lease liability is 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 in case of renegotiation, changes of an index or rate or 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, initial direct costs and the expected dismantling and removing costs (when we incur an obligation for such costs), less any lease incentives received from the lessors. After initial recognition, the right-of-use assets are measured at cost and depreciated over the shorter of the underlying asset’s useful life and 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. In determining the lease term, we consider all facts and circumstances that create an economic incentive to exercise an extension option, or not exercise a termination option. 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. Each lease payment is allocated between the liability and financial expenses. The finance cost is charged to the statement of operations over the lease period so as to produce a constant periodic rate of interest on the remaining balance of the liability for each period. Accounting policy until January 1, 2019 Until the end of 2018, leases of property, plant and equipment were classified as either finance or operating leases. Leases were classified as finance leases whenever the terms of the lease substantially transferred all the risks and rewards of ownership to the lessee. All other leases were classified as operating leases. Assets held under finance leases were recognized as our assets at their fair value or, if lower, at the present value of the minimum lease payments, each determined at the inception of the lease. These assets held under finance leases were depreciated over their useful lives on the same bases as owned assets or, where shorter, over the term of the related lease agreement. The corresponding liability to the lessor was included in the balance sheet as a finance lease obligation. The payments were divided proportionally between the financial costs and a diminution of the outstanding balance of the obligation, so that the periodic interest rate on the outstanding balance of the obligation would be constant. Interest was recognized in the statement of operations, unless it was directly attributable to the corresponding asset, in which case it was capitalized. Rents paid on operating leases were charged to income on a straight-line basis over the term of the relevant lease. Benefits received and receivable as an incentive to enter into an operating lease were also spread on a straight-line basis over the lease term.
Impairment	IMPAIRMENT (i) Financial assets The impairment loss of a financial asset measured at amortized cost is calculated based on the expected loss model. For trade receivables, in the absence of a significant financing component, the loss allowance is measured at an amount equal to lifetime expected credit losses. Those are the expected credit losses that result from all possible default events over the expected life of those trade receivables. Impairment losses are recognized in the consolidated statement of operations. (ii) Property, plant and equipment and intangible assets For intangible assets with an indefinite life or intangible assets not available for use yet, we perform an impairment test at least on an annual basis. Furthermore we review at each balance sheet date the carrying amount of our tangible and intangible assets to determine whether there is any indication that those assets have suffered an impairment loss. If any such indication exists, the recoverable amount of the asset is estimated in order to determine the extent of the impairment loss (if any). Where the asset does not generate cash flows that are independent from other assets, we estimate the recoverable amount of the cash-generating unit to which the asset belongs. If the recoverable amount of an asset or cash generating unit is estimated to be less than the carrying amount, the carrying amount of the asset is reduced to its recoverable amount. An impairment loss is recognized as an expense immediately. When an impairment loss subsequently reverses, the carrying amount of the asset is increased to the revised estimate of its recoverable amount, but so that the increased carrying amount does not exceed the carrying amount that would have been determined, had no impairment loss been recognized for the asset in prior years. A reversal of an impairment loss resulting from a sale of a subsidiary is recognized as income. In other cases impairment losses of goodwill are never reversed.
Net Income / Loss Per Share	NET INCOME / LOSS PER SHARE Basic net income/loss per share is computed based on the weighted average number of shares outstanding during the period. Diluted net income per share is computed based on the weighted average number of shares outstanding including the dilutive effect of warrants, if any.
Segment Reporting	Segment reporting The gro up had reportable s single

Significant accounting polici_3

Significant accounting policies (Tables)	12 Months Ended
	Dec. 31, 2020
Significant accounting policies
Schedule of differences between operating lease commitments as reported as per IAS 17 and after adoption IFRS 16	(Euro, in thousands) Operating lease commitments disclosed as at December 31, 2018 € 27,704 Less : discounting effect using the lessee's incremental borrowing rate at the date of initial application (1,223) Less : other (569) Lease liability recognized as at January 1, 2019 25,912 Of which are : current lease liabilities 4,516 non-current lease liabilities € 21,396
IFRS 16
Significant accounting policies
Schedule of change in accounting policy	The change in accounting policy affected the statement of financial position as at January 1, 2019 as follows: January 1, 2019 (Euro, in thousands) Property, plant and equipment (right-of-use assets) € 26,406 Ot her current assets (prepaid expenses) (494) Effect on total assets 25,912 Accumulated losses 416 Lease liabilities (current and non-current) 25,912 De ferred income (416) Effect on total equity and liabilities € 25,912

Segment information (Tables)

Segment information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment information
Summary of revenues by destination	Year ended December 31, 2020 2019 2018 (Euro, in thousands) United States of America € 472,445 € 793,873 € 116,680 Europe 5,607 41,028 161,986 Total € 478,053 € 834,901 € 278,666
Summary of revenues by major customers	Year ended December 31, 2020 2019 2018 Spilt up of revenues by major customers (Euro, in thousands) % (Euro, in thousands) % (Euro, in thousands) % Gilead: U nited States of (1) € 472,445 99% € 793,873 95% € 116,640 42% E uro (1) 1,460 0% (4,570) -1% 7,793 3% AbbVie: Europe (52) 0% 26,356 3% 89,936 32% Novartis: Europe 4,125 1% 19,177 2% 55,218 20% Les Laboratoires Servier: Europe — 0% — 0% 9,000 3% Total revenues from major customers € 477,978 100% € 834,836 100% 278,587 100%
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, 2020 2019 (*) 2018 (*) (Euro, in thousands) Belgium € 113,524 € 57,007 € 13,134 France 18,398 18,102 5,413 The Netherlands 28,210 7,951 3,947 Croatia — 6,182 3,661 Switzerland 7,668 1,057 519 Spain 2,755 — — Other 388 681 95 Total € 170,943 € 90,979 € 26,769

Total revenues and other inco_2

Total revenues and other income (Tables)	12 Months Ended
	Dec. 31, 2020
Total revenues and other income
Summary of Revenues	Year ended December 31, 2020 2019 2018 (Euro, in thousands) Recognition of non-refun dable upfront payments and license fees € 411,417 € 812,058 € 196,486 Milestone payments 46,261 2,878 73,394 Reimbursement income 4,073 19,900 8,722 Other revenues 70 66 63 Commercial revenues 16,232 — — Total revenues € 478,053 € 834,901 € 278,666
Revenue by collaboration and by category of revenue	Over time Point in time 2020 2019 (Euro, in (Euro, in thousands) thousands) Recognition of non-refundable up front payments and license fees € 411,417 € 812,058 Gilead collaboration agreement for ziritaxestat  - 666,968 Gilead collaboration agreement for filgotinib (1)  181,816 62,602 Gilead collaboration agreement for drug discovery platform  229,601 80,918 AbbVie collaboration agreement for CF  - 1,569 Milestone payments 46,261 2,878 Gilead collaboration agreement for filgotinib (1)  46,261 (21,187) AbbVie collaboration agreement for CF  - 24,065 Reimbursement income 4,073 19,900 Novartis collaboration agreement for MOR106  4,125 19,177 AbbVie collaboration agreement for CF  ( 52 723 Other revenues 70 66 Other revenues  70 66 Commercial revenues 16,232 - Sale of goods  2 Royalties  16,227 Other commercial revenues  2 Total revenues € 478,053 € 834,901 ( 1 € million, resu
Summary of allocation of transaction price	(Euro, in thousands) Allo cation of transac Filgotinib agreement 2015 Milestones achieved during 2015-2019 Option, License and Collaboration agreement (July 14, 2019) D ecember 31, 20 Other movements in 2020 Filgotinib amendment (December 15, 2020) D e cember 31, 20 U pf ront consider € 275,558 € 3,569,815 € 3,845,373 € 160,000 € 4,005,373 Milestones achieved € 104,171 104,171 € 90,192 194,363 Royalties — 16,227 16,227 Impa ct initial valuation of share subscription 39,003 85,601 124,604 124,604 314,561 104,171 3,655,416 4,074,148 106,419 160,000 4,340,567 Less : Warrants issuance liabilities Wa rrant A (43,311) (43,311) Initial warrant B (2,545) (2,545) Subsequent warrant B (16,184) 8,325 (7,859) 314,561 104,171 3,655,416 4,012,108 114,744 160,000 4,286,852 Allocation to performance obligations Ziritaxestat 666,967 666,967 666,967 Filgotin (1) € 314,561 € 104,171 641,663 1,060,395 106,419 160,000 1,326,814 D rug discovery platfo € 2,284,747 € 2,284,747 8,325 2,293,072
Schedule of the revenue recognition of upfront payments, license fees and milestone payments and the impact of the adoption of IFRS 15	Over time Point in time 2019 2018 (Euro, in (Euro, in thousands) thousands) Recognition of non-refun dable upfront paym € 812,058 € 196,486 Gilead collaboration agreement for ziritaxestat  666,968 - Gilead collaboration agreement for filgotinib (1)  62,602 96,809 Gilead collaboration agreement for drug discovery platform  80,918 - AbbVie collaboration agreement for CF  1,569 52,176 Novartis collaboration agreement for MOR106  - 47,500 Milestone payments 2,878 73,394 Gilead collaboration agreement for filgotinib (1)  (21,187) 27,623 AbbVie collaboration agreement for CF  24,065 36,771 Servier collaboration agreement for osteoarthritis  - 9,000 Reimbursement income 19,900 8,722 Novartis collaboration agreement for MOR106  19,177 7,718 AbbVie collaboration agreement for CF  723 989 Other reimbursement income - 16 Other revenues 66 63 Other revenues 66 63 Total revenues € 834,901 € 278,666 (1) Following the contract amendment, the revenue recognized for filgotinib for the year ended December 31, 2019 included a negative catch-up effect on closing date of € million
Schedule of other income	Year ended December 31, 2020 2019 2018 (Euro, in thousands) Grant income € 5,452 € 6,549 € 1,609 R&D incentives 45,951 43,923 26,912 Other income 804 425 479 Total other income € 52,207 € 50,896 € 29,000

Operating costs (Tables)

Operating costs (Tables)	12 Months Ended
	Dec. 31, 2020
Expenses by nature [abstract]
Summary of research and development expenditure	Year ended December 31, 2020 2019 2018 (Euro, in thousands) Personnel costs € (161,509) € (118,875) € (75,819) Subcontracting (301,841) (255,725) (203,406) Disposables and lab fees and premises costs (22,349) (19,573) (20,967) Depreciation (11,707) (9,330) (4,846) Professional fees (12,692) (1,834) (262) Other operating expenses (13,570) (14,753) (10,922) Total R&D expenses € (523,667) € (420,090) € (316,222)
Summary of research and development expenditure by program	Year ended December 31, 2020 2019 2018 (Euro, in thousands) Filgotinib program € (126,879) € (100,032) € (66,138) Ziritaxestat program (55,902) (75,951) (72,718) OA program on GLPG1972 (22,966) (19,958) (15,751) Toledo program (87,107) (47,204) (20,967) CF program (69) (3,897) (30,137) AtD program on MOR106 (7,618) (24,051) (14,999) Other programs (223,126) (148,997) (95,512) Total R&D expenses € (523,667) € (420,090) € (316,222)
Summary of sales and marketing expenses	Year ended December 31, 2020 2019 2018 (Euro, in thousands) Personnel costs € (31,727) € (7,558) € (2,282) Depreciation (140) (61) — External outsourcing costs (27,174) (15,721) (1,284) Professional fees (3,420) (459) — Other operating expenses (4,007) (777) (580) Total sales and marketing expenses € (66,468) € (24,577) € (4,146)
Summary of general and administrative expenses	Year ended December 31, 2020 2019 2018 (Euro, in thousands) Personnel costs € (70,110) € (51,204) € (24,740) Depreciation (5,147) (1,421) (449) Legal and professional fees (25,592) (11,568) (4,026) Other operating expenses (17,908) (8,190) (5,162) Total general and administrative expenses € (118,757) € (72,382) € (34,377)

Staff costs (Tables)

Staff costs (Tables)	12 Months Ended
	Dec. 31, 2020
Staff costs
Staff costs	Year ended December 31, 2020 2019 2018 (Euro, in thousands) Wages and salaries € (139,681) € (113,660) € (57,237) Social security costs (26,471) (14,566) (10,290) Pension costs (7,337) (4,715) (2,994) Costs related to subscription right plans (79,959) (38,297) (26,757) Other personnel costs (9,897) (6,399) (5,564) Total personnel costs € (263,345) € (177,636) € (102,842)

Fair value re-measurement of _2

Fair value re-measurement of share subscription agreement and warrants granted to Gilead (Tables)	12 Months Ended
	Dec. 31, 2020
Fair value re-measurement of share subscription agreement and warrants granted to Gilead
Schedule of fair value re-measurement of the financial instrument related to the share subscription agreement, issuance of warrant A and B	Year ended December 31, 2020 2019 (Euro, in thousands) Fair value re-measurement of the share subscription agreement € — € (142,350) Fair value re-meas urement of warrant A — (35,642) Fair value re-measurement of initial warrant B 3,034 (3,653) Total fair value re-measurement of share subscription agreement and warrants € 3,034 € (181,644) Fair value re-measurement of the Gilead share subscription agreement (Euro, in thousands) Fair value of financial asset at signing date € 85,601 Change i n fair value recorded in prof (142,350) Fair value of financial liability at closing date (56,749) Derecognition at closing date 56,749 Fair value on December 31, 2019 € — Fair value re-measurement of the financial instrument related to the issuance of warrant A (Euro, in thousands) Fair val ue of financial liability at warrant approval date € (43,311) Change in fai r value recorded in pro (35,642) Derecognition at warrant A exercise date 78,953 Fair value on December 31, 2019 € — Fair value re-measurement of the financial instrument related to the issuance of initial warrant B 2020 2019 (Euro, in thousands) Fair value of financial liability at January 1, € (6,198) Fair value of financial liability at warrant approval date € (2,545) Change i n fair value recorded in profit or lo 3,034 (3,653) Fair value on December 31, € (3,164) € (6,198)

Other financial income _ expe_2

Other financial income / expenses (Tables)	12 Months Ended
	Dec. 31, 2020
Other financial income / expenses
Schedule of other financial income and expense	Year ended December 31, 2020 2019 2018 (Euro, in thousands) Other financial income: Interest income € 10,030 € 14,305 € 5,217 Effect of discounting long term R&D incentives receivables 93 93 199 Currency exchange gain 4,697 775 10,978 Fair value gain on financial assets held at fair value through profit or loss 2,397 5,355 1,203 Fair value gain on current financial investments — 611 — Gain upon sale of financial assets held at fair value through profit or loss — 2 667 Other finance income 1,450 248 — Total other financial income 18,667 21,389 18,264 Other financial expenses: Interest expenses (9,389) (1,268) (780) Effect of discounting long term deferred income (16,278) (6,900) — Currency exchange loss (110,416) (47,720) (1,057) Loss upon sale of financial assets held at fair value through profit or loss (88) — — Fair value loss on current financial investments (15,901) (3,700) — Other finance charges (773) (380) (764) Total other financial expense (152,844) (59,968) (2,602) Total net other financial expense (-)/ income € (134,177) € (38,579) € 15,663

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Taxes
Income tax recognized in profit or loss	Year ended December 31, 2020 2019 2018 (Euro, in thousands) Current tax € (1,069) € (1,372) € (584) Deferred tax (157) 1,537 (238) Income taxes € (1,226) € 165 € (822)
Tax Liabilities	December 31, 2020 2019 2018 (Euro, in thousands) Current tax payable € 1,248 € 2,037 € 1,175 Total tax liabilities € 1,248 € 2,037 € 1,175
Tax reconciled to the accounting result	Year ended December 31, 2020 2019 2018 (Euro, in thousands) Income/loss (-) before tax € (309,775) € 148,525 € (31,417) Income tax debit/credit (-), calculated using the Belgian statutory tax rate on the accounting income/loss (-) before tax (theoretical) (77,444) 43,934 (9,293) Tax expenses/income (-) in statement of operations (effective) 1,226 (165) 822 Difference in tax expense/income to explain € 78,670 € (44,097) € 10,116 Effect of tax rates in other jurisdictions € 184 € 960 € 599 Effect of no n-taxable revenues (10,196) (13,079) (11,547) Effect of share based payment expenses without tax impact 19,990 10,318 7,530 Effect of expe nses/income (-) no (639) 53,394 175 Effect of non tax-deductible expenses 1,053 724 914 Effect of recognition of previously non recognized deferred tax assets (475) (2,286) (532) Effect of tax losses (utilized) reversed (150) (136) (150) Effect of under or over provision in prior periods (25) 30 — Effect of non-recognition of deferred tax assets 69,141 47,413 13,127 Effect of derecognition of previously recognized deferred tax assets 157 — — Effect of use of investment deduction (370) — — Effect of use of IID — (141,435) — Total explanations € 78,670 € (44,097) € 10,116

Income_loss (-) per share (Tabl

Income/loss (-) per share (Tables)	12 Months Ended
	Dec. 31, 2020
Income/loss (-) per share
Schedule of income/loss (-) per share	Year ended December 31, 2020 2019 2018 Net income/loss (-) attributable to owners of the parent (Euro, in thousands) € (305,436) € 149,845 € (29,259) Number of shares (thousands) Weighted average number of shares for the purpose of basic income/loss (-) per share 65,075 57,614 52,113 Basic income/loss (-) per share (Euros) € (4.69) € 2.60 € (0.56) Net income/loss (-) attributable to owners of the parent (Euro, in thousands) € (305,436) € 149,845 € (29,259) Number of shares (thousands) Weighted average number of shares for the purpose of diluted income/loss (-) per share 65,075 57,614 52,113 Number of dilutive potential ordinary shares — 2,498 — Diluted income/loss (-) per share (Euros) € (4.69) € 2.49 € (0.56)

Intangible assets (Tables)

Intangible assets (Tables)	12 Months Ended
	Dec. 31, 2020
Intangible assets
Schedule of intangible assets	Software & databases Brands, licenses, patents & know-how Contract costs Total (Euro, in thousands) Acquisition value On January 1 , 2018 € 7,496 € 8,586 € — € 16,082 Additions 1,561 1,763 3,325 Sales and disposals (20) (7,630) (7,650) Translation differences 74 74 On December 31, 2018 9,111 2,719 — 11,832 Additions 5,463 2,453 15,384 23,300 Sales and disposals (64) (64) Translation differences 31 31 On December 31, 2019 14,541 5,172 15,384 35,099 Additions 9,494 39,299 48,793 Sales and disposals (17) (17) Reclassifications to assets held for sale (159) (38) (197) Translation differences (143) (1) (144) On December 31, 2020 € 23,717 € 44,432 € 15,384 € 83,534 Amortization and impairment On January 1 , € 6,514 € 7,070 € — € 13,587 Amortization 681 426 1,107 Impairment 1,083 1,083 Sa les and disposa (20) (7,630) (7,650) Translation differences 74 74 On December 31, 2018 7,250 949 — 8,200 Amortization 816 678 512 2,006 Sales and disposals (63) (63) Translation differences 31 31 On December 31, 2019 8,034 1,626 512 10,173 Amortization 2,303 2,289 1,538 6,130 Sales and disposals (17) (17) Reclassifications to assets held for sale (143) (33) (176) Translation differences (142) (142) On December 31, 2020 € 10,034 € 3,883 € 2,050 € 15,968 Carrying amount On December 31, 2018 € 1,862 € 1,771 € — € 3,632 On December 31, 2019 € 6,507 € 3,546 € 14,872 € 24,927 On December 31, 2020 € 13,683 € 40,549 € 13,334 € 67,565

Property, plant and equipment (

Property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, plant and equipment
Schedule of property, plant and equipment - Fully owned	FULLY OWNED Land & leasehold improvements Installation & machinery Furniture, fixtures & vehic les Other tangible assets Total (Euro, in thousands) Acquisition value On January 1, 2018 € 4,736 € 33,060 € 3,209 € 1,189 € 42,195 Additions 275 4,674 1,039 4,404 10,392 Sales and disposals (486) (826) (1,311) Reclassifications 753 13 (766) — Translation differences 29 16 46 On December 31, 2018 5,011 38,031 3,452 4,827 51,321 Additions 273 6,382 649 15,076 22,380 Sales and disposals (1,521) (97) (1,618) Reclassifications 1,792 3 (1,795) — Reclassifications to right of use (251) (251) Translation differences (30) 22 (8) On December 31, 2019 5,284 44,655 4,028 17,856 71,823 Additions 885 3,737 1,824 32,218 38,664 Sales and disposals (51) (1,096) (81) (1,228) Reclassifications 10,625 (623) 2,084 (12,086) — Reclassifications to assets held for sale (2) (8,938) (484) (686) (10,110) Translation differences (2) (127) (19) (30) (178) On December 31, 2020 € 16,739 € 37,607 € 7,352 € 37,273 € 98,972 Depreciations and impairment On January 1 , 2018 € 2,342 € 20,495 € 2,407 € 258 € 25,502 Depreciation 344 3,377 236 17 3,974 Sales and disposals (485) (826) (1,310) Translation differences 16 2 18 On December 31, 2018 2,686 23,403 1,819 275 28,184 Depreciation 394 4,018 399 7 4,818 Sales and disposals (1,521) (99) (1,620) Reclassifications to right of use (251) (251) Translation differences (15) (15) On December 31, 2019 3,080 25,885 2,119 31 31,117 Depreciation 654 3,587 1,418 7 5,666 Sales and disposals (51) (1,058) (77) (1,186) Reclassifications 46 (1,675) 1,629 — Reclassifications to assets held for sale (4,327) (448) (39) (4,814) Translation differences (1) (61) (13) (75) On December 31, 2020 € 3,728 € 22,350 € 4,628 € — € 30,708 Carrying amount On December 31, 2018 € 2,325 € 14,628 € 1,632 € 4,552 € 23,137 On December 31, 2019 € 2,204 € 18,770 € 1,909 € 17,825 € 40,707 On December 31, 2020 € 13,011 € 15,257 € 2,724 € 37,273 € 68,264
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 December 31, 2018 € — € — € — € — Change in accounting policy ( modified retrospective application IFRS 16 24,056 219 2,130 26,406 Restated balance on January 1, 2019 24,056 219 2,130 26,406 Additions 3,270 84 1,176 4,530 Reclassifications to right of use 251 251 Translation differences 38 38 On December 31, 2019 27,364 554 3,307 31,225 Additions 18,341 186 2,932 21,459 Sales and disposals (6) (161) (167) Reclassifications to assets held for sale (5,940) (263) (6,202) Translation differences (88) — (3) (90) On December 31, 2020 € 39,678 € 734 € 5,812 € 46,225 Depreciations and impairment On December 31, 2018 € — € — € — € — Depreciation 4,666 91 867 5,624 Reclassifications to right of use 251 251 Translation differences 4 4 On December 31, 2019 4,670 342 867 5,879 Depreciation 5,350 128 1,405 6,883 Sales and disposal (6) (161) (167) Reclassifications to assets held for sale (1,334) (115) (1,448) Translation differences (36) (1) (36) On December 31, 2020 € 8,651 € 464 € 1,995 € 11,111 Carrying amount On December 31, 2019 € 22,694 € 212 € 2,440 € 25,345 On December 31, 2020 € 31,027 € 270 € 3,817 € 35,113 December 31, Carrying amount 2020 2019 2018 Property, plant and e quipment fully owned € 68,264 € 40,707 € 23,137 Right-of-use 35,113 25,345 — Total property, plant and equipment € 103,378 € 66,052 € 23,137

Other non-current assets (Table

Other non-current assets (Tables)	12 Months Ended
	Dec. 31, 2020
Other non-current assets
Schedule of other non-current assets	December 31, 2020 2019 2018 (Euro, in thousands) Non-current restricted cash € 1,482 € 1,418 € 1,276 Financial assets held at fair value through profit or loss 8,951 11,275 6,000 Other non-current assets 910 1,399 643 Total other non-current assets € 11,343 € 14,091 € 7,919
Schedule of financial assets held at fair value through profit or loss	December 31, 2020 2019 2018 (Euro, in thousands) Costs at January 1, € 4,736 € 4,818 € 2,373 Acquisitions of the year 1,994 — 4,736 Disposals of the year (2,820) (82) (2,291) Costs at December 31, 3,910 4,736 4,818 Fair value adjustment at January 1, 6,539 1,182 (619) Cancellation of fair value adjustment following disposal (3,894) 2 598 Fair value adjustment of the year 2,397 5,355 1,203 Fair value adjustment at December 31, 5,042 6,539 1,182 Net book value at December 31, € 8,951 € 11,275 € 6,000

Research and Development ince_2

Research and Development incentives receivables (Tables)	12 Months Ended
	Dec. 31, 2020
Research and Development incentives receivables
Schedule of the classifications of R&D incentives receivables	December 31, 2020 2019 2018 (Euro, in thousands) Non-current R&D incentives receivables € 111,624 € 93,407 € 73,443 Current R&D incentives receivables 24,104 21,949 11,203 Total R&D incentives receivables € 135,728 € 115,356 € 84,646
Schedule of maturities of non-current R&D incentives receivables	December 31, 2020 Maturity date 2022 2023 2024 2025 2026-2030 Total (Euro, in thousands) French non-current R&D incentives receivables - discounted value € 10,223 11,911 11,722 € 33,856 Belgian non-current R&D incentives receivables - discounted value 6,647 8,429 11,078 13,716 37,898 77,768 Total non-current R&D incentives receivables - discounted value € 16,870 € 20,340 22,800 13,716 37,898 € 111,624

Trade and other receivables a_2

Trade and other receivables and other current assets (Tables)	12 Months Ended
	Dec. 31, 2020
Trade and other receivables and other current assets
Schedule of trade and other receivables and other current assets	December 31, 2020 2019 2018 (Euro, in thousands) Non-current trade receivables € 50,000 € — € — Trade receivables 134,632 39,603 9,206 Prepayments 219 292 142 Other receivables 13,568 14,114 9,261 Trade and other receivables 148,418 54,009 18,609 Inventories 355 255 276 Accrued income 1,096 4,443 3,863 Deferred charges 10,502 4,439 4,104 Other current assets 11,953 9,138 8,244 Total trade and other receivables & other current assets € 210,371 € 63,147 € 26,852

Cash and cash equivalents (Tabl

Cash and cash equivalents (Tables)	12 Months Ended
	Dec. 31, 2020
Cash and cash equivalents.
Schedule of cash and cash equivalents	December 31, 2020 2019 2018 (Euro, in thousands) Cash at banks € 1,239,993 € 907,939 € 358,016 Term deposits 895,194 953,677 733,537 Money market fund — — 199,243 Cash and cash equivalents from continuing ope 2,135,187 1,861,616 1,290,796 Cash and cash equivalents included in assets classified as held for sale 7,884 — — Total cash and cash equivalents € 2,143,071 € 1,861,616 € 1,290,796

Share capital (Tables)

Share capital (Tables)	12 Months Ended
	Dec. 31, 2020
Share capital
Schedule of reconciliation of share capital	2020 2019 2018 (Euro, in thousands) On January 1 € 287,282 € 236,540 € 233,414 Share capital increase 4,031 55,189 19,090 Costs of capital increase — (4,447) (15,964) Share capital on December 31, € 291,312 € 287,282 € 236,540 Aggregate share capital € 353,819 € 349,789 € 294,600 Costs of capital increase (accumulated) (62,507) (62,507) (58,060) Share capital on December 31, € 291,312 € 287,282 € 236,540
Schedule of history of the share capital	Date Share capital increase new shares (in thousands €) Share capital increase due to exe rcise 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, 2018 46,256 € 250,187 March 20, 2018 1,613 298 June 20, 2018 556 103 September 17, 2018 16,021 2,961 October 3, 2018 733 135 November 23, 2018 167 31 December 31, 2018 54,466 294,600 March 20, 2019 808 149 Ju ne 20, 20 1,127 208 August 23, 2019 36,945 6,829 S eptember 19, 201 1,632 302 November 6, 2019 14,162 2,618 November 25, 2019 515 95 December 31, 2019 64,667 349,789 March 17, 2020 824 152 May 28, 2020 2,356 436 September 18, 2020 467 86 December 4, 2020 384 71 December 31, 2020 65,412 € 353,819
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, 2018 50,936,778 € 233,414 € 993,025 € 1,226,439 March 20, 2018 : exercise of subscription rights 298,184 1,613 2,311 3,924 13.16 83.72 June 20, 2018 : exercise of subscription rights 102,801 556 781 1,337 13.01 85.00 September 17, 2018 : U.S. public offering ADSs (fully paid) 2,961,373 16,021 280,167 296,188 Underwriter discounts and offering expenses (paid) (15,964) (15,964) Total U.S. public offering 2,961,373 57 280,167 280,224 99.68 October 3, 2018 : exercise of subscription rights 135,485 733 1,281 2,014 14.86 94.32 November 23, 2018 : exercise of subscription rights 30,800 167 215 382 12.40 88.90 On December 31, 2018 54,465,421 236,540 1,277,780 1,514,320 March 20, 2019 : exercise of subscription rights 149,370 808 2,673 3,481 23.30 90.32 June 20, 2019 : exercise of subscription rights 208,310 1,127 3,198 4,325 20.76 113.55 Aug ust 23, 2019 : share subsc Ordinary shares (fully paid) 6,828,985 36,945 923,142 960,087 148.90 Derecognition of financial liability from share subscription agreement 56,749 56,749 Underwriter discounts and offering expenses (paid) (4,447) (4,447) Total share subscription by Gilead 6,828,985 32,498 979,891 1,012,389 September 19, 2019 : exercise of subscription rights 301,745 1,632 5,043 6,675 22.12 145.25
Summary of other information	Ordinary shares Total Accounting par value of shares (€) 5.41 5.41

Deferred tax (Tables)

Deferred tax (Tables)	12 Months Ended
	Dec. 31, 2020
Deferred tax
Schedule of deferred tax	December 31, 2020 2019 2018 (Euro, in thousands) Recognized deferred tax assets and liabilities Assets € 4,475 € 4,205 € 2,514 Liabilities € — € — € — Deferred tax assets unrecognized € 365,639 € 289,833 € 223,377 Deferred taxes in the consolidated statement of o € (157) € 1,537 € (238) Tax benefit arising from previously unrecognized tax assets used to reduce deferred tax expense (+) 581 1,537 528 Deferred tax expenses relating to temporary differences (44) — — Deferred tax expenses relating to use or derecognition of previously recognized deferred tax assets (695) — (766)

Lease liabilities (Tables)

Lease liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Lease liabilities.
Schedule of lease liabilities	December 31, December 31, 2020 2019 2018 2020 2019 2018 (Euro, in thousands) (Euro, in thousands) Lease payments Present value of lease payments Lease liabilities Within one year € 6,772 € 6,189 € 6,401 € 5,826 In the second to fifth years inclusive 20,399 16,320 19,833 15,783 After five years 3,214 3,844 3,201 3,775 € 30,385 € 26,353 € - € 29,436 € 25,384 € - Less future finance charges 949 969 Present value of lease liabilities € 29,436 € 25,384 € - Less amount due for settlement within 12 months 6,401 5,826 Amount due for settlement after 12 months € 23,035 € 19,558 € -

Trade and other liabilities (Ta

Trade and other liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Trade and other liabilities
Schedule of trade and other liabilities	December 31, 2020 2019 2018 (Euro, in thousands) Trade and other liabilities € 171,316 € 142,510 € 68,038 Other non-current liabilities 8,096 6,989 1,578 Accrued charges 1,070 923 890 Total trade and other liabilities € 180,482 € 150,422 € 70,506

Deferred income (Tables)

Deferred income (Tables)	12 Months Ended
	Dec. 31, 2020
Deferred income.
Schedule of movement in the non-current and current deferred income	Total Gilead collaboration agreement for filgotinib Gilead collaboration agreement for ziritaxestat Gilead collaboration agreement for drug discovery platform ( 2 AbbVie collaboration agreement for CF Servier collaboration agreement for osteoarthritis Deferred income related to contracts in our fee-for-service segment Other deferred income (grants) (Euro, in thousands) On December 31, 2017 € 219,892 € 213,981 € — € — € — € 5,362 € 248 € 300 Reclassified from equity following adoption of IFRS 15 83,220 43,832 44,749 (5,362) On Januari 1, 2018 303,112 257,814 — — 44,749 — 248 300 Upfront received 38,874 38,874 Milestones received 20,965 12,417 8,548 Revenue recognition of upfront (148,985) (96,809) (52,176) Revenue recognition of milestones (64,394) (27,623) (36,771) Other movements 229 222 7 On December 31, 2018 149,801 145,798 — — 3,224 — 471 308 Upfront received and impact of initial valuation of share subscription 3,655,416 641,663 666,967 2,346,787 Milestones received 49,727 27,317 22,410 Significant financing component ( 3 6,900 6,900 Revenue recognition of upfront (1,009,663) (260,207) (666,967) (80,918) (1,570) Revenue recognition of milestones (51,156) (27,092) (24,064) Catch-up effect on closing date ( 1 245,883 245,883 Other movements (46,262) (45,856) (109) (297) On December 31, 2019 3,000,646 780,261 — 2,220,013 — — 362 10 Upfr ont payments 160,000 160,000 Milestones received 90,192 90,192 Significant financing component ( 3 16,278 16,278 Revenue recognition of upfront (411,417) (181,816) (229,601) Revenue recognition of milestones (46,261) ( 46,261 ) Other movements (305) (362) 57 On December 31, 2020 € 2,809,133 € 818,654 € — € 1,990,412 € — € — € — € 67

Discontinued operations (Tables

Discontinued operations (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure of analysis of single amount of discontinued operations [abstract]
Schedule of financial statements in relation to the discontinued operations	Year ended December 31, 2020 2019 2018 (Euro, in thousands, except share and per share data) Revenues € 16,140 € 10,084 € 10,170 Other income 8 9 Total revenues and other income 16,140 10,092 10,179 Research and development expenses (7,685) (7,229) (6,653) General and administrative expenses (2,000) (1,319) (1,253) Total operating expenses (9,685) (8,548) (7,906) Operating income 6,455 1,544 2,273 Other financial income 179 93 71 Other financial expenses (176) (102) (135) Income before tax 6,458 1,535 2,209 Income taxes (893) (379) 773 Net income € 5,565 € 1,156 € 2,981 Basic income per share from discontinued operations € 0.09 € 0.02 € 0.06 Diluted income per share from discontinued operations € 0.08 € 0.02 € 0.06 Weighted average number of shares (in thousands of shares) 65,075 57,614 52,113 Weighted average number of shares - Diluted (in thousands of shares) 67,572 60,112 53,922 2020 (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 assets 863 Tota l assets classified as held 23,406 Non-current lease liabilities 4,115 Other non-current liabilities 70 Trade and other liabilities 3,649 Current lease liabilities 727 Income tax payable 356 Liabilities associated with assets classified as held for sale 8,917 Net assets € 14,488 2020 2019 2018 (Euro, in thousands) Net cash flows generated in operating activities € 7,173 € 2,911 € 3,335 Net cash flows used in investing activities (2,284) (1,350) (799) Net cash flows used in financing activities (664) (709) — Net cash flow from discontinued operations € 4,225 € 852 € 2,536

Operating Cash Flow (Tables)

Operating Cash Flow (Tables)	12 Months Ended
	Dec. 31, 2020
Consolidated Statement of Cash Flows
Adjustments related to operating cash flow	2020 2019 2018 (Euro, in thousands) Adjustment for non-cash transactions Depreciation and amortization € 18,682 € 12,448 € 5,081 Im pairmen 1,083 Share-based compensation expenses 79,959 38,297 26,757 Decrease (-)/increase in retirement benefit obligations and provisions (260) (156) 99 Unrealized exchange losses/gains (-) and non-cash other financial result 105,055 11,169 (10,063) Discounting effect of deferred income 16,278 6,900 Fair value re-measurement of share subscription agreement and warrants (3,034) 181,644 Net change in (fair) value of current financial investments 15,900 3,081 Fair value a djustment financial assets held at fair value t (2,396) (5,355) (1,203) Other non-cash expenses 539 Total adjustment for non-cash transactions € 230,723 € 248,027 € 21,753 Adjustment for items to disclose separately under operating cash flow Interest expense € 9,424 € 1,302 € 780 Interest income (7,476) (9,247) (5,219) Tax expense 2,119 214 50 Total adjustment for items to disclose separately under operating cash flow € 4,067 € (7,731) € (4,389) Adjustment for items to disclose under investing and financing cash flows Gain ( -)/loss on sale of fixed a € 82 € (2) € (668) Interest income on current financial investments (2,554) (5,059) Total adjustment for items to disclose separately under investing and financing cash flow € ( 2,472 ) € (5,061) € (668) Change in working capital other than deferred income Increase (-)/decrease in inventories € (100) € 20 € 3 Increase in receivables (177,155) (67,263) (76) Increase in liabilities 31,163 79,940 19,996 Total change in working capital other than deferred income € (146,092) € 12,698 € 19,922

Off-balance sheet arrangements

Off-balance sheet arrangements (Tables)	12 Months Ended
	Dec. 31, 2020
Off-balance sheet arrangements
Schedule of outstanding obligation for future lease and purchase commitments	We entered into lease agreements for offices, labora tories and cars. As a consequence of the adoption of IFRS 16 Leases, on January 1, 2019, lease obligations in the scope of the new standard are presented as lease liabilities in the statements of financia l position and no longer disclosed separately as off -balance sheet commitments. We refer to note 22 for a breakdown of our lease liabilities. On December 31, 20 20 , we had outstanding obligations for future purchase commitments, whi ch become due as Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years (Euro, in thousands) Purchase commitments € 347,873 € 271,922 € 73,009 € 2,870 € 72 On December 31, 20 19 , we had outst anding obligations for future purchase commitments, which become due as follows: Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years (Euro, in thousands) Purchase commitments € 251,670 € 175,006 € 70,675 € 5,989 € —
Schedule of future cash outflows for leases that had not yet commenced	On December 31, 2019 we were committed to two leases which have not yet started. The total future cash outflows for leases that had not yet commenced were as follows: Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years (Euro, in thousands) Lease commitments not yet commenced € 8,986 € 5,793 € 1,502 € 1,502 € 188
Schedule of future minimum rent payments and purchase commitments	On December 31, 201 8 , we had outstanding obligations for future minimum rent pa yments and purchase commitments, which become due as follows: Total Less than 1 year 1 - 3 years 3 - 5 years More than 5 years (Euro, in thousands) Operating lease obligations € 27,704 € 4,722 € 10,024 € 6,234 € 6,724 Purchase commitments (*) 222,033 121,139 81,879 19,014 — Total contractual obligations & commitments € 249,737 € 125,862 € 91,903 € 25,248 € 6,724 In addition to the tables above, we have a contractual cost sharing obligation related to our collaboration agreement with Gilead for filgotinib. The contractual cost sharing commitment amounted to € 614.1 million at December 31, 201 9 , (€ 74.0 million at December 31, 201 8 ). On December 31, 2020, after the recent renegotiation of the filgotinib collaboration, our estimate of this cost sharing commitment amounts to €493.4 million, ch we have direct purchase commitments of €18.1 million at December 31, 20 20 (€ 27.5 million at December 31, 201 9 , € 20.3 million at December 31, 201 8 ) reflected i n the tables above.

Share based payments (Tables)

Share based payments (Tables)	12 Months Ended
	Dec. 31, 2020
Subscription rights
Share based payments
Schedule of summary of other equity instruments outstanding and exercisable per plan	Outstanding Outstanding Exercisable per Granted Exercised Forfeited Expired per per Subscription Allocation Expiry Exe rcis January 1, during during during during December 31, December 31, right plan date date price (€) 2020 year year year year 2020 2020 2006 BNL 12/21/2007 12/20/2020 7.12 1,050 (1,050) — — 2007 RMV 10/25/2007 10/24/2020 8.65 14,980 (14,980) — — 2008 06/26/2008 06/25/2021 5.6 1,365 1,365 1,365 2012 09/03/2012 09/02/2020 14.19 80,040 (80,040) — — 2013 05/16/2013 05/15/2021 19.38 120,434 (64,770) 55,664 55,664 2014 07/25/2014 07/24/2022 14.54 252,340 (83,000) 169,340 169,340 2015 04/30/2015 04/29/2023 28.75 282,473 (63,000) 219,473 219,473 2015 (B) 12/22/2015 12/21/2023 49.00 329,500 (68,000) 261,500 261,500 2015 RMV 12/22/2015 12/21/2023 49.00 57,500 (17,500) 40,000 40,000 2016 06/01/2016 05/31/2024 46.10 504,250 (161,625) 342,625 342,625 2016 RMV 06/01/2016 05/31/2024 46.10 120,000 (51,000) 69,000 69,000 2016 (B) 01/20/2017 01/19/2025 62.50 150,000 (140,000) 10,000 10,000 2017 05/17/2017 05/16/2025 80.57 595,500 595,500 2017 RMV 05/17/2017 05/16/2025 80.57 127,500 127,500 2018 04/19/2018 04/18/2026 79.88 1,085,245 (2,000) 1,083,245 2018 RMV 04/19/2018 04/18/2026 79.88 137,500 137,500 2019 04/10/2019 04/09/2027 95.11 1,486,690 (8,850) 1,477,840 2019 RMV 04/10/2019 04/09/2027 95.11 194,750 (1,750) 193,000 2020 04/17/2020 04/16/2028 168.42 — 1,925,185 (19,151) 1,906,034 2020RMV 04/17/2020 04/16/2028 168.42 — 248,150 (8,625) 239,525 Total 5,541,117 2,173,335 (744,965) (40,376) — 6,929,111 1,168,967
Schedule of summary of other equity instruments outstanding and exercisable	Weighted a verag Subscription rights exercise price (Euro) Outstanding on January 1, 2018 3,970,807 € 39.3 Exercisable on December 31, 2017 763,344 13.7 Granted during the period 1,235,245 79.9 Forfeited during the year (12,000) 43.2 Exercised during the period (567,270) 13.5 Expired during the year — — Outstanding on December 31, 2018 4,626,782 € 53.3 Exercisable on December 31, 2018 882,734 14.0 Granted during the period 1,699,690 95.1 Forfeited during the year (30,750) 88.9 Exercised during the period (754,605) 22.8 Expired during the year — — Outstanding on December 31, 2019 5,541,117 € 70.1 Exercisable on December 31, 2019 1,139,682 30.2 Granted during the period 2,173,335 168.4 Forfeited during the year (40,376) 144.8 Exercised during the period (744,965) 38.0 Expired during the year — — Outstanding on December 31, 2020 6,929,111 € 104.0 Exercisable on December 31, 2020 1,168,967 37.8
Schedule of inputs into the valuation of the other equity instruments	2020 2020 RMV 2019 2019 RMV 2018 2018 RMV April 17 April 17 April 19 April 19 April 18 April 18 Exercise Price (€) € 168.42 € 168.42 € 95.11 € 95.11 € 79.88 € 79.88 Weigh ted average share price at acceptance d € 178.95 € 178.95 € 107.05 € 107.45 € 84.88 € 84.88 Weight ed average fair value on the accep € 86.45 € 85.79 € 40.04 € 40.05 € 38.39 € 38.39 Weight ed average estimated vola 51.30 51.32 35.86 35.63 39.44 39.44 Weighte d average expected life of the subsc 6.00 6.00 6.02 6.00 8.00 8.00 Weigh ted average risk free ra (0.44) (0.44) (0.27) (0.28) 0.51 0.51 Expected dividends None None None None None None
Schedule of summary of other equity instruments outstanding by category	December 31, 2020 2019 2018 (in number of subscription rights) Supervisory board members 157,560 222,600 216,780 Management board members 2,101,874 2,171,874 2,139,374 Other 4,669,677 3,146,643 2,270,628 Total subscription rights outstanding 6,929,111 5,541,117 4,626,782
Restricted Stock Units (RSUs)
Share based payments
Summary of other equity instruments per plan	Outstanding Outstanding per Granted Forfeited Paid in cash per Offer January 1, during during during December 31, RSU plan date 2020 year year year 2020 Plan 2019.I 10/16/2019 33,000 33,000 Plan 2019.II 10/16/2019 109,075 (27,268) 81,807 Plan 2019.III 10/16/2019 71,072 71,072 Plan 2020.I 6/5/2020 55,928 (1,052) 54,876 Plan 2020.II 7/5/2020 72,841 72,841 Total 213,147 128,769 (1,052) (27,268) 313,596
Summary of number of other equity instruments per plan	2020 2019 (in number of RSUs) Outstanding on January 1, 213,147 — Granted during the period 128,769 213,147 Forfeited during the year (1,052) Paid in cash during the period (27,268) Outstanding on December 31, 313,596 213,147
Schedule of summary of other equity instruments outstanding by category	December 31, Category 2020 2019 (in number of RSUs) Management board members 229,276 188,571 Other 84,320 24,576 Total outstanding RSUs 313,596 213,147

Related parties (Tables)

Related parties (Tables)	12 Months Ended
	Dec. 31, 2020
Related parties
Summary of outstanding balances	December 31, 2020 2019 (Euro, in thousands) Non-current trade receivables € 50,000 € — Trade and other receivables € 132,825 € 31,645 Trade and other payables € 27,074 € 39,100
Summary of remuneration package of the members of key management personnel	Year ended December 31, 2020 2019 2018 Remuneration of key management personnel: Euro, in thousands (except for the number of subscription rights Short-term benefits € 3,102 € 14,129 € 2,909 Management board members as a group ( 1 Gross salary 2,531 2,121 1,920 Employer social security on gross salary — 61 125 Cash bonus 433 1,230 757 Exceptional bonus — 10,500 — Employer social security on exceptional bonus — 108 — Other short-term benefits 138 109 107 Long-term benefits f or management board members as a group (2 ) — 1,874 1,812 Board fees and other short-term benefits for supervisory board members Raj Parekh 220 90 92 Harrold van Barlingen ( 3 ) — — 15 Howard Rowe 125 55 53 Werner Cautreels ( 4 ) — 15 48 Katrine Bosley 115 45 45 Christine Mummery ( 4 ) — 13 40 Mary Kerr 115 45 46 Peter ( 5 ) 115 30 — Daniel O'Day ( 6 ) — — — Linda Higgins ( 6 ) — — — Elisabeth Svanberg ( 7 ) 78 — — Post-employment benefits ( 8 ) 392 323 305 Total benefits excluding subscription rights and RSUs ( 9 ) € 4,262 € 16,618 € 5,346 Number of subscription rights granted in the year Management board members as a group 275,000 315,000 350,000 Onno van de Stolpe 85,000 100,000 Bart Filius 50,000 65,000 Andre Hoekema 30,000 50,000 Piet Wigerinck 40,000 50,000 Walid Abi-Saab 40,000 50,000 Michele Manto 30,000 40,000 Supervisory board members as a group — 45,000 52,500 Raj Parekh 15,000 15,000 Harrold van Barlingen (3) — — Howard Rowe 7,500 7,500 Werner Ca utreels ( 4 ) 7,500 Katrine Bosley 7,500 7,500 Christine Mummery ( 4 ) 7,500 Mary Kerr 7,500 7,500 Peter Guenter ( 5 ) 7,500 Daniel O'Day ( 6 ) Linda Higgins ( 6 ) Elisabeth Svanberg ( 7 Total number of subscription rights granted in the year 275,000 360,000 402,500 Total cost of subscription rights granted in the year under IFRS 2 € 22,921 € 14,236 € 15,507 Number of RSUs granted in the year (10) Onno van de Stolpe 18,317 57,528 0 Bart Filius 12,600 39,846 0 Andre Hoekema 832 19,922 0 Piet Wigerinck 12,080 33,077 0 Walid Abi-Saab 12,080 33,077 0 Michele Manto 5,920 5,121 0 Total number of RSUs granted in the year 61,829 188,571 -

Consolidated companies as of _2

Consolidated companies as of December 31, 2020 (Tables)	12 Months Ended
	Dec. 31, 2020
Consolidated companies as of December 31, 2020
Disclosure of voting rights in consolidated companies	Year ended December 31, 2020 2019 2018 Name of the subsidiary Country % voting right Galapagos NV (directly or indirectly through subsidiaries) Change in % voting right previous period ( 2020 vs 2019 % voting right Galapagos NV (directly or indirectly thro ugh subsidiaries) % voting right Galapagos NV (directly or indirectly through subsidiaries) BioFocus DPI AG (liquidated) Switzerland 0% (100%) 100% 100% Galapagos Biopharma Belgium BV Belgium 100% 100% Galapagos Biopharma Netherlands B.V. The Netherlands 100% 100% Galapagos Biopharma Spain S.L.U Spain 100% 100% Galapagos Biopharma Italy S.r.l. Italy 100% 100% Galapagos Biopharma Germany GmbH Germany 100% 100% Galapagos B.V. The Netherlands 100% 100% 100% Galapagos Biotech Ltd. (formerly Inpharmatica Ltd.) United Kingdom 100% 100% 100% Galapagos GmbH Switzerland 100% 100% 100% Galapagos, Inc. (formerly Biofocus, 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 2 BV Belgium 0% (100%) 100% 100% Galapagos Real Estate Netherlands B.V. The Netherlands 100% 100% Galapagos SASU France 100% 100% 100% Fidelta d.o.o. Croatia 100% 100% 100% Xenometrix, Inc. in liquidation United States 100% 100% 100%

Financial risk management (Tabl

Financial risk management (Tables)	12 Months Ended
	Dec. 31, 2020
Financial risk management
Disclosure of categories of material financial assets and liabilities	December 31, 2020 2019 2018 (*) (Euro, in thousands) Financial assets held at fair value through profit or loss Equity instruments € 8,951 € 11,275 € 6,000 Current financial investments 1,571,858 3,919,216 — Financial assets at amortised cost Curr ent financial i 1,454,420 — — Cash and cash equivalents 2,135,187 1,861,616 1,290,796 Restricted cash (current and non-current) 1,482 1,418 1,276 Other non-current assets 907 1,399 644 Trade receivables 184,632 39,603 9,206 Total financial assets € 5,357,438 € 5,834,526 € 1,307,922 Financial liabilities held at fair value through profit or loss Current financial instruments € 3,164 € 6,198 € — Financial liabilities at amortised cost Trade liabilities 134,905 116,749 52,466 Lease liabilities 29,436 25,384 — Total financial liabilities € 167,505 € 148,331 € 52,466 (*) The historical consolidated financial information for 2019 and 2018 presented in this disclosure note has been adjusted mainly to correct for the amounts of other receivables and other payables that are outside the scope of IFRS 9.
Disclosure of aging balance of receivables	December 31, 2020 2019 2018 (Euro, in thousands) 60 - 90 days € — € 87 € 236 90 - 120 days — — 12 more than 120 days € — € — € —
Foreign exchange risk
Financial risk management
Disclosure of sensitivity of exchange rate risk	December 31, 2020 2019 2018 Net book value (Euro, in thousands) Increase in Euros - U.S. Dollars € (116,690) € (133,373) € (27,200) Increase in Euros - GB Pounds 303 113 100 Increase in Euros - CH Francs 2,013 538 208 Increase in Euros - HR Kunas — 650 611 Increase in U.S. Dollars - GB Pounds € — € (894) € (923)

General information (Details)

General information (Details) € in Millions	Apr. 01, 2021EUR (€)	Dec. 31, 2020employee
Summary of financial statements in relation to the discontinued operations
Number of employees related to continuing operations		1,304
Fee-for-service business (held for sale)
Summary of financial statements in relation to the discontinued operations
Total consideration received | €	€ (37.1)
Fidelta d.o.o. (fee-for-service segment)
Summary of financial statements in relation to the discontinued operations
Number of employees		185

Summary of significant transa_2

Summary of significant transaction (Details) € / shares in Units, € in Thousands

Dec. 15, 2020EUR (€)

Nov. 06, 2019EUR (€)

Oct. 22, 2019€ / shares

Aug. 23, 2019

Aug. 22, 2019

Jul. 14, 2019EUR (€)€ / shares

Jul. 14, 2019USD ($)

Dec. 31, 2020USD ($)

Dec. 31, 2020EUR (€)

Dec. 31, 2019EUR (€)

Dec. 31, 2018EUR (€)

Dec. 31, 2020USD ($)

Jul. 14, 2019USD ($)

Summary of significant transaction

Global research and development collaboration term

10 years

10 years

Upfront payment received

€ 3,569,800

$ 3,950,000,000

Equity investment

€ 960,100

$ 1,100,000,000

Additional equity investment from warrant exercise | €

€ 28,287

€ 17,167

€ 7,657

Cost share for global development activities

50.00%

50.00%

Option rights period

10 years

10 years

Extension option rights period

3 years

3 years

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

$ 150,000,000

Milestones achieved | €

€ 46,261

€ 2,878

€ 73,394

GLPG 1690 License

Summary of significant transaction

Regulatory milestone fee | $

325,000,000

GLPG 1972 License

Summary of significant transaction

Regulatory milestone fee | $

550,000,000

Additional milestone fee | $

200,000,000

Filgotinib drug license

Summary of significant transaction

Development and regulatory milestones | $

295,000,000

Sales based milestone payment | $

600,000,000

Number of milestone payments achieved | $

2

Proceeds from milestone payments | $

$ 105,000,000

United States | GLPG 1972 License

Summary of significant transaction

License fee on election of option to license | $

$ 250,000,000

Minimum | Outside Europe

Summary of significant transaction

Tiered royalty Percentage

20.00%

20.00%

Minimum | Outside Europe | Filgotinib drug license

Summary of significant transaction

Tiered royalty Percentage

20.00%

20.00%

20.00%

Maximum | Outside Europe

Summary of significant transaction

Tiered royalty Percentage

24.00%

24.00%

Maximum | Outside Europe | Filgotinib drug license

Summary of significant transaction

Tiered royalty Percentage

30.00%

30.00%

30.00%

Gilead

Summary of significant transaction

Global research and development collaboration term

10 years

10 years

Cost share for global development activities

50.00%

50.00%

Number of directors represented as board members

2

Premium

20.00%

20.00%

Volume of days

30 days

30 days

Percentage of stake

25.10%

22.04%

12.30%

25.54%

Restricting Gilead's ability to seek to acquire

10 years

Maximum share holding percentage

29.90%

Subscription Price | € / shares

€ 140.59

Gilead | Filgotinib drug license

Summary of significant transaction

Future global development cost sharing ratio before predetermined level

100.00%

Amount receivable in relation to the collaboration | €

€ 160,000

Amounts Receivable Related Party Transactions in Next Twelve Months | €

110,000

Amounts Receivable Related Party Transactions Year Two | €

50,000

Upfront payments receivable

125,000

$ 151,800,000

Upfront Payments Receivable Related Party Transactions In Next Fiscal Year | €

75,000

Upfront Payments Receivable Related Party Transactions In Year Two | €

€ 50,000

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

Summary of significant transaction

Cost share for global development activities

50.00%

50.00%

Gilead | Reassessment Responsibilities [Member] | Filgotinib drug license

Summary of significant transaction

Upfront payments | €

€ 35,000

Upfront payments receivable

€ 35,000

$ 42,500,000

Gilead | Minimum

Summary of significant transaction

Cost share for global development activities

20.00%

20.00%

Gilead | Minimum | Filgotinib drug license

Summary of significant transaction

Future global development cost sharing ratio before predetermined level

20.00%

Gilead | Minimum | Europe | Filgotinib drug license

Summary of significant transaction

Percentage of future net sales from 2024

8.00%

8.00%

Gilead | Maximum

Summary of significant transaction

Percentage of stake

29.90%

Gilead | Maximum | Filgotinib drug license

Summary of significant transaction

Future global development cost sharing ratio before predetermined level

50.00%

Gilead | Maximum | Europe | Filgotinib drug license

Summary of significant transaction

Percentage of future net sales from 2024

15.00%

15.00%

Warrant A | Gilead

Summary of significant transaction

Additional equity investment from warrant exercise | €

€ 368,000

Warrant B

Summary of significant transaction

Multiplier used to calculate exercise price per share

120.00%

Initial term of the warrant

5 years

Volume of days

30 days

Exercise Price | € / shares

€ 140.59

Warrant B | Gilead | Minimum

Summary of significant transaction

EGM Conducted period for approval of subsequent warrant B

57 months

Warrant B | Gilead | Maximum

Summary of significant transaction

EGM Conducted period for approval of subsequent warrant B

59 months

Significant accounting polici_4

Significant accounting policies (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Disclosure of detailed information about adoption of IFRS 16
Operating lease commitments disclosed as at December 31, 2018				€ 27,704
Current lease liabilities	€ 6,401	€ 5,826		0
Non-current lease liabilities	23,035	19,558		0
Change in accounting policy affected the statement of financial position
Property, plant and equipment (right-of-use assets)	68,264	40,707		23,137
Other current assets (prepaid expenses)	(11,953)	(9,138)		(8,244)
Total assets	5,717,731	6,068,609		1,439,496
Accumulated losses	(334,701)	(109,223)		(297,779)
Deferred income	(443,159)	(414,298)		(149,801)
Total equity and liabilities	€ 5,717,731	€ 6,068,609		1,439,496
IFRS 16
Disclosure of detailed information about adoption of IFRS 16
Weighted average incremental borrowing rate			1.55%
Operating lease commitments disclosed as at December 31, 2018				€ 27,704
Less : discounting effect using the lessee's incremental borrowing rate at the date of initial application			€ (1,223)
Less : other			(569)
Lease liability			25,912
Current lease liabilities			4,516
Non-current lease liabilities			21,396
Change in accounting policy affected the statement of financial position
Property, plant and equipment (right-of-use assets)			26,406
Other current assets (prepaid expenses)			(494)
Total assets			25,912
Accumulated losses			416
Lease liabilities (current and non-current)			25,912
Deferred income			(416)
Total equity and liabilities			€ 25,912

Significant accounting polici_5

Significant accounting policies - Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2020
Software and databases | Minimum
Disclosure of detailed information about intangible assets
Useful lives	3 years
Software and databases | Maximum
Disclosure of detailed information about intangible assets
Useful lives	5 years
Brands, licenses, patents and know-how | Minimum
Disclosure of detailed information about intangible assets
Useful lives	5 years
Brands, licenses, patents and know-how | Maximum
Disclosure of detailed information about intangible assets
Useful lives	20 years

Significant accounting polici_6

Significant accounting policies - Property, Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2020
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
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

Significant accounting polici_7

Significant accounting policies - Employee Benefits (Details)	12 Months Ended
	Dec. 31, 2020
Significant accounting policies
Percentage of bonus paid immediately around year-end, Senior Management Bonus Scheme	50.00%
Percentage of deferred bonus paid for three years, Senior Management Bonus Scheme	50.00%
Term of deferrment for the remaining 50% bonus payment, Senior Management Bonus Scheme	3 years
Share price below threshold in which the deferred bonus will be adjusted and the remainder will be forfeited	10.00%
Share price above threshold in which the deferred bonus will be forfeited	10.00%

Significant accounting polici_8

Significant accounting policies - Segment Reporting (Details) - segment	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Significant accounting policies
Number of reportable segments	1	2

Critical accounting judgments_2

Critical accounting judgments and key sources of estimation uncertainty - IFRS 15 – Revenue recognition Gilead (Details) € in Thousands	12 Months Ended
	Dec. 31, 2020EUR (€)item	Dec. 31, 2019EUR (€)	Jul. 14, 2019EUR (€)	Dec. 31, 2018EUR (€)	Dec. 31, 2017EUR (€)
Critical accounting estimates and judgments
Drug discovery platform revenue period		10 years
Deferred income	€ 2,809,133	€ 3,000,646		€ 149,801	€ 219,892
Collaboration agreement for filgotinib
Critical accounting estimates and judgments
Deferred income	€ 818,700
Gilead
Critical accounting estimates and judgments
Number of performance obligations exceeding one year | item	2
Period recognized to consideration paid for the platform	10 years
Deferred income	€ 4,286,852	4,012,108
Gilead | Collaboration agreement for filgotinib
Critical accounting estimates and judgments
Deferred income	€ 818,654	€ 780,261		€ 145,798	€ 213,981
Gilead | Derivative financial instrument
Critical accounting estimates and judgments
Offsetting short term financial asset (derivative)			€ 85,600
Number of performance obligations exceeding one year | item	3

Segment information (Details)

Segment information (Details) - segment	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Segment information
Number of reportable segments	1	2

Segment information - Major cus

Segment information - Major customers (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Disclosure of major customers [line items]
Revenue	€ 478,053	€ 834,901	[1]	€ 278,666	[1]
United States of America
Disclosure of major customers [line items]
Revenue	472,445	793,873		116,680
Europe
Disclosure of major customers [line items]
Revenue	5,607	41,028		161,986
Gilead | United States of America
Disclosure of major customers [line items]
Revenue	€ 472,445	€ 793,873	[2]	€ 116,640
Percentage of entity's revenue	99.00%	95.00%	[2]	42.00%
Gilead | North America and Europe
Disclosure of major customers [line items]
Negative catch-up effect on closing date resulting from the decrease in the percentage of completion applied to previously received upfront and milestones		€ 245,900
Gilead | Europe
Disclosure of major customers [line items]
Revenue	€ 1,460	€ (4,570)		€ 7,793
Percentage of entity's revenue	0.00%	1.00%		3.00%
AbbVie | Europe
Disclosure of major customers [line items]
Revenue	€ (52)	€ 26,356		€ 89,936
Percentage of entity's revenue	0.00%	3.00%		32.00%
Novartis | Europe
Disclosure of major customers [line items]
Revenue	€ 4,125	€ 19,177		€ 55,218
Percentage of entity's revenue	1.00%	2.00%		20.00%
Les Laboratoires Servier | Europe
Disclosure of major customers [line items]
Revenue	€ 0	€ 0		€ 9,000
Percentage of entity's revenue	0.00%	0.00%		3.00%
Major customers
Disclosure of major customers [line items]
Revenue	€ 477,978	€ 834,836		€ 278,587
Percentage of entity's revenue	100.00%	100.00%		100.00%
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.
[2]	Following the contract amendment with Gilead in 2019, the revenue recognized for filgotinib for the year ended December 31, 2019, included a negative catch-up effect on closing date of €245.9 million resulting from the decrease in the percentage of completion applied to previously received upfront and milestones for that program.

Segment information - Non-curre

Segment information - Non-current assets by location (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Disclosure of geographical areas [line items]
Property, plant and equipment and intangible assets	€ 170,943	€ 90,979	[1]	€ 26,769	[1]
Belgium
Disclosure of geographical areas [line items]
Property, plant and equipment and intangible assets	113,524	57,007	[1]	13,134	[1]
France
Disclosure of geographical areas [line items]
Property, plant and equipment and intangible assets	18,398	18,102	[1]	5,413	[1]
The Netherlands
Disclosure of geographical areas [line items]
Property, plant and equipment and intangible assets	28,210	7,951	[1]	3,947	[1]
Croatia
Disclosure of geographical areas [line items]
Property, plant and equipment and intangible assets	0	6,182	[1]	3,661	[1]
Switzerland
Disclosure of geographical areas [line items]
Property, plant and equipment and intangible assets	7,668	1,057	[1]	519	[1]
Spain
Disclosure of geographical areas [line items]
Property, plant and equipment and intangible assets	2,755	0		0
Other Countries [Member]
Disclosure of geographical areas [line items]
Property, plant and equipment and intangible assets	€ 388,000	€ 681,000	[1]	€ 95,000	[1]
[1]	In accordance with IFRS 8 we only present the total of the property, plant and equipment and intangible assets in this disclosure note. This is a change in presentation compared to the amounts that were published in the disclosure note for the years ended December 31, 2019 and December 31, 2018. We elected to adjust the historical consolidated financial information presented in this disclosure note to reflect this change in presentation.

Total revenues and other inco_3

Total revenues and other income - Disaggregation of revenues (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Total revenues and other income
Recognition of non-refundable upfront payments and license fees	€ 411,417	€ 812,058		€ 196,486
Milestones achieved	46,261	2,878		73,394
Reimbursement income	4,073	19,900		8,722
Other revenues	70	66		63
Commercial revenues	16,232	0		0
Total revenues	€ 478,053	€ 834,901	[1]	€ 278,666	[1]
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Total revenues and other inco_4

Total revenues and other income - Revenue by collaboration and by category of revenue (Details) € in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)	Dec. 31, 2020USD ($)	Dec. 31, 2019EUR (€)		Dec. 31, 2018EUR (€)
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees	€ 411,417		€ 812,058		€ 196,486
Milestones achieved	46,261		2,878		73,394
Reimbursement income	4,073		19,900		8,722
Other revenues	70		66		63
Total revenues	478,053		834,901	[1]	278,666	[1]
Negative catch-up effect on closing date resulting from the decrease in the percentage of completion applied to previously received upfront and milestones			(245,883)
Commercial revenues	16,232		0		0
Other
Disclosure of disaggregation of revenue from contracts with customers [line items]
Reimbursement income					16
Other revenues					63
Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Sale of goods	2
Royalties	16,227
Other commercial revenues	2
Point in time | Other
Disclosure of disaggregation of revenue from contracts with customers [line items]
Other revenues	70		66
Gilead collaboration agreement for ziritaxestat | Gilead | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees			666,968
Collaboration agreement for filgotinib | Gilead
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved	90,200	$ 105
Negative catch-up effect on closing date resulting from the decrease in the percentage of completion applied to previously received upfront and milestones			(245,883)
Collaboration agreement for filgotinib | Gilead | Over time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees	181,816		62,602		96,809
Milestones achieved	46,261		(21,187)
Negative catch-up effect on closing date resulting from the decrease in the percentage of completion applied to previously received upfront and milestones			(245,900)
Collaboration agreement for filgotinib | Gilead | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved					27,623
Gilead collaboration agreement for drug discovery platform | Gilead | Over time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees	229,601		80,918
Collaboration agreement for CF | AbbVie | Over time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees			1,569		52,176
Milestones achieved			24,065
Reimbursement income	(52)		723
Collaboration agreement for CF | AbbVie | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved					36,771
Reimbursement income					989
Servier collaboration agreement for osteoarthritis | Servier | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved					9,000
Collaboration agreement for MOR106 | Novartis | Over time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Reimbursement income	€ 4,125		€ 19,177		7,718
Collaboration agreement for MOR106 | Novartis | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees					€ 47,500
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Total revenues and other inco_5

Total revenues and other income - Allocation of transaction price (Details) € in Thousands, $ in Millions		Dec. 15, 2020EUR (€)	Jul. 14, 2019EUR (€)	Jul. 14, 2019EUR (€)	Jul. 14, 2019USD ($)	Jul. 31, 2018EUR (€)	Dec. 31, 2020EUR (€)yritem	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)	Dec. 31, 2017EUR (€)
Disclosure of disaggregation of revenue from contracts with customers [line items]
Upfront payment received				€ 3,569,800	$ 3,950
Milestones achieved							€ 46,261	€ 2,878	€ 73,394
Allocation to performance obligations							€ 2,809,133	€ 3,000,646	€ 149,801	€ 219,892
Drug discovery platform revenue period								10 years
Global research and development collaboration term				10 years	10 years
Period over which to recognize the drug discovery platform revenue							101010 years
Maximum extension period for specific program							3 years
Filgotinib
Disclosure of disaggregation of revenue from contracts with customers [line items]
Number of performance obligations exceeding one year | yr							1
Subsequent warrant B
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations							€ 7,900	€ 16,200
Novartis
Disclosure of disaggregation of revenue from contracts with customers [line items]
Upfront consideration						€ 95,000
Filgotinib agreement 2015
Disclosure of disaggregation of revenue from contracts with customers [line items]
Upfront payment received								275,558
Impact initial valuation of share subscription								39,003
Total transaction price								314,561
Allocation to performance obligations								314,561
Filgotinib agreement 2015 | Filgotinib performance obligations
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations	[1]							314,561
Milestones achieved during 2015-2019
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved								104,171
Total transaction price								104,171
Allocation to performance obligations								104,171
Milestones achieved during 2015-2019 | Filgotinib performance obligations
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations	[1]							104,171
Option, License and Collaboration agreement (July 14, 2019)
Disclosure of disaggregation of revenue from contracts with customers [line items]
Upfront payment received			€ 3,569,815
Impact initial valuation of share subscription			85,601
Total transaction price			3,655,416
Allocation to performance obligations			3,655,416	€ 3,655,416
Option, License and Collaboration agreement (July 14, 2019) | Ziritaxestat
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations			666,967	666,967
Option, License and Collaboration agreement (July 14, 2019) | Filgotinib performance obligations
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations	[1]		641,663	641,663
Option, License and Collaboration agreement (July 14, 2019) | Drug discovery platform (10 years)
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations			2,284,747	2,284,747
Other movements in 2020
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved							90,192
Royalties							16,227
Total transaction price							106,419
Allocation to performance obligations							114,744
Other movements in 2020 | Subsequent warrant B
Disclosure of disaggregation of revenue from contracts with customers [line items]
Less : Warrants issuance liabilities							8,325
Other movements in 2020 | Filgotinib performance obligations
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations	[1]						106,419
Other movements in 2020 | Drug discovery platform (10 years)
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations							8,325
Filgotinib amendment (December 15, 2020)
Disclosure of disaggregation of revenue from contracts with customers [line items]
Upfront consideration		€ 160,000
Total transaction price		160,000
Allocation to performance obligations		160,000
Filgotinib amendment (December 15, 2020) | Filgotinib performance obligations
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations	[1]	160,000
Gilead
Disclosure of disaggregation of revenue from contracts with customers [line items]
Upfront payment received								3,845,373
Upfront consideration							4,005,373
Impact initial valuation of share subscription							124,604	124,604
Total transaction price							4,340,567	4,074,148
Allocation to performance obligations							€ 4,286,852	4,012,108
Number of performance obligations exceeding one year | item							2
Period recognized to consideration paid for the platform							10 years
Gilead | Warrant A
Disclosure of disaggregation of revenue from contracts with customers [line items]
Less : Warrants issuance liabilities							€ 43,311	43,311
Gilead | Initial Warrant B
Disclosure of disaggregation of revenue from contracts with customers [line items]
Less : Warrants issuance liabilities							2,545	2,545
Gilead | Subsequent warrant B
Disclosure of disaggregation of revenue from contracts with customers [line items]
Less : Warrants issuance liabilities							7,859	16,184
Fair value of the underlying warrants issuance liability							7,900
Gilead | Ziritaxestat
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations							666,967	666,967
Gilead | Filgotinib
Disclosure of disaggregation of revenue from contracts with customers [line items]
Royalties							16,200
Allocation to performance obligations		€ 160,000
Gilead | Filgotinib performance obligations
Disclosure of disaggregation of revenue from contracts with customers [line items]
Estimated significant financing component							55,300	44,500
Gilead | Drug discovery platform (10 years)
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations							€ 2,293,072	2,284,747
Gilead | Derivative financial instrument
Disclosure of disaggregation of revenue from contracts with customers [line items]
Number of performance obligations exceeding one year | item							3
Offsetting short term financial asset (derivative)			€ 85,600	€ 85,600
Gilead | Collaboration agreement for filgotinib
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved							€ 194,363	104,171
Royalties							16,227	0
Gilead | Collaboration agreement for filgotinib | Filgotinib performance obligations
Disclosure of disaggregation of revenue from contracts with customers [line items]
Allocation to performance obligations	[1]						€ 1,326,814	€ 1,060,395
[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 €55.3 million as of December 31, 2020, considering the effects of the amendment of December 15, 2020.

Total revenues and other inco_6

Total revenues and other income - Schedule of the revenue recognition of upfront payments, license fees and milestone payments and the impact of the adoption of IFRS 15 (Details) € in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)	Dec. 31, 2020USD ($)	Dec. 31, 2019EUR (€)		Dec. 31, 2018EUR (€)
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees	€ 411,417		€ 812,058		€ 196,486
Milestones achieved	46,261		2,878		73,394
Reimbursement income	4,073		19,900		8,722
Other revenues	70		66		63
Total revenues	478,053		834,901	[1]	278,666	[1]
Negative catch-up effect on closing date resulting from the decrease in the percentage of completion applied to previously received upfront and milestones			(245,883)
Other
Disclosure of disaggregation of revenue from contracts with customers [line items]
Reimbursement income					16
Other revenues					63
Point in time | Other
Disclosure of disaggregation of revenue from contracts with customers [line items]
Other revenues	70		66
Gilead collaboration agreement for ziritaxestat | Gilead | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees			666,968
Collaboration agreement for filgotinib | Gilead
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved	90,200	$ 105
Negative catch-up effect on closing date resulting from the decrease in the percentage of completion applied to previously received upfront and milestones			(245,883)
Collaboration agreement for filgotinib | Gilead | Over time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees	181,816		62,602		96,809
Milestones achieved	46,261		(21,187)
Negative catch-up effect on closing date resulting from the decrease in the percentage of completion applied to previously received upfront and milestones			(245,900)
Collaboration agreement for filgotinib | Gilead | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved					27,623
Gilead collaboration agreement for drug discovery platform | Gilead | Over time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees	229,601		80,918
Collaboration agreement for CF | AbbVie | Over time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees			1,569		52,176
Milestones achieved			24,065
Reimbursement income	(52)		723
Collaboration agreement for CF | AbbVie | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved					36,771
Reimbursement income					989
Collaboration agreement for MOR106 | Novartis | Over time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Reimbursement income	€ 4,125		19,177		7,718
Collaboration agreement for MOR106 | Novartis | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees					47,500
Servier collaboration agreement for osteoarthritis | Servier | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved					€ 9,000
IFRS 15
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees			812,058
Milestones achieved			2,878
Reimbursement income			19,900
Other revenues			66
Total revenues			834,901
IFRS 15 | Other
Disclosure of disaggregation of revenue from contracts with customers [line items]
Reimbursement income
Other revenues			66
IFRS 15 | Collaboration agreement for filgotinib | Gilead | Over time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees			62,602
Milestones achieved			(21,187)
IFRS 15 | Collaboration agreement for CF | AbbVie | Over time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees			1,569
Milestones achieved			24,065
Reimbursement income			723
IFRS 15 | Collaboration agreement for MOR106 | Novartis | Over time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Reimbursement income			19,177
IFRS 15 | Collaboration agreement for MOR106 | Novartis | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Recognition of non-refundable upfront payments and license fees
IFRS 15 | Servier collaboration agreement for osteoarthritis | Servier | Point in time
Disclosure of disaggregation of revenue from contracts with customers [line items]
Milestones achieved
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Total revenues and other inco_7

Total revenues and other income - Summary of other income (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Total revenues and other income
Grant income	€ 5,452	€ 6,549		€ 1,609
R&D incentives	45,951	43,923		26,912
Other income	804	425		479
Total other income	€ 52,207	€ 50,896	[1]	€ 29,000	[1]
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Operating costs - Summary of re

Operating costs - Summary of research and development expenditure (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Expenses by nature [abstract]
Personnel costs	€ (161,509)	€ (118,875)		€ (75,819)
Subcontracting	(301,841)	(255,725)		(203,406)
Disposables and lab fees and premise costs	(22,349)	(19,573)		(20,967)
Depreciation	(11,707)	(9,330)		(4,846)
Professional fees	(12,692)	(1,834)		(262)
Other operating expenses	(13,570)	(14,753)		(10,922)
Total R&D expenses	€ (523,667)	€ (420,090)	[1]	€ (316,222)	[1]
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Operating costs - Summary of _2

Operating costs - Summary of research and development expenditure by program (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Operating costs
Total research and development expenditure	€ (523,667)	€ (420,090)	[1]	€ (316,222)	[1]
Filgotinib program
Operating costs
Total research and development expenditure	(126,879)	(100,032)		(66,138)
Ziritaxestat program
Operating costs
Total research and development expenditure	(55,902)	(75,951)		(72,718)
OA program on GLPG1972
Operating costs
Total research and development expenditure	(22,966)	(19,958)		(15,751)
Toledo Program
Operating costs
Total research and development expenditure	(87,107)	(47,204)		(20,967)
CF program
Operating costs
Total research and development expenditure	(69)	(3,897)		(30,137)
AtD program on MOR106
Operating costs
Total research and development expenditure	(7,618)	(24,051)		(14,999)
Other programs
Operating costs
Total research and development expenditure	€ (223,126)	€ (148,997)		€ (95,512)
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Operating costs - Summary of sa

Operating costs - Summary of sales and marketing expenses (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Expenses by nature [abstract]
Personnel costs	€ (31,727)	€ (7,558)		€ (2,282)
Depreciation	(140)	(61)
External outsourcing costs	(27,174)	(15,721)		(1,284)
Professional fees	(3,420)	(459)
Other operating expenses	(4,007)	(777)		(580)
Total sales and marketing expenses	€ (66,468)	€ (24,577)	[1]	€ (4,146)	[1]
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Operating costs - Summary of ge

Operating costs - Summary of general and administrative expenses (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Expenses by nature [abstract]
Personnel costs	€ (70,110)	€ (51,204)		€ (24,740)
Depreciation	(5,147)	(1,421)		(449)
Legal and professional fees	(25,592)	(11,568)		(4,026)
Other operating expenses	(17,908)	(8,190)		(5,162)
Total general and administrative expenses	€ (118,757)	€ (72,382)	[1]	€ (34,377)	[1]
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Staff costs (Details)

Staff costs (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Staff costs
Wages and salaries	€ (139,681)	€ (113,660)	€ (57,237)
Social security costs	(26,471)	(14,566)	(10,290)
Pension costs	(7,337)	(4,715)	(2,994)
Costs related to subscription right plans	(79,959)	(38,297)	(26,757)
Other personnel costs	(9,897)	(6,399)	(5,564)
Total personnel costs	(263,345)	(177,636)	(102,842)
Costs for warrants granted	€ 79,959	€ 38,297	€ 26,757

Fair value re-measurement of _3

Fair value re-measurement of share subscription agreement and warrants granted to Gilead - Financial assets (Details) - EUR (€) € in Thousands	Nov. 06, 2019	Nov. 06, 2019	Aug. 23, 2019	Aug. 23, 2019	Dec. 31, 2019		Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018		Oct. 22, 2019	Jul. 14, 2019
Disclosure of fair value measurement of assets [line items]
Upfront payments										€ 38,874
Share subscription increase								€ 960,087		296,188
Fair value of financial asset at inception related to the share subscription agreement with Gilead					€ 5,834,526	[1]	€ 5,357,438	5,834,526	[1]	1,307,922	[1]
Fair value of financial liability related to the share subscription agreement with Gilead					148,331	[1]	167,505	148,331	[1]	52,466	[1]
Change in fair value related to the share subscription agreement and warrants with/granted to Gilead							3,034	(181,644)	[2]	0	[2]
Fair value of financial liability					148,331	[1]	167,505	148,331	[1]	52,466	[1]
Current financial liabilities related to the share subscription agreement					6,198		3,164	6,198		€ 0
Derivative financial instrument | Gilead | Level 3
Disclosure of fair value measurement of assets [line items]
Fair value of financial asset at inception related to the share subscription agreement with Gilead					0			0					€ 85,601
Fair value of financial liability related to the share subscription agreement with Gilead			€ (56,749)	€ (56,749)
Change in fair value related to the share subscription agreement and warrants with/granted to Gilead				(142,350)
Fair value of financial liability			(56,749)	€ (56,749)
Derecognition of the financial asset through the share premium account related to the share subscription agreement with Gilead			€ 56,749
Fair value re-measurement of the share subscription agreement
Disclosure of fair value measurement of assets [line items]
Change in fair value related to the share subscription agreement and warrants with/granted to Gilead							0	(142,350)
Fair value re-measurement of the financial instrument related to the issuance of warrant A | Warrant A
Disclosure of fair value measurement of assets [line items]
Change in fair value related to the share subscription agreement and warrants with/granted to Gilead							0	(35,642)
Fair value re-measurement of the financial instrument related to the issuance of warrant A | Gilead | Warrant A
Disclosure of fair value measurement of assets [line items]
Fair value of financial liability related to the share subscription agreement with Gilead					0			0				€ (43,311)
Change in fair value related to the share subscription agreement and warrants with/granted to Gilead	€ (35,642)
Fair value of financial liability					0			0				(43,311)
Derecognition of the financial asset through the share premium account related to the share subscription agreement with Gilead		€ 78,953
Fair value re-measurement of the financial instrument related to the issuance of initial warrant B
Disclosure of fair value measurement of assets [line items]
Change in fair value related to the share subscription agreement and warrants with/granted to Gilead							3,034	(3,653)
Fair value re-measurement of the financial instrument related to the issuance of initial warrant B | Gilead | Warrant B
Disclosure of fair value measurement of assets [line items]
Fair value of financial liability related to the share subscription agreement with Gilead					(6,198)		(3,164)	(6,198)				(2,545)
Change in fair value related to the share subscription agreement and warrants with/granted to Gilead					(3,653)		3,034
Fair value of financial liability					€ (6,198)		€ (3,164)	€ (6,198)				€ (2,545)
[1]	The historical consolidated financial information for 2019 and 2018 presented in this disclosure note has been adjusted mainly to correct for the amounts of other receivables and other payables that are outside the scope of IFRS 9.
[2]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Other financial income _ expe_3

Other financial income / expenses (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Other financial income:
Interest on bank deposit	€ 10,030	€ 14,305		€ 5,217
Effect of discounting long term R&D incentives receivables	93	93		199
Currency exchange gain	4,697	775		10,978
Fair value gain on financial assets held at fair value through profit or loss	2,397	5,355		1,203
Fair value gain on current financial investments	0	611		0
Gain upon sale of financial assets held at fair value through profit or loss	0	2		667
Other finance income	1,450	248		0
Total other financial income	18,667	21,389	[1]	18,264	[1]
Other financial expenses:
Interest expenses	(9,389)	(1,268)		(780)
Effect of discounting long term deferred income	(16,278)	(6,900)		0
Currency exchange loss	(110,416)	(47,720)		(1,057)
Loss upon sale of financial assets held at fair value through profit or loss	(88)	0		0
Fair value loss on current financial investments	(15,901)	(3,700)		0
Other finance charges	(773)	(380)		(764)
Total other financial expense	(152,844)	(59,968)	[1]	(2,602)	[1]
Total net other financial expense (-)/ income	€ (134,177)	€ (38,579)		€ 15,663
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Income Taxes - Summary of incom

Income Taxes - Summary of income tax recognized (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Income Taxes
Current tax	€ (1,069)	€ (1,372)		€ (584)
Deferred tax	(157)	1,537		(238)
Income taxes	€ (1,226)	€ 165	[1]	€ (822)	[1]
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Income Taxes - Schedule of tax

Income Taxes - Schedule of tax liabilities (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes
Current tax payable	€ 1,248	€ 2,037	€ 1,175
Total tax liabilities	€ 1,248	€ 2,037	€ 1,175

Income Taxes - Summary of inc_2

Income Taxes - Summary of income tax reconciliation (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Income Taxes
Income/loss (-) before tax	€ (309,775)	€ 148,525	[1]	€ (31,417)	[1]
Income tax debit / credit (-), calculated using the Belgian statutory tax rate on the accounting income / loss (-) before tax (theoretical)	(77,444)	43,934		(9,293)
Tax expenses/income (-) in statement of operations (effective)	1,226	(165)	[1]	822	[1]
Difference in tax expense / income to explain	78,670	(44,097)		10,116
Effect of tax rates in other jurisdictions	184	960		599
Effect of non taxable revenues	(10,196)	(13,079)		(11,547)
Effect of share based payment expenses without tax impact	19,990	10,318		7,530
Effect of expenses/income (-) not subject to tax	(639)	53,394		175
Effect of non tax deductible expenses	1,053	724		914
Effect of recognition of previously non recognized deferred tax assets	(475)	(2,286)		(532)
Effect of tax losses (utilized) reversed	(150)	(136)		(150)
Effect of under or over provision in prior periods	(25)	30		0
Effect of non recognition of deferred tax assets	69,141	47,413		13,127
Effect of derecognition of previously recognized deferred tax assets	157	0		0
Effect of use of investment deduction	(370)	0		0
Effect of use of IID	0	(141,435)		0
Total explanations	€ 78,670	€ (44,097)		€ 10,116
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Effect of change in effective tax rate due to use of IID	3.75%
Belgium
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Applicable tax rate	25.00%	29.58%	29.58%

Income_loss (-) per share (Deta

Income/loss (-) per share (Details) - EUR (€) € / shares in Units, € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Income/loss (-) per share: Basic
Net income/loss (-) attributable to owners of the parent (Euro, in thousands)	€ (305,436)	€ 149,845		€ (29,259)
Weighted average number of shares for the purpose of basic income/loss (-) per share	65,075	57,614		52,113
Basic income/loss (-) per share	€ (4.69)	€ 2.60	[1]	€ (0.56)	[1]
Income/loss per share: Diluted
Net income/loss (-) attributable to owners of the parent (Euro, in thousands)	€ (305,436)	€ 149,845		€ (29,259)
Weighted average number of shares for the purpose of diluted income/loss (-) per share	65,075	57,614		52,113
Number of dilutive potential ordinary shares		2,498
Diluted income/loss (-) per share	€ (4.69)	€ 2.49	[1]	€ (0.56)	[1]
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Intangible assets (Details)

Intangible assets (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about intangible assets [line items]
Beginning balance	€ 24,927	€ 3,632
Ending balance	67,565	24,927	€ 3,632
Acquisition value
Disclosure of detailed information about intangible assets [line items]
Beginning balance	35,099	11,832	16,082
Additions	48,793	23,300	3,325
Sales and disposals	(17)	(64)	(7,650)
Reclassifications to assets held for sale	(197)
Translation differences	(144)	31	74
Ending balance	83,534	35,099	11,832
Amortization and impairment
Disclosure of detailed information about intangible assets [line items]
Beginning balance	(10,173)	(8,200)	(13,587)
Amortization	6,130	2,006	1,107
Impairment			1,083
Sales and disposals	17	63	7,650
Reclassifications to assets held for sale	176
Translation differences	(142)	31	74
Ending balance	(15,968)	(10,173)	(8,200)
Software and databases
Disclosure of detailed information about intangible assets [line items]
Beginning balance	6,507	1,862
Ending balance	13,683	6,507	1,862
Software and databases | Acquisition value
Disclosure of detailed information about intangible assets [line items]
Beginning balance	14,541	9,111	7,496
Additions	9,494	5,463	1,561
Sales and disposals	(17)	(64)	(20)
Reclassifications to assets held for sale	(159)
Translation differences	(143)	31	74
Ending balance	23,717	14,541	9,111
Software and databases | Amortization and impairment
Disclosure of detailed information about intangible assets [line items]
Beginning balance	(8,034)	(7,250)	(6,514)
Amortization	2,303	816	681
Sales and disposals	17	63	20
Reclassifications to assets held for sale	143
Translation differences	(142)	31	74
Ending balance	(10,034)	(8,034)	(7,250)
Brands, licenses, patents and know-how
Disclosure of detailed information about intangible assets [line items]
Beginning balance	3,546	1,771
Ending balance	40,549	3,546	1,771
Brands, licenses, patents and know-how | Acquisition value
Disclosure of detailed information about intangible assets [line items]
Beginning balance	5,172	2,719	8,586
Additions	39,299	2,453	1,763
Sales and disposals			(7,630)
Reclassifications to assets held for sale	(38)
Translation differences	(1)
Ending balance	44,432	5,172	2,719
Brands, licenses, patents and know-how | Amortization and impairment
Disclosure of detailed information about intangible assets [line items]
Beginning balance	(1,626)	(949)	(7,070)
Amortization	2,289	678	426
Impairment			1,083
Sales and disposals			7,630
Reclassifications to assets held for sale	33
Ending balance	(3,883)	(1,626)	(949)
Contract costs
Disclosure of detailed information about intangible assets [line items]
Beginning balance	14,872	0
Ending balance	13,334	14,872	0
Contract costs | Acquisition value
Disclosure of detailed information about intangible assets [line items]
Beginning balance	15,384	0	0
Additions		15,384
Ending balance	15,384	15,384	0
Contract costs | Amortization and impairment
Disclosure of detailed information about intangible assets [line items]
Beginning balance	(512)	0	0
Amortization	1,538	512
Ending balance	€ (2,050)	€ (512)	€ 0

Property, plant and equipment -

Property, plant and equipment - Fully Owned (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	€ 40,707	€ 23,137
Ending balance	68,264	40,707	€ 23,137
Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	71,823	51,321	42,195
Additions	38,664	22,380	10,392
Sales and disposals	(1,228)	(1,618)	(1,311)
Reclassifications	0	0	0
Reclassifications to right of use		(251)
Reclassifications to assets held for sale	(10,110)
Translation differences	(178)	(8)	46
Ending balance	98,972	71,823	51,321
Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	(31,117)	(28,184)	(25,502)
Depreciation	5,666	4,818	3,974
Sales and disposals	1,186	1,620	1,310
Reclassifications	0
Reclassifications to right of use		(251)
Reclassifications to assets held for sale	4,814
Translation differences	(75)	(15)	18
Ending balance	(30,708)	(31,117)	(28,184)
Land and leasehold improvements
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	2,204	2,325
Ending balance	13,011	2,204	2,325
Land and leasehold improvements | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	5,284	5,011	4,736
Additions	885	273	275
Sales and disposals	(51)
Reclassifications	10,625
Reclassifications to assets held for sale	(2)
Translation differences	(2)
Ending balance	16,739	5,284	5,011
Land and leasehold improvements | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	(3,080)	(2,686)	(2,342)
Depreciation	654	394	344
Sales and disposals	51
Reclassifications	46
Translation differences	(1)
Ending balance	(3,728)	(3,080)	(2,686)
Installation and machinery
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	18,770	14,628
Ending balance	15,257	18,770	14,628
Installation and machinery | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	44,655	38,031	33,060
Additions	3,737	6,382	4,674
Sales and disposals	(1,096)	(1,521)	(486)
Reclassifications	(623)	1,792	753
Reclassifications to assets held for sale	(8,938)
Translation differences	(127)	(30)	29
Ending balance	37,607	44,655	38,031
Installation and machinery | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	(25,885)	(23,403)	(20,495)
Depreciation	3,587	4,018	3,377
Sales and disposals	1,058	1,521	485
Reclassifications	(1,675)
Reclassifications to assets held for sale	4,327
Translation differences	(61)	(15)	16
Ending balance	(22,350)	(25,885)	(23,403)
Furniture, fixtures & vehicles
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	1,909	1,632
Ending balance	2,724	1,909	1,632
Furniture, fixtures & vehicles | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	4,028	3,452	3,209
Additions	1,824	649	1,039
Sales and disposals	(81)	(97)	(826)
Reclassifications	2,084	3	13
Reclassifications to assets held for sale	(484)
Translation differences	(19)	22	16
Ending balance	7,352	4,028	3,452
Furniture, fixtures & vehicles | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	(2,119)	(1,819)	(2,407)
Depreciation	1,418	399	236
Sales and disposals	77	99	826
Reclassifications	1,629
Reclassifications to assets held for sale	448
Translation differences	(13)		2
Ending balance	(4,628)	(2,119)	(1,819)
Other tangible assets
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	17,825	4,552
Ending balance	37,273	17,825	4,552
Other tangible assets | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	17,856	4,827	1,189
Additions	32,218	15,076	4,404
Reclassifications	(12,086)	(1,795)	(766)
Reclassifications to right of use		(251)
Reclassifications to assets held for sale	(686)
Translation differences	(30)
Ending balance	37,273	17,856	4,827
Other tangible assets | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	(31)	(275)	(258)
Depreciation	7	7	17
Reclassifications to right of use		(251)
Reclassifications to assets held for sale	39
Ending balance	€ 0	€ (31)	€ (275)

Property, plant and equipment_2

Property, plant and equipment - Right of Use (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	€ 25,345	€ 0
Ending balance	35,113	25,345
Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	31,225	0
Additions	21,459	4,530
Sales and disposals	(167)
Reclassifications to right of use		251
Reclassifications to assets held for sale	(6,202)
Translation differences	(90)	38
Ending balance	46,225	31,225
Acquisition value | Restated equity (modified retrospective application IFRS)
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance		26,406
Acquisition value | IFRS 16
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance		26,406
Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	(5,879)	0
Depreciation	6,883	5,624
Sales and disposals	(167)
Reclassifications to right of use		251
Reclassifications to assets held for sale	(1,448)
Translation differences	(36)	4
Ending balance	(11,111)	(5,879)
Land and building
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	22,694
Ending balance	31,027	22,694
Land and building | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	27,364	0
Additions	18,341	3,270
Reclassifications to assets held for sale	(5,940)
Translation differences	(88)	38
Ending balance	39,678	27,364
Land and building | Acquisition value | Restated equity (modified retrospective application IFRS)
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance		24,056
Land and building | Acquisition value | IFRS 16
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance		24,056
Land and building | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	(4,670)	0
Depreciation	5,350	4,666
Reclassifications to assets held for sale	(1,334)
Translation differences	(36)	4
Ending balance	(8,651)	(4,670)
Installation and machinery
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	212
Ending balance	270	212
Installation and machinery | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	554	0
Additions	186	84
Sales and disposals	(6)
Reclassifications to right of use		251
Translation differences	0
Ending balance	734	554
Installation and machinery | Acquisition value | Restated equity (modified retrospective application IFRS)
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance		219
Installation and machinery | Acquisition value | IFRS 16
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance		219
Installation and machinery | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	(342)	0
Depreciation	128	91
Sales and disposals	(6)
Reclassifications to right of use		251
Ending balance	(464)	(342)
Furniture, fixtures & vehicles
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	2,440
Ending balance	3,817	2,440
Furniture, fixtures & vehicles | Acquisition value
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	3,307	0
Additions	2,932	1,176
Sales and disposals	(161)
Reclassifications to assets held for sale	(263)
Translation differences	(3)
Ending balance	5,812	3,307
Furniture, fixtures & vehicles | Acquisition value | Restated equity (modified retrospective application IFRS)
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance		2,130
Furniture, fixtures & vehicles | Acquisition value | IFRS 16
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance		2,130
Furniture, fixtures & vehicles | Depreciations and impairment
Disclosure of detailed information about property, plant and equipment [line items]
Beginning balance	(867)	0
Depreciation	1,405	867
Sales and disposals	(161)
Reclassifications to assets held for sale	(115)
Translation differences	(1)
Ending balance	€ (1,995)	€ (867)

Property, plant and equipment_3

Property, plant and equipment - Carrying Amount (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Property, plant and equipment
Property, plant and equipment fully owned	€ 68,264	€ 40,707		€ 23,137
Right-of-use assets	35,113	25,345	€ 26,400	0
Total property, plant and equipment	€ 103,378	€ 66,052		€ 23,137

Other non-current assets - Summ

Other non-current assets - Summary (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other non-current assets
Non-current restricted cash	€ 1,482	€ 1,418	€ 1,276
Financial assets held at fair value through profit or loss	8,951	11,275	6,000
Other non-current assets	910	1,399	643
Total other non-current assets	11,343	14,091	€ 7,919
Belgium
Other non-current assets
Non-current restricted cash	1,000	900
The Netherlands
Other non-current assets
Non-current restricted cash	€ 500	€ 500

Other non-current assets - Fina

Other non-current assets - Financial assets held at fair value through profit or loss (Details) - Equity instruments - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of fair value remeasurement
Costs at January 1,	€ 4,736	€ 4,818	€ 2,373
Acquisitions of the year	1,994	0	4,736
Disposals of the year	(2,820)	(82)	(2,291)
Costs at December 31,	3,910	4,736	4,818
Net book value at December 31,	8,951	11,275	6,000
Level 1
Reconciliation of fair value remeasurement
Fair value adjustment at January 1	6,539	1,182	(619)
Cancellation of fair value adjustment following disposal	(3,894)	2	598
Fair value adjustment of the year	2,397	5,355	1,203
Fair value adjustment at December 31,	€ 5,042	€ 6,539	€ 1,182

Research and Development ince_3

Research and Development incentives receivables - Current and non-current (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	€ 111,624	€ 93,407	€ 73,443
Current R&D incentives receivables	24,104	21,949	11,203
Total R&D incentives receivables	135,728	€ 115,356	€ 84,646
France
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	33,856
Belgium
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	€ 77,768

Research and Development ince_4

Research and Development incentives receivables - Maturities (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	€ 111,624	€ 93,407	€ 73,443
France
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	33,856
Belgium
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	77,768
Later than one year and not later than two years [member]
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	16,870
Later than one year and not later than two years [member] | France
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	10,223
Later than one year and not later than two years [member] | Belgium
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	6,647
Later than two years and not later than three years [member]
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	20,340
Later than two years and not later than three years [member] | France
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	11,911
Later than two years and not later than three years [member] | Belgium
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	8,429
Later than three years and not later than four years [member]
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	22,800
Later than three years and not later than four years [member] | France
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	11,722
Later than three years and not later than four years [member] | Belgium
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	11,078
Later than four years and not later than five years [member]
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	13,716
Later than four years and not later than five years [member] | Belgium
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	13,716
Later than five years and not later than ten years [member]
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	37,898
Later than five years and not later than ten years [member] | Belgium
Disclosure of financial assets [line items]
Non-current R&D incentives receivables-discounted value	€ 37,898

Trade and other receivables a_3

Trade and other receivables and other current assets (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Trade and other receivables and other current assets
Non-current trade receivables	€ 50,000	€ 0	€ 0
Trade receivables	134,632	39,603	9,206
Prepayments	219	292	142
Other receivables	13,568	14,114	9,261
Trade and other receivables	148,418	54,009	18,609
Inventories	355	255	276
Accrued income	1,096	4,443	3,863
Deferred charges	10,502	4,439	4,104
Other current assets	11,953	9,138	8,244
Total trade and other receivables & other current assets	€ 210,371	€ 63,147	€ 26,852

Current financial investments (

Current financial investments (Details) € in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)	Dec. 31, 2020USD ($)	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)
Current financial investments
Current financial investments	€ 3,026,278		€ 3,919,216	€ 0
Treasury bills	1,454,400
Money market funds	€ 1,571,900
Current financial investments held in USD | $		$ 524.6

Cash and cash equivalents (Deta

Cash and cash equivalents (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash and cash equivalents.
Cash at banks	€ 1,239,993	€ 907,939	€ 358,016
Term deposits	895,194	953,677	733,537
Money market funds	0	0	199,243
Total cash and cash equivalents	2,135,187	1,861,616	1,290,796
Cash and cash equivalents classified as assets held for sale	7,884	0	0
Total cash and cash equivalents	€ 2,143,071	€ 1,861,616	€ 1,290,796	€ 1,151,211

Cash and cash equivalents - Nar

Cash and cash equivalents - Narrative (Details) € in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020EUR (€)	Dec. 31, 2020USD ($)	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)
Cash and cash equivalents.
Term deposits | €	€ 895,194		€ 953,677	€ 733,537
Cash and cash equivalents held in USD | $		$ 894.3
Maturity Period	3 months

Share capital - Reconciliation

Share capital - Reconciliation (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of classes of share capital [line items]
Balance at beginning of period	€ 2,875,658	€ 1,214,249	€ 1,011,983
Costs of capital increase		(4,447)	(15,964)
Aggregate share capital	353,819	349,789	294,600	€ 250,187
Balance at end of period	2,670,355	2,875,658	1,214,249	1,011,983
Share capital.
Disclosure of classes of share capital [line items]
Balance at beginning of period	287,282	236,540	233,414
Share capital increase	4,031	55,189	19,090
Costs of capital increase	0	(4,447)	(15,964)
Aggregate share capital	353,819	349,789	294,600
Costs of capital increase (accumulated)	(62,507)	(62,507)	(58,060)
Balance at end of period	€ 291,312	€ 287,282	€ 236,540	€ 233,414

Share capital - History (Detail

Share capital - History (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
History of the share capital
Aggregate number of shares after transaction	65,412	64,667	54,466	46,256
Aggregate share capital after transaction	€ 353,819	€ 349,789	€ 294,600	€ 250,187
March 20, 2018
History of the share capital
Share capital increase warrants			€ 1,613
Number of shares issued			298
June 20, 2018
History of the share capital
Share capital increase warrants			€ 556
Number of shares issued			103
September 17, 2018
History of the share capital
Share capital increase new shares			€ 16,021
Number of shares issued			2,961
October 3, 2018
History of the share capital
Share capital increase warrants			€ 733
Number of shares issued			135
November 23, 2018
History of the share capital
Share capital increase warrants			€ 167
Number of shares issued			31
March 20, 2019
History of the share capital
Share capital increase warrants		€ 808
Number of shares issued		149
June 20, 2019
History of the share capital
Share capital increase warrants		€ 1,127
Number of shares issued		208
August 23, 2019
History of the share capital
Share capital increase new shares		€ 36,945
Number of shares issued		6,829
September 18, 2019
History of the share capital
Share capital increase warrants		€ 1,632
Number of shares issued		302
November 6 2019
History of the share capital
Share capital increase warrants		€ 14,162
Number of shares issued		2,618
November 25, 2019
History of the share capital
Share capital increase warrants		€ 515
Number of shares issued		95
March 17, 2020
History of the share capital
Share capital increase warrants	€ 824
Number of shares issued	152
May 28, 2020
History of the share capital
Share capital increase warrants	€ 2,356
Number of shares issued	436
September 18, 2020
History of the share capital
Share capital increase warrants	€ 467
Number of shares issued	86
December 4, 2020
History of the share capital
Share capital increase warrants	€ 384
Number of shares issued	71

Share capital - History - Narra

Share capital - History - Narrative (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share capital
Aggregate share capital	€ 353,819	€ 349,789	€ 294,600	€ 250,187
Aggregate number of shares after transaction	65,412	64,667	54,466	46,256
Number of shares	65,411,767	64,666,802	54,465,421	50,936,778

Share capital - Capital increas

Share capital - Capital increase (Details) € / shares in Units, € in Thousands	12 Months Ended
	Dec. 31, 2020EUR (€)shares€ / shares	Dec. 31, 2019EUR (€)shares€ / shares	Dec. 31, 2018EUR (€)shares€ / shares	Dec. 31, 2017EUR (€)
Disclosure of classes of share capital [line items]
Balance at beginning of period, shares | shares	64,666,802	54,465,421	50,936,778
Balance at beginning of period	€ 2,875,658	€ 1,214,249	€ 1,011,983
Share capital	291,312	287,282	236,540
Net issue of equity		960,087	296,188
Share premium	2,727,840	2,703,583	1,277,780
Exercise of warrants	€ 28,288	€ 17,167	€ 7,657
Average exercise price warrants | € / shares	€ 38	€ 22.8	€ 13.5
Balance at end of period, shares | shares	65,411,767	64,666,802	54,465,421
Balance at end of period	€ 2,670,355	€ 2,875,658	€ 1,214,249
Accounting par value of shares | € / shares	€ 5.41
March 20, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares			298,184
Average exercise price warrants | € / shares			€ 13.16
Closing share price on date of capital increase | € / shares			€ 83.72
June 20, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares			102,801
Average exercise price warrants | € / shares			€ 13.01
Closing share price on date of capital increase | € / shares			€ 85
October 03, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares			135,485
Average exercise price warrants | € / shares			€ 14.86
Closing share price on date of capital increase | € / shares			€ 94.32
November 23, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares			30,800
Average exercise price warrants | € / shares			€ 12.40
Closing share price on date of capital increase | € / shares			€ 88.90
March 20, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares		149,370
Average exercise price warrants | € / shares		€ 23.30
Closing share price on date of capital increase | € / shares		€ 90.32
June 20, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares		208,310
Average exercise price warrants | € / shares		€ 20.76
Closing share price on date of capital increase | € / shares		€ 113.55
August 23, 2019 : share subscription by Gilead | Gilead
Disclosure of classes of share capital [line items]
Issue of shares | shares		6,828,985
Closing share price on date of capital increase | € / shares		€ 148.90
September 19, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares		301,745
Average exercise price warrants | € / shares		€ 22.12
Closing share price on date of capital increase | € / shares		€ 145.25
November 6, 2019 : exercise of warrant A by Gilead | Gilead
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares		2,617,791
Average exercise price warrants | € / shares		€ 140.59
Closing share price on date of capital increase | € / shares		€ 170.75
November 25, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares		95,180
Average exercise price warrants | € / shares		€ 28.23
Closing share price on date of capital increase | € / shares		€ 172.95
March 17, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares	152,220
Average exercise price warrants | € / shares	€ 35.18
Closing share price on date of capital increase | € / shares	€ 141.40
May 28, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares	435,540
Average exercise price warrants | € / shares	€ 41.13
Closing share price on date of capital increase | € / shares	€ 186.60
September 18, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares	86,280
Average exercise price warrants | € / shares	€ 27.85
Closing share price on date of capital increase | € / shares	€ 117.70
December 4, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares	70,925
Average exercise price warrants | € / shares	€ 36.88
Closing share price on date of capital increase | € / shares	€ 100.30
Share capital.
Disclosure of classes of share capital [line items]
Balance at beginning of period	€ 287,282	€ 236,540	€ 233,414
Share capital	291,312	287,282	236,540	€ 233,414
Net issue of equity		36,945	16,021
Exercise of warrants	4,031	4,082	3,069
Underwriter discounts and offering expenses (paid)			(15,964)
Balance at end of period	291,312	287,282	236,540
Share capital. | March 20, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			1,613
Share capital. | June 20, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			556
Share capital. | October 03, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			733
Share capital. | November 23, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			167
Share capital. | March 20, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		808
Share capital. | June 20, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		1,127
Share capital. | August 23, 2019 : share subscription by Gilead | Gilead
Disclosure of classes of share capital [line items]
Net issue of equity		32,498
Underwriter discounts and offering expenses (paid)		(4,447)
Share capital. | September 19, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		1,632
Share capital. | November 6, 2019 : exercise of warrant A by Gilead | Gilead
Disclosure of classes of share capital [line items]
Exercise of warrants		14,162
Share capital. | November 25, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		515
Share capital. | March 17, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	824
Share capital. | May 28, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	2,356
Share capital. | September 18, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	467
Share capital. | December 4, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	384
Share premium account
Disclosure of classes of share capital [line items]
Balance at beginning of period	2,703,583	1,277,780	993,025
Net issue of equity		923,142	280,167
Share premium	2,727,840	2,703,583	1,277,780	€ 993,025
Exercise of warrants	24,257	13,085	4,588
Balance at end of period	2,727,840	2,703,583	1,277,780
Share premium account | March 20, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			2,311
Share premium account | June 20, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			781
Share premium account | October 03, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			1,281
Share premium account | November 23, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			215
Share premium account | March 20, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		2,673
Share premium account | June 20, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		3,198
Share premium account | August 23, 2019 : share subscription by Gilead | Gilead
Disclosure of classes of share capital [line items]
Net issue of equity		979,891
Derecognition of Financial Liability		56,749
Share premium account | September 19, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		5,043
Share premium account | November 6, 2019 : exercise of warrant A by Gilead | Gilead
Disclosure of classes of share capital [line items]
Exercise of warrants		432,826
Derecognition of Financial Liability		78,953
Share premium account | November 25, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		2,172
Share premium account | March 17, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	4,531
Share premium account | May 28, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	15,558
Share premium account | September 18, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	1,936
Share premium account | December 4, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	2,232
Share capital and share premium
Disclosure of classes of share capital [line items]
Balance at beginning of period	2,990,865	1,514,320	1,226,439
Underwriter discounts and offering expenses (paid)			(15,964)
Balance at end of period	3,019,153	2,990,865	1,514,320
Share capital and share premium | March 20, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			3,924
Share capital and share premium | June 20, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			1,337
Share capital and share premium | October 03, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			2,014
Share capital and share premium | November 23, 2018 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants			€ 382
Share capital and share premium | March 20, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		3,481
Share capital and share premium | June 20, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		4,325
Share capital and share premium | August 23, 2019 : share subscription by Gilead | Gilead
Disclosure of classes of share capital [line items]
Net issue of equity		1,012,389
Underwriter discounts and offering expenses (paid)		(4,447)
Derecognition of Financial Liability		56,749
Share capital and share premium | September 19, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		6,675
Share capital and share premium | November 6, 2019 : exercise of warrant A by Gilead | Gilead
Disclosure of classes of share capital [line items]
Exercise of warrants		446,988
Derecognition of Financial Liability		78,953
Share capital and share premium | November 25, 2019 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants		2,687
Share capital and share premium | March 17, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	5,355
Share capital and share premium | May 28, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	17,914
Share capital and share premium | September 18, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	2,403
Share capital and share premium | December 4, 2020 : exercise of warrants
Disclosure of classes of share capital [line items]
Exercise of warrants	€ 2,616
Ordinary Shares
Disclosure of classes of share capital [line items]
Accounting par value of shares | € / shares	€ 5.41
Ordinary Shares | Share capital. | August 23, 2019 : share subscription by Gilead | Gilead
Disclosure of classes of share capital [line items]
Net issue of equity		36,945
Ordinary Shares | Share premium account | August 23, 2019 : share subscription by Gilead | Gilead
Disclosure of classes of share capital [line items]
Net issue of equity		923,142
Ordinary Shares | Share capital and share premium | August 23, 2019 : share subscription by Gilead | Gilead
Disclosure of classes of share capital [line items]
Net issue of equity		€ 960,087
American Depositary Receipts
Disclosure of classes of share capital [line items]
Issue of shares | shares			2,961,373
American Depositary Receipts | August 23, 2019 : share subscription by Gilead | Gilead
Disclosure of classes of share capital [line items]
Issue of shares | shares		6,828,985
American Depositary Receipts | Share capital.
Disclosure of classes of share capital [line items]
Net issue of equity			€ 16,021
American Depositary Receipts | Share premium account
Disclosure of classes of share capital [line items]
Net issue of equity			280,167
American Depositary Receipts | Share capital and share premium
Disclosure of classes of share capital [line items]
Net issue of equity			€ 296,188
U.S. public offering
Disclosure of classes of share capital [line items]
Issue of shares | shares			2,961,373
Closing share price on date of capital increase | € / shares			€ 99.68
U.S. public offering | Share capital.
Disclosure of classes of share capital [line items]
Net issue of equity			€ 57
U.S. public offering | Share premium account
Disclosure of classes of share capital [line items]
Net issue of equity			280,167
U.S. public offering | Share capital and share premium
Disclosure of classes of share capital [line items]
Net issue of equity			€ 280,224
Warrants | November 6, 2019 : exercise of warrant A by Gilead | Gilead
Disclosure of classes of share capital [line items]
Exercise of warrants, shares | shares		2,617,791
Warrants | Share capital. | November 6, 2019 : exercise of warrant A by Gilead | Gilead
Disclosure of classes of share capital [line items]
Exercise of warrants		€ 14,162
Warrants | Share premium account | November 6, 2019 : exercise of warrant A by Gilead | Gilead
Disclosure of classes of share capital [line items]
Exercise of warrants		353,873
Warrants | Share capital and share premium | November 6, 2019 : exercise of warrant A by Gilead | Gilead
Disclosure of classes of share capital [line items]
Exercise of warrants		€ 368,035

Share capital - Other informati

Share capital - Other information (Details) - EUR (€)	Oct. 22, 2019	Apr. 25, 2017	Dec. 31, 2020
Disclosure of classes of share capital [line items]
Authorization period			5 years
Minimum
Disclosure of classes of share capital [line items]
Percentage of share capital		20.00%
Maximum
Disclosure of classes of share capital [line items]
Percentage of share capital		33.00%
Ordinary Shares
Disclosure of classes of share capital [line items]
Authorized capital, remained available under the general part			€ 55,264,659,690
Authorized capital, remained available under the specific part			€ 13,717,929,800
General authorization of share capital
Disclosure of classes of share capital [line items]
Authorization period	5 years
Authorized capital, approved	€ 67,022,402,040
Percentage of share capital	20.00%
Specific authorization of share capital
Disclosure of classes of share capital [line items]
Authorization period		5 years
Authorized capital, approved		€ 82,561,764,930

Deferred tax - Summary of defer

Deferred tax - Summary of deferred tax assets and liabilities (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of analysis of single amount of discontinued operations [line items]
Deferred tax assets	€ 4,475	€ 4,205	€ 2,514
Deferred tax assets unrecognized	365,639
Deferred taxes in the consolidated statement of operations	(157)	1,537	(238)
Tax benefit arising from previously unrecognized tax assets used to reduce deferred tax expense (+)	581	1,537	528
Deferred tax expenses relating to temporary differences	(44)	0	0
Deferred tax expenses relating to use or derecognition of previously recognized deferred tax assets	€ (695)	0	(766)
Aggregate continuing and discontinued operations [member]
Disclosure of analysis of single amount of discontinued operations [line items]
Deferred tax assets		4,205	2,514
Deferred tax assets unrecognized		€ 289,833	€ 223,377

Deferred tax - Narrative (Detai

Deferred tax - Narrative (Details)	12 Months Ended
	Dec. 31, 2020EUR (€)subsidiary	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Total amount of tax attributes and deductible temporary differences	€ 1,485,800,000	€ 1,179,000,000
Tax losses carried forward and deductible temporary differences	1,229,300,000	953,300,000	€ 688,700,000
Tax losses carried forward	478,600,000
Deferred tax assets	€ 4,475,000	4,205,000	2,514,000
Number of subsidiaries operating on cost-plus basis | subsidiary	4
Expiry between 2020 and 2028
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Tax losses carried forward	€ 2,700,000
Belgium. | Galapagos NV
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Tax losses carried forward	416,600,000
Investment deduction carried forward to be offset against future income | Galapagos NV
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Investment deduction	1,000,000	1,000,000	1,000,000
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]
Investment deduction	8,400,000
Innovation Income Deduction Dividend Received Deduction and Investment Deduction
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Investment deduction	256,500	225,700	196,400
Due To Innovation Income Deduction [Member] | 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	€ 247,200,000	€ 224,700,000	€ 195,400,000

Lease liabilities (Details)

Lease liabilities (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Lease liabilities
Less amount due for settlement within 12 months	€ 6,401	€ 5,826	€ 0
Amount due for settlement after 12 months	23,035	19,558	0
IFRS 16
Lease liabilities
Lease payments	30,385	26,353	0
Present value of lease payments		25,384	0
Less future finance charges	949	969
Lease liability	29,436	25,384	0
Less amount due for settlement within 12 months	6,401	5,826
Amount due for settlement after 12 months	23,035	19,558	€ 0
IFRS 16 | Less than 1 year
Lease liabilities
Lease payments	6,772	6,189
Present value of lease payments	6,401	5,826
IFRS 16 | In the second to fifth years inclusive
Lease liabilities
Lease payments	20,399	16,320
Present value of lease payments	19,833	15,783
IFRS 16 | More than 5 years
Lease liabilities
Lease payments	3,214	3,844
Present value of lease payments	€ 3,201	€ 3,775

Trade and other liabilities (De

Trade and other liabilities (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Trade and other liabilities
Trade and other liabilities.	€ 171,316	€ 142,510	€ 68,038
Other non-current liabilities	8,096	6,989	1,578
Accrued charges	1,070	923	890
Total trade and other liabilities	€ 180,482	€ 150,422	€ 70,506

Deferred income (Details)

Deferred income (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred income related to contracts
Deferred Income	€ 2,809,133,000	€ 3,000,646,000	€ 149,801,000	€ 219,892,000
Non-current deferred income	2,365,974,000	2,586,348,000	0
Increase in deferred income (contract liabilities)	(207,787,000)	2,804,202,000	(153,312,000)
IFRS 15
Deferred income related to contracts
Deferred Income				303,112,000
Fee for services segment
Deferred income related to contracts
Deferred Income		362,000	471,000	248,000
Fee for services segment | IFRS 15
Deferred income related to contracts
Deferred Income				248,000
Gilead
Deferred income related to contracts
Deferred Income	4,286,852,000	4,012,108,000
Collaboration agreement for filgotinib
Deferred income related to contracts
Deferred Income	818,700,000
Collaboration agreement for filgotinib | Gilead
Deferred income related to contracts
Deferred Income	818,654,000	780,261,000	€ 145,798,000	213,981,000
Non-current deferred income	604,900,000	594,700,000
Collaboration agreement for filgotinib | Gilead | IFRS 15
Deferred income related to contracts
Deferred Income				€ 257,814,000
Gilead collaboration agreement for drug discovery platform
Deferred income related to contracts
Deferred Income	1,990,400,000	2,220,000,000
Non-current deferred income	1,761,100	1,991,600
Gilead collaboration agreement for drug discovery platform | Gilead
Deferred income related to contracts
Deferred Income	1,990,412,000	2,220,013,000
Subsequent warrant B
Deferred income related to contracts
Deferred Income	7,900,000	€ 16,200,000
Grants
Deferred income related to contracts
Deferred Income	€ 100

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, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance	€ 3,000,646	€ 149,801	€ 219,892
Upfront payments	160,000
Upfront/license fees received			38,874
Upfront received and impact of initial valuation of share subscription		3,655,416
Milestones received	90,192	49,727	20,965
Significant financing component	16,278	6,900
Revenue recognition of upfront/license fees	(411,417)	(1,009,663)	(148,985)
Revenue recognition of milestones	(46,261)	(51,156)	(64,394)
Catch-up effect on closing date (1)		245,883
Other movements	(305)	(46,262)	229
Deferred income, ending balance	2,809,133	3,000,646	149,801
Gilead
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance	4,012,108
Deferred income, ending balance	4,286,852	4,012,108
Other
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance	10	308	300
Other movements	57	(297)	7
Deferred income, ending balance	67	10	308
IFRS 15
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance			303,112
Reclassified from equity following adoption of IFRS 15				€ 83,220
IFRS 15 | Other
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance			300
Fee for services segment
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance	362	471	248
Other movements	(362)	(109)	222
Deferred income, ending balance		362	471
Fee for services segment | IFRS 15
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance			248
Collaboration agreement for filgotinib
Disclosure of Deferred Income [Line Items]
Deferred income, ending balance	818,700
Collaboration agreement for filgotinib | Gilead
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance	780,261	145,798	213,981
Upfront payments	160,000
Upfront received and impact of initial valuation of share subscription		641,663
Milestones received	90,192	27,317	12,417
Significant financing component	16,278	6,900
Revenue recognition of upfront/license fees	(181,816)	(260,207)	(96,809)
Revenue recognition of milestones	(46,261)	(27,092)	(27,623)
Catch-up effect on closing date (1)		245,883
Deferred income, ending balance	818,654	780,261	145,798
Collaboration agreement for filgotinib | IFRS 15 | Gilead
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance			257,814
Reclassified from equity following adoption of IFRS 15				43,832
Gilead collaboration agreement for ziritaxestat | Gilead
Disclosure of Deferred Income [Line Items]
Upfront received and impact of initial valuation of share subscription		666,967
Revenue recognition of upfront/license fees		(666,967)
Gilead collaboration agreement for drug discovery platform
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance	2,220,000
Deferred income, ending balance	1,990,400	2,220,000
Gilead collaboration agreement for drug discovery platform | Gilead
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance	2,220,013
Upfront received and impact of initial valuation of share subscription		2,346,787
Revenue recognition of upfront/license fees	(229,601)	(80,918)
Other movements		(45,856)
Deferred income, ending balance	€ 1,990,412	2,220,013
AbbVie collaboration agreement for CF | AbbVie
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance		3,224
Upfront/license fees received			38,874
Milestones received		22,410	8,548
Revenue recognition of upfront/license fees		(1,570)	(52,176)
Revenue recognition of milestones		€ (24,064)	(36,771)
Deferred income, ending balance			3,224
AbbVie collaboration agreement for CF | IFRS 15 | AbbVie
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance			44,749
Reclassified from equity following adoption of IFRS 15				44,749
Servier collaboration agreement for osteoarthritis | Servier
Disclosure of Deferred Income [Line Items]
Deferred income, beginning balance			€ 5,362
Servier collaboration agreement for osteoarthritis | IFRS 15 | Servier
Disclosure of Deferred Income [Line Items]
Reclassified from equity following adoption of IFRS 15				€ (5,362)

Discontinued operations (Detail

Discontinued operations (Details) - EUR (€)	Jan. 04, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Summary of financial statements in relation to the discontinued operations
Purchase commitments		€ 347,873,000	€ 251,670,000	€ 222,033,000
Fee-for-service business (held for sale)
Summary of financial statements in relation to the discontinued operations
Total consideration received	€ (37,100,000)
Purchase Commitments Term	5 years	5 years
Purchase commitments	€ 27,000	€ 27,000,000

Discontinued operations - Finan

Discontinued operations - Financial performance (Details) - EUR (€) € / shares in Units, € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
(i) Financial performance
Revenues	€ 478,053	€ 834,901	[1]	€ 278,666	[1]
Other income	52,207	50,896	[1]	29,000	[1]
Total revenues and other income	530,260	885,797	[1]	307,666	[1]
Research and development expenses	(523,667)	(420,090)	[1]	(316,222)	[1]
Sales and marketing expenses	(66,468)	(24,577)	[1]	(4,146)	[1]
General and administrative expenses	(118,757)	(72,382)	[1]	(34,377)	[1]
Total operating expenses	(708,892)	(517,049)	[1]	(354,746)	[1]
Operating income/loss (-)	(178,632)	368,748	[1]	(47,080)	[1]
Other financial income	18,667	21,389	[1]	18,264	[1]
Other financial expenses	(152,844)	(59,968)	[1]	(2,602)	[1]
Net income	€ 5,565	€ 1,156	[1]	€ 2,981	[1]
Weighted average number of shares (in thousands of shares)	65,075	57,614		52,113
Fidelta d.o.o. (fee-for-service segment)
(i) Financial performance
Revenues	€ 16,140	€ 10,084		€ 10,170
Other income		8		9
Total revenues and other income	16,140	10,092		10,179
Research and development expenses	(7,685)	(7,229)		(6,653)
General and administrative expenses	(2,000)	(1,319)		(1,253)
Total operating expenses	(9,685)	(8,548)		(7,906)
Operating income/loss (-)	6,455	1,544		2,273
Other financial income	179	93		71
Other financial expenses	(176)	(102)		(135)
Income before tax	6,458	1,535		2,209
Income taxes	(893)	(379)		773
Net income	€ 5,565	€ 1,156		€ 2,981
Basic income per share from discontinued operations	€ 0.09	€ 0.02		€ 0.06
Diluted income per share from discontinued operations	€ 0.08	€ 0.02		€ 0.06
Weighted average number of shares (in thousands of shares)	65,075	57,614		52,113
Weighted average number of shares - Diluted (in thousands of shares)	67,572	60,112		53,922
[1]	The 2019 and 2018 comparatives have been restated to consider the impact of classifiying the Fidelta business as discontinued opearations in 2020.

Discontinued operations - Asset

Discontinued operations - Assets and liabilities (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
(ii) Assets and liabilities
Intangible assets	€ 67,565	€ 24,927	€ 3,632
Property, plant and equipment	103,378	66,052	23,137
Other non current assets	11,343	14,091	7,919
Trade and other receivables	148,418	54,009	18,609
Cash and cash equivalents	7,884	0	0
Other assets	11,953	9,138	8,244
Total assets classified as held for sale	23,406	0	0
Non-current lease liabilities	23,035	19,558	0
Other non-current liabilities	8,096	6,989	1,578
Trade and other liabilities	172,386	143,434	68,928
Current lease liabilities	6,401	5,826	0
Income tax payable	1,248	2,037	1,175
Deferred income	443,159	414,298	149,801
Liabilities associated with assets classified as held for sale	8,917	€ 0	€ 0
Fidelta d.o.o. (fee-for-service segment)
(ii) Assets and liabilities
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 assets	863
Total assets classified as held for sale	23,406
Non-current lease liabilities	4,115
Other non-current liabilities	70
Trade and other liabilities	3,649
Current lease liabilities	727
Income tax payable	356
Liabilities associated with assets classified as held for sale	8,917
Net assets	€ 14,488

Discontinued operations - Ass_2

Discontinued operations - Assets and liabilities (Details 2) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flow
Net cash flows generated in operating activities	€ 7,173	€ 2,911	€ 3,335
Net cash flows used in investing activities	(2,284)	(1,350)	(799)
Net cash flows used in financing activities	(664)	(709)
Net cash flow from discontinued operations	€ 4,225	€ 852	€ 2,536

Operating Cash Flow (Details)

Operating Cash Flow (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Consolidated Statement of Cash Flows
Depreciation and amortization	€ 18,682	€ 12,448	€ 5,081
Impairment loss			1,083
Share-based compensation expenses	79,959	38,297	26,757
Decrease (-)/increase in retirement benefit obligations and provisions	(260)	(156)	99
Unrealized exchange losses/gains (-) and non-cash other financial expenses	105,055	11,169	(10,063)
Discounting effect of deferred income	16,278	6,900
Fair value re-measurement of share subscription agreement and warrants	(3,034)	181,644
Net fair value adjustment current financial investments	15,900	3,081
Fair value adjustment financial assets held at fair value through profit or loss	(2,396)	(5,355)	(1,203)
Other non-cash expenses	539
Total adjustment for non-cash transactions	230,723	248,027	21,753
Interest expense	9,424	1,302	780
Interest income	(7,476)	(9,247)	(5,219)
Tax expense	2,119	214	50
Total adjustment for items to disclose separately under operating cash flow	4,067	(7,731)	(4,389)
Gain (-)/loss on sale of fixed assets	82	(2)	(668)
Interest income on current financial investments	(2,554)	(5,059)
Total adjustment for items to disclose separately under investing and financing cash flow	(2,472)	(5,061)	(668)
Decrease in inventories	(100)	20	3
Increase in receivables	(177,155)	(67,263)	(76)
Increase in liabilities	31,163	79,940	19,996
Total change in working capital other than deferred income	€ 146,092	€ (12,698)	€ (19,922)

Off-balance sheet arrangement_2

Off-balance sheet arrangements (Details) € in Thousands	12 Months Ended
	Dec. 31, 2019EUR (€)lease	Dec. 31, 2020EUR (€)	Dec. 31, 2018EUR (€)
Off-balance sheet arrangements
Operating lease obligations			€ 27,704
Purchase commitments	€ 251,670	€ 347,873	222,033
Total contractual obligations and commitments			249,737
Number of leases not yet commenced | lease	2
Lease commitments not yet commenced	€ 8,986
Less than 1 year
Off-balance sheet arrangements
Operating lease obligations			4,722
Purchase commitments	175,006	271,922	121,139
Total contractual obligations and commitments			125,862
Lease commitments not yet commenced	5,793
1-3 years
Off-balance sheet arrangements
Operating lease obligations			10,024
Purchase commitments	70,675	73,009	81,879
Total contractual obligations and commitments			91,903
Lease commitments not yet commenced	1,502
3-5 years
Off-balance sheet arrangements
Operating lease obligations			6,234
Purchase commitments	5,989	2,870	19,014
Total contractual obligations and commitments			25,248
Lease commitments not yet commenced	1,502
More than 5 years
Off-balance sheet arrangements
Operating lease obligations			6,724
Purchase commitments		72
Total contractual obligations and commitments			6,724
Lease commitments not yet commenced	188
Collaboration agreement for filgotinib | Gilead
Off-balance sheet arrangements
Purchase commitments	27,500	18,100	20,300
Total contractual obligations and commitments	€ 614,100	€ 493,400	€ 74,000

Contingent assets and liabili_2

Contingent assets and liabilities (Details) € in Thousands, $ in Millions	Jan. 04, 2021EUR (€)	Dec. 15, 2020EUR (€)	Jul. 14, 2019USD ($)	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)Milestone	Dec. 31, 2020EUR (€)	Dec. 31, 2020USD ($)	Dec. 31, 2019EUR (€)	Dec. 31, 2018EUR (€)
Disclosure of contingent liabilities [line items]
Cost share mechanism						50.00%
Milestones achieved						€ 46,261		€ 2,878	€ 73,394
Gilead | Filgotinib drug license
Disclosure of contingent liabilities [line items]
Amount receivable in relation to the collaboration						€ 160,000
Outside Europe | Minimum
Disclosure of contingent liabilities [line items]
Tiered royalty Percentage			20.00%
Outside Europe | Minimum | Gilead collaboration agreement for ziritaxestat
Disclosure of contingent liabilities [line items]
Tiered royalty Percentage			20.00%
Outside Europe | Maximum
Disclosure of contingent liabilities [line items]
Tiered royalty Percentage			24.00%
Outside Europe | Maximum | Gilead collaboration agreement for ziritaxestat
Disclosure of contingent liabilities [line items]
Tiered royalty Percentage			24.00%
Europe | Gilead | Filgotinib drug license | Minimum
Disclosure of contingent liabilities [line items]
Percentage of future net sales from 2024						8.00%
Europe | Gilead | Filgotinib drug license | Maximum
Disclosure of contingent liabilities [line items]
Percentage of future net sales from 2024						15.00%
Filgotinib drug license
Disclosure of contingent liabilities [line items]
Proceeds from milestone payments | $				$ 105
Sales based milestone payment | $			$ 600
Filgotinib drug license | Gilead
Disclosure of contingent liabilities [line items]
Number of milestones achieved | Milestone					2
Achievement of milestone payments | $					$ 105
Upfront payments receivable in 2021						€ 75,000
Upfront payments receivable in 2022						€ 50,000
Filgotinib drug license | Gilead | Group B activities [Member]
Disclosure of contingent liabilities [line items]
Cost share mechanism						50.00%
Filgotinib drug license | Gilead | Maximum
Disclosure of contingent liabilities [line items]
Potential development and regulatory milestones						€ 295,000
Sales based milestone payment | $							$ 600
Filgotinib drug license | Outside Europe | Minimum
Disclosure of contingent liabilities [line items]
Tiered royalty Percentage			20.00%			20.00%	20.00%
Filgotinib drug license | Outside Europe | Maximum
Disclosure of contingent liabilities [line items]
Tiered royalty Percentage			30.00%			30.00%	30.00%
Fee-for-service business (held for sale)
Disclosure of contingent liabilities [line items]
Total consideration received	€ (37,100)
Reassessment Responsibilities [Member] | Filgotinib drug license | Gilead
Disclosure of contingent liabilities [line items]
Upfront payments		€ 35,000
Fidelta d.o.o. | Fee-for-service business (held for sale) | Selvita SA [Member]
Disclosure of contingent liabilities [line items]
Percentage of voting rights held directly or indirectly through subsidiaries	100.00%

Share based payments - Subscrip

Share based payments - Subscription right plans (Details Textual) - EUR (€) € / shares in Units, € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Subscription rights
Average exercise price	€ 104	€ 70.1	€ 53.3	€ 39.3
Subscription rights
Subscription rights
Share based compensation expense	€ 79,959	€ 38,297	€ 26,757
Average exercise price	€ 103.95	€ 70.09	€ 53.30
Weighted average remaining expected life	2050 days	2023 days	1975 days
Subscription rights | Supervisory board members
Subscription rights
Share based payments, Vesting period	36 months

Share based payments - Summary

Share based payments - Summary of subscription rights outstanding and exercisable (Details)	12 Months Ended
	Dec. 31, 2020EquityInstruments€ / shares	Dec. 31, 2019EquityInstruments€ / shares	Dec. 31, 2018EquityInstruments€ / shares	Dec. 31, 2017EquityInstruments€ / shares
Subscription rights
Exercise Price | € / shares	€ 104	€ 70.1	€ 53.3	€ 39.3
Outstanding at the beginning of the year	5,541,117	4,626,782	3,970,807
Granted during the period	2,173,335	1,699,690	1,235,245
Exercised during the period	(744,965)	(754,605)	(567,270)
Forfeited during the year	(40,376)	(30,750)	(12,000)
Expired during the year	0
Outstanding at the end of the year	6,929,111	5,541,117	4,626,782
Exercisable	1,168,967	1,139,682	882,734	763,344
Subscription rights
Subscription rights
Exercise Price | € / shares	€ 103.95	€ 70.09	€ 53.30
Outstanding at the beginning of the year	5,541,117
Granted during the period	2,173,335
Exercised during the period	(744,965)
Forfeited during the year	(40,376)
Outstanding at the end of the year	6,929,111	5,541,117
Exercisable	1,168,967
2006 BNL allocated on December 2007
Subscription rights
Exercise Price | € / shares	€ 7.12
Outstanding at the beginning of the year	1,050
Exercised during the period	(1,050)
Outstanding at the end of the year		1,050
2007 RMV allocated on October 2007
Subscription rights
Exercise Price | € / shares	€ 8.65
Outstanding at the beginning of the year	14,980
Exercised during the period	(14,980)
Outstanding at the end of the year		14,980
2008 allocated on June 2008
Subscription rights
Exercise Price | € / shares	€ 5.6
Outstanding at the beginning of the year	1,365
Outstanding at the end of the year	1,365	1,365
Exercisable	1,365
2012 allocated on September 2012
Subscription rights
Exercise Price | € / shares	€ 14.19
Outstanding at the beginning of the year	80,040
Exercised during the period	(80,040)
Outstanding at the end of the year		80,040
2013 allocated on May 2013
Subscription rights
Exercise Price | € / shares	€ 19.38
Outstanding at the beginning of the year	120,434
Exercised during the period	(64,770)
Outstanding at the end of the year	55,664	120,434
Exercisable	55,664
2014 allocated on July 2014
Subscription rights
Exercise Price | € / shares	€ 14.54
Outstanding at the beginning of the year	252,340
Exercised during the period	(83,000)
Outstanding at the end of the year	169,340	252,340
Exercisable	169,340
2015 allocated on April 2015
Subscription rights
Exercise Price | € / shares	€ 28.75
Outstanding at the beginning of the year	282,473
Exercised during the period	(63,000)
Outstanding at the end of the year	219,473	282,473
Exercisable	219,473
2015 (B) allocated on December 2015
Subscription rights
Exercise Price | € / shares	€ 49
Outstanding at the beginning of the year	329,500
Exercised during the period	(68,000)
Outstanding at the end of the year	261,500	329,500
Exercisable	261,500
2015 RMV allocated on December 2015
Subscription rights
Exercise Price | € / shares	€ 49
Outstanding at the beginning of the year	57,500
Exercised during the period	(17,500)
Outstanding at the end of the year	40,000	57,500
Exercisable	40,000
2016 allocated on June 2016
Subscription rights
Exercise Price | € / shares	€ 46.10
Outstanding at the beginning of the year	504,250
Exercised during the period	(161,625)
Outstanding at the end of the year	342,625	504,250
Exercisable	342,625
2016 RMV allocated on June 2016
Subscription rights
Exercise Price | € / shares	€ 46.10
Outstanding at the beginning of the year	120,000
Exercised during the period	(51,000)
Outstanding at the end of the year	69,000	120,000
Exercisable	69,000
2016 (B) allocated on January 2017
Subscription rights
Exercise Price | € / shares	€ 62.50
Outstanding at the beginning of the year	150,000
Exercised during the period	(140,000)
Outstanding at the end of the year	10,000	150,000
Exercisable	10,000
2017 allocated on May 2017
Subscription rights
Exercise Price | € / shares	€ 80.57
Outstanding at the beginning of the year	595,500
Outstanding at the end of the year	595,500	595,500
2017 RMV allocated on May 2017
Subscription rights
Exercise Price | € / shares	€ 80.57
Outstanding at the beginning of the year	127,500
Outstanding at the end of the year	127,500	127,500
2018 allocated on April 2018
Subscription rights
Exercise Price | € / shares	€ 79.88
Outstanding at the beginning of the year	1,085,245
Forfeited during the year	(2,000)
Outstanding at the end of the year	1,083,245	1,085,245
2018 RMV allocated on April 2018
Subscription rights
Exercise Price | € / shares	€ 79.88
Outstanding at the beginning of the year	137,500
Outstanding at the end of the year	137,500	137,500
2019 allocated on April 2019
Subscription rights
Exercise Price | € / shares	€ 95.11
Outstanding at the beginning of the year	1,486,690
Forfeited during the year	(8,850)
Outstanding at the end of the year	1,477,840	1,486,690
2019 RMV allocated on April 2019
Subscription rights
Exercise Price | € / shares	€ 95.11
Outstanding at the beginning of the year	194,750
Forfeited during the year	(1,750)
Outstanding at the end of the year	193,000	194,750
2020 allocated on April 2020
Subscription rights
Exercise Price | € / shares	€ 168.42
Granted during the period	1,925,185
Forfeited during the year	(19,151)
Outstanding at the end of the year	1,906,034
2020 RMV allocated on April 2020
Subscription rights
Exercise Price | € / shares	€ 168.42
Granted during the period	248,150
Forfeited during the year	(8,625)
Outstanding at the end of the year	239,525

Share based payments - Rollforw

Share based payments - Rollforward (Details)	12 Months Ended
	Dec. 31, 2020EquityInstruments€ / shares	Dec. 31, 2019EquityInstruments€ / shares	Dec. 31, 2018EquityInstruments€ / shares	Dec. 31, 2017EquityInstruments€ / shares
Share based payments
Outstanding at the beginning of the year | EquityInstruments	5,541,117	4,626,782	3,970,807
Granted during the period | EquityInstruments	2,173,335	1,699,690	1,235,245
Forfeited during the year | EquityInstruments	(40,376)	(30,750)	(12,000)
Exercised during the period | EquityInstruments	(744,965)	(754,605)	(567,270)
Expired during the year | EquityInstruments	0
Outstanding at the end of the year | EquityInstruments	6,929,111	5,541,117	4,626,782
Exercisable | EquityInstruments	1,168,967	1,139,682	882,734	763,344
Weighted average exercise price at beginning of the year | € / shares	€ 70.1	€ 53.3	€ 39.3
Granted during the period | € / shares	168.4	95.1	79.9
Forfeited during the year | € / shares	144.8	88.9	43.2
Exercised during the period | € / shares	38	22.8	13.5
Expired during the year | € / shares	0
Weighted average exercise price at end of the year | € / shares	104	70.1	53.3
Exercisable | € / shares	€ 37.8	€ 30.2	€ 14	€ 13.7

Share based payments - Valuatio

Share based payments - Valuation (Details)	12 Months Ended
	Dec. 31, 2020€ / shares
2019 allocated on April 2019
Subscription rights
Exercise Price	€ 95.11
Weighted average share price at acceptance date	107.05
Weighted average fair value at acceptance date	€ 40.04
Weighted average estimated volatility	35.86%
Weighted average expected life of the subscription rights (years)	6 years 7 days
Weighted average risk free rate (%)	(0.27%)
2019 RMV allocated on April 2019
Subscription rights
Exercise Price	€ 95.11
Weighted average share price at acceptance date	107.45
Weighted average fair value at acceptance date	€ 40.05
Weighted average estimated volatility	35.63%
Weighted average expected life of the subscription rights (years)	6 years
Weighted average risk free rate (%)	(0.28%)
2018 allocated on April 2018
Subscription rights
Exercise Price	€ 79.88
Weighted average share price at acceptance date	84.88
Weighted average fair value at acceptance date	€ 38.39
Weighted average estimated volatility	39.44%
Weighted average expected life of the subscription rights (years)	8 years
Weighted average risk free rate (%)	0.51%
2018 RMV allocated on April 2018
Subscription rights
Exercise Price	€ 79.88
Weighted average share price at acceptance date	84.88
Weighted average fair value at acceptance date	€ 38.39
Weighted average estimated volatility	39.44%
Weighted average expected life of the subscription rights (years)	8 years
Weighted average risk free rate (%)	0.51%
2020 April 17
Subscription rights
Exercise Price	€ 168.42
Weighted average share price at acceptance date	178.95
Weighted average fair value at acceptance date	€ 86.45
Weighted average estimated volatility	51.30%
Weighted average expected life of the subscription rights (years)	6 years
Weighted average risk free rate (%)	(0.44%)
2020 RMV April 17
Subscription rights
Exercise Price	€ 168.42
Weighted average share price at acceptance date	178.95
Weighted average fair value at acceptance date	€ 85.79
Weighted average estimated volatility	51.32%
Weighted average expected life of the subscription rights (years)	6 years
Weighted average risk free rate (%)	(0.44%)

Share based payments - Category

Share based payments - Category (Details)	Dec. 31, 2020EquityInstruments€ / shares	Dec. 31, 2019EquityInstruments€ / shares	Dec. 31, 2018EquityInstruments€ / shares	Dec. 31, 2017EquityInstruments€ / shares
Subscription rights
Total warrants outstanding	6,929,111	5,541,117	4,626,782	3,970,807
Exercise Price | € / shares	€ 104	€ 70.1	€ 53.3	€ 39.3
Non-executive directors
Subscription rights
Total warrants outstanding	157,560	222,600	216,780
Executive team
Subscription rights
Total warrants outstanding	2,101,874	2,171,874	2,139,374
Other
Subscription rights
Total warrants outstanding	4,669,677	3,146,643	2,270,628

Share based payments - Summar_2

Share based payments - Summary of RSU's outstanding (Details) - EquityInstruments	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share based payments
Outstanding at the beginning of the year	5,541,117	4,626,782	3,970,807
Granted during the period	2,173,335	1,699,690	1,235,245
Forfeited during the year	(40,376)	(30,750)	(12,000)
Outstanding at the end of the year	6,929,111	5,541,117	4,626,782
Restricted Stock Units (RSUs)
Share based payments
Outstanding at the beginning of the year	213,147	0
Granted during the period	128,769	213,147
Forfeited during the year	(1,052)
Paid in cash during the year	(27,268)
Outstanding at the end of the year	313,596	213,147	0
Plan 2019.I
Share based payments
Outstanding at the beginning of the year	33,000
Outstanding at the end of the year	33,000	33,000
Plan 2019.II
Share based payments
Outstanding at the beginning of the year	109,075
Paid in cash during the year	(27,268)
Outstanding at the end of the year	81,807	109,075
Plan 2019.III
Share based payments
Outstanding at the beginning of the year	71,072
Outstanding at the end of the year	71,072	71,072
Plan 2020.I
Share based payments
Granted during the period	55,928
Forfeited during the year	(1,052)
Outstanding at the end of the year	54,876
Plan 2020.II
Share based payments
Granted during the period	72,841
Outstanding at the end of the year	72,841

Share based payments - Restrict

Share based payments - Restricted stock units - Rollforward (Details) - EquityInstruments	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share based payments
Outstanding at the beginning of the year	5,541,117	4,626,782	3,970,807
Granted during the period	2,173,335	1,699,690	1,235,245
Forfeited during the year	(40,376)	(30,750)	(12,000)
Outstanding at the end of the year	6,929,111	5,541,117	4,626,782
Restricted Stock Units (RSUs)
Share based payments
Outstanding at the beginning of the year	213,147	0
Granted during the period	128,769	213,147
Forfeited during the year	(1,052)
Paid in cash during the year	(27,268)
Outstanding at the end of the year	313,596	213,147	0

Share based payments - Restri_2

Share based payments - Restricted stock units - Category (Details) - EquityInstruments	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share based payments
Total outstanding RSU's	6,929,111	5,541,117	4,626,782	3,970,807
Other
Share based payments
Total outstanding RSU's	4,669,677	3,146,643	2,270,628
Restricted Stock Units (RSUs)
Share based payments
Total outstanding RSU's	313,596	213,147	0
Restricted Stock Units (RSUs) | Management board members
Share based payments
Total outstanding RSU's	229,276	188,571
Restricted Stock Units (RSUs) | Other
Share based payments
Total outstanding RSU's	84,320	24,576

Share based payments - Restri_3

Share based payments - Restricted stock units (RSU's) (Details Textual)	12 Months Ended
	Dec. 31, 2020dshares
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
Number of calendar days period preceding reporting period for calculate value of weighted average price of entity share traded on stock-exchange	30
Plan 2019.I
Share based payments
Share based payments, Vesting period	3 years
Plan 2019.II
Share based payments
Share based payments, Vesting period	4 years
Share based payments, Percentage of other equity instruments vested per month	25.00%
Plan 2019.III | Share based payments, Vesting percentage portion one
Share based payments
Share based payments, Vesting period	2 years
Plan 2019.III | Share based payments, Vesting percentage portion two
Share based payments
Share based payments, Vesting period	3 years
Plan 2019.III | Warrants vested on date of grant
Share based payments
Share based payments, Percentage of other equity instruments vested in certain period	50.00%
Plan 2019.III | Warrants vested on first anniversary
Share based payments
Share based payments, Percentage of other equity instruments vested in certain period	50.00%
Plan 2020.I
Share based payments
Share based payments, Vesting period	3 years
Plan 2020.II
Share based payments
Share based payments, Vesting period	4 years
Share based payments, Percentage of other equity instruments vested per month	25.00%

Related parties - Narrative (De

Related parties - Narrative (Details) € / shares in Units, $ in Millions	Sep. 25, 2020EUR (€)	Sep. 25, 2020USD ($)	Nov. 06, 2019EUR (€)	Oct. 22, 2019	Aug. 28, 2019	Jul. 14, 2019EUR (€)	Jul. 14, 2019USD ($)	Dec. 31, 2020EUR (€)EquityInstrumentsitememployee€ / shares	Dec. 31, 2019EUR (€)EquityInstrumentsemployee€ / shares	Dec. 31, 2018EUR (€)EquityInstruments€ / shares	Dec. 31, 2017EUR (€)
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Number of executive committee members | employee								6	6
Number of board of directors | employee								8
Granted during the period | EquityInstruments								2,173,335	1,699,690	1,235,245
Exercise price of warrants | € / shares								€ 168.4	€ 95.1	€ 79.9
Milestones received								€ 90,192,000	€ 49,727,000	€ 20,965,000
Cross charges payable relating to development of Filgotinib								24,800
Upfront payment received						€ 3,569,800,000	$ 3,950
Deferred income classified as current								443,159,000	414,298,000	149,801,000
Deferred Income								€ 2,809,133,000	€ 3,000,646,000	149,801,000	€ 219,892,000
Cost share mechanism								50.00%
Restricted Stock Units (RSUs)
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period | EquityInstruments								128,769	213,147
Gilead
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Upfront payment received									€ 3,845,373,000
Deferred Income								€ 4,286,852,000	4,012,108,000
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]
Deferred Income								1,990,400,000	2,220,000,000
Impact on revenues from performance obligations								229,600,000	80,900,000
Gilead collaboration agreement for drug discovery platform | Gilead
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Deferred Income								1,990,412,000	2,220,013,000
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								818,700,000
Collaboration agreement for filgotinib | Gilead
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Milestones received								90,192,000	27,317,000	12,417,000
Deferred Income								818,654,000	€ 780,261,000	€ 145,798,000	€ 213,981,000
Gilead collaboration agreement for ziritaxestat and filgotinib
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Amount receivable in relation to the collaboration								€ 22,800,000
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								25.54%	25.84%
Number of capital increases | item								4
Non-current trade receivables								€ 50,000,000
Trade and other receivables								132,825,000	€ 31,645,000
Trade and other payables								27,074,000	39,100,000
Additional equity investment			€ 368,000,000
Gilead | Japanese authorities
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Milestones received	€ 25,800,000	$ 30
Gilead | European authorities
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Milestones received	€ 64,400,000	$ 75
Gilead | Maximum
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Percentage of stake				29.90%
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]
Deferred Income								2,000,000,000
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]
Amount receivable in relation to the collaboration								160,000,000
Amount receivable in relation to the collaboration, Year One								110,000,000
Amount receivable in relation to the collaboration, Year Two								50,000,000
Deferred Income								819,000,000
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 recognized								34,100,000	17,700,000
Filgotinib drug license
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Total impact on revenue								228,100,000	41,400,000
Filgotinib drug license | Gilead
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Amount receivable in relation to the collaboration								160,000,000
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								16,200,000
Cost reimbursements recognized								101,000,000	72,000,000
Adddition (deduction) of sales & marketing expenses								(4,700,000)	€ 8,200,000
Deduction of research and development expenditure								€ (3,100,000)
Cost share mechanism									50.00%

Related parties - Summary of re

Related parties - Summary of remuneration package (Details)	12 Months Ended
	Dec. 31, 2020EUR (€)EquityInstruments	Dec. 31, 2019EUR (€)EquityInstruments	Dec. 31, 2018EUR (€)EquityInstruments
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Short-term benefits for executive committee members as a group | €	€ 3,102,000
Post-employment benefits | €	392,000	€ 323,000	€ 305,000
Total benefits excluding warrants and RSUs | €	€ 4,262,000	€ 16,618,000	€ 5,346,000
Granted during the period	2,173,335	1,699,690	1,235,245
Total cost of warrants granted in the year | €	€ 22,921,000	€ 14,236,000	€ 15,507,000
Key management personnel compensation, tax advisory services amount | €			€ 20,100
Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period	275,000	360,000	402,500
Restricted Stock Units (RSUs)
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period	128,769	213,147
Number of RSUs granted in the year	61,829	188,571	0
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 for executive committee members as a group | €		€ 14,129,000	€ 2,909,000
Gross salary | €	€ 2,531,000	2,121,000	1,920,000
Employer social security on gross salary | €		61,000	125,000
Cash bonus | €	433,000	1,230,000	757,000
Exceptional bonus | €		10,500,000
Employer social security on exceptional bonus | €		108,000
Other short-term benefits | €	€ 138,000	109,000	107,000
Long-term benefits for executive committee members as a group | €		€ 1,874,000	€ 1,812,000
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]
Granted during the period	275,000	315,000	350,000
Onno van de Stolpe | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period	85,000	100,000
Onno van de Stolpe | Restricted Stock Units (RSUs)
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Number of RSUs granted in the year	18,317	57,528	0
Bart Filus | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period	50,000	65,000
Bart Filus | Restricted Stock Units (RSUs)
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Number of RSUs granted in the year	12,600	39,846	0
Andre Hoekema | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period	30,000	50,000
Andre Hoekema | Restricted Stock Units (RSUs)
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Number of RSUs granted in the year	832	19,922	0
Piet Wigerink | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period	40,000	50,000
Piet Wigerink | Restricted Stock Units (RSUs)
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Number of RSUs granted in the year	12,080	33,077	0
Walid Abi-Saab | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period	40,000	50,000
Walid Abi-Saab | Restricted Stock Units (RSUs)
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Number of RSUs granted in the year	12,080	33,077	0
Michele Manto | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period	30,000	40,000
Michele Manto | Restricted Stock Units (RSUs)
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Number of RSUs granted in the year	5,920	5,121	0
Supervisory board members as a group
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period		45,000	52,500
Raj Parekh
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 directors | €	€ 220,000	€ 90,000	€ 92,000
Raj Parekh | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period		15,000	15,000
Harrold van Barlingen
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 directors | €			€ 15,000
Howard Rowe
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 directors | €	125,000	€ 55,000	€ 53,000
Howard Rowe | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period		7,500	7,500
Werner Cautreels
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 directors | €		€ 15,000	€ 48,000
Werner Cautreels | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period			7,500
Katrine Bosley
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 directors | €	115,000	€ 45,000	€ 45,000
Katrine Bosley | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period		7,500	7,500
Christine Mummery
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 directors | €		€ 13,000	€ 40,000
Christine Mummery | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period			7,500
Mary Kerr
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 directors | €	115,000	€ 45,000	€ 46,000
Mary Kerr | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period		7,500	7,500
Peter Guenter
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 directors | €	115,000	€ 30,000
Peter Guenter | Warrants
Disclosure of amounts incurred by entity for provision of key management personnel services provided by separate management entities [line items]
Granted during the period		7,500
Elisabeth Svanberg
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 directors | €	€ 78,000

Consolidated companies as of _3

Consolidated companies as of December 31, 2020 (Details)	Jan. 04, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
BioFocus DPI AG | Switzerland
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		0.00%	100.00%	100.00%
Changes in voting rights		(100.00%)
Fidelta d.o.o. | Selvita SA [Member] | Fee-for-service business (held for sale)
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries	100.00%
Fidelta d.o.o. | Croatia
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%	100.00%
Galapagos Biopharma BV | The Netherlands
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%
Galapagos Biopharma BV | Belgium
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%
Galapagos B.V | The Netherlands
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%	100.00%
Galapagos Biopharma Spain S.L.U | Spain
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%
Galapagos Biopharma Italy S.r.l. | Italy
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%
Galapagos Biopharma Germany GmbH | Germany
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%
Galapagos Biotech Ltd. (formerly Inpharmatica Ltd.) | United Kingdom
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%	100.00%
Galapagos GmbH | Switzerland
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%	100.00%
Galapagos Real Estate 1 BV | Belgium
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%	100.00%
Galapagos Real Estate 2 BV | Belgium
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		0.00%	100.00%	100.00%
Changes in voting rights		(100.00%)
Galapagos Real Estate B.V. | The Netherlands
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%
Galapagos SASU (France) | France
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%	100.00%
Galapagos, Inc. (formerly Biofocus, Inc.) | United States
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%	100.00%
Xenometrix, Inc. | United States
Consolidated companies as of December 31, 2019
Percentage of voting rights held directly or indirectly through subsidiaries		100.00%	100.00%	100.00%

Financial risk management - Fin

Financial risk management - Financial risk factors (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Financial risk management
Financial assets held at fair value through profit or loss	€ 8,951	€ 11,275		€ 6,000
Financial assets	5,357,438	5,834,526	[1]	1,307,922	[1]
Financial liabilities	167,505	148,331	[1]	52,466	[1]
Equity instruments
Financial risk management
Financial assets held at fair value through profit or loss	8,951	11,275	[1]	6,000	[1]
Current financial investments
Financial risk management
Financial assets held at fair value through profit or loss	1,571,858	3,919,216	[1]	0
Financial assets at amortised cost	1,454,420	0		0	[1]
Cash and cash equivalents
Financial risk management
Financial assets at amortised cost	2,135,187	1,861,616	[1]	1,290,796	[1]
Restricted cash (current and non-current)
Financial risk management
Financial assets at amortised cost	1,482	1,418	[1]	1,276	[1]
Other non-current assets
Financial risk management
Financial assets at amortised cost	907	1,399	[1]	644	[1]
Trade and other receivables (excl prepayments)
Financial risk management
Financial assets at amortised cost	184,632	39,603	[1]	9,206	[1]
Current financial instruments
Financial risk management
Financial liabilities held at fair value through profit or loss	3,164	6,198	[1]	0
Trade liabilities
Financial risk management
Financial liabilities at amortised cost	134,905	116,749	[1]	52,466	[1]
Lease liabilities.
Financial risk management
Financial liabilities at amortised cost	€ 29,436	€ 25,384	[1]	€ 0
[1]	The historical consolidated financial information for 2019 and 2018 presented in this disclosure note has been adjusted mainly to correct for the amounts of other receivables and other payables that are outside the scope of IFRS 9.

Financial risk management - Agi

Financial risk management - Aging of Debtors (Details) - EUR (€) € in Thousands	Dec. 31, 2020	Dec. 31, 2019		Dec. 31, 2018
Financial risk management
Financial assets	€ 5,357,438	€ 5,834,526	[1]	€ 1,307,922	[1]
60 - 90 days | Trade receivables | Credit risk
Financial risk management
Financial assets	0	87		236
90 - 120 days | Trade receivables | Credit risk
Financial risk management
Financial assets	0	0		12
more than 120 days | Trade receivables | Credit risk
Financial risk management
Financial assets	€ 0	€ 0		€ 0
[1]	The historical consolidated financial information for 2019 and 2018 presented in this disclosure note has been adjusted mainly to correct for the amounts of other receivables and other payables that are outside the scope of IFRS 9.

Financial risk management - Int

Financial risk management - Interest rate risk and foreign exchange risk (Details) - EUR (€) € in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest rate risk
Financial risk management
Increase in interest rates	1.00%	1.00%	1.00%
Decrease in interest rates	1.00%	1.00%	1.00%
Change in profit or loss and equity due to reasonably possible change in 100 basis points	€ 51,700	€ 57,800	€ 12,900
Euros - U.S. Dollars Exchange rate value | Foreign exchange risk
Financial risk management
Increase (Decrease) in net book value	(116,690)	(133,373)	(27,200)
Euros - GB Pounds Exchange rate value | Foreign exchange risk
Financial risk management
Increase (Decrease) in net book value	303	113	100
Euros - CH Francs Exchange rate value | Foreign exchange risk
Financial risk management
Increase (Decrease) in net book value	2,013	538	208
Euros - HR Kunas Exchange rate value | Foreign exchange risk
Financial risk management
Increase (Decrease) in net book value	0	650	611
U.S. Dollars - GB Pounds Exchange rate value | Foreign exchange risk
Financial risk management
Increase (Decrease) in net book value	€ 0	€ (894)	€ (923)

Auditor's remuneration (Details

Auditor's remuneration (Details) - EUR (€)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Auditor's remuneration
Statutory auditor's fees	€ 1,202,800	€ 1,406,800
Fees for performance of the audit or review of the company’s affiliates financial statements	23,900	29,200
Fees for services executed for company’s affiliates	29,200	29,200
Other fees related to audit-related general fees	161,300	43,000
Other fees related to non-audit services executed by the statutory auditor	47,700	148,200
Other fees related to non-audit services executed by persons related to the statutory auditor	€ 890,700
Other fees related to IT services		€ 46,600

Events after balance sheet da_2

Events after balance sheet date (Details)	Mar. 19, 2021EUR (€)EquityInstruments€ / sharesshares	Jan. 04, 2021EUR (€)	Dec. 31, 2020EquityInstruments	Dec. 31, 2019EquityInstruments	Dec. 31, 2018EquityInstruments
Disclosure of non-adjusting events after reporting period [line items]
Warrants exercised			744,965	754,605	567,270
Exercise of Warrants [Member]
Disclosure of non-adjusting events after reporting period [line items]
Warrants exercised	99,814
Average exercise price warrants | € / shares	€ 22.62
Increase to share capital and issuance premium due to warrants issued | €	€ 2,258,042.82
Number of shares issued | shares	99,814
Closing share price | € / shares	€ 68.48
Fee-for-service business (held for sale)
Disclosure of non-adjusting events after reporting period [line items]
Total consideration received | €		€ (37,100,000)
CEO [member] | Exercise of Warrants [Member]
Disclosure of non-adjusting events after reporting period [line items]
Warrants exercised	41,874
Members of Executive Committee [member] | Exercise of Warrants [Member]
Disclosure of non-adjusting events after reporting period [line items]
Warrants exercised	10,000
Members of Board of Directors [member] | Exercise of Warrants [Member]
Disclosure of non-adjusting events after reporting period [line items]
Warrants exercised	5,040