argenx SE (ARGX) 20-F 21 Mar 24 2023 FY Annual report (foreign) Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2023 shares
Entity Information [Line Items]
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, 2023
Entity File Number	001-38097
Entity Incorporation, State or Country Code	P7
Entity Registrant Name	ARGENX SE
Entity Address, Address Line One	Laarderhoogtweg 25
Entity Address, Address Line Two	1101EB
Entity Address, City or Town	Amsterdam
Entity Address, Country	NL
Entity Common Stock, Shares Outstanding	59,194,488
Auditor Name	Deloitte Accountants B.V.
Auditor Firm ID	1243
Auditor Location	Rotterdam, The Netherlands
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
Document Financial Statement Error Correction [Flag]	false
Document Accounting Standard	International Financial Reporting Standards
Entity Shell Company	false
Entity Central Index Key	0001697862
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false
ICFR Auditor Attestation Flag	true
Business Contact [Member]
Entity Information [Line Items]
Entity Address, Address Line One	Industriepark Zwijnaarde 7,
Entity Address, Address Line Two	Building C9052 Zwijnaarde
Entity Address, City or Town	Ghent
Entity Address, Country	BE
Contact Personnel Name	Tim Van Hauwermeiren
Contact Personnel Email Address	TVanHauwermeiren@argenx.com
Entity Address, Postal Zip Code	9052
City Area Code	0
Local Phone Number	10 70 38 441
American Depositary Shares
Entity Information [Line Items]
Title of 12(b) Security	American Depositary Shares, each representing one ordinary share with a nominal value of €0.10 per share
Trading Symbol	ARGX
Security Exchange Name	NASDAQ
Ordinary shares
Entity Information [Line Items]
Title of 12(b) Security	Ordinary shares with a nominal value of €0.10 per share
Trading Symbol	ARGX
Security Exchange Name	NASDAQ

CONSOLIDATED STATEMENTS OF FINA

CONSOLIDATED STATEMENTS OF FINANCIAL POSITION $ in Thousands, € in Millions, ¥ in Millions	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Non-current assets
Property, plant and equipment	$ 22,675	$ 16,234	$ 15,844
Intangible assets	125,228	174,901	171,684
Deferred tax asset	97,211	79,222	32,191
Research and development incentive receivables	76,706	47,488	32,707
Investment in joint venture	9,912	1,323
Prepaid expenses	47,327
Other non-current assets	39,662	40,894	54,876
Total noncurrent assets	418,721	360,064	307,303
Current assets
Inventories	310,550	228,353	109,076
Prepaid expenses	134,072	76,022	58,946
Trade and other receivables	496,687	275,697	38,221
Research and development incentive receivables	2,584	1,578
Financial assets	1,131,000	1,391,808	1,002,052
Cash and cash equivalents	2,048,800	800,740	1,334,676
Total current assets	4,123,737	2,774,197	2,542,971
TOTAL ASSETS	4,542,458	3,134,261	2,850,274
Equity
Share capital	7,058	6,640	6,233
Share premium	5,651,497	4,309,880	3,462,775
Translation differences	131,543	129,280	131,684
Accumulated losses	(2,404,844)	(2,109,791)	(1,400,197)
Other reserves	712,253	477,691	333,729
Total equity	4,097,507	2,813,699	2,534,224
Non-current liabilities
Provisions for employee benefits	1,449	870	417
Lease liabilities	15,354	9,009	7,956
Deferred tax liabilities	5,155	8,406	6,438
Total non-current liabilities	21,958	18,285	14,811
Current liabilities
Lease liabilities	4,646	3,417	3,509
Trade and other payables	414,013	295,679	293,415
Tax liabilities	4,334	3,181	4,315
Total current liabilities	422,993	302,277	301,239
Total liabilities	444,951	320,562	316,050
TOTAL EQUITY AND LIABILITIES	$ 4,542,458	$ 3,134,261	$ 2,850,274

CONSOLIDATED STATEMENTS OF PROF

CONSOLIDATED STATEMENTS OF PROFIT OR LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CONSOLIDATED STATEMENTS OF PROFIT OR LOSS
Product net sales	$ 1,190,783	$ 400,720
Collaboration revenue	35,533	10,026	$ 497,277
Other operating income	42,278	34,520	42,141
Total operating income	1,268,594	445,267	539,418
Cost of sales	(117,835)	(29,431)
Research and development expenses	(859,492)	(663,366)	(580,520)
Selling, general and administrative expenses	(711,905)	(472,132)	(307,644)
Loss from investment in joint venture	(4,411)	(677)
Total operating expenses	(1,693,643)	(1,165,607)	(888,164)
Operating loss	(425,049)	(720,341)	(348,746)
Financial income	107,386	27,665	3,633
Financial expense	(906)	(3,906)	(4,578)
Exchange gains/(losses)	14,073	(32,732)	(50,053)
Loss for the year before taxes	(304,496)	(729,314)	(399,743)
Income tax benefit / (expense)	9,443	19,720	(8,522)
Loss for the year	(295,053)	(709,594)	(408,265)
Owners of the parent	$ (295,053)	$ (709,594)	$ (408,265)
Weighted average number of shares outstanding	57,169,253	54,381,371	51,075,827
Basic loss per share (in $)	$ (5.16)	$ (13.05)	$ (7.99)
Diluted (loss) per share (in $)	$ (5.16)	$ (13.05)	$ (7.99)

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Loss for the year	$ (295,053)	$ (709,594)	$ (408,265)
Currency translation differences, arisen from translating foreign activities	2,263	(2,404)	(3,048)
Fair value gain/(loss) on investments in equity instruments designated as at FVTOCI	(1,915)	(18,267)	(39,290)
Other comprehensive income/(loss), net of income	348	(20,671)	(42,338)
Owners of the parent	$ (294,705)	$ (730,266)	$ (450,603)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands, € in Millions, ¥ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
CASH FLOWS (USED IN) / FROM OPERATING ACTIVITIES
Operating loss	$ (425,049)	$ (720,341)	$ (348,746)
Adjustments for non-cash items
Amortization of intangible assets	105,674	99,766	776
Depreciation of property, plant and equipment	5,633	4,576	5,091
Provisions for employee benefits	573	459	260
Expense recognized in respect of share-based payments	232,974	157,026	179,366
Fair value gains on financial assets at fair value through profit or loss		(4,256)	(11,152)
Non-cash revenue			(75,000)
Loss from investment in joint venture	4,411	677
Other non-cash expenses	2,074
Adjustments for non-cash items	(73,710)	(462,093)	(249,405)
Movements in current assets/liabilities
(Increase)/decrease in trade and other receivables	(185,694)	(222,260)	(31,632)
(Increase)/decrease in inventories	(83,030)	(119,277)	(83,880)
(Increase)/decrease in other current assets	(59,024)	(18,294)	(30,990)
Increase/(decrease) in trade and other payables	95,600	329	134,892
Increase/(decrease) in deferred revenue - current			(46,327)
Movements in non-current assets/liabilities
(Increase)/decrease in other noncurrent assets	(29,416)	(16,220)	(13,975)
(Increase)/decrease in non-current prepaid expense	(47,327)
Increase/(decrease) in deferred revenue - non-current			(269,039)
Net cash flows used in operating activities, before interest and taxes	(382,601)	(837,815)	(590,356)
Interest paid	(211)	(851)	(684)
Income taxes paid	(37,515)	(24,141)	(15,772)
Net cash flows used in operating activities	(420,327)	(862,807)	(606,812)
CASH FLOWS (USED IN) / FROM INVESTING ACTIVITIES
Purchase of intangible assets	(43,000)	(102,986)	(117,811)
Purchase of property, plant and equipment	(812)	(837)	(3,623)
(Increase)/decrease in current financial assets			(228,239)
Purchase of current financial investments	(1,271,730)	(1,694,046)
Sale of current financial investments	1,543,999	1,325,540
Interest received	92,753	13,146	2,603
Investment in joint venture	(13,000)	(2,000)
Net cash flows from / (used in) investing activities	308,210	(461,184)	(347,070)
CASH FLOWS (USED IN) / FROM FINANCING ACTIVITIES
Principal elements of lease payments	(3,801)	(4,165)	(3,855)
Proceeds from issue of new shares, gross amount	1,196,731	760,953	1,091,326
Issue costs paid	(821)	(781)	(528)
Exchange (losses)/gains from currency conversion on proceeds from issue of new shares	(1,507)	410	966
Payment of employee withholding taxes relating to restricted stock unit awards	(12,138)	(5,855)
Proceeds from exercise of stock options	158,263	93,195	33,433
Net cash flows from financing activities	1,336,727	843,757	1,121,342
Increase/(decrease) in cash and cash equivalents	1,224,610	(480,234)	167,460
Cash and cash equivalents at the beginning of the period	800,740	1,334,676	1,216,803
Exchange gains/(losses) on cash and cash equivalents	23,494	(53,702)	(49,587)
Cash and cash equivalents at the end of the period	$ 2,048,800	$ 800,740	$ 1,334,676

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Share Capital	Share Premium	Accumulated Losses	Translation Difference	Share-based payment and income tax deduction on share-based payments	Fair value movement on investment in equity instruments designated as at FVTOCI	Total Equity Attributable to Owners of the Parent	Total
Equity at beginning of period at Dec. 31, 2020	$ 5,744	$ 2,339,033	$ (991,932)	$ 134,732	$ 186,474		$ 1,674,051	$ 1,674,051
Loss for the year			(408,265)				(408,265)	(408,265)
Other comprehensive income / (loss)				(3,048)		$ (39,290)	(42,338)	(42,338)
Total comprehensive income / (loss) for the year			(408,265)	(3,048)		(39,290)	(450,603)	(450,603)
Income tax benefit from excess tax deductions related to share-based payments					7,179		7,179	7,179
Share-based payment					179,366		179,366	179,366
Issue of share capital	430	1,090,896					1,091,326	1,091,326
Transaction costs for equity issue		(528)					(528)	(528)
Exercise of stock options	59	33,374					33,433	33,433
Equity at end of period at Dec. 31, 2021	6,233	3,462,775	(1,400,197)	131,684	373,019	(39,290)	2,534,224	2,534,224
Loss for the year			(709,594)				(709,594)	(709,594)
Other comprehensive income / (loss)				(2,404)		(18,267)	(20,671)	(20,671)
Total comprehensive income / (loss) for the year			(709,594)	(2,404)		(18,267)	(730,266)	(730,266)
Income tax benefit from excess tax deductions related to share-based payments					3,946		3,946	3,946
Share-based payment					158,282		158,282	158,282
Issue of share capital	294	760,659					760,953	760,953
Transaction costs for equity issue		(781)					(781)	(781)
Exercise of stock options	113	93,082					93,195	93,195
Ordinary shares withheld for payment of employees' withholding tax liability		(5,855)					(5,855)	(5,855)
Equity at end of period at Dec. 31, 2022	6,640	4,309,880	(2,109,791)	129,280	535,247	(57,557)	2,813,699	2,813,699
Loss for the year			(295,053)				(295,053)	(295,053)
Other comprehensive income / (loss)				2,263		(1,915)	348	348
Total comprehensive income / (loss) for the year			(295,053)	2,263		(1,915)	(294,705)	(294,705)
Income tax benefit from excess tax deductions related to share-based payments					2,310		2,310	2,310
Share-based payment					234,168		234,168	234,168
Issue of share capital	288	1,196,444					1,196,732	1,196,732
Transaction costs for equity issue		(821)					(821)	(821)
Exercise of stock options	130	158,133					158,263	158,263
Ordinary shares withheld for payment of employees' withholding tax liability		(12,139)					(12,139)	(12,139)
Equity at end of period at Dec. 31, 2023	$ 7,058	$ 5,651,497	$ (2,404,844)	$ 131,543	$ 771,725	$ (59,472)	$ 4,097,507	$ 4,097,507

General information about the c

General information about the company	12 Months Ended
	Dec. 31, 2023
General information about the company
General information about the company	1. General information about the company argenx SE is a Dutch European public company with limited liability incorporated under the laws of the Netherlands. The company (COC 24435214) has its official seat in Rotterdam, the Netherlands, and its registered office is at Laarderhoogtweg 25, 1101 EB Amsterdam, the Netherlands. An overview of the company and its subsidiaries (the Company) are described in note 31. argenx SE is a publicly traded company with ordinary shares listed on Euronext Brussels under the symbol “ARGX” since July 2014 and with American Depositary Shares listed on Nasdaq under the symbol “ARGX” since May 2017.

Material accounting policy info

Material accounting policy information	12 Months Ended
	Dec. 31, 2023
Material accounting policy information
Material accounting policy information	2. Material accounting policy information The Company’s material accounting policies are summarized below. 2.1 Statement of compliance and basis of preparation 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 the Company’s activities and the results achieved. They present fairly the entity’s financial position, its financial performance and cash flows, on a going concern basis. The material accounting policy information applied in the preparation of the above consolidated financial statements are set out below. All amounts are presented in thousands of dollar, unless otherwise indicated, rounded to the nearest $ ‘000. The consolidated financial statements have been approved for issue by the Company’s Board of Directors (the “Board”) on March 19, 2024. 2.2 Adoption of new and revised standards New standards and interpretations applicable for the annual period beginning on January 1, 2023 ● Amendments to IAS 1 – Presentation of Financial Statements and IFRS Practice Statement 2 – Making Materiality Judgements . The amendments to IAS 1 require companies to disclose their material accounting policy information rather than their significant accounting policies. The amendments to IFRS Practice Statement 2 provide guidance on how to apply the concept of materiality to accounting policy disclosures. As result the Company revised its accounting policy disclosure in the consolidated financial statements and removed accounting policy information that the Company deemed to relate to immaterial transactions or other events or conditions. No other standards and interpretations for the annual period beginning on January 1, 2023 have any material impact on the consolidated financial statements. New standards and interpretations issued, but not yet applicable for the annual period beginning on January 1, 2023 ● Amendments to IAS 12 - issued International Tax Reform—Pillar Two Model Rules. On 23 May 2023, the International Accounting Standards Board (the IASB or Board) issued International Tax Reform – Pillar Two Model Rules – Amendments to IAS 12 which clarified the application of IAS 12 income taxes arising from tax law enacted or substantively enacted to implement the OECD/G20 Inclusive Framework on Base Erosion and Profit Shifting Pillar Two model rules. Based on current information, management expects that the Company could become subject to the Pillar Two Directive and implementing domestic laws as early as 2025. Thus, there is no impact for argenx in 2023. The company is currently in the process of determining the impact, if any, for 2025. Based on the preliminary analysis, we do not expect the Pillar Two Rules to have a material impact on our effective tax rate. It is unclear if the Pillar Two model rules create additional temporary differences, whether to remeasure deferred taxes for the Pillar Two model rules, and which tax rate to use to measure deferred taxes. In response to this unclarity, the amendments mentioned above introduced a mandatory temporary exception to the requirements of IAS 12 under which a company does not recognise or disclose information about deferred tax assets and liabilities related to the Pillar Two model rules. We applied the temporary exception in financial year 2023. We have not early adopted any other standard, interpretation, or amendment that has been issued but is not yet effective. Of the standards that are not yet effective, we expect no standard to have a material impact on the financial statements in the period of initial application. 2.3 Basis of consolidation The consolidated financial statements include the financial statements of the Company and entities controlled by the Company (its subsidiaries). Control is achieved when the Company: ● has power over the investee; ● is exposed, or has rights, to variable returns from its involvement with the investee; and ● has the ability to use its power to affect its returns. The Company reassesses whether or not it controls an investee if facts and circumstances indicate that there are changes to one or more of the three elements of control listed above. The results of the subsidiaries are included in the consolidated statements of profit or loss and consolidated statements of other comprehensive income (loss) from the effective date of acquisition up to the date when control ceases to exist. When necessary, adjustments are made to the financial statements of subsidiaries to bring their accounting policies into line with those used by other members of the Group. All intercompany transactions and unrealized gains on transactions between group companies are eliminated. Unrealised losses are also eliminated unless the transaction provides evidence of an impairment of the transferred asset. 2.4 Foreign currency transactions 2.4.1 Functional and presentation currency Items included in the consolidated financial statements of each of the entities are valued using the currency of their economic environment in which the entity operates. The consolidated financial statements are presented in USD ($), which is the Company’s presentation currency. 2.4.2 Transactions and balances Transactions in foreign currencies are translated at the exchange rate ruling at the date of the transaction. Monetary assets and liabilities denominated in foreign currencies are translated at the exchange rate ruling at the reporting date. Foreign exchange differences arising on translation are recognized in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) as “Exchange gains /(losses)”. Non-monetary assets and liabilities denominated in foreign currencies are translated at the foreign exchange rate ruling at the date of the transaction. 2.4.3 Financial statements of foreign entities For foreign entities using a different functional currency than USD: ● assets and liabilities for each balance sheet presented are translated at the closing rate at the date of the balance sheet. ● income and expenses for each statement presenting profit or loss and statements of other comprehensive income (loss) are translated at average exchange rates (unless this average is not a reasonable approximation of the cumulative effect of the rates prevailing on the transaction dates, in which case income and expenses are translated at the rate on the dates of the transactions). ● all resulting exchange differences are recognized in the statements of other comprehensive income (loss). 2.5 Intangible assets 2.5.1 Internally generated intangible assets Expenditure on research activities is recognized as an expense in the period in which it is incurred. Due to uncertainties inherent to the development and registration with the relevant healthcare authorities of its products, the Company estimates that the conditions for capitalization per IAS 38 can not be met before the regulatory procedures required by such healthcare authorities have been finalized. Also once regulatory approval has been obtained, an internally generated intangible asset arising from development is capitalized if, and only if, all of the criteria under IAS 38 have been demonstrated. 2.5.2 Acquired In-Process R&D and Acquired R&D available for use Upfront payments and development milestone payments for “Acquired In-Process R&D obtained through in-licensing arrangements are capitalized as intangible assets under “Acquired In-Process R&D” upon meeting the IAS 38 capitalization criteria. These intangibles are considered as intangible assets with definite useful lives and are carried at cost less accumulated impairment losses. “Acquired In-Process R&D” is not amortized, but is evaluated for potential impairment on an annual basis or when facts and circumstances warrant. Any impairment charge is recorded in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) under “Research and development expense”. Once an asset included in “Acquired In-Process R&D” has received marketing approval from a regulatory authority, it is recorded under “Acquired R&D available for Regulatory milestone payments and sales-based milestone payments for R&D obtained through in-licensing arrangements acquired are capitalized intangible assets under “Acquired R&D available for use” upon meeting the IAS 38 capitalization criteria. All intangibles classified under “Acquired R&D available for use” are considered as intangible assets with finite useful lives and are carried at cost less accumulated amortization and accumulated impairment losses. “Acquired R&D available for use” is evaluated for potential impairment when the Company identifies indications based on facts and circumstances of the asset. Any impairment charge is recorded in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) under "Cost of sales". “Acquired R&D available for use” is amortized under “Cost of sales” on a straight-line basis over the estimated useful life, being the longer of the current patent protection life of the acquired R&D and patent protection life of the combined product. 2.5.3. Other intangible assets Other intangible assets could include the Priority Review Voucher (“PRV”) which the Company can use to obtain the priority review by the FDA for one of its future regulatory submissions or may sell or transfer to a third party. The PRV is initially measured at cost and annually reviewed for impairment when events or circumstances indicate that the carrying value may not be recoverable. Any impairment charge is recorded in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) under “Research and development expenses.” Using the PRV results in amortization recorded in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) under “Research and development expenses” and subsequent derecognition of the intangible asset. 2.6 Research and development incentives receivables The current and non-current research and development incentive receivables relate to refunds resulting from research and development incentives on Research and development expenses in Belgium and are credited to the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) under the line “Other operating income” when the relevant expenditure has been incurred and there is a reasonable assurance that the research and development incentives will be received. 2.7 Inventories Inventories are carried at cost or net realisable value, whichever is lowest. Cost comprises of costs of purchase, costs of conversion and other costs incurred in bringing the inventories to their present location and condition. If the expected sales price less completion costs to execute sales (net realizable value) is lower than the carrying amount, a write-down is recognized for the amount by which the carrying amount exceeds its net realisable value Included in inventory are products which could, besides commercial activities, be used in preclinical and clinical programs, and free-of-charge, compassionate use and pre-approval access program. These products are charged to “Research & development expenses” or “Selling, general and administrative expenses”, respectively, when dedicated to this channel. We capitalize inventory costs associated with products prior to the regulatory approval of these products, or for inventory produced in production facilities not yet approved, when it is highly probable that the pre-approval inventories will be saleable. The determination to capitalize is based on the particular facts and circumstances relating to the expected regulatory approval of the product or production facility being considered. The assessment of whether or not the product is considered highly probable to be saleable is made and includes, but is not limited to, how far a particular product or facility has progressed along the approval process, any known safety or efficacy concern and other impediments. Previously capitalized costs related to pre-launch inventories could be required to be written down upon a change in such judgement or due to a denial or delay of approval by regulatory bodies, a delay in commercialization or other potential factors, which will be recorded under “Research and development expenses” in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss). 2.8 Trade and other receivables Trade and other receivables are designated as financial assets measured at amortized cost. They are initially measured either at their invoiced amounts or at transaction price, in the absence of a significant financing component less adjustments for estimated revenue deductions such as rebates, chargebacks and returns. All receivables are subsequently measured at amortized cost, which generally corresponds to nominal value less expected credit loss provision. Loss allowance for expected credit losses are established using a simplified approach of forward-looking expected credit loss model (ECL), which includes possible default events on the trade receivables over the entire holding period of the trade receivable. These provisions represent the difference between the trade receivable’s carrying amount in the consolidated statements of financial position and the estimated collectible amount. Charges for loss allowance for expected credit losses are recorded under “Selling, general and administrative expenses” in the consolidated statements of profit or loss and consolidated statements of other comprehensive income (loss). 2.9 Current financial assets Current financial assets measured at amortized costs comprise of term accounts that have an initial maturity equal or less than 12 months, but exceeding 3 months. Current financial assets measured at fair value through profit or loss comprise of money market funds. Interests on Current financial assets is reported under Cash Flow from investment activities under “Interest received”. 2.10 Cash and cash equivalents Cash are financial assets measured at amortized cost and comprise of cash at bank. Cash equivalents measured at amortized cost comprise of term accounts that have an initial maturity of less than 3 months that are subject to an insignificant risk of changes in values. Those are used by the Company in the management of short-term commitments. Cash and cash equivalents exclude restricted cash, which is presented in the consolidated statements of financial position under the line “Other non-current assets”. Cash equivalents measured at fair value through profit or loss comprise of money market funds that are readily convertible to cash and are subject to insignificant risk of changes in value. These financial assets are used by the Company in the management of the short-term commitments. Interests on Cash equivalents is reported under Cash Flow from investment activities under “Interest received”. 2.11 Trade and other payables Trade and other payables 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 the Company’s research and development activities, gross-to-net accruals and short-term employee benefits. Trade and other payables are initially measured at their transaction price, which are subsequent to initial recognition measured at amortized cost. Short-term employee benefits include payables and accruals for salaries and bonuses to be paid to the employees of the Company. They are recognized as expenses for the period in which employees perform the corresponding services. 2.12 Leases The Company assesses whether a contract is or contains a lease, at inception of the contract. The Company recognises a right-of-use asset and a corresponding lease liability with respect to all lease arrangements in which it is the lessee, except for short-term leases (defined as leases with a lease term of 12 months or less) and leases of low value assets. For these leases, the Company recognises the lease payments as an operating expense on a straight-line basis over the term of the lease unless another systematic basis is more representative of the time pattern in which economic benefits from the leased assets are consumed. The lease liability is initially measured at the present value of the lease payments that are not paid at the commencement date, discounted by using the rate implicit in the lease. If this rate cannot be readily determined, the lessee uses its incremental borrowing rate. The lease liability is subsequently measured by increasing the carrying amount to reflect interest on the lease liability (using the effective interest method) and by reducing the carrying amount to reflect the lease payments made. The lease liability is presented as a separate line in the consolidated statements of financial position. The right-of-use assets comprise the initial measurement of the corresponding lease liability, lease payments made at or before the commencement day, less any lease incentives received and any initial direct costs. They are subsequently measured at cost less accumulated depreciation and impairment losses. Right-of-use assets are depreciated over the shorter period of lease term and useful life of the underlying asset. If a lease transfers ownership of the underlying asset or the cost of the right-of-use asset reflects that the Company expects to exercise a purchase option, the related right-of-use asset is depreciated over the useful life of the underlying asset. The right-of-use assets are presented in the consolidated statements of financial position under the caption “Property, plant and equipment”. 2.13 Financial instruments Financial instruments are initially recognized either at fair value or at transaction price and subsequently measured at either amortized cost or fair value under IFRS 9 on the basis of both the Company’s model for managing the financial assets and the contractual cash flow characteristics of the financial asset. A financial asset is classified as current when the cash flows expected to flow from the instrument mature within one year. Profit share in AgomAb Therapeutics NV: Shares of Zai Lab: 2.14 Shareholder’s equity An equity instrument is any contract that evidences a residual interest in the assets of an entity after deducting all of its liabilities. Equity instruments issued by the Company are recognized at the proceeds received, net of direct issue costs. The Company has never distributed any dividends to its shareholders. As of December 31, 2023, no profits were available for distribution. As of January 1, 2021, the Company changed its functional and presentation currency from EUR to USD. Differences resulting from the re-presentation have been presented as translation difference, a component within shareholders’ equity. Share capital, share premium, and other reserves are translated at historic rates prevailing at the date of transaction. 2.15 Share-based payments Equity-settled share-based payments to employees and others providing similar services are measured at the fair value of the equity instruments at the acceptance date. Equity settled share based payments includes expenses related to stock options and restricted stock units granted by the Company. The fair value determined at the acceptance date of the equity-settled share-based payments is expensed on a straight-line basis over the vesting period, based on the Company’s estimate of equity instruments that will eventually vest, with a corresponding increase in equity. At the end of each reporting period, the Company revises its estimate of the number of equity instruments expected to vest. The impact of the revision of the original estimates, if any, is recognized in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) such that the cumulative expense reflects the revised estimate, with a corresponding adjustment to the equity-settled share-based payment reserve. The share-based payment expense is recorded under “Research and development expenses” or “Selling, general & administrative expenses” depending on the nature of the services provided by each beneficiary. 2.16 Income taxes Income tax in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) represents the total of the current tax and deferred tax. The current tax is based on taxable profit for the year. Taxable profit differs from profit as reported in the consolidated statements of profit or loss and consolidated statements of other comprehensive income (loss) as it excludes items of income or expense that are taxable or deductible in other years and items that are never taxable or deductible. The Company’s liability for current tax is calculated using tax rates that have been enacted or substantively enacted by the end of the reporting period. Deferred tax is recognized on temporary differences between the carrying amounts of assets and liabilities in the consolidated financial statements and the corresponding tax basis used in the computation of taxable profit. Deferred tax assets are recognized to the extent that it is probable that future taxable profits will be available against which those deductible temporary differences can be utilized. The carrying amount of deferred tax assets is reviewed at the end of each reporting period and reduced to the extent that it is not probable that sufficient taxable profits will be available to allow all or part of the asset to be recovered. Deferred tax assets and liabilities are offset if there is a legally enforceable right to offset. Deferred tax assets and liabilities are measured at the tax rates that are expected to apply in the period in which the liability is settled or the asset realized, based on tax rates (and tax laws) that have been enacted or substantially enacted by the end of the reporting period. The Company records uncertain tax positions in accordance with IAS 12 using the 2 step test whereby (1) the Company determines whether it is probable that the tax positions will be accepted by relevant taxing authorities, and (2) for those tax positions that are not probable that a tax authority will accept in full the position, the Company recognizes uncertain tax positions using either the most likely amount or the expected value, depending on specific facts and circumstances. 2.17 Product net sales Revenue from the sale of goods is recognized at an amount that reflects the consideration that the Company expects to be entitled to receive in exchange for transferring goods to a customer, at the time when the customer obtains control of the goods rendered, this means when the customer has the ability to direct the use of the asset. The consideration that is committed in a contract with a customer can include fixed amounts, variable amounts, or both. The amount of the consideration may vary due to discounts, rebates, returns, chargebacks or other similar items. Contingent consideration is included in the transaction price when it is highly probable that the amount of revenue recognized is not subject to future significant reversals. Product net sales are recognized once we satisfy the performance obligation at a point in time under the revenue recognition criteria in accordance with IFRS 15 Revenue from contracts with customers Revenue arising from the commercial sale of commercial product is presented in the consolidated statements of profit or loss under “Product net sales”. In accordance with IFRS 15 Revenue from contracts with customers , such revenue is recognized when the product is physically transferred, in accordance with the delivery and acceptance terms agreed with the customer. Payment of the transaction price is payable at the point the customer obtains the legal title to the goods. The amount of revenue recognized reflects the various types of price reductions or rights of return offered by the Company to its customers. Such price reductions and rights of return qualify as variable consideration under IFRS 15 Revenue from contracts with customers . Products sold are covered by various Government and State programs (such as Medicare and Medicaid) under which products are sold at a discount. Rebates are granted to healthcare authorities, and under contractual arrangements with certain customers. Some wholesalers are entitled to chargeback incentives based on the selling price to the end customer, under specific contractual arrangements. Rebates, chargebacks and other incentives are recognized in the period in which the underlying sales are recognized as a reduction of product sales. The significant components of variable consideration are as follows: Co-payment assistance: Chargebacks: Rebates: Medicare Part D Coverage Gap: Distributor fees: Value-based arrangements (VBAs The estimated amounts described above are recognized in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) within “Product net sales” as a reduction of gross sales, and within “Trade and other payables” in the consolidated statements of financial position. They are subject to regular review and adjustment as appropriate based on the most recent data available to management. Each of the above items require significant estimates, judgement and information obtained from external sources. If management’s estimates differ from actual results, we will record adjustments that would affect product sales in the period of adjustment. 2.18 Collaborations and license agreements The Company has currently two active collaboration and license agreements in scope of IFRS 15: Zai Lab For the collaboration agreement with Zai Lab the Company has assessed that there is more than one distinct performance obligation, being the transfer of a license and supply of clinical and commercial product. The Company concluded that these performance obligations are distinct in the context of the contract. Therefore, the Company assesses to allocate the transaction price to all performance obligations identified. The transaction price of these two agreements is composed of (i) a fixed part, that being an upfront payment in the form of newly issued Zai Lab shares, and a guaranteed, non-creditable, non-refundable payment and (ii) a milestone payment for approval of efgartigimod in the U.S. and the consideration received in return for the supply of clinical and commercial product. The fixed part of the transaction price, as well as the milestone for approval of efgartigimod in the U.S. has been allocated to the transfer of a license performance obligation. The Company concluded that the license as of the effective date of the contract, being January 2021, has standalone value. As such, the Company concluded that the promise in granting the license to Zai Lab is to provide a right to use the entity’s intellectual property as it exists at the point in time at which the license is granted and therefore, revenue was recognized at a point in time in January 2021. Under the collaboration agreement, the Company provides clinical and commercial supply to Zai Lab. Company concludes to recognize such sales as revenue given that the Company acts as principal in the transaction as the risk related to inventory is born by the Company until the inventory is transferred to Zai Lab. The revenue related to clinical supply is recorded under line item “Collaboration revenue”. The revenue related to commercial supply is recorded under line item “product net sales” in the Consolidated statements of other comprehensive Income (Loss). The income related to royalties is recorded under line item item “Collaboration revenue”. AbbVie For the collaboration agreement with AbbVie the Company has determined that the transfer of license combined with the performance of research and development activities represent one single performance obligation. The Company concluded that the license is not distinct in the context of the contract. The transaction price is composed of a fixed part, that being an upfront license fee, and a variable part, being milestone payments and cost reimbursements of research and development activities delivered. Milestone payments are only included in the transaction price to the extent it is highly probable that a significant reversal in the amount of cumulative revenue recognition will not occur when the uncertainty associate with the variable consideration is subsequently resolved. Management estimates the amount to be included in the transaction price upon achievement of the milestone event. Sales-based milestones and sales-based royalties are a part of the Company’s arrangements but are not yet included in its revenues. The transaction price has been allocated to the single performance obligation and revenues has been recognized over the estimated service period based on an input model, being the percentage of completion method. The upfront license fee has been fully recognized since 2021 as the performance obligation has been fulfilled at that time. Milestone payments that become highly probable after the performance obligation has been fulfilled are therefore recognized at that point in time. 2.19 Cost of Sales Cost of sales are recognized when the associated revenue from product net sales is recognized. Cost of sales include material, manufacturing costs and other costs attributable to production, including shipping costs, as well as royalties payable on sold products.

Critical accounting estimates a

Critical accounting estimates and judgments	12 Months Ended
	Dec. 31, 2023
Critical accounting estimates and judgments
Critical accounting estimates and judgments	3. Critical accounting estimates and judgments In the application of the Company’s accounting policies, which are described above, the Company is 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. The estimates and underlying 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 revision and future periods if the revision affects both current and future periods. Critical estimates in applying accounting policies Gross to net adjustments The product gross sales are subject to various deductions, which are primarily composed of rebates to government agencies, distributors, health insurance companies and managed healthcare organizations. These deductions represent estimates of the related obligations, requiring the use of judgment when estimating the effect of these sales deductions on product gross sales for a reporting period. These adjustments are deducted from product gross sales to arrive at product net sales. The significant components of variable consideration under revenue recognition policy summarizes the nature of these deductions and how the deduction is estimated, see note 2.17. After recording these, product net sales represent the Company’s best estimate of the cash that we expect to ultimately collect. If in future periods the actuals vary from prior period best estimates, this would affect revenue in the period of adjustment. Please refer to note 14 for the movement over the period and the ending balance of the gross-to-net-accruals.

Property, plant and equipment

Property, plant and equipment	12 Months Ended
	Dec. 31, 2023
Property, plant and equipment.
Property, plant and equipment	4. Property, plant and equipment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ IT, office and lab Right-of-use assets Right-of-use assets Leasehold Lease ​ ​ (in thousands of $) ​ equipment ​ Buildings ​ Vehicles ​ improvements ​ equipment ​ Total Cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2021 ​ $ 4,889 ​ ​ 11,721 ​ ​ 2,273 ​ ​ 1,424 ​ ​ 346 ​ ​ 20,653 Additions ​ ​ 3,163 ​ ​ 4,923 ​ ​ 802 ​ ​ 543 ​ ​ — ​ ​ 9,430 Disposals ​ ​ (217) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (217) Currency translation adjustment ​ ​ 104 ​ ​ (182) ​ ​ — ​ ​ 14 ​ ​ — ​ ​ (64) On December 31, 2021 ​ ​ 7,938 ​ ​ 16,462 ​ ​ 3,075 ​ ​ 1,981 ​ ​ 346 ​ ​ 29,802 Additions ​ ​ 962 ​ ​ 3,353 ​ ​ 905 ​ ​ — ​ ​ — ​ ​ 5,219 Disposals ​ ​ (105) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (105) Currency translation adjustment ​ ​ (635) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (635) On December 31, 2022 ​ ​ 8,160 ​ $ 19,815 ​ $ 3,980 ​ $ 1,981 ​ $ 346 ​ $ 34,282 Additions ​ ​ 937 ​ ​ 8,770 ​ ​ 2,327 ​ ​ 48 ​ ​ — ​ ​ 12,082 Disposals ​ ​ (202) ​ ​ — ​ ​ (757) ​ ​ (54) ​ ​ — ​ ​ (1,013) On December 31, 2023 ​ $ 8,895 ​ $ 28,585 ​ $ 5,550 ​ $ 1,975 ​ $ 346 ​ $ 45,350 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2021 ​ $ (3,642) ​ ​ (4,044) ​ ​ (760) ​ ​ (543) ​ ​ (82) ​ ​ (9,071) Depreciation ​ ​ (1,118) ​ ​ (2,714) ​ ​ (651) ​ ​ (539) ​ ​ (34) ​ ​ (5,055) Disposals ​ ​ 158 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 158 Currency translation adjustment ​ ​ 37 ​ ​ (15) ​ ​ — ​ ​ (11) ​ ​ — ​ ​ 10 On December 31, 2021 ​ ​ (4,565) ​ ​ (6,774) ​ ​ (1,411) ​ ​ (1,093) ​ ​ (116) ​ ​ (13,958) Depreciation ​ ​ (1,388) ​ ​ (2,179) ​ ​ (735) ​ ​ (257) ​ ​ (35) ​ ​ (4,593) Disposals ​ ​ 90 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 90 Currency translation adjustment ​ ​ 408 ​ ​ 5 ​ ​ 1 ​ ​ 1 ​ ​ — ​ ​ 414 On December 31, 2022 ​ ​ (5,454) ​ $ (8,948) ​ $ (2,145) ​ $ (1,350) ​ $ (150) ​ $ (18,047) Depreciation ​ ​ (1,539) ​ ​ (2,839) ​ ​ (971) ​ ​ (189) ​ ​ (36) ​ ​ (5,574) Disposals ​ ​ 189 ​ ​ — ​ ​ 757 ​ ​ — ​ ​ — ​ ​ 946 On December 31, 2023 ​ $ (6,804) ​ $ (11,787) ​ $ (2,359) ​ $ (1,539) ​ $ (186) ​ $ (22,675) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2021 ​ $ 3,373 ​ $ 9,688 ​ $ 1,664 ​ $ 888 ​ $ 230 ​ $ 15,844 On December 31, 2022 ​ ​ 2,706 ​ ​ 10,867 ​ ​ 1,835 ​ ​ 631 ​ ​ 196 ​ ​ 16,234 On December 31, 2023 ​ $ 2,091 ​ $ 16,798 ​ $ 3,191 ​ $ 436 ​ $ 160 ​ $ 22,675 ​ Depreciation is recognized as from acquisition date onwards (unless asset is not ready for use) so as to write off the cost or valuation of assets less their residual values over their useful lives, using the straight-line method. Unless revised due to specific changes in the estimated useful life, annual depreciation rates are as follows: ● Office and lab equipment: 3 – 5 years ● IT equipment: 3 years As of December 31, 2023, there are no material commitments to acquire property, plant and equipment. Furthermore, no items of property, plant and equipment are pledged. See note 22 for information for leases where the Company is a lessee.

Intangible assets

Intangible assets	12 Months Ended
	Dec. 31, 2023
Intangible assets
Intangible assets	5. Intangible assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) Acquired R&D available for use ​ Acquired In-Process R&D ​ Software & databases ​ Other Intangibles ​ Total Cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2021 ​ $ — ​ $ 65,180 ​ $ 3,543 ​ $ 99,058 ​ $ 167,781 Additions ​ ​ — ​ ​ 5,000 ​ ​ — ​ ​ — ​ ​ 5,000 Translation differences ​ ​ — ​ ​ — ​ ​ (190) ​ ​ — ​ ​ (190) On December 31, 2021 ​ ​ — ​ ​ 70,180 ​ ​ 3,353 ​ ​ 99,058 ​ ​ 172,591 Additions ​ ​ — ​ ​ — ​ ​ 992 ​ ​ 102,000 ​ ​ 102,992 Disposals ​ ​ — ​ ​ — ​ ​ (5) ​ ​ — ​ ​ (5) Derecognition ​ ​ — ​ ​ — ​ ​ — ​ ​ (99,058) ​ ​ (99,058) On December 31, 2022 ​ ​ — ​ ​ 70,180 ​ ​ 4,340 ​ ​ 102,000 ​ ​ 176,519 Additions ​ ​ 56,000 ​ ​ — ​ ​ — ​ ​ — ​ ​ 56,000 Derecognition ​ ​ — ​ ​ — ​ ​ — ​ ​ (102,000) ​ ​ (102,000) Reclassification ​ ​ 52,931 ​ ​ (52,931) ​ ​ — ​ ​ — ​ ​ — On December 31, 2023 ​ $ 108,931 ​ $ 17,249 ​ $ 4,340 ​ $ — ​ $ 130,520 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization and impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2021 ​ $ — ​ $ — ​ $ (437) ​ $ — ​ $ (437) Amortization ​ ​ ​ ​ ​ ​ ​ ​ (470) ​ ​ — ​ ​ (470) On December 31, 2021 ​ ​ — ​ ​ — ​ ​ (907) ​ ​ — ​ ​ (907) Amortization ​ ​ — ​ ​ — ​ ​ (711) ​ ​ (99,058) ​ ​ (99,768) Derecognition ​ ​ — ​ ​ — ​ ​ — ​ ​ 99,058 ​ ​ 99,058 On December 31, 2022 ​ ​ — ​ ​ — ​ ​ (1,618) ​ ​ — ​ ​ (1,618) Amortization ​ ​ (3,392) ​ ​ — ​ ​ (282) ​ ​ (102,000) ​ ​ (105,674) Derecognition ​ ​ — ​ ​ — ​ ​ — ​ ​ 102,000 ​ ​ 102,000 On December 31, 2023 ​ $ (3,392) ​ $ — ​ $ (1,900) ​ $ — ​ $ (5,292) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2021 ​ $ — ​ $ 70,180 ​ $ 2,446 ​ $ 99,058 ​ $ 171,684 On December 31, 2022 ​ ​ — ​ ​ 70,180 ​ ​ 2,722 ​ ​ 102,000 ​ ​ 174,901 On December 31, 2023 ​ $ 105,539 ​ $ 17,249 ​ $ 2,440 ​ $ — ​ $ 125,228 ​ Acquired In-Process R&D is mainly related to the in-licensing of the ENHANZE® drug delivery technology from Halozyme. In line with its accounting policies, the Company has capitalized the upfront payment upon commencement of the in-license agreement in 2019 and the development milestone payments when the respective milestone has been achieved. In June 2023, the Company obtained the FDA approval for VYVGART Hytrulo, which is a subcutaneous product combination of efgartigimod alfa and Halozyme’s ENHANZE® drug delivery technology. Upon this regulatory approval, the $52.9 million Further, the additions to “Acquired R&D available for use” are related to regulatory and sales-based milestones triggered during 2023 related to the in-licensing of the ENHANZE® drug delivery technology from Halozyme. In line with its accounting policies, the Company has capitalized the regulatory and sales-based milestone payments when the respective milestones have been achieved. The “Acquired R&D available for use” are amortized under “Cost of sales” on a straight-line basis over their useful life, being the longer of the patent protection life of the Acquired R&D available for use and patent protection life of the combined product, which is 2036 for VYVGART Hytrulo. The Company performs an annual impairment review on the intangible assets. This review did not result in the recognition of an impairment charge for the years ended December 31, 2023, 2022 and 2021. In the fourth quarter of 2023, the Company utilized the PRV submitted with the sBLA filing for VYVGART Hytrulo for the treatment of CIDP, which resulted in amortization of $102.0 million of intangible asset which is recognized under “Research and development expenses” within the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) and subsequent derecognition of $102.0 million of intangibles included under “other intangibles” on the consolidated statements of financial position As of December 31, 2023, there are no material commitments to acquire intangible assets, except as set forth in note 29. No intangible assets are pledged as security for liabilities nor are there any intangible assets whose title is restricted.

Other non-current assets

Other non-current assets	12 Months Ended
	Dec. 31, 2023
Other non-current assets,
Other non-current assets	6. Other non-current assets Other non-current assets consisted of non-current restricted cash and financial assets held at fair value through profit or loss or through OCI. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Non-current restricted cash $ 2,419 $ 1,736 $ 1,707 Non-current financial assets held at fair value through profit or loss ​ 21,715 ​ 21,715 ​ 17,459 Non-current financial assets held at fair value through OCI ​ ​ 15,528 ​ ​ 17,443 ​ ​ 35,710 Total other non-current assets $ 39,662 $ 40,894 $ 54,876 ​ Non-current restricted cash on December 31, 2023 was mainly composed of deposit guarantees paid under the lease agreements for the laboratory and offices of the Company. Non-current financial assets held at fair value through profit or loss is comprised of the profit share in AgomAb Therapeutics NV. In March 2019, the Company entered into a license agreement with AgomAb Therapeutics NV for the use of HGF-mimetic SIMPLE Antibodies™, developed under the Company’s Immunology Innovative Program. In exchange for granting this license, the Company received a profit share in AgomAb Therapeutics NV. Since AgomAb Therapeutics NV is a private company, the valuation of the profit share is based on level 3 assumptions. In June 2022, AgomAb Therapeutics NV secured €38.4 million as a result of the extension of Series B. The Company used the post-money valuation of this Series B financing round and the number of outstanding shares in determining the fair value of the profit-sharing instrument, which resulted in a change in fair value of non-current financial assets of $4.3 million recorded through profit or loss in 2022. In October 2023, AgomAb Therapeutics NV secured $100.0 million as a result of a Series C financing round. The Company’s profit share diluted as the number of shares held by the company stayed stable where the post-money valuation of AgomAb increased, which results in no change in fair value of the non-current asset. Fair value changes on non-current financial assets with fair value through profit or loss are recognized in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) under “Other operating income”. As part of the license agreement for the development and commercialization for efgartigimod in Greater China, in 2021 the Company obtained, amongst others, 568,182 newly issued Zai Lab shares calculated at a price of $132 per share. The fair value of the equity instrument at reporting date is determined by reference to the closing price of such securities at each reporting date (classified as level 1 in the fair value hierarchy). The Company made the irrevocable election to recognize subsequent changes in fair value through OCI under “Fair value gain/(loss) on investments in equity instruments designated as at FVTOCI”. The table below illustrates these non-current financials assets at fair value through profit or loss or OCI as of December 31, 2023, 2022 and 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Cost at January 1 $ 76,659 $ 76,659 $ 1,659 Additions of the year ​ ​ — ​ ​ — ​ ​ 75,000 Cost at December 31 ​ $ 76,659 ​ $ 76,659 ​ $ 76,659 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value adjustments at January 1 ​ $ (37,501) ​ $ (23,490) ​ $ 4,648 Fair value adjustment of the year through profit or loss ​ ​ — ​ ​ 4,256 ​ ​ 11,152 Fair value adjustment of the year through OCI ​ ​ (1,915) ​ ​ (18,267) ​ ​ (39,290) Fair value adjustment at December 31 ​ $ (39,416) ​ $ (37,501) ​ $ (23,490) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net book value at December 31 $ 37,243 $ 39,158 $ 53,169 ​

Inventories

Inventories	12 Months Ended
	Dec. 31, 2023
Inventories
Inventories	7. Inventories ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Raw materials and consumables ​ $ 240,836 $ 126,046 $ 70,134 Inventories in process ​ ​ 47,074 ​ ​ 65,016 ​ ​ 37,705 Finished goods ​ ​ 22,640 ​ ​ 37,291 ​ ​ 1,237 Total inventories $ 310,550 $ 228,353 $ 109,076 ​ The cost of inventories, which is recognized under “Cost of sales” in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss), amounted to $101.2 million for the year ended December 31, 2023 (compared to $29.4 million for the year ended December 31, 2022). On December 31, 2023, pre-launch inventory awaiting facility approval amounted to $101.3 million. As a result of the detection of a latent defect in the second quarter of 2023 in drug substance batches produced in 2022 at one of the facilities awaiting approval, the Company has decreased inventory with an amount of $47.3 million. The Company has obtained the commitment from the supplier to replace the drug substance from these batches in the coming years, which is reflected under “non-current prepaid expense” in the consolidated statement of financial position amounting to $47.3 million.

Prepaid expenses (Current)

Prepaid expenses (Current)	12 Months Ended
	Dec. 31, 2023
Prepaid expenses (Current)
Prepaid expenses (Current)	8. Prepaid expenses (Current) The current prepaid expenses are composed of prepayments which are details below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Prepaid inventory ​ ​ 22,460 ​ ​ 11,667 ​ ​ 10,786 Prepaid research and development expenses ​ ​ 71,201 ​ ​ 44,905 ​ ​ 39,684 Prepaid advertising expenses ​ ​ 19,933 ​ ​ 13,479 ​ ​ 2,006 Prepaid software ​ ​ 6,240 ​ ​ 4,309 ​ ​ 2,272 Other prepaid expenses ​ ​ 14,238 ​ ​ 1,662 ​ ​ 4,198 Total prepaid expenses $ 134,072 $ 76,022 $ 58,946 ​

Trade and other receivables

Trade and other receivables	12 Months Ended
	Dec. 31, 2023
Trade and other receivables.
Trade and other receivables	9. Trade and other receivables The trade and other receivables are composed of receivables which are detailed below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Trade receivable ​ $ 417,994 ​ $ 241,228 ​ $ 28,058 Interest receivable ​ ​ 13,126 ​ ​ 12,918 ​ ​ 1,325 Tax receivables ​ ​ 63,605 ​ ​ 20,526 ​ ​ 7,974 Other receivable ​ ​ 1,962 ​ ​ 1,025 ​ ​ 864 Total trade and other receivables $ 496,687 $ 275,697 $ 38,221 ​ The carrying amounts of trade and other receivables approximate their respective fair values. On December 31, 2023, 2022 and 2021, we did not have any provision for expected credit losses. Please also refer to Note 26 for more information on the financial risk management.

Financial assets - current

Financial assets - current	12 Months Ended
	Dec. 31, 2023
Financial assets - current.
Financial assets - current	10. Financial assets — current These current financial assets relate to term accounts with an initial maturity longer than 3 months but less than 12 months and money market funds that do not qualify as cash equivalents. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Money market funds $ — $ 46,162 $ 73,052 Term accounts ​ ​ 1,131,000 ​ ​ 1,345,646 ​ ​ 929,000 Total current financial assets $ 1,131,000 $ 1,391,808 $ 1,002,052 ​ On December 31, 2023, the current financial assets included $221.0 million (€200.0 million) held in EUR, which could generate a foreign currency exchange gain or loss in the financial results in accordance with the fluctuations of the USD/EUR exchange rate as the Company’s functional currency is USD. Please also refer to Note 26 for more information on the financial risk management.

Cash and cash equivalents

Cash and cash equivalents	12 Months Ended
	Dec. 31, 2023
Cash and cash equivalents
Cash and cash equivalents	11. Cash and cash equivalents ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Money market funds $ 1,678,100 $ 669,147 $ 997,092 Term accounts ​ ​ 350,000 ​ ​ 54,116 ​ ​ 95,090 Cash and bank balances ​ 20,744 ​ 77,477 ​ 242,494 Total cash and cash equivalents $ 2,048,844 $ 800,740 $ 1,334,676 ​ Cash and cash equivalents may comprise of cash and bank balances, saving accounts, term accounts with an original maturity not exceeding 3 months and money market funds that are readily convertible to cash and are subject to an insignificant risk of changes in value. Cash positions are invested with preferred financial partners, which are mostly considered to be high quality financial institutions with sound credit ratings to reduce credit risk. On December 31, 2023, the cash and cash equivalents included $702.8 million (€636.0 million) held in EUR, and $8.2 million (¥1,164.6 million) held in JPY which could generate a foreign currency exchange gain or loss in the financial results in accordance with the fluctuations of the USD/EUR and USD/JPY exchange rates as the Company’s functional currency is USD. Please also refer to Note 26 for more information on the financial risk management.

Share capital and share premium

Share capital and share premium	12 Months Ended
	Dec. 31, 2023
Share capital and share premium
Share capital and share premium	12. Share capital and share premium On December 31, 2023, the Company’s share capital was represented by 59,194,488 shares. All shares were issued, fully paid up and of the same class. The table below summarizes the share issuances as a result of offerings, exercise of stock options and the vesting of restricted stock units under the Company’s Employee Stock Option Plan. Roll forward of number of shares outstanding: ​ ​ ​ ​ Number of shares outstanding on January 1, 2021 47,571,283 Exercise of stock options ​ 503,282 Global public offering in Euronext and Nasdaq on February 2, 2021 ​ 3,125,000 Over-allotment option exercised by underwriters on February 4, 2021 ​ 468,750 Number of shares outstanding on December 31, 2021 51,668,315 Exercise of stock options ​ 1,024,626 Vesting of RSUs ​ 19,581 Global public offering in Euronext and Nasdaq on March 23, 2022 ​ 2,333,334 Over-allotment option exercised by underwriters on March 29, 2022 ​ 350,000 Number of shares outstanding on December 31, 2022 55,395,856 Exercise of stock options ​ 1,137,439 Vesting of RSUs ​ 79,560 Global public offering in Nasdaq on July 18, 2023 ​ 2,244,899 Over-allotment option exercised by underwriters on July 19, 2023 ​ 336,734 Number of shares outstanding on December 31, 2023 59,194,488 ​ ​ ​ ​ On May 2, 2023, at the annual general meeting, the shareholders of the Company approved the authorization to the Board to issue up to a maximum of 10% of the then-outstanding share capital, for a period of 18 months. On July 18, 2023, argenx SE offered 2,244,899 of its ordinary shares through a global offering which consisted of 1,580,981 ADSs in the U.S. at a price of $490.0 per ADS, before underwriting discounts and commissions and offering expenses; and 663,918 ordinary shares in the European Economic Area at a price of €436.37 per share, before underwriting discounts and commissions and offering expenses. On July 19, 2023, the underwriters of the offering exercised their overallotment option to purchase 336,734 additional ADSs in full. As a result, argenx SE received $1.26 billion in gross proceeds from this offering, decreased by $65.9 million of underwriter discounts and commissions, and offering expenses, of which $0.8 million has been deducted from equity. The total net cash proceeds from the offering amounted to $1.2 billion. On December 31, 2023, an amount of €202,408.2, represented by 2,024,082 shares, still remained available under the authorization to issue shares as granted to the Board by the shareholders of the Company.

Share-based payments

Share-based payments	12 Months Ended
	Dec. 31, 2023
Share-based payments
Share-based payments	13. Share-based payments The Company has an equity incentive plan for the employees, key consultants, board members, senior management and key outside advisors (“key persons”) of the Company and its subsidiaries. In accordance with the terms of the plan, as approved by shareholders, employees may be granted stock options and/or restricted stock units. 13.1 Stock Option The stock options are granted to key persons of the Company and its subsidiaries. The stock options may be granted to purchase ordinary shares at an exercise price. The stock options have been granted free of charge. Each employee’s stock option converts into one ordinary share of the Company upon exercise. The stock options carry neither rights to dividends nor voting rights. Stock options may be exercised at any time from the date of vesting to the date of their expiry. The stock options granted vest, in principle, as follows: ● 1/3rd of the total stock options granted will vest on the first anniversary of the granting of the stock options, and ● 1/36th of the total grant on the first day of each month following the first anniversary of the date of grant of the stock options. Stock options granted to non-executive directors vest on the third anniversary of the date of grant. Upon leave of the key persons stock options must be exercised before the later of (i) 90 days after the last working day at argenx, or (ii) March 31 of the 4th year following the date of grant of those stock options, and in any case no later than the expiration date of the option. In order to prefinance the taxes that are paid upon the grant of stock options, Belgian employees have the ability, in exchange for the taxes due upon the grant of the stock options, to transfer the economic benefits related to part of those stock options to a third party. In the year ending December 31, 2023, the economic benefits of 43,336 stock options, for which accelerated vesting applies, were transferred to a third party. No other conditions are attached to the stock options. The following stock option arrangements were in existence during the current and prior years and which are exercisable at the end of each period presented: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Exercise price ​ Outstanding ​ ​ per stock ​ stock options on ​ ​ options ​ December 31, Expiry date (in $) (1) 2023 2022 2021 2022 ​ $ 2.70 ​ — ​ — ​ 125,339 2024 ​ 2.70 3,308 19,743 94,088 2024 ​ 4.36 532 5,127 6,113 2024 ​ 7.92 81,500 214,800 276,500 2025 ​ 12.64 1,600 2,000 4,500 2025 ​ 10.46 99,326 101,861 105,857 2026 ​ 12.57 24,400 30,000 41,000 2026 ​ 12.67 97,972 99,772 102,840 2026 ​ 15.62 111,811 115,211 117,581 2027 ​ ​ 20.34 ​ 38,434 ​ 42,509 ​ 53,143 2027 ​ ​ 23.39 ​ 225,852 ​ 303,867 ​ 361,350 2023 ​ ​ 89.31 ​ — ​ 12,111 ​ 85,080 2028 ​ ​ 89.31 ​ 13,890 ​ 19,490 ​ 39,515 2023 ​ ​ 95.38 ​ — ​ 124,338 ​ 321,473 2028 ​ ​ 95.38 ​ 225,457 ​ 264,392 ​ 350,631 2024 ​ ​ 125.40 ​ 26,171 ​ 110,774 ​ 111,174 2029 ​ ​ 125.40 ​ 71,573 ​ 110,756 ​ 146,765 2024 ​ ​ 150.00 ​ 104,176 ​ 202,852 ​ 203,658 2029 ​ ​ 150.00 ​ 370,566 ​ 537,110 ​ 611,122 2025 ​ ​ 132.08 ​ 16,712 ​ 16,712 ​ 16,712 2030 ​ ​ 132.08 ​ 50,801 ​ 71,486 ​ 102,558 2025 ​ ​ 216.75 ​ 126,331 ​ 127,731 ​ 129,711 2030 ​ ​ 216.75 ​ 160,677 ​ 223,812 ​ 282,475 2025 ​ ​ 221.24 ​ 31,424 ​ 32,100 ​ 32,100 2030 ​ ​ 221.24 ​ 78,534 ​ 117,790 ​ 136,601 2030 ​ ​ 273.60 ​ 559,173 ​ 620,014 ​ 692,214 2025 ​ ​ 273.60 ​ 202,205 ​ 202,475 ​ 203,214 2026 ​ ​ 259.01 ​ 23,491 ​ 23,491 ​ 24,366 2026 ​ ​ 281.89 ​ 59,626 ​ 60,890 ​ 61,505 2026 ​ ​ 286.75 ​ 45,228 ​ 45,862 ​ 48,138 2031 ​ ​ 259.01 ​ 27,201 ​ 35,214 ​ 42,282 2031 ​ ​ 281.89 ​ 128,600 ​ 167,406 ​ 207,464 2031 ​ ​ 286.75 ​ 62,138 ​ 81,311 ​ 92,456 2026 ​ ​ 341.67 ​ 80,425 ​ 80,833 ​ 82,430 2031 ​ ​ 341.67 ​ 226,520 ​ 286,353 ​ 307,158 2027 ​ ​ 312.16 ​ 13,957 ​ 14,976 ​ — 2032 ​ ​ 312.16 ​ 58,255 ​ 79,155 ​ — 2027 ​ ​ 395.04 ​ 58,091 ​ 61,816 ​ — 2032 ​ ​ 395.04 ​ 192,291 ​ 238,532 ​ — 2027 ​ ​ 407.19 ​ 13,764 ​ 13,764 ​ — 2032 ​ ​ 407.19 ​ 73,288 ​ 85,199 ​ — 2032 ​ ​ 397.36 ​ 347,765 ​ 370,354 ​ — 2027 ​ ​ 397.36 ​ 136,459 ​ 137,778 ​ — 2025 ​ ​ 341.67 ​ 16,000 ​ — ​ — 2028 ​ ​ 376.47 ​ 15,014 ​ — ​ — 2033 ​ ​ 376.47 ​ 43,856 ​ — ​ — 2028 ​ ​ 392.72 ​ 127,490 ​ — ​ — 2033 ​ ​ 392.72 ​ 495,821 ​ — ​ — 2028 ​ ​ 508.96 ​ 2,235 ​ — ​ — 2033 ​ ​ 508.96 ​ 69,704 ​ — ​ — 2028-2032 (2) ​ $ 330.06 ​ 79,305 ​ — ​ — ​ ​ ​ ​ ​ 5,118,949 5,511,767 ​ 5,619,113 (1) Amounts have been converted to USD at the closing rate as of December 31, 2023. (2) In December 2023, the Company granted stock options for which the Belgian taxed beneficiaries had a 60-day period to choose between a contractual term of five or ten years ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 ​ 2022 ​ 2021 ​ Number of Weighted average Number of Weighted average Number of Weighted average ​ ​ stock options ​ exercise price (*) ​ stock options ​ exercise price (*) ​ stock options ​ exercise price (*) Outstanding at January 1 5,511,767 $ 205.02 5,619,113 $ 164.33 5,365,743 $ 142.87 Granted 844,011 ​ 395.92 1,021,642 ​ 375.58 882,584 ​ 314.99 Exercised (1,137,439) ​ 142.31 (1,025,780) ​ 92.62 (503,282) ​ 64.72 Forfeited (99,390) ​ 356.57 (103,208) ​ 273.93 (125,932) ​ 234.98 Outstanding at December 31 5,118,949 ​ 255.41 5,511,767 ​ 205.02 5,619,113 ​ 164.33 Exercisable at December 31 3,030,486 $ 179.22 3,983,960 $ 148.11 3,613,371 $ 106.53 (*) amounts have been converted to USD at the closing rate of the respective period. The weighted average share price at the date of exercise of options exercised during the year ended December 31, 2023 was $456.8, compared to $336.5 during the year ended December 31, 2022 and ​ ​ ​ ​ ​ ​ ​ ​ Weighted average ​ ​ ​ ​ remaining ​ ​ Outstanding on ​ contractual life Exercise price (in $) December 31, 2023 (in years) 2.7 - 7.92 ​ 85,340 ​ 0.96 10.46 - 12.64 100,926 ​ 1.95 12.57 - 15.62 234,183 ​ 2.67 20.34 - 23.39 ​ 264,286 ​ 3.89 89.31 - 95.38 ​ 239,347 ​ 4.95 125.4 - 150 ​ 572,486 ​ 4.75 132.08 - 273.6 ​ 1,225,857 ​ 5.26 259.01 - 341.67 ​ 669,229 ​ 6.04 312.16 - 407.19 ​ 893,870 ​ 7.53 330.06 - 508.96 ​ 833,425 ​ 8.69 ​ The fair market value of the stock options has been determined based on the Black and Scholes model using the following unobservable assumptions: ● The expected volatility, determined on the basis of the implied volatility of the share price over the expected life of the option. ● The expected option life, calculated as the estimated duration until exercise, taking into account the specific features of the plans. Below is an overview of the parameters used in relation to the determination of the fair value of the grants during 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options granted in April 2023 July 2023 ​ October 2023 ​ December 2023 (1) ​ Number of options granted ​ 61,056 ​ 629,121 ​ ​ 74,529 ​ ​ 79,305 ​ Average Fair value of options (in $) (*) $ 158.21-196.18 $ 176.44 - 271.59 ​ $ 123.94 - 209.04 ​ $ 161.88 - 165.69 ​ Share price (in $) (*) $ 361.64-401.21 $ 380.81 - 521.19 ​ $ 439.42 - 491.75 ​ $ 371.36 ​ Exercise price (in $) (*) $ 370.34 $ 387.35 ​ $ 485.01 ​ $ 329.26 ​ Expected volatility ​ 41.00 - 42.18 % ​ 36.22 - 43.99 % ​ 35.35 - 36.67 % ​ 36.20 - 36.21 % Average Expected option life (in years) ​ 4 - 6.50 ​ 4 - 6.50 ​ 4 - 6.50 ​ ​ 6.15 - 6.50 ​ Risk‑free interest rate ​ 2.96 - 3.14 % ​ 2.90 - 3.03 % ​ 2.80 - 3.44 % ​ 2.40 % Expected dividends ​ — % ​ — % ​ — % ​ — % (1) In December 2023, the Company granted a total of 79,305 stock options of which 8,459 stock options to Belgian taxed beneficiaries. Belgian taxed beneficiaries can choose between a contractual term of five or ten years . The expected option life ranges between 6.15 and 6.50 years. This estimate will be reassessed once the acceptance period of 60 days has passed and the beneficiaries will have made a choice between a contractual term of five or ten years . The total fair value of the grant to Belgian taxed beneficiaries would range from $ 1.1 million ( 100% of the stock options of Belgian taxed beneficiaries with a contractual term of five years ) to $1.4 million ( 100% of the stock options of Belgian taxed beneficiaries with a contractual term of ten years ). (*) amounts have been converted to USD at the applicable rate prevailing at the grant date. Below is an overview of the parameters used in relation to the determination of the fair value of grants during 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options granted in April 2022 July 2022 ​ October 2022 December 2022 (1) ​ Number of options granted ​ 102,081 ​ 311,311 ​ ​ 100,118 ​ ​ 508,132 ​ Average Fair value of options (in $) (*) $ 111.27 - 140.23 $ 153.45 - 190.53 ​ $ 136.66 - 169.96 ​ $ 127.68 - 163.94 ​ Share price (in $) (*) $ 320.84 - 321.06 $ 378.11 - 397.92 ​ $ 352.97 - 376.01 ​ $ 368.69 - 377.61 ​ Exercise price (in $) (*) $ 312.22 $ 372.69 ​ $ 359.80 ​ $ 381.97 ​ Expected volatility ​ 39.18 - 40.87 % ​ 41.30 - 43.10 % ​ 39.64 - 45.97 % ​ 39.74 - 40.26 % Average Expected option life (in years) ​ 4 - 6.50 ​ 4 - 6.50 ​ 4 - 6.50 ​ ​ 4 - 6.50 ​ Risk‑free interest rate ​ 1.05 - 1.62 % ​ 1.77 - 2.28 % ​ 2.57 - 2.80 % ​ 3.09 - 3.29 % Expected dividends ​ — % ​ — % ​ — % ​ — % (*) amounts have been converted to USD at the applicable rate prevailing at the grant date. (1) In December 2022, the Company granted a total of 508,132 stock options. Belgian beneficiaries could choose between a contractual term of five or ten years impacting the parameters used in determination of the fair value of the grant. Once the acceptance period of 60 days has passed in which the beneficiaries made a choice between a contractual term of five or ten years , the parameters and fair value used in the financial year ending December 31, 2022 has been reassessed. Below is an overview of the parameter used in relation to the determination of the fair value of grants during 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options granted in April 2021 July 2021 October 2021 ​ December 2021 ​ Number of options granted ​ 67,833 ​ 280,339 ​ ​ 144,824 ​ ​ 389,588 ​ Average Fair value of options (in $) (*) $ 98.96 - 154.88 $ 131.65 - 159.13 ​ $ 101.53 - 131.80 ​ $ 75.03 - 145.34 ​ Share price (in $) (*) $ 248.9 - 283.67 $ 300.78 - 340.95 ​ $ 286.52 - 304.5 ​ $ 277.72 - 351.73 ​ Exercise price (in $) (*) $ 275.33 $ 303.16 ​ $ 301.02 ​ $ 349.92 ​ Expected volatility ​ 54.24 - 60.08 % ​ 45.58 - 47.96 % ​ 46.01 - 48.46 % ​ 43.24 - 43.64 % Average expected option life (in years) ​ 4 - 6.50 ​ 4 - 6.50 ​ 4 - 6.50 ​ ​ 4 - 6.50 ​ Risk‑free interest rate ​ (0.41) - (0.08) % ​ (0.41) - (0.17) % ​ (0.18) - (0.05) % ​ 0.03 - 0.67 % Expected dividends ​ — % ​ — % ​ — % ​ — % (*) amounts have been converted to USD at the closing rate of the respective period. The total share-based payment expense related to stock options recognized in the consolidated statements of profit or loss totaled $164.0 million for the year ended December 31, 2023, compared to $120.2 million for the year ended December 31, 2022 and $171.2 million for the year ended December 31, 2021. 13.2 Restricted Stock Units (RSUs) The RSUs are granted to key persons of the Company and its subsidiaries. The RSUs have been granted free of charge. Each employee’s RSUs converts into one ordinary share of the Company upon vesting. The RSUs carry neither rights to dividends nor voting rights. RSUs once converted into ordinary shares, may be sold at any time from the date of vesting, have no expiry date and may be held by the participant without limitation. The fair value of RSUs is based on the closing sale price of the Company’s common stock on the day prior to the date of issuance. RSUs vest over a period of 4 years with 1/4th The following restricted stock units arrangements were in existence during the current and prior years: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 ​ 2022 ​ 2021 ​ ​ Weighted average ​ Weighted average ​ Weighted average ​ ​ Number of ​ Grant Date ​ Number of ​ Grant Date ​ Number of ​ Grant Date ​ ​ RSUs ​ Fair Value ​ RSUs ​ Fair Value ​ RSUs ​ Fair Value Non-vested units at January 1 385,280 ​ $ 387.20 ​ 213,038 ​ $ 314.25 ​ — ​ $ — Granted 192,237 ​ ​ 396.22 ​ 243,010 ​ ​ 375.81 ​ 216,522 ​ ​ 313.84 Vested (105,678) ​ ​ 352.61 ​ (53,872) ​ ​ — ​ — ​ ​ — Forfeited (29,517) ​ ​ 358.49 ​ (16,896) ​ ​ 307.11 ​ (3,484) ​ ​ 288.92 Non-vested units at December 31 442,322 ​ $ 375.89 ​ 385,280 ​ $ 387.20 ​ 213,038 ​ $ 314.25 ​ The total share-based payment expense related to RSUs recognized in the consolidated statements of profit or loss totaled $69.0 million for the year ended December 31, 2023 compared to $36.9 million for the year ended December 31, 2022 and $8.1 million for the year ended December 31, 2021.

Trade and other payables

Trade and other payables	12 Months Ended
	Dec. 31, 2023
Trade and other payables.
Trade and other payables	14. Trade and other payables ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Trade payables $ 245,557 $ 188,721 $ 208,850 Short‑term employee benefits ​ 95,104 ​ 84,337 ​ 83,737 Gross-to-net-accruals ​ ​ 55,788 ​ ​ 19,478 ​ ​ — Other ​ ​ 17,564 ​ ​ 3,142 ​ ​ 828 Total trade and other payables $ 414,013 $ 295,679 $ 293,415 ​ The carrying amounts of trade and other payables approximate their respective fair values. Trade payables correspond primarily to clinical and manufacturing activities and include accrued expenses related to these activities. Short-term employee benefits include payables and accruals for salaries and bonuses to be paid to the employees of the Company. The following table summerizes the movement in the gross-to-net-accruals for the year ended December 31, 2023, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) ​ ​ Rebates and chargebacks ​ ​ Distribution fees, product returns and other ​ ​ Total Balance at January 1, 2022 ​ $ — ​ $ — ​ $ — Current estimate related to the sales made in the current year ​ ​ 35,426 ​ ​ 10,740 ​ ​ 46,166 (Credits or payments related to sales made during the year) ​ ​ (20,028) ​ ​ (6,661) ​ ​ (26,689) Balance at December 31, 2022 ​ $ 15,398 ​ $ 4,079 ​ $ 19,478 Current estimate related to the sales made in the current year ​ ​ 123,542 ​ ​ 26,427 ​ ​ 149,969 Adjustment for prior year sales ​ ​ (4,041) ​ ​ (883) ​ ​ (4,924) (Credits or payments related to sales made during the year) ​ ​ (78,327) ​ ​ (20,722) ​ ​ (99,049) (Credit or payments related to sales made during prior year) ​ ​ (6,910) ​ ​ (2,775) ​ ​ (9,685) Balance at December 31, 2023 ​ $ 49,662 ​ $ 6,126 ​ $ 55,788 ​

Product net sales

Product net sales	12 Months Ended
	Dec. 31, 2023
Product net sales.
Product net sales	15. Product net sales ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) ​ 2023 ​ 2022 2021 Product gross sales ​ $ 1,342,148 ​ ​ 446,923 ​ ​ - Gross to net adjustment ​ ​ (151,365) ​ ​ (46,203) ​ ​ - Product net sales ​ $ 1,190,783 ​ ​ 400,720 ​ ​ - ​ For the twelve months ended December 31, 2023, the product net sales was related to sales of VYVGART and VYVGART SC. For the twelve months ended December 31, 2022, the product net sales was related to sales of VYVGART. Refer to note 18 for the breakdown of Product net sales by country of sale.

Collaboration revenue

Collaboration revenue	12 Months Ended
	Dec. 31, 2023
Collaboration revenue
Collaboration revenue	16. Collaboration revenue The following table summarizes details of collaboration revenues for the year ended December 31, 2023, 2022 and 2021 by collaboration agreement and by category of revenue: upfront payments, milestone payments, research and development service fees and other revenue. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, (in thousands of $) ​ 2023 ​ 2022 2021 Zai Lab ​ ​ $ — ​ ​ — ​ ​ J&J ​ ​ — ​ ​ — ​ ​ 292,279 AbbVie ​ ​ — ​ ​ — ​ ​ 121 Upfront payments ​ ​ ​ — ​ ​ — ​ ​ 444,303 Zai Lab ​ ​ ​ — ​ ​ — ​ ​ 25,634 J&J ​ ​ ​ — ​ ​ — ​ ​ 22,865 AbbVie ​ ​ ​ 30,000 ​ ​ — ​ ​ 102 Other ​ ​ ​ — ​ ​ 5,365 ​ ​ 1,214 Milestone payments ​ ​ ​ 30,000 ​ ​ 5,365 ​ ​ 49,815 J&J ​ ​ ​ — ​ ​ — ​ ​ 2,028 Other ​ ​ ​ — ​ ​ 424 ​ ​ 298 Research and development service fees ​ ​ ​ — ​ ​ 424 ​ ​ 2,326 Zai Lab ​ ​ ​ 5,533 ​ ​ 4,238 ​ ​ 833 Other collaboration revenue ​ ​ ​ 5,533 ​ ​ 4,238 ​ ​ 833 Total collaboration revenue ​ ​ $ 35,533 ​ $ 10,026 ​ $ 497,277 ​ For the years ended December 31, 2023, 2022 and 2021, the collaboration revenue was generated under the agreements with Zai Lab, J&J and AbbVie, each as described below. Zai Lab On January 6, 2021, argenx and Zai Lab announced the License agreement for the development and commercialization of efgartigimod in Greater China, granting Zai Lab the exclusive rights to develop and commercialize efgartigimod in Greater China. Under the terms of the agreement, the Company received $175.0 million in collaboration payments, comprised of a $75 million upfront payment in the form of 568,182 newly issued Zai Lab shares calculated at a price of $132 per share, $75 million as guaranteed non-creditable, non-refundable payment, received in the first quarter of 2021, and an additional $25 million milestone payment upon regulatory approval of efgartigimod by FDA in the U.S. The Company is also eligible to receive tiered royalties (mid-teen to low twenties on a percentage basis) based on annual net sales of efgartigimod in Greater China. As stated in the accounting policies regarding this collaboration with Zai Lab, the Company concluded there are two performance obligations under IFRS 15, being the transfer of a license and the at arms-length supply of clinical and commercial product. The transaction price of these two agreements was composed of a fixed part, that being an upfront payment of $75 million in the form of newly issued Zai Lab shares, and a $75 million guaranteed, non-creditable, non-refundable payment and $25 million milestone for approval of efgartigimod in the U.S. and the consideration received in return for the supply of clinical and commercial product. The fixed part of the transaction price, as well as the $25 million milestone for approval of efgartigimod in the U.S. has been allocated to the transfer of a license performance obligation, which has been satisfied as of the effective date of the contract, being January 2021 and therefore the revenue is recognized at that point in time. Under the collaboration agreement, the Company provides clinical supply to Zai Lab. The revenue related to clinical supply is recorded under line item “Other revenues” within the collaboration revenue. The income related to royalties is recorded as “Other revenues” under “collaboration revenue”. During the year ending December 31, 2023 the first revenue related to commercial supply and related royalties are recognized. Please refer to Note 2 for the material accounting policies on the remainder elements of the agreement. AbbVie In April 2016, the Company entered into a collaboration agreement with AbbVie to develop and commercialize ARGX-115 (ABBV-151). The Company granted AbbVie an exclusive option, for a specified period following completion of IND enabling studies, to obtain a worldwide, exclusive license to the ARGX-115 (ABBV-151) program to develop and commercialize products. In October 2023, the Company achieved the second development milestone upon initiation of a non-pivotal Clinical Trial, triggering a $30.0 million payment. Subject to the continuing progress of ARGX-115 (ABBV-151) by AbbVie, the Company is eligible to receive future development, regulatory and commercial milestone payments in aggregate amounts of up to $50 million, $190 million and $325 million, respectively, as well as tiered royalties on sales at percentages ranging from the mid-single digits to the lower teens, subject to customary reductions. J&J Innovative Medicines On June 4, 2021, the Company received a termination notification from Cilag GmbH International, an affiliate of J&J Innovative Medicines (J&J), which results in the termination of the Collaboration Agreement to jointly develop and commercialize cusatuzumab. Following the termination, the Company concluded that it has substantially satisfied the performance obligation, and as a consequence, recorded $315.1 million for the 12 months ending December 31, 2021.

Other operating income

Other operating income	12 Months Ended
	Dec. 31, 2023
Other operating income
Other operating income	17. Other operating income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Grants $ 2,538 $ 2,186 $ 4,398 Research and development incentives ​ 27,815 ​ 19,502 ​ 13,970 Payroll tax rebates ​ 11,925 ​ 8,576 ​ 12,621 Change in fair value on non-current financial assets ​ ​ — ​ ​ 4,256 ​ ​ 11,152 Total other operating income $ 42,278 $ 34,520 $ 42,141 ​ 17.1 Research and development incentives The Company has accounted for a tax incentive following a research and development tax incentive scheme in Belgium according to which the incentive will be refunded after a five year period, if not offset against the current tax payable over the period. 17.2 Payroll tax rebates The Company accounted for payroll tax rebates as a reduction in withholding income taxes for its highly qualified personnel employed in its research and development department.

Segment reporting

Segment reporting	12 Months Ended
	Dec. 31, 2023
Segment reporting
Segment reporting	18. Segment reporting The Company manages its activities and operates as one business unit which is reflected in its organizational structure and internal reporting. The Company does not distinguish in its internal reporting different segments, neither business nor geographical segments. The chief operating decision-maker is the Board of Directors. Following table summarizes the product net sales by country of sales based on the country of the entity that recognizes product net sales: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, (in thousands of $) 2023 2022 United States ​ $ 1,046,592 ​ $ 377,659 Japan ​ ​ 56,432 ​ ​ 15,764 EMEA ​ ​ 72,852 ​ ​ 7,297 China ​ ​ 14,907 ​ ​ — Total product net sales $ 1,190,783 $ 400,720 ​ The Company sells its products through a limited number of distributors and wholesellers. Four U.S. customers represent approximately 86% of the product net sales in U.S. during twelve months ended December 31, 2023 (compared to 91% for the same period in 2022). Collaboration revenue is generated by external customers with their main registered office geographically located as shown in the table below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended ​ ​ ​ December 31, ​ (in thousands of $) 2023 2022 2021 Denmark $ — $ 5,365 $ 1,389 United States ​ 30,000 ​ — ​ 317,396 China ​ ​ 5,533 ​ ​ 4,238 ​ ​ 178,370 ​ Other ​ — ​ 424 ​ 123 Total collaboration revenue $ 35,533 $ 10,026 $ 497,277 ​ The property plant and equipment and intangible assets of the Company are geographically located as shown in the table below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-current assets ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Netherlands $ — $ — $ — Belgium ​ 138,252 ​ 186,923 ​ 182,118 United States ​ 6,219 ​ 2,275 ​ 3,091 Japan ​ 2,971 ​ 1,938 ​ 2,319 Germany ​ ​ 461 ​ ​ — ​ ​ — Total $ 147,903 $ 191,136 $ 187,528 ​ Prior year amounts were updated/recast to match current year presentation ​

Research and development expens

Research and development expenses	12 Months Ended
	Dec. 31, 2023
Research and development expenses
Research and development expenses	19. Research and development expenses ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 ​ 2021 Personnel expenses $ 226,344 $ 162,010 $ 160,464 External research and development expenses ​ 483,192 ​ 366,955 ​ 382,902 Materials and consumables ​ 4,057 ​ 2,396 ​ 2,735 Depreciation and amortization ​ 105,546 ​ 102,132 ​ 3,742 IT expenses ​ ​ 19,935 ​ ​ 12,678 ​ ​ 7,798 Other expenses ​ 20,418 ​ 17,194 ​ 22,879 Total Research and development expenses $ 859,492 $ 663,366 $ 580,520 ​

Selling, general and administra

Selling, general and administrative expenses	12 Months Ended
	Dec. 31, 2023
Selling, general and administrative expenses
Selling, general and administrative expenses	20. Selling, general and administrative expenses ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Personnel expenses $ 303,033 $ 234,740 $ 164,646 Marketing services ​ 202,146 ​ ​ 115,950 ​ 59,968 Professional fees ​ ​ 108,820 ​ ​ 62,620 ​ ​ 42,707 Supervisory board ​ 8,362 ​ 6,912 ​ 12,958 Depreciation and amortization ​ ​ 2,366 ​ ​ 2,211 ​ ​ 2,126 IT expenses ​ ​ 20,408 ​ ​ 17,431 ​ ​ 8,977 Other expenses ​ 66,770 ​ 32,268 ​ 16,263 Total Selling, general and administrative expenses $ 711,905 $ 472,132 $ 307,644 ​

Personnel expenses

Personnel expenses	12 Months Ended
	Dec. 31, 2023
Personnel expenses
Personnel expenses	21. Personnel expenses The personnel expenses mentioned in notes 19 and 20 above are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Short‑term employee benefits—Salaries $ 266,482 $ 216,847 $ 135,676 Short‑term employee benefits—Social Security ​ 19,231 ​ 16,274 ​ 12,785 Post‑employment benefits ​ 7,758 ​ 5,406 ​ 2,864 Termination benefits ​ 1,089 ​ 401 ​ 818 Share‑based payment ​ 226,830 ​ 151,912 ​ 167,965 Employer social security contributions stock options ​ 7,987 ​ 5,910 ​ 5,002 Total personnel expenses $ 529,377 $ 396,750 $ 325,110 ​ The post-employment benefits relate to the pension plans the Company has in place for its employees. The average number of full-time equivalents (FTE) employees by function is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, Average Number of FTE 2023 2022 2021 Research and development ​ 607.3 ​ 474.8 ​ 349.7 Selling, general and administrative ​ 681.2 ​ 442.4 ​ 264.4 ​ ​ 1,288.5 ​ 917.2 ​ 614.1 ​

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases
Leases	22. Leases The statements of financial position shows the following amounts relating to leases: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ December 31, ​ December 31, In thousands of $ 2023 ​ 2022 ​ 2021 Right-of-use assets ​ ​ ​ ​ ​ ​ ​ ​ Buildings $ 16,798 $ 10,867 $ 9,688 Vehicles ​ ​ 3,191 ​ ​ 1,835 ​ ​ 1,664 Equipment ​ ​ 160 ​ ​ 196 ​ ​ 230 ​ $ 20,149 ​ $ 12,897 ​ $ 11,583 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Lease liabilities ​ ​ ​ ​ ​ ​ ​ ​ Current $ 4,646 $ 3,417 $ 3,509 Non-current ​ ​ 15,354 ​ ​ 9,009 ​ ​ 7,956 ​ $ 20,000 ​ $ 12,426 ​ $ 11,465 ​ Additions to the right-of-use assets amounted to $11.1 million for the year ended December 31, 2023, compared to $4.2 million and $5.7 million for the years ended December 31, 2022 and 2021 respectively. The table below shows a maturity analysis of the lease liabilities as on December 31, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) Less than 1 year ​ 1-3 years ​ 3-5 years ​ More than 5 years ​ Total contractual cash flows ​ Carrying amount Lease liabilities $ 4,286 $ 8,136 ​ $ 5,754 ​ $ 1,824 ​ $ 20,000 $ 20,000 ​ The consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) shows the following amounts relating to leases: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, In thousands of $ 2023 2022 ​ 2021 Depreciation charges ​ ​ ​ ​ ​ ​ ​ ​ Buildings $ 2,839 $ 2,179 $ 2,714 Vehicles ​ ​ 971 ​ ​ 735 ​ ​ 651 Equipment ​ ​ 36 ​ ​ 35 ​ ​ 34 ​ $ 3,846 $ 2,949 $ 3,399 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest expense (included in finance cost) ​ $ 693 ​ $ 1,343 ​ $ 412 Expense relating to short-term leases ​ ​ 1,517 ​ ​ 732 ​ ​ 212 Expense relating to leases of low-value assets that are not shown above as short-term leases ​ ​ 40 ​ ​ 21 ​ ​ 7 ​ The total cash outflow for leases in 2023, 2022 and 2021 was $3.8 million, $4.2 million and $4.5 million respectively. The Company did not enter into any lease agreement with variable lease payments or residual value guarantees. The Company has leases that include extension options. These options provide flexibility in managing the leased assets and align with the Company’s business needs. The Company exercises judgement in deciding whether it is reasonably certain that the extension options will be exercised.

Financial result and exchange g

Financial result and exchange gains (losses)	12 Months Ended
	Dec. 31, 2023
Financial result and exchange gains/(losses)
Financial result and exchange gains/(losses)	23. Financial result and exchange gains/(losses) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Interest income $ 92,962 $ 24,741 $ 3,489 Net gain on cash equivalents & current financial assets held at fair value through profit or loss and cash equivalents ​ 14,424 ​ 2,924 ​ 144 Financial income $ 107,386 $ 27,665 $ 3,633 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss on cash equivalents & current financial assets held at fair value through profit or loss and cash equivalents ​ $ (2) ​ $ (1,713) ​ $ (3,482) Other financial expense ​ ​ (904) ​ ​ (2,193) ​ ​ (1,096) Financial expense ​ $ (906) ​ $ (3,906) ​ $ (4,578) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Realized exchange gains/(losses) $ 29 $ (3,743) $ 15 Unrealized exchange gains/(losses) ​ ​ 14,044 ​ ​ (28,989) ​ ​ (50,068) Exchange gains/(losses) $ 14,073 $ (32,732) $ (50,053) ​ The exchange gains of $14.1 million for the year ended December 31, 2023 were primarily attributable to unrealized exchange rate gains on the cash and cash equivalents and current financial assets position in EUR due to the fluctuation of the EUR/USD exchange rate over the period.

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2023
Income taxes
Income taxes	24. Income taxes Income taxes recognized in the income statements can be detailed as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Current year $ (9,592) $ (27,162) $ (15,224) Income tax prior years ​ (2,080) ​ (12) ​ 398 Current tax (expense) / benefit ​ (11,672) ​ (27,174) ​ (14,826) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Originating and reversal of temporary differences ​ ​ 21,115 ​ ​ 46,894 ​ ​ 6,304 Deferred tax (expense) / benefit ​ 21,115 ​ 46,894 ​ 6,304 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total tax (expense) / benefit ​ $ 9,443 ​ $ 19,720 ​ $ (8,522) ​ The difference between the provision for income taxes and the amount that would result from applying the Dutch statutory tax rate to income before provision for income taxes is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Loss before taxes $ 304,496 $ 729,314 $ 399,743 Income tax (expense)/benefit calculated at the Dutch statutory federal income tax rates for applicable tax years (1) ​ 78,560 ​ 188,163 ​ 99,936 Effect of intercompany asset deal / transaction ​ ​ 396 ​ ​ (112,200) ​ ​ — Effect of expenses not deductible in determining taxable results ​ (2,674) ​ (1,570) ​ (4,441) Effect of share based payment expenses that are not deductible in determining taxable results ​ ​ (43,040) ​ ​ (27,043) ​ ​ (29,925) Effect of stock issue expenses that are not taxable in determining taxable results ​ 18,620 ​ 11,412 ​ 14,119 Effect of concessions ​ 87,123 ​ 18,263 ​ 13,413 Effect of change of (de)recognition of deferred tax assets on tax losses ​ ​ (2,282) ​ ​ (194) ​ ​ (44,232) Effect of different tax rates in jurisdictions in which the company operates ​ (3,509) ​ (5,566) ​ (2,084) Effect of change of (de)recognition of deferred tax assets ​ (124,457) ​ (51,320) ​ (50,389) Withholding tax paid ​ ​ (68) ​ ​ — ​ ​ (5,076) (Underprovided)/overprovided in prior years ​ ​ (2,080) ​ ​ (12) ​ ​ 398 Other ​ ​ 2,854 ​ ​ (213) ​ ​ (241) Income tax (expense)/benefit recognized in the consolidated statements of profit or loss $ 9,443 $ 19,720 $ (8,522) (1) Applicable tax rates are 25.8% for 2022 and 2023, and 25.0% for 2021 ​ During 2022, argenx Benelux BV transferred certain pipeline activities to argenx BV through a transfer of assets, (hereafter referred to as “asset deal”), for a total amount of $449.0 million. As a result of the asset deal, argenx Benelux BV realised a capital gain on this intellectual property, which results in the rate reconciling item categorized as “effect of intercompany asset deal / transaction”. The available deferred tax assets relates to argenx US Inc., argenx UK Ltd and argenx Japan KK which are profitable due to the global transfer pricing model of argenx, and the deferred tax liabilities are related to argenx BV. The amount of deferred tax assets and liability by type of temporary difference can be detailed as follow: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2023 (in thousands of $) Assets ​ Liabilities Net Deferred tax assets / (liabilities) ​ ​ ​ ​ ​ ​ ​ ​ ​ Accruals and allowances ​ $ 13,189 ​ $ — ​ $ 13,189 Income tax benefit from excess tax deductions related to share-based payments ​ ​ 23,310 ​ ​ — ​ ​ 23,310 Profit in inventory ​ ​ 52,026 ​ ​ — ​ ​ 52,026 Other tax carryforwards ​ ​ 6,339 ​ ​ — ​ ​ 6,339 Property, plant and equipment ​ ​ 2,136 ​ ​ (1,550) ​ ​ 586 Non-current fixed assets ​ ​ — ​ ​ (5,155) ​ ​ (5,155) Other ​ ​ 1,760 ​ ​ — ​ ​ 1,760 Netting by taxable entity ​ ​ (1,549) ​ ​ 1,550 ​ ​ 1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net deferred tax assets / (liabilities) $ 97,211 $ (5,155) $ 92,056 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2022 (in thousands of $) Assets ​ Liabilities Net Deferred tax assets / (liabilities) ​ ​ ​ ​ ​ ​ ​ ​ ​ Accruals and allowances ​ $ 8,884 ​ $ — ​ $ 8,884 Income tax benefit from excess tax deductions related to share-based payments ​ ​ 26,887 ​ ​ — ​ ​ 26,887 Profit in inventory ​ ​ 29,711 ​ ​ — ​ ​ 29,711 R&D capitalized expense ​ ​ 11,316 ​ ​ — ​ ​ 11,316 Property, plant and equipment ​ ​ 856 ​ ​ (549) ​ ​ 307 Intangible assets ​ ​ — ​ ​ (3,430) ​ ​ (3,430) Non-current fixed assets ​ ​ — ​ ​ (4,975) ​ ​ (4,975) Other ​ ​ 2,117 ​ ​ — ​ ​ 2,117 Netting by taxable entity ​ ​ (549) ​ ​ 549 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net deferred tax assets / (liabilities) $ 79,222 $ (8,406) $ 70,817 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2021 (in thousands of $) Assets ​ Liabilities Net Deferred tax assets / (liabilities) ​ ​ ​ ​ ​ ​ ​ ​ ​ Accruals and allowances ​ $ 2,858 ​ $ — ​ $ 2,858 Income tax benefit from excess tax deductions related to share-based payments ​ ​ 26,026 ​ ​ — ​ ​ 26,026 Profit in inventory ​ ​ 3,305 ​ ​ — ​ ​ 3,305 Property, plant and equipment ​ ​ 532 ​ ​ (740) ​ ​ (208) Intangible assets ​ ​ — ​ ​ (2,714) ​ ​ (2,714) Non-current fixed assets ​ ​ — ​ ​ (3,725) ​ ​ (3,725) Other ​ ​ 210 ​ ​ — ​ ​ 210 Netting by taxable entity ​ ​ (740) ​ ​ 740 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net deferred tax assets / (liabilities) $ 32,191 $ (6,438) $ 25,753 ​ The change in net deferred taxes recorded in the consolidated statements of financial position can be detailed as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) Deferred tax assets Deferred tax liabilities Balance at January 1, 2023 $ 79,222 $ (8,406) Recognized in profit or loss ​ ​ 17,685 ​ ​ 3,430 Recognized in equity ​ ​ 381 ​ ​ — Effects of change in foreign exchange rate ​ ​ (77) ​ ​ (179) Balance at December 31, 2023 ​ $ 97,211 ​ $ (5,155) ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) Deferred tax assets Deferred tax liabilities Balance at January 1, 2022 $ 32,191 $ (6,438) Recognized in profit or loss ​ ​ 49,075 ​ ​ (2,180) Recognized in equity ​ ​ (1,960) ​ ​ — Effects of change in foreign exchange rate ​ ​ (84) ​ ​ 212 Balance at December 31, 2022 ​ $ 79,222 ​ $ (8,406) ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) Deferred tax assets Deferred tax liabilities Balance at January 1, 2021 $ 15,038 $ (1,487) Recognized in profit or loss ​ ​ 11,385 ​ ​ (5,082) Recognized in equity ​ ​ 5,494 ​ ​ — Effects of change in foreign exchange rate ​ ​ 274 ​ ​ 131 Balance at December 31, 2021 ​ $ 32,191 ​ $ (6,438) ​ The unrecognized deferred tax asset on unused tax losses amounts to $196.1 million on December 31, 2023, compared to $189.3 million on December 31, 2022 and $203.8 million on December 31, 2021. The Company has unused tax losses carried forward for an amount of $783.3 million on December 31, 2023, compared to $756.1 million on December 31, 2022, and $789.6 million on December 31, 2021. All available tax losses carried forward are in Belgium ($750.1 million on December 31, 2023 versus $720.7 million on December 31, 2022 and $764.7 million on December 31, 2021) and the Netherlands ($33.2, million on December 31, 2023 versus $35.4 million on December 31, 2022 and $24.9 million on December 31, 2021), and do not have an expiration date based upon the applicable enacted tax legislation. As a company active in research and development in Belgium, we expect to benefit from the innovation income deduction, or IID, in Belgium. The innovation income deduction regime allows net profits attributable to revenue from among others patented products to be taxed at a lower effective tax rate than other revenues. At the end of 2023, 2022 and 2021, we had $654.9 million, $428.8 million and $213.6 million of cumulative carry-forward IID in Belgium (argenx BV). The unrecognized deferred tax asset on IID amounts to $163.7 million on December 31, 2023, compared to $107.2 million on December 31, 2022, and $53.4 million on December 31, 2021. Also, the unrecognized deferred tax asset on the excess depreciations on R&D costs in Belgium amounts to $278.2 million on December 31, 2023 compared to $204.7 million on December 31, 2022 and $166.3 million on December 31, 2021 (argenx BV). Additionally, argenx BV has unrecognized deferred tax asset amounting to $106.3 million on December 31, 2023 compared to $112.2 million on December 31, 2022 on the future amortizations on IP assets. As of December 31, 2023, the Company had an estimated $127.9 million of undistributed earnings attributable to foreign subsidiaries for which no provision for deferred tax liabilities have been recognized because the Company has control over the timing of the reversal of the temporary differences and there are no plans of distributions in the foreseeable future.

Loss per share

Loss per share	12 Months Ended
	Dec. 31, 2023
Loss per share
Loss per share	25. Loss per share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (in thousands of $) 2023 2022 2021 Loss for the year $ (295,053) $ (709,594) $ (408,265) Weighted average number of shares outstanding ​ 57,169,253 ​ 54,381,371 ​ 51,075,827 Basic and diluted (loss) per share (in $) $ (5.16) $ (13.05) $ (7.99) ​ Earnings/losses per ordinary share are calculated by dividing the loss for the period by the weighted average number of ordinary shares during the year. As the Company reported a net loss in 2023, 2022 and 2021, stock options and RSUs have an anti-dilutive effect rather than a dilutive effect. As such, there is no difference between basic and diluted loss per ordinary share.

Financial risk management

Financial risk management	12 Months Ended
	Dec. 31, 2023
Financial risk management
Financial risk management	26. Financial risk management The financial risks are managed centrally. The Company coordinates the access to national and international financial markets and considers and manages continuously the financial risks concerning the Company’s activities. These relate to the financial markets risk, credit risk, liquidity risk and currency risk. There are no other important risks, such as interest rate risk on borrowings, as the Company has no financial debt. The Company does not buy or trade financial instruments for speculative purposes. Categories of financial assets and liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Measurement category ​ Carrying amount ​ ​ ​ ​ At December 31, (in thousands of $) ​ 2023 ​ 2022 2021 Financial assets — non-current FVTPL $ 21,715 ​ $ 21,715 $ 17,459 Financial assets — non-current ​ FVTOCI ​ ​ 15,528 ​ ​ 17,443 ​ ​ 35,710 Research and development incentive receivables — non-current Amortised cost ​ ​ 76,706 ​ ​ 47,488 ​ 32,707 Restricted cash — non-current Amortised cost ​ ​ 2,419 ​ ​ 1,736 ​ 1,707 Trade and other receivables ​ Amortised cost ​ ​ 496,687 ​ ​ 275,697 ​ 38,221 Financial assets—current ​ FVTPL ​ ​ — ​ ​ 46,162 ​ ​ 73,052 Financial assets—current ​ Amortised cost ​ ​ 1,131,000 ​ ​ 1,345,646 ​ ​ 929,000 Research and development incentive receivables — current ​ Amortised cost ​ ​ 2,584 ​ ​ 1,578 ​ ​ — Cash and bank balances Amortised cost ​ ​ 20,744 ​ ​ 77,477 ​ 242,494 Cash equivalents ​ FVTPL ​ ​ 1,678,100 ​ ​ 669,147 ​ ​ 997,092 Cash equivalents ​ Amortised cost ​ ​ 350,000 ​ ​ 54,116 ​ ​ 95,090 Trade and other payables ​ Amortised cost ​ ​ 414,013 ​ ​ 295,679 ​ 293,415 ​ The carrying amounts of trade and other payables and trade and other receivables are considered to be the same as their fair values, due to their short-term nature. Financial assets held at fair value through profit or loss or OCI Financial assets held at fair value through profit or loss or OCI consisted of equity instruments of listed and non-listed companies and money market funds. The Company has no restrictions on the sale of these equity instruments and the assets are not pledged under any of its liabilities. These instruments are classified as financial assets held at fair value through profit or loss or OCI which qualify for: ● Level 1 fair value measurement with respect to current financial assets and cash equivalents based upon the closing price (net asset value) of such securities at each reporting date. ● Level 3 fair value measurement with respect to non-current financial assets. The market price of these financial instruments might face fluctuations and might be affected by a variety of factors, such as the global economic situation. Current financial assets and cash equivalents include collective investment funds nominated in € and $ of which the underlying investments include bonds and other international debt securities. Based on the weighted average maturity of the underlying instruments, amongst others, these investments are either classified as current financial assets or cash equivalents. The maximum exposure to credit risk is the carrying amount at reporting date. The Company carried the following assets at fair value on December 31, 2023, 2022 and 2021 respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2023 (in thousands of $) Level 1 Level 2 Level 3 Non-current financial assets $ 15,528 $ — $ 21,715 Cash and cash equivalents ​ ​ 1,678,100 ​ ​ — ​ ​ — Assets carried at fair value $ 1,693,628 $ — $ 21,715 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2022 (in thousands of $) Level 1 Level 2 Level 3 Non-current financial assets $ 17,443 $ — $ 21,715 Current financial assets ​ 46,162 ​ — ​ — Cash and cash equivalents ​ ​ 669,147 ​ ​ — ​ ​ — Assets carried at fair value $ 732,752 $ — $ 21,715 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2021 (in thousands of $) Level 1 Level 2 Level 3 Non-current financial assets $ 35,710 $ — $ 17,459 Current financial assets ​ 73,052 ​ — ​ — Cash and cash equivalents ​ ​ 997,092 ​ ​ — ​ ​ — Assets carried at fair value $ 1,105,854 $ — $ 17,459 ​ During the disclosed calendar year, no transfers occurred between the applicable categories. Non-current financial assets – Level 3 In March 2019, the Company entered into a license agreement with AgomAb Therapeutics NV for the use of HGF-mimetic SIMPLE Antibodies™, developed under the Company’s Immunology Innovative Program. In exchange for granting this license, the Company received a profit share in AgomAb Therapeutics NV. In March 2021, AgomAb Therapeutics NV secured $74.0 million in Series B financing by issuing 286,705 of Preferred B Shares. The Company used the post-money valuation of Series B financing round and the number of outstanding shares in determining the fair value of the profit-sharing instrument, which results in a change in fair value of non-current financial assets of $11.2 million recorded through profit or loss. Since AgomAb Therapeutics NV is a private company, the valuation of the profit share is based on level 3 assumptions. In June 2022, AgomAb Therapeutics NV secured €38.4 million as a result of the extension of Series B. The Company used the post-money valuation of this Series B financing round and the number of outstanding shares in determining the fair value of the profit-sharing instrument, which results in a change in fair value of non-current financial assets of $4.3 million recorded through profit or loss. In October 2023, AgomAb Therapeutics NV secured $100.0 million as a result of a Series C financing round. The Company’s profit share diluted as the number of shares held by the company stayed stable where the post-money valuation of AgomAb increased, which results in unchanged fair value of the non-current asset . Non-current financial assets – Level 1 In January 2021, as part of the license agreement for the development and commercialization for efgartigimod in Greater China (see note 16 for further information), the Company obtained, amongst others, 568,182 newly issued Zai Lab shares calculated at a price of $132 per share. The fair value of the equity instrument at period-end is determined by reference to the closing price of such securities at each reporting date (classified as level 1 in the fair value hierarchy), resulting in a change in fair value. The Company made the irrevocable election to recognize subsequent changes in fair value through OCI. Capital risk The Company manages its capital to ensure that it will be able to continue as a going concern. The capital structure of the Company consists of equity attributed to the holders of equity instruments of the Company, such as capital, reserves and accumulated losses as mentioned in the consolidated statements of changes in equity. The Company makes the necessary adjustments in the light of changes in the economic circumstances, risks associated to the different assets and the projected cash needs of the current and projected research activities. On December 31, 2023, cash and cash equivalents amounted to $2,048.8 million, current financial assets amounted to $1,131.0 million and total capital amounted to $5,658.6 million. The current cash situation and the anticipated cash generation and usage are the most important parameters in assessing the capital structure. The Company’s objective is to maintain the capital structure at a level to be able to finance its activities for at least twelve months. Cash income from existing and new partnerships is taken into account and, if needed and possible, the Company can issue new shares or enter into financing agreements. Credit risk Credit risk refers to the risk that a counterparty will default on its contractual obligations resulting in financial loss to the Company. The Company has adopted a policy of only dealing with creditworthy counterparties and obtaining sufficient collateral, where appropriate, as a means of mitigating the risk of financial loss from defaults. Concentrations in credit risk are determined based on an analysis of counterparties and their importance on the overall outstanding contractual obligations at year-end. The Company has a limited number of collaboration and license partners and therefore has a significant concentration of credit risk. However, it has policies in place to ensure that credit exposure is kept to a minimum and significant concentrations of credit exposure are only granted for short periods of time to high credit quality collaboration partners. The Company 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 the Company’s customers. Cash and cash equivalents and current financial assets are invested with several highly reputable banks and financial institutions. The Company holds its cash and cash equivalents mainly with different banks which are independently rated with a minimum rating of ‘A-’. The Company also holds cash equivalents in the form of money market funds with a recommended investment horizon of 6 months or shorter but with a low historical volatility. These money market funds are highly liquid investments, can be readily convertible into a known amount of cash. The company has adopted a policy whereby money market funds must have an average rating of “BBB” or higher. Liquidity risk The Company manages liquidity risk by maintaining adequate reserves, by continuously monitoring forecast and actual cash flows, and by matching the maturity profiles of financial assets and liabilities. The Company’s main sources of cash inflows are obtained through sale of commercial product, capital increases and collaboration agreements. This cash is invested in savings accounts, term accounts and short term investment funds in the form of money market funds. These money market funds represent the majority of the Company’s available sources of liquidity. Since all of these are immediately tradable and convertible in cash they have a no impact on the liquidity risk. Interest rate risk The only variable interest-bearing financial instruments are cash and cash equivalents and current financial assets. Changes in interest rates may cause variations in interest income and expense resulting from short-term interest-bearing assets. Interest rate cuts may have a negative impact on the interest income of the Company. For the year ended December 31, 2023, if applicable interest rates would increase/decrease by 25 basis points, this would have a positive/negative impact of $7.9 million (compared to $6.2 million for the year ended December 31, 2022 and $0.9 million for the year ended December 31, 2021). Foreign exchange risk The Company undertakes transactions denominated in foreign currencies, causing exposures to exchange rate fluctuations. The Company is mainly exposed to the Euro, Japanese yen, British pound and Swiss franc. To limit this risk, the Company attempts to align incoming and outgoing cash flows in currencies other than USD. The net exposure to exchange differences of the monetary assets (being cash, cash equivalents and current financial assets) of the Company at the end of the reporting period are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 EUR 923,773 613,866 591,887 JPY ​ 8,232 ​ 5,613 ​ 6,316 GBP 7 59,026 1,237 CHF ​ 193 ​ 3,832 ​ 727 CAD ​ 266 ​ 657 ​ — SEK ​ 1 ​ 7 ​ — DKK 9 6 ​ — ​ On December 31, 2023, if the EUR would have strengthened/weakened negative/positive December 31, 2022 December 31, 2021 strengthen/weakened against the USD by impact

Related party transactions

Related party transactions	12 Months Ended
	Dec. 31, 2023
Related party transactions
Related party transactions	27. Related party transactions 27.1 Relationship and transactions with joint venture entity In July 2022, the Company entered into a joint venture agreement with the University of Colorado Anschutz Medical Campus and UCHealth and created a separate legal entity, OncoVerity, Inc., which is focused on optimizing and advancing the development of cusatuzumab, a novel anti-CD70 antibody, in AML. The Company contributed $2 million in 2022 and $13 million in 2023. The investment has been accounted under IAS 28 Investment in associates and joint ventures using the equity method of accounting and has been designated as “investment in joint venture” in the consolidated statements of financial position. The share of net loss resulting from investment in joint ventures is presented in consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) in line “Loss from investment in joint ventures”. The cash contributions made by the Company to the Joint Venture is reported under Cash flow from investing activities under “Investment in joint venture”. 27.2 Relationship and transactions with subsidiaries See note 31 for an overview of the consolidated companies of the group, which are all wholly-owned subsidiaries of argenx SE. Balances and transactions between the Company and its subsidiaries, which are related parties of the Company, have been eliminated on consolidation and are not disclosed in this note. 27.3 Relationship and transactions with key personnel The Company’s key management personnel consists of the members of the management team and the members of the board of directors. Remuneration of key management personnel On December 31, 2023, the senior management consisted of 8 members: Chief Executive Officer, Chief Operating Officer, Chief Financial Officer, Chief Scientific Officer, General Counsel, Chief Medical Officer, Vice President Corporate Development and Strategy and Global Head of Quality Assurance. They provide their services on a full-time basis. On December 31, 2023, the board of directors consisted of 9 members: Peter Verhaeghe, Don deBethizy, Pamela M. Klein, A.A. Rosenberg, James M. Daly, Camilla Sylvest, Ana Cespedes, Steve Krognes and Tim Van Hauwermeiren. Only the Chief Executive Officer is a member of both the senior management team and the board of directors. The Chief Executive Officer does not receive any remuneration for his board membership, as this is part of his total remuneration package in his capacity as member of the senior management team. The remuneration package of the members of key management personnel comprises: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (in thousands of $, except for the number of stock options & RSUs) 2023 2022 2021 Remuneration of key management personnel ​ ​ ​ ​ ​ ​ Short-term benefits for senior management members as a group ​ ​ ​ ​ ​ ​ Gross salary ​ $ 4,161 ​ $ 4,199 ​ $ 3,465 Variable pay ​ ​ 2,816 ​ ​ 3,077 ​ ​ 2,020 Employer social security ​ ​ 807 ​ ​ 1,015 ​ ​ 789 Other short term benefits ​ ​ 545 ​ ​ 372 ​ ​ 274 Termination Benefits ​ ​ — ​ ​ — ​ ​ 382 Post-employment benefits for senior management members as a group ​ ​ 167 ​ ​ 104 ​ ​ 150 Cost of stock options granted in the year for senior management members as a group ​ ​ 27,983 ​ ​ 18,393 ​ ​ 15,060 Cost of restricted stock units granted in the year for senior management members as a group ​ ​ 11,694 ​ ​ 9,594 ​ ​ 8,025 Employer social security cost related to stock options ​ ​ (494) ​ ​ 1,101 ​ ​ 4,172 Total benefits for key management personnel ​ ​ 47,679 ​ ​ 37,855 ​ ​ 34,337 Numbers of stock options granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior Management as a group ​ ​ 132,100 ​ ​ 117,600 ​ ​ 101,446 Numbers of restricted stock units granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior Management as a group ​ ​ 30,425 ​ ​ 26,500 ​ ​ 22,888 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Remuneration of non-executive directors ​ ​ ​ ​ ​ ​ ​ ​ ​ Board fees and other short-term benefits for non-executive directors ​ ​ 533 ​ ​ 437 ​ ​ 435 Cost of stock options granted in the year for non-executive directors ​ ​ 2,280 ​ ​ 3,643 ​ ​ 3,263 Cost of restricted stock units granted in the year for non-executive directors ​ ​ 1,034 ​ ​ 1,850 ​ ​ 1,731 Total benefits for non-executive board members ​ $ 3,847 ​ $ 5,929 ​ $ 5,429 Numbers of stock options granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-executive directors ​ ​ 12,400 ​ ​ 21,600 ​ ​ 22,950 Numbers of restricted stock units granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-executive directors ​ ​ 2,713 ​ ​ 4,800 ​ ​ 5,100 ​ Other No loans, quasi-loans or other guarantees were given by the Company or any of its subsidiaries to members of the board of directors or the senior management. We have not entered into transactions with the Company’s key management personnel, other than as described above with respect to remuneration arrangements relating to the exercise of their mandates as members of the senior management and the board of directors.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2023
Contingencies
Contingencies	28. Contingencies The Company is currently not facing any outstanding claims or litigations that may have a significant adverse impact on the Company’s consolidated financial position.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2023
Commitments
Commitments	29. Commitments At balance sheet date, there were no commitments signed for the acquisition of property, plant and equipment. In February 2019, and as amended in September 2020, the Company entered into a global collaboration and license agreement with Halozyme Therapeutics, Inc. Under the terms of the agreement, the Company will pay up to $124.0 million to achievement of specific regulatory and sales-based milestones related to VYVGART SC. This amount represents the maximum amount that would be paid if all milestones would be achieved but excludes variable royalty payments based on unit sales. Further, the Company will pay $12.5 million per target for future target nominations and potential future payments of up to $160.0 million per selected target subject to achievement of specified development, regulatory and sales-based milestones and up to $40.0 million subject to the achievement of additional, specified sales-based milestones. This amount represents the maximum amount that would be paid if all milestones would be achieved but excludes variable royalty payments based on unit sales. The Company’s manufacturing commitments with Lonza, its drug substance manufacturing contractor, relate to the ongoing execution of the biologic license application (BLA) services for efgartigimod and its manufacturing activities related to the potential future commercialisation. In December 2018, the Company signed its first commercial supply agreement with Lonza related to the reservation of commercial drug substance supply capacity for efgartigimod. In the aggregate, the Company has outstanding commitments for efgartigimod under the commercial supply agreements of $361.8 million. During 2022, Company signed an agreement with Fujifilm, for activities relating to the large-scale manufacturing of efgartigimod drug substance. In the aggregate, the Company has outstanding commitments for efgartigimod under the commercial supply agreement of $13.3 million. As of December 31, 2023, the Company had a line of credit totalling to $7.2 million (€6.5 million) with the banks.

Audit fees

Audit fees	12 Months Ended
	Dec. 31, 2023
Audit fees
Audit fees	30. Audit fees The following auditors’ fees were expensed in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, Fees 2023 2022 2021 ​ ​ in thousands of $ Audit fees (1) $ 1,979 $ 1,394 $ 1,183 Audit-related fees ​ 330 ​ 380 ​ 267 Tax fees (2) ​ — ​ — ​ 79 Total $ 2,309 $ 1,774 $ 1,529 (1) Auditor services performed by Deloitte Accountants B.V. as the external auditor referred to in Section 1 of the Dutch Accounting Firms Oversight Act (Wta) as well as by the Deloitte network. (2) Tax services performed by the Deloitte network .

Overview of consolidation scope

Overview of consolidation scope	12 Months Ended
	Dec. 31, 2023
Overview of consolidation scope
Overview of consolidation scope	31. Overview of consolidation scope The parent company argenx SE is domiciled in the Netherlands. The Company, argenx SE, has two subsidiaries, argenx BV and argenx Benelux BV, based in Belgium. argenx BV has ten subsidiaries. Details of the Company’s consolidated entities at the end of the reporting period are as follows: ​ ​ ​ ​ ​ ​ ​ Name Country Participation argenx SE ​ The Netherlands ​ 100.00 % argenx BV Belgium 100.00 % argenx Benelux BV ​ Belgium ​ 100.00 % argenx US, Inc. USA 100.00 % argenx Switzerland, SA ​ Switzerland ​ 100.00 % argenx Japan KK Japan 100.00 % argenx France SAS ​ France ​ 100.00 % argenx Germany GmbH ​ Germany ​ 100.00 % argenx Canada Inc. ​ Canada ​ 100.00 % argenx UK Ltd. ​ United Kingdom ​ 100.00 % argenx Netherlands Services B.V. ​ The Netherlands ​ 100.00 % argenx Italy S.r.l. ​ Italy ​ 100.00 % argenx Spain S.L. ​ Spain ​ 100.00 % ​

Events after the balance sheet

Events after the balance sheet date	12 Months Ended
	Dec. 31, 2023
Events after the balance sheet date
Events after the balance sheet date	32. Events after the balance sheet date No events have occurred after the balance sheet date that could have a material impact on the consolidated financial statements.

Material accounting policy in_2

Material accounting policy information (Policies)	12 Months Ended
	Dec. 31, 2023
Material accounting policy information
Statement of compliance and basis of preparation	2.1 Statement of compliance and basis of preparation 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 the Company’s activities and the results achieved. They present fairly the entity’s financial position, its financial performance and cash flows, on a going concern basis. The material accounting policy information applied in the preparation of the above consolidated financial statements are set out below. All amounts are presented in thousands of dollar, unless otherwise indicated, rounded to the nearest $ ‘000. The consolidated financial statements have been approved for issue by the Company’s Board of Directors (the “Board”) on March 19, 2024.
Adoption of new and revised standards	2.2 Adoption of new and revised standards New standards and interpretations applicable for the annual period beginning on January 1, 2023 ● Amendments to IAS 1 – Presentation of Financial Statements and IFRS Practice Statement 2 – Making Materiality Judgements . The amendments to IAS 1 require companies to disclose their material accounting policy information rather than their significant accounting policies. The amendments to IFRS Practice Statement 2 provide guidance on how to apply the concept of materiality to accounting policy disclosures. As result the Company revised its accounting policy disclosure in the consolidated financial statements and removed accounting policy information that the Company deemed to relate to immaterial transactions or other events or conditions. No other standards and interpretations for the annual period beginning on January 1, 2023 have any material impact on the consolidated financial statements. New standards and interpretations issued, but not yet applicable for the annual period beginning on January 1, 2023 ● Amendments to IAS 12 - issued International Tax Reform—Pillar Two Model Rules. On 23 May 2023, the International Accounting Standards Board (the IASB or Board) issued International Tax Reform – Pillar Two Model Rules – Amendments to IAS 12 which clarified the application of IAS 12 income taxes arising from tax law enacted or substantively enacted to implement the OECD/G20 Inclusive Framework on Base Erosion and Profit Shifting Pillar Two model rules. Based on current information, management expects that the Company could become subject to the Pillar Two Directive and implementing domestic laws as early as 2025. Thus, there is no impact for argenx in 2023. The company is currently in the process of determining the impact, if any, for 2025. Based on the preliminary analysis, we do not expect the Pillar Two Rules to have a material impact on our effective tax rate. It is unclear if the Pillar Two model rules create additional temporary differences, whether to remeasure deferred taxes for the Pillar Two model rules, and which tax rate to use to measure deferred taxes. In response to this unclarity, the amendments mentioned above introduced a mandatory temporary exception to the requirements of IAS 12 under which a company does not recognise or disclose information about deferred tax assets and liabilities related to the Pillar Two model rules. We applied the temporary exception in financial year 2023. We have not early adopted any other standard, interpretation, or amendment that has been issued but is not yet effective. Of the standards that are not yet effective, we expect no standard to have a material impact on the financial statements in the period of initial application.
Basis of consolidation	2.3 Basis of consolidation The consolidated financial statements include the financial statements of the Company and entities controlled by the Company (its subsidiaries). Control is achieved when the Company: ● has power over the investee; ● is exposed, or has rights, to variable returns from its involvement with the investee; and ● has the ability to use its power to affect its returns. The Company reassesses whether or not it controls an investee if facts and circumstances indicate that there are changes to one or more of the three elements of control listed above. The results of the subsidiaries are included in the consolidated statements of profit or loss and consolidated statements of other comprehensive income (loss) from the effective date of acquisition up to the date when control ceases to exist. When necessary, adjustments are made to the financial statements of subsidiaries to bring their accounting policies into line with those used by other members of the Group. All intercompany transactions and unrealized gains on transactions between group companies are eliminated. Unrealised losses are also eliminated unless the transaction provides evidence of an impairment of the transferred asset.
Foreign currency transactions	2.4 Foreign currency transactions 2.4.1 Functional and presentation currency Items included in the consolidated financial statements of each of the entities are valued using the currency of their economic environment in which the entity operates. The consolidated financial statements are presented in USD ($), which is the Company’s presentation currency. 2.4.2 Transactions and balances Transactions in foreign currencies are translated at the exchange rate ruling at the date of the transaction. Monetary assets and liabilities denominated in foreign currencies are translated at the exchange rate ruling at the reporting date. Foreign exchange differences arising on translation are recognized in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) as “Exchange gains /(losses)”. Non-monetary assets and liabilities denominated in foreign currencies are translated at the foreign exchange rate ruling at the date of the transaction. 2.4.3 Financial statements of foreign entities For foreign entities using a different functional currency than USD: ● assets and liabilities for each balance sheet presented are translated at the closing rate at the date of the balance sheet. ● income and expenses for each statement presenting profit or loss and statements of other comprehensive income (loss) are translated at average exchange rates (unless this average is not a reasonable approximation of the cumulative effect of the rates prevailing on the transaction dates, in which case income and expenses are translated at the rate on the dates of the transactions). ● all resulting exchange differences are recognized in the statements of other comprehensive income (loss).
Intangible assets	2.5 Intangible assets 2.5.1 Internally generated intangible assets Expenditure on research activities is recognized as an expense in the period in which it is incurred. Due to uncertainties inherent to the development and registration with the relevant healthcare authorities of its products, the Company estimates that the conditions for capitalization per IAS 38 can not be met before the regulatory procedures required by such healthcare authorities have been finalized. Also once regulatory approval has been obtained, an internally generated intangible asset arising from development is capitalized if, and only if, all of the criteria under IAS 38 have been demonstrated. 2.5.2 Acquired In-Process R&D and Acquired R&D available for use Upfront payments and development milestone payments for “Acquired In-Process R&D obtained through in-licensing arrangements are capitalized as intangible assets under “Acquired In-Process R&D” upon meeting the IAS 38 capitalization criteria. These intangibles are considered as intangible assets with definite useful lives and are carried at cost less accumulated impairment losses. “Acquired In-Process R&D” is not amortized, but is evaluated for potential impairment on an annual basis or when facts and circumstances warrant. Any impairment charge is recorded in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) under “Research and development expense”. Once an asset included in “Acquired In-Process R&D” has received marketing approval from a regulatory authority, it is recorded under “Acquired R&D available for Regulatory milestone payments and sales-based milestone payments for R&D obtained through in-licensing arrangements acquired are capitalized intangible assets under “Acquired R&D available for use” upon meeting the IAS 38 capitalization criteria. All intangibles classified under “Acquired R&D available for use” are considered as intangible assets with finite useful lives and are carried at cost less accumulated amortization and accumulated impairment losses. “Acquired R&D available for use” is evaluated for potential impairment when the Company identifies indications based on facts and circumstances of the asset. Any impairment charge is recorded in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) under "Cost of sales". “Acquired R&D available for use” is amortized under “Cost of sales” on a straight-line basis over the estimated useful life, being the longer of the current patent protection life of the acquired R&D and patent protection life of the combined product. 2.5.3. Other intangible assets Other intangible assets could include the Priority Review Voucher (“PRV”) which the Company can use to obtain the priority review by the FDA for one of its future regulatory submissions or may sell or transfer to a third party. The PRV is initially measured at cost and annually reviewed for impairment when events or circumstances indicate that the carrying value may not be recoverable. Any impairment charge is recorded in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) under “Research and development expenses.” Using the PRV results in amortization recorded in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) under “Research and development expenses” and subsequent derecognition of the intangible asset.
Research and development incentives	2.6 Research and development incentives receivables The current and non-current research and development incentive receivables relate to refunds resulting from research and development incentives on Research and development expenses in Belgium and are credited to the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) under the line “Other operating income” when the relevant expenditure has been incurred and there is a reasonable assurance that the research and development incentives will be received.
Inventories	2.7 Inventories Inventories are carried at cost or net realisable value, whichever is lowest. Cost comprises of costs of purchase, costs of conversion and other costs incurred in bringing the inventories to their present location and condition. If the expected sales price less completion costs to execute sales (net realizable value) is lower than the carrying amount, a write-down is recognized for the amount by which the carrying amount exceeds its net realisable value Included in inventory are products which could, besides commercial activities, be used in preclinical and clinical programs, and free-of-charge, compassionate use and pre-approval access program. These products are charged to “Research & development expenses” or “Selling, general and administrative expenses”, respectively, when dedicated to this channel. We capitalize inventory costs associated with products prior to the regulatory approval of these products, or for inventory produced in production facilities not yet approved, when it is highly probable that the pre-approval inventories will be saleable. The determination to capitalize is based on the particular facts and circumstances relating to the expected regulatory approval of the product or production facility being considered. The assessment of whether or not the product is considered highly probable to be saleable is made and includes, but is not limited to, how far a particular product or facility has progressed along the approval process, any known safety or efficacy concern and other impediments. Previously capitalized costs related to pre-launch inventories could be required to be written down upon a change in such judgement or due to a denial or delay of approval by regulatory bodies, a delay in commercialization or other potential factors, which will be recorded under “Research and development expenses” in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss).
Trade and other receivables	2.8 Trade and other receivables Trade and other receivables are designated as financial assets measured at amortized cost. They are initially measured either at their invoiced amounts or at transaction price, in the absence of a significant financing component less adjustments for estimated revenue deductions such as rebates, chargebacks and returns. All receivables are subsequently measured at amortized cost, which generally corresponds to nominal value less expected credit loss provision. Loss allowance for expected credit losses are established using a simplified approach of forward-looking expected credit loss model (ECL), which includes possible default events on the trade receivables over the entire holding period of the trade receivable. These provisions represent the difference between the trade receivable’s carrying amount in the consolidated statements of financial position and the estimated collectible amount. Charges for loss allowance for expected credit losses are recorded under “Selling, general and administrative expenses” in the consolidated statements of profit or loss and consolidated statements of other comprehensive income (loss).
Current financial assets	2.9 Current financial assets Current financial assets measured at amortized costs comprise of term accounts that have an initial maturity equal or less than 12 months, but exceeding 3 months. Current financial assets measured at fair value through profit or loss comprise of money market funds. Interests on Current financial assets is reported under Cash Flow from investment activities under “Interest received”.
Cash and cash equivalents	2.10 Cash and cash equivalents Cash are financial assets measured at amortized cost and comprise of cash at bank. Cash equivalents measured at amortized cost comprise of term accounts that have an initial maturity of less than 3 months that are subject to an insignificant risk of changes in values. Those are used by the Company in the management of short-term commitments. Cash and cash equivalents exclude restricted cash, which is presented in the consolidated statements of financial position under the line “Other non-current assets”. Cash equivalents measured at fair value through profit or loss comprise of money market funds that are readily convertible to cash and are subject to insignificant risk of changes in value. These financial assets are used by the Company in the management of the short-term commitments. Interests on Cash equivalents is reported under Cash Flow from investment activities under “Interest received”.
Trade and other payables	2.11 Trade and other payables Trade and other payables 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 the Company’s research and development activities, gross-to-net accruals and short-term employee benefits. Trade and other payables are initially measured at their transaction price, which are subsequent to initial recognition measured at amortized cost. Short-term employee benefits include payables and accruals for salaries and bonuses to be paid to the employees of the Company. They are recognized as expenses for the period in which employees perform the corresponding services.
Leases	2.12 Leases The Company assesses whether a contract is or contains a lease, at inception of the contract. The Company recognises a right-of-use asset and a corresponding lease liability with respect to all lease arrangements in which it is the lessee, except for short-term leases (defined as leases with a lease term of 12 months or less) and leases of low value assets. For these leases, the Company recognises the lease payments as an operating expense on a straight-line basis over the term of the lease unless another systematic basis is more representative of the time pattern in which economic benefits from the leased assets are consumed. The lease liability is initially measured at the present value of the lease payments that are not paid at the commencement date, discounted by using the rate implicit in the lease. If this rate cannot be readily determined, the lessee uses its incremental borrowing rate. The lease liability is subsequently measured by increasing the carrying amount to reflect interest on the lease liability (using the effective interest method) and by reducing the carrying amount to reflect the lease payments made. The lease liability is presented as a separate line in the consolidated statements of financial position. The right-of-use assets comprise the initial measurement of the corresponding lease liability, lease payments made at or before the commencement day, less any lease incentives received and any initial direct costs. They are subsequently measured at cost less accumulated depreciation and impairment losses. Right-of-use assets are depreciated over the shorter period of lease term and useful life of the underlying asset. If a lease transfers ownership of the underlying asset or the cost of the right-of-use asset reflects that the Company expects to exercise a purchase option, the related right-of-use asset is depreciated over the useful life of the underlying asset. The right-of-use assets are presented in the consolidated statements of financial position under the caption “Property, plant and equipment”.
Financial instruments	2.13 Financial instruments Financial instruments are initially recognized either at fair value or at transaction price and subsequently measured at either amortized cost or fair value under IFRS 9 on the basis of both the Company’s model for managing the financial assets and the contractual cash flow characteristics of the financial asset. A financial asset is classified as current when the cash flows expected to flow from the instrument mature within one year. Profit share in AgomAb Therapeutics NV: Shares of Zai Lab:
Shareholder's equity	2.14 Shareholder’s equity An equity instrument is any contract that evidences a residual interest in the assets of an entity after deducting all of its liabilities. Equity instruments issued by the Company are recognized at the proceeds received, net of direct issue costs. The Company has never distributed any dividends to its shareholders. As of December 31, 2023, no profits were available for distribution. As of January 1, 2021, the Company changed its functional and presentation currency from EUR to USD. Differences resulting from the re-presentation have been presented as translation difference, a component within shareholders’ equity. Share capital, share premium, and other reserves are translated at historic rates prevailing at the date of transaction.
Share-based payments	2.15 Share-based payments Equity-settled share-based payments to employees and others providing similar services are measured at the fair value of the equity instruments at the acceptance date. Equity settled share based payments includes expenses related to stock options and restricted stock units granted by the Company. The fair value determined at the acceptance date of the equity-settled share-based payments is expensed on a straight-line basis over the vesting period, based on the Company’s estimate of equity instruments that will eventually vest, with a corresponding increase in equity. At the end of each reporting period, the Company revises its estimate of the number of equity instruments expected to vest. The impact of the revision of the original estimates, if any, is recognized in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) such that the cumulative expense reflects the revised estimate, with a corresponding adjustment to the equity-settled share-based payment reserve. The share-based payment expense is recorded under “Research and development expenses” or “Selling, general & administrative expenses” depending on the nature of the services provided by each beneficiary.
Income taxes	2.16 Income taxes Income tax in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) represents the total of the current tax and deferred tax. The current tax is based on taxable profit for the year. Taxable profit differs from profit as reported in the consolidated statements of profit or loss and consolidated statements of other comprehensive income (loss) as it excludes items of income or expense that are taxable or deductible in other years and items that are never taxable or deductible. The Company’s liability for current tax is calculated using tax rates that have been enacted or substantively enacted by the end of the reporting period. Deferred tax is recognized on temporary differences between the carrying amounts of assets and liabilities in the consolidated financial statements and the corresponding tax basis used in the computation of taxable profit. Deferred tax assets are recognized to the extent that it is probable that future taxable profits will be available against which those deductible temporary differences can be utilized. The carrying amount of deferred tax assets is reviewed at the end of each reporting period and reduced to the extent that it is not probable that sufficient taxable profits will be available to allow all or part of the asset to be recovered. Deferred tax assets and liabilities are offset if there is a legally enforceable right to offset. Deferred tax assets and liabilities are measured at the tax rates that are expected to apply in the period in which the liability is settled or the asset realized, based on tax rates (and tax laws) that have been enacted or substantially enacted by the end of the reporting period. The Company records uncertain tax positions in accordance with IAS 12 using the 2 step test whereby (1) the Company determines whether it is probable that the tax positions will be accepted by relevant taxing authorities, and (2) for those tax positions that are not probable that a tax authority will accept in full the position, the Company recognizes uncertain tax positions using either the most likely amount or the expected value, depending on specific facts and circumstances.
Product net sales	2.17 Product net sales Revenue from the sale of goods is recognized at an amount that reflects the consideration that the Company expects to be entitled to receive in exchange for transferring goods to a customer, at the time when the customer obtains control of the goods rendered, this means when the customer has the ability to direct the use of the asset. The consideration that is committed in a contract with a customer can include fixed amounts, variable amounts, or both. The amount of the consideration may vary due to discounts, rebates, returns, chargebacks or other similar items. Contingent consideration is included in the transaction price when it is highly probable that the amount of revenue recognized is not subject to future significant reversals. Product net sales are recognized once we satisfy the performance obligation at a point in time under the revenue recognition criteria in accordance with IFRS 15 Revenue from contracts with customers Revenue arising from the commercial sale of commercial product is presented in the consolidated statements of profit or loss under “Product net sales”. In accordance with IFRS 15 Revenue from contracts with customers , such revenue is recognized when the product is physically transferred, in accordance with the delivery and acceptance terms agreed with the customer. Payment of the transaction price is payable at the point the customer obtains the legal title to the goods. The amount of revenue recognized reflects the various types of price reductions or rights of return offered by the Company to its customers. Such price reductions and rights of return qualify as variable consideration under IFRS 15 Revenue from contracts with customers . Products sold are covered by various Government and State programs (such as Medicare and Medicaid) under which products are sold at a discount. Rebates are granted to healthcare authorities, and under contractual arrangements with certain customers. Some wholesalers are entitled to chargeback incentives based on the selling price to the end customer, under specific contractual arrangements. Rebates, chargebacks and other incentives are recognized in the period in which the underlying sales are recognized as a reduction of product sales. The significant components of variable consideration are as follows: Co-payment assistance: Chargebacks: Rebates: Medicare Part D Coverage Gap: Distributor fees: Value-based arrangements (VBAs The estimated amounts described above are recognized in the consolidated statements of profit or loss and the consolidated statements of other comprehensive income (loss) within “Product net sales” as a reduction of gross sales, and within “Trade and other payables” in the consolidated statements of financial position. They are subject to regular review and adjustment as appropriate based on the most recent data available to management. Each of the above items require significant estimates, judgement and information obtained from external sources. If management’s estimates differ from actual results, we will record adjustments that would affect product sales in the period of adjustment.
Collaborations and license agreements	2.18 Collaborations and license agreements The Company has currently two active collaboration and license agreements in scope of IFRS 15: Zai Lab For the collaboration agreement with Zai Lab the Company has assessed that there is more than one distinct performance obligation, being the transfer of a license and supply of clinical and commercial product. The Company concluded that these performance obligations are distinct in the context of the contract. Therefore, the Company assesses to allocate the transaction price to all performance obligations identified. The transaction price of these two agreements is composed of (i) a fixed part, that being an upfront payment in the form of newly issued Zai Lab shares, and a guaranteed, non-creditable, non-refundable payment and (ii) a milestone payment for approval of efgartigimod in the U.S. and the consideration received in return for the supply of clinical and commercial product. The fixed part of the transaction price, as well as the milestone for approval of efgartigimod in the U.S. has been allocated to the transfer of a license performance obligation. The Company concluded that the license as of the effective date of the contract, being January 2021, has standalone value. As such, the Company concluded that the promise in granting the license to Zai Lab is to provide a right to use the entity’s intellectual property as it exists at the point in time at which the license is granted and therefore, revenue was recognized at a point in time in January 2021. Under the collaboration agreement, the Company provides clinical and commercial supply to Zai Lab. Company concludes to recognize such sales as revenue given that the Company acts as principal in the transaction as the risk related to inventory is born by the Company until the inventory is transferred to Zai Lab. The revenue related to clinical supply is recorded under line item “Collaboration revenue”. The revenue related to commercial supply is recorded under line item “product net sales” in the Consolidated statements of other comprehensive Income (Loss). The income related to royalties is recorded under line item item “Collaboration revenue”. AbbVie For the collaboration agreement with AbbVie the Company has determined that the transfer of license combined with the performance of research and development activities represent one single performance obligation. The Company concluded that the license is not distinct in the context of the contract. The transaction price is composed of a fixed part, that being an upfront license fee, and a variable part, being milestone payments and cost reimbursements of research and development activities delivered. Milestone payments are only included in the transaction price to the extent it is highly probable that a significant reversal in the amount of cumulative revenue recognition will not occur when the uncertainty associate with the variable consideration is subsequently resolved. Management estimates the amount to be included in the transaction price upon achievement of the milestone event. Sales-based milestones and sales-based royalties are a part of the Company’s arrangements but are not yet included in its revenues. The transaction price has been allocated to the single performance obligation and revenues has been recognized over the estimated service period based on an input model, being the percentage of completion method. The upfront license fee has been fully recognized since 2021 as the performance obligation has been fulfilled at that time. Milestone payments that become highly probable after the performance obligation has been fulfilled are therefore recognized at that point in time.
Cost of sales	2.19 Cost of Sales Cost of sales are recognized when the associated revenue from product net sales is recognized. Cost of sales include material, manufacturing costs and other costs attributable to production, including shipping costs, as well as royalties payable on sold products.

Property, plant and equipment (

Property, plant and equipment (Tables)	12 Months Ended
	Dec. 31, 2023
Property, plant and equipment.
Schedule of property, plant and equipment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ IT, office and lab Right-of-use assets Right-of-use assets Leasehold Lease ​ ​ (in thousands of $) ​ equipment ​ Buildings ​ Vehicles ​ improvements ​ equipment ​ Total Cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2021 ​ $ 4,889 ​ ​ 11,721 ​ ​ 2,273 ​ ​ 1,424 ​ ​ 346 ​ ​ 20,653 Additions ​ ​ 3,163 ​ ​ 4,923 ​ ​ 802 ​ ​ 543 ​ ​ — ​ ​ 9,430 Disposals ​ ​ (217) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (217) Currency translation adjustment ​ ​ 104 ​ ​ (182) ​ ​ — ​ ​ 14 ​ ​ — ​ ​ (64) On December 31, 2021 ​ ​ 7,938 ​ ​ 16,462 ​ ​ 3,075 ​ ​ 1,981 ​ ​ 346 ​ ​ 29,802 Additions ​ ​ 962 ​ ​ 3,353 ​ ​ 905 ​ ​ — ​ ​ — ​ ​ 5,219 Disposals ​ ​ (105) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (105) Currency translation adjustment ​ ​ (635) ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ (635) On December 31, 2022 ​ ​ 8,160 ​ $ 19,815 ​ $ 3,980 ​ $ 1,981 ​ $ 346 ​ $ 34,282 Additions ​ ​ 937 ​ ​ 8,770 ​ ​ 2,327 ​ ​ 48 ​ ​ — ​ ​ 12,082 Disposals ​ ​ (202) ​ ​ — ​ ​ (757) ​ ​ (54) ​ ​ — ​ ​ (1,013) On December 31, 2023 ​ $ 8,895 ​ $ 28,585 ​ $ 5,550 ​ $ 1,975 ​ $ 346 ​ $ 45,350 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2021 ​ $ (3,642) ​ ​ (4,044) ​ ​ (760) ​ ​ (543) ​ ​ (82) ​ ​ (9,071) Depreciation ​ ​ (1,118) ​ ​ (2,714) ​ ​ (651) ​ ​ (539) ​ ​ (34) ​ ​ (5,055) Disposals ​ ​ 158 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 158 Currency translation adjustment ​ ​ 37 ​ ​ (15) ​ ​ — ​ ​ (11) ​ ​ — ​ ​ 10 On December 31, 2021 ​ ​ (4,565) ​ ​ (6,774) ​ ​ (1,411) ​ ​ (1,093) ​ ​ (116) ​ ​ (13,958) Depreciation ​ ​ (1,388) ​ ​ (2,179) ​ ​ (735) ​ ​ (257) ​ ​ (35) ​ ​ (4,593) Disposals ​ ​ 90 ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 90 Currency translation adjustment ​ ​ 408 ​ ​ 5 ​ ​ 1 ​ ​ 1 ​ ​ — ​ ​ 414 On December 31, 2022 ​ ​ (5,454) ​ $ (8,948) ​ $ (2,145) ​ $ (1,350) ​ $ (150) ​ $ (18,047) Depreciation ​ ​ (1,539) ​ ​ (2,839) ​ ​ (971) ​ ​ (189) ​ ​ (36) ​ ​ (5,574) Disposals ​ ​ 189 ​ ​ — ​ ​ 757 ​ ​ — ​ ​ — ​ ​ 946 On December 31, 2023 ​ $ (6,804) ​ $ (11,787) ​ $ (2,359) ​ $ (1,539) ​ $ (186) ​ $ (22,675) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2021 ​ $ 3,373 ​ $ 9,688 ​ $ 1,664 ​ $ 888 ​ $ 230 ​ $ 15,844 On December 31, 2022 ​ ​ 2,706 ​ ​ 10,867 ​ ​ 1,835 ​ ​ 631 ​ ​ 196 ​ ​ 16,234 On December 31, 2023 ​ $ 2,091 ​ $ 16,798 ​ $ 3,191 ​ $ 436 ​ $ 160 ​ $ 22,675

Intangible assets (Tables)

Intangible assets (Tables)	12 Months Ended
	Dec. 31, 2023
Intangible assets
Schedule of intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) Acquired R&D available for use ​ Acquired In-Process R&D ​ Software & databases ​ Other Intangibles ​ Total Cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2021 ​ $ — ​ $ 65,180 ​ $ 3,543 ​ $ 99,058 ​ $ 167,781 Additions ​ ​ — ​ ​ 5,000 ​ ​ — ​ ​ — ​ ​ 5,000 Translation differences ​ ​ — ​ ​ — ​ ​ (190) ​ ​ — ​ ​ (190) On December 31, 2021 ​ ​ — ​ ​ 70,180 ​ ​ 3,353 ​ ​ 99,058 ​ ​ 172,591 Additions ​ ​ — ​ ​ — ​ ​ 992 ​ ​ 102,000 ​ ​ 102,992 Disposals ​ ​ — ​ ​ — ​ ​ (5) ​ ​ — ​ ​ (5) Derecognition ​ ​ — ​ ​ — ​ ​ — ​ ​ (99,058) ​ ​ (99,058) On December 31, 2022 ​ ​ — ​ ​ 70,180 ​ ​ 4,340 ​ ​ 102,000 ​ ​ 176,519 Additions ​ ​ 56,000 ​ ​ — ​ ​ — ​ ​ — ​ ​ 56,000 Derecognition ​ ​ — ​ ​ — ​ ​ — ​ ​ (102,000) ​ ​ (102,000) Reclassification ​ ​ 52,931 ​ ​ (52,931) ​ ​ — ​ ​ — ​ ​ — On December 31, 2023 ​ $ 108,931 ​ $ 17,249 ​ $ 4,340 ​ $ — ​ $ 130,520 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization and impairment ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On January 1, 2021 ​ $ — ​ $ — ​ $ (437) ​ $ — ​ $ (437) Amortization ​ ​ ​ ​ ​ ​ ​ ​ (470) ​ ​ — ​ ​ (470) On December 31, 2021 ​ ​ — ​ ​ — ​ ​ (907) ​ ​ — ​ ​ (907) Amortization ​ ​ — ​ ​ — ​ ​ (711) ​ ​ (99,058) ​ ​ (99,768) Derecognition ​ ​ — ​ ​ — ​ ​ — ​ ​ 99,058 ​ ​ 99,058 On December 31, 2022 ​ ​ — ​ ​ — ​ ​ (1,618) ​ ​ — ​ ​ (1,618) Amortization ​ ​ (3,392) ​ ​ — ​ ​ (282) ​ ​ (102,000) ​ ​ (105,674) Derecognition ​ ​ — ​ ​ — ​ ​ — ​ ​ 102,000 ​ ​ 102,000 On December 31, 2023 ​ $ (3,392) ​ $ — ​ $ (1,900) ​ $ — ​ $ (5,292) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Carrying Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ On December 31, 2021 ​ $ — ​ $ 70,180 ​ $ 2,446 ​ $ 99,058 ​ $ 171,684 On December 31, 2022 ​ ​ — ​ ​ 70,180 ​ ​ 2,722 ​ ​ 102,000 ​ ​ 174,901 On December 31, 2023 ​ $ 105,539 ​ $ 17,249 ​ $ 2,440 ​ $ — ​ $ 125,228

Other non-current assets (Table

Other non-current assets (Tables)	12 Months Ended
	Dec. 31, 2023
Other non-current assets,
Schedule of other non-current assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Non-current restricted cash $ 2,419 $ 1,736 $ 1,707 Non-current financial assets held at fair value through profit or loss ​ 21,715 ​ 21,715 ​ 17,459 Non-current financial assets held at fair value through OCI ​ ​ 15,528 ​ ​ 17,443 ​ ​ 35,710 Total other non-current assets $ 39,662 $ 40,894 $ 54,876
Schedule of non current financial assets at fair value through profit or loss	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Cost at January 1 $ 76,659 $ 76,659 $ 1,659 Additions of the year ​ ​ — ​ ​ — ​ ​ 75,000 Cost at December 31 ​ $ 76,659 ​ $ 76,659 ​ $ 76,659 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value adjustments at January 1 ​ $ (37,501) ​ $ (23,490) ​ $ 4,648 Fair value adjustment of the year through profit or loss ​ ​ — ​ ​ 4,256 ​ ​ 11,152 Fair value adjustment of the year through OCI ​ ​ (1,915) ​ ​ (18,267) ​ ​ (39,290) Fair value adjustment at December 31 ​ $ (39,416) ​ $ (37,501) ​ $ (23,490) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net book value at December 31 $ 37,243 $ 39,158 $ 53,169 ​

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2023
Inventories
Schedule of inventories	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Raw materials and consumables ​ $ 240,836 $ 126,046 $ 70,134 Inventories in process ​ ​ 47,074 ​ ​ 65,016 ​ ​ 37,705 Finished goods ​ ​ 22,640 ​ ​ 37,291 ​ ​ 1,237 Total inventories $ 310,550 $ 228,353 $ 109,076

Prepaid expenses (Current) (Tab

Prepaid expenses (Current) (Tables)	12 Months Ended
	Dec. 31, 2023
Prepaid expenses (Current)
Schedule of current prepaid expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Prepaid inventory ​ ​ 22,460 ​ ​ 11,667 ​ ​ 10,786 Prepaid research and development expenses ​ ​ 71,201 ​ ​ 44,905 ​ ​ 39,684 Prepaid advertising expenses ​ ​ 19,933 ​ ​ 13,479 ​ ​ 2,006 Prepaid software ​ ​ 6,240 ​ ​ 4,309 ​ ​ 2,272 Other prepaid expenses ​ ​ 14,238 ​ ​ 1,662 ​ ​ 4,198 Total prepaid expenses $ 134,072 $ 76,022 $ 58,946 ​

Trade and other receivables (Ta

Trade and other receivables (Tables)	12 Months Ended
	Dec. 31, 2023
Trade and other receivables.
Schedule of trade and other receivables	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Trade receivable ​ $ 417,994 ​ $ 241,228 ​ $ 28,058 Interest receivable ​ ​ 13,126 ​ ​ 12,918 ​ ​ 1,325 Tax receivables ​ ​ 63,605 ​ ​ 20,526 ​ ​ 7,974 Other receivable ​ ​ 1,962 ​ ​ 1,025 ​ ​ 864 Total trade and other receivables $ 496,687 $ 275,697 $ 38,221

Financial assets - current (Tab

Financial assets - current (Tables)	12 Months Ended
	Dec. 31, 2023
Financial assets - current.
Schedule of current financial assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Money market funds $ — $ 46,162 $ 73,052 Term accounts ​ ​ 1,131,000 ​ ​ 1,345,646 ​ ​ 929,000 Total current financial assets $ 1,131,000 $ 1,391,808 $ 1,002,052

Cash and cash equivalents (Tabl

Cash and cash equivalents (Tables)	12 Months Ended
	Dec. 31, 2023
Cash and cash equivalents
Schedule of cash and cash equivalents	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Money market funds $ 1,678,100 $ 669,147 $ 997,092 Term accounts ​ ​ 350,000 ​ ​ 54,116 ​ ​ 95,090 Cash and bank balances ​ 20,744 ​ 77,477 ​ 242,494 Total cash and cash equivalents $ 2,048,844 $ 800,740 $ 1,334,676

Share capital and share premi_2

Share capital and share premium (Tables)	12 Months Ended
	Dec. 31, 2023
Share capital and share premium.
Schedule of number of share outstanding	​ ​ ​ ​ Number of shares outstanding on January 1, 2021 47,571,283 Exercise of stock options ​ 503,282 Global public offering in Euronext and Nasdaq on February 2, 2021 ​ 3,125,000 Over-allotment option exercised by underwriters on February 4, 2021 ​ 468,750 Number of shares outstanding on December 31, 2021 51,668,315 Exercise of stock options ​ 1,024,626 Vesting of RSUs ​ 19,581 Global public offering in Euronext and Nasdaq on March 23, 2022 ​ 2,333,334 Over-allotment option exercised by underwriters on March 29, 2022 ​ 350,000 Number of shares outstanding on December 31, 2022 55,395,856 Exercise of stock options ​ 1,137,439 Vesting of RSUs ​ 79,560 Global public offering in Nasdaq on July 18, 2023 ​ 2,244,899 Over-allotment option exercised by underwriters on July 19, 2023 ​ 336,734 Number of shares outstanding on December 31, 2023 59,194,488 ​ ​ ​

Share-based payments (Tables)

Share-based payments (Tables)	12 Months Ended
	Dec. 31, 2023
Share-based payments
Schedule of share based payment arrangement	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Exercise price ​ Outstanding ​ ​ per stock ​ stock options on ​ ​ options ​ December 31, Expiry date (in $) (1) 2023 2022 2021 2022 ​ $ 2.70 ​ — ​ — ​ 125,339 2024 ​ 2.70 3,308 19,743 94,088 2024 ​ 4.36 532 5,127 6,113 2024 ​ 7.92 81,500 214,800 276,500 2025 ​ 12.64 1,600 2,000 4,500 2025 ​ 10.46 99,326 101,861 105,857 2026 ​ 12.57 24,400 30,000 41,000 2026 ​ 12.67 97,972 99,772 102,840 2026 ​ 15.62 111,811 115,211 117,581 2027 ​ ​ 20.34 ​ 38,434 ​ 42,509 ​ 53,143 2027 ​ ​ 23.39 ​ 225,852 ​ 303,867 ​ 361,350 2023 ​ ​ 89.31 ​ — ​ 12,111 ​ 85,080 2028 ​ ​ 89.31 ​ 13,890 ​ 19,490 ​ 39,515 2023 ​ ​ 95.38 ​ — ​ 124,338 ​ 321,473 2028 ​ ​ 95.38 ​ 225,457 ​ 264,392 ​ 350,631 2024 ​ ​ 125.40 ​ 26,171 ​ 110,774 ​ 111,174 2029 ​ ​ 125.40 ​ 71,573 ​ 110,756 ​ 146,765 2024 ​ ​ 150.00 ​ 104,176 ​ 202,852 ​ 203,658 2029 ​ ​ 150.00 ​ 370,566 ​ 537,110 ​ 611,122 2025 ​ ​ 132.08 ​ 16,712 ​ 16,712 ​ 16,712 2030 ​ ​ 132.08 ​ 50,801 ​ 71,486 ​ 102,558 2025 ​ ​ 216.75 ​ 126,331 ​ 127,731 ​ 129,711 2030 ​ ​ 216.75 ​ 160,677 ​ 223,812 ​ 282,475 2025 ​ ​ 221.24 ​ 31,424 ​ 32,100 ​ 32,100 2030 ​ ​ 221.24 ​ 78,534 ​ 117,790 ​ 136,601 2030 ​ ​ 273.60 ​ 559,173 ​ 620,014 ​ 692,214 2025 ​ ​ 273.60 ​ 202,205 ​ 202,475 ​ 203,214 2026 ​ ​ 259.01 ​ 23,491 ​ 23,491 ​ 24,366 2026 ​ ​ 281.89 ​ 59,626 ​ 60,890 ​ 61,505 2026 ​ ​ 286.75 ​ 45,228 ​ 45,862 ​ 48,138 2031 ​ ​ 259.01 ​ 27,201 ​ 35,214 ​ 42,282 2031 ​ ​ 281.89 ​ 128,600 ​ 167,406 ​ 207,464 2031 ​ ​ 286.75 ​ 62,138 ​ 81,311 ​ 92,456 2026 ​ ​ 341.67 ​ 80,425 ​ 80,833 ​ 82,430 2031 ​ ​ 341.67 ​ 226,520 ​ 286,353 ​ 307,158 2027 ​ ​ 312.16 ​ 13,957 ​ 14,976 ​ — 2032 ​ ​ 312.16 ​ 58,255 ​ 79,155 ​ — 2027 ​ ​ 395.04 ​ 58,091 ​ 61,816 ​ — 2032 ​ ​ 395.04 ​ 192,291 ​ 238,532 ​ — 2027 ​ ​ 407.19 ​ 13,764 ​ 13,764 ​ — 2032 ​ ​ 407.19 ​ 73,288 ​ 85,199 ​ — 2032 ​ ​ 397.36 ​ 347,765 ​ 370,354 ​ — 2027 ​ ​ 397.36 ​ 136,459 ​ 137,778 ​ — 2025 ​ ​ 341.67 ​ 16,000 ​ — ​ — 2028 ​ ​ 376.47 ​ 15,014 ​ — ​ — 2033 ​ ​ 376.47 ​ 43,856 ​ — ​ — 2028 ​ ​ 392.72 ​ 127,490 ​ — ​ — 2033 ​ ​ 392.72 ​ 495,821 ​ — ​ — 2028 ​ ​ 508.96 ​ 2,235 ​ — ​ — 2033 ​ ​ 508.96 ​ 69,704 ​ — ​ — 2028-2032 (2) ​ $ 330.06 ​ 79,305 ​ — ​ — ​ ​ ​ ​ ​ 5,118,949 5,511,767 ​ 5,619,113 (1) Amounts have been converted to USD at the closing rate as of December 31, 2023.
Schedule of number of stock options	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 ​ 2022 ​ 2021 ​ Number of Weighted average Number of Weighted average Number of Weighted average ​ ​ stock options ​ exercise price (*) ​ stock options ​ exercise price (*) ​ stock options ​ exercise price (*) Outstanding at January 1 5,511,767 $ 205.02 5,619,113 $ 164.33 5,365,743 $ 142.87 Granted 844,011 ​ 395.92 1,021,642 ​ 375.58 882,584 ​ 314.99 Exercised (1,137,439) ​ 142.31 (1,025,780) ​ 92.62 (503,282) ​ 64.72 Forfeited (99,390) ​ 356.57 (103,208) ​ 273.93 (125,932) ​ 234.98 Outstanding at December 31 5,118,949 ​ 255.41 5,511,767 ​ 205.02 5,619,113 ​ 164.33 Exercisable at December 31 3,030,486 $ 179.22 3,983,960 $ 148.11 3,613,371 $ 106.53 (*) amounts have been converted to USD at the closing rate of the respective period.
Schedule of weighted average remaining contractual life for each range of exercise price:	​ ​ ​ ​ ​ ​ ​ ​ Weighted average ​ ​ ​ ​ remaining ​ ​ Outstanding on ​ contractual life Exercise price (in $) December 31, 2023 (in years) 2.7 - 7.92 ​ 85,340 ​ 0.96 10.46 - 12.64 100,926 ​ 1.95 12.57 - 15.62 234,183 ​ 2.67 20.34 - 23.39 ​ 264,286 ​ 3.89 89.31 - 95.38 ​ 239,347 ​ 4.95 125.4 - 150 ​ 572,486 ​ 4.75 132.08 - 273.6 ​ 1,225,857 ​ 5.26 259.01 - 341.67 ​ 669,229 ​ 6.04 312.16 - 407.19 ​ 893,870 ​ 7.53 330.06 - 508.96 ​ 833,425 ​ 8.69
Schedule of parameters used in relation to the new grants	Below is an overview of the parameters used in relation to the determination of the fair value of the grants during 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options granted in April 2023 July 2023 ​ October 2023 ​ December 2023 (1) ​ Number of options granted ​ 61,056 ​ 629,121 ​ ​ 74,529 ​ ​ 79,305 ​ Average Fair value of options (in $) (*) $ 158.21-196.18 $ 176.44 - 271.59 ​ $ 123.94 - 209.04 ​ $ 161.88 - 165.69 ​ Share price (in $) (*) $ 361.64-401.21 $ 380.81 - 521.19 ​ $ 439.42 - 491.75 ​ $ 371.36 ​ Exercise price (in $) (*) $ 370.34 $ 387.35 ​ $ 485.01 ​ $ 329.26 ​ Expected volatility ​ 41.00 - 42.18 % ​ 36.22 - 43.99 % ​ 35.35 - 36.67 % ​ 36.20 - 36.21 % Average Expected option life (in years) ​ 4 - 6.50 ​ 4 - 6.50 ​ 4 - 6.50 ​ ​ 6.15 - 6.50 ​ Risk‑free interest rate ​ 2.96 - 3.14 % ​ 2.90 - 3.03 % ​ 2.80 - 3.44 % ​ 2.40 % Expected dividends ​ — % ​ — % ​ — % ​ — % (1) In December 2023, the Company granted a total of 79,305 stock options of which 8,459 stock options to Belgian taxed beneficiaries. Belgian taxed beneficiaries can choose between a contractual term of five or ten years . The expected option life ranges between 6.15 and 6.50 years. This estimate will be reassessed once the acceptance period of 60 days has passed and the beneficiaries will have made a choice between a contractual term of five or ten years . The total fair value of the grant to Belgian taxed beneficiaries would range from $ 1.1 million ( 100% of the stock options of Belgian taxed beneficiaries with a contractual term of five years ) to $1.4 million ( 100% of the stock options of Belgian taxed beneficiaries with a contractual term of ten years ). (*) amounts have been converted to USD at the applicable rate prevailing at the grant date. Below is an overview of the parameters used in relation to the determination of the fair value of grants during 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options granted in April 2022 July 2022 ​ October 2022 December 2022 (1) ​ Number of options granted ​ 102,081 ​ 311,311 ​ ​ 100,118 ​ ​ 508,132 ​ Average Fair value of options (in $) (*) $ 111.27 - 140.23 $ 153.45 - 190.53 ​ $ 136.66 - 169.96 ​ $ 127.68 - 163.94 ​ Share price (in $) (*) $ 320.84 - 321.06 $ 378.11 - 397.92 ​ $ 352.97 - 376.01 ​ $ 368.69 - 377.61 ​ Exercise price (in $) (*) $ 312.22 $ 372.69 ​ $ 359.80 ​ $ 381.97 ​ Expected volatility ​ 39.18 - 40.87 % ​ 41.30 - 43.10 % ​ 39.64 - 45.97 % ​ 39.74 - 40.26 % Average Expected option life (in years) ​ 4 - 6.50 ​ 4 - 6.50 ​ 4 - 6.50 ​ ​ 4 - 6.50 ​ Risk‑free interest rate ​ 1.05 - 1.62 % ​ 1.77 - 2.28 % ​ 2.57 - 2.80 % ​ 3.09 - 3.29 % Expected dividends ​ — % ​ — % ​ — % ​ — % (*) amounts have been converted to USD at the applicable rate prevailing at the grant date. (1) In December 2022, the Company granted a total of 508,132 stock options. Belgian beneficiaries could choose between a contractual term of five or ten years impacting the parameters used in determination of the fair value of the grant. Once the acceptance period of 60 days has passed in which the beneficiaries made a choice between a contractual term of five or ten years , the parameters and fair value used in the financial year ending December 31, 2022 has been reassessed. Below is an overview of the parameter used in relation to the determination of the fair value of grants during 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options granted in April 2021 July 2021 October 2021 ​ December 2021 ​ Number of options granted ​ 67,833 ​ 280,339 ​ ​ 144,824 ​ ​ 389,588 ​ Average Fair value of options (in $) (*) $ 98.96 - 154.88 $ 131.65 - 159.13 ​ $ 101.53 - 131.80 ​ $ 75.03 - 145.34 ​ Share price (in $) (*) $ 248.9 - 283.67 $ 300.78 - 340.95 ​ $ 286.52 - 304.5 ​ $ 277.72 - 351.73 ​ Exercise price (in $) (*) $ 275.33 $ 303.16 ​ $ 301.02 ​ $ 349.92 ​ Expected volatility ​ 54.24 - 60.08 % ​ 45.58 - 47.96 % ​ 46.01 - 48.46 % ​ 43.24 - 43.64 % Average expected option life (in years) ​ 4 - 6.50 ​ 4 - 6.50 ​ 4 - 6.50 ​ ​ 4 - 6.50 ​ Risk‑free interest rate ​ (0.41) - (0.08) % ​ (0.41) - (0.17) % ​ (0.18) - (0.05) % ​ 0.03 - 0.67 % Expected dividends ​ — % ​ — % ​ — % ​ — % (*) amounts have been converted to USD at the closing rate of the respective period.
Schedule of restricted stock units	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 ​ 2022 ​ 2021 ​ ​ Weighted average ​ Weighted average ​ Weighted average ​ ​ Number of ​ Grant Date ​ Number of ​ Grant Date ​ Number of ​ Grant Date ​ ​ RSUs ​ Fair Value ​ RSUs ​ Fair Value ​ RSUs ​ Fair Value Non-vested units at January 1 385,280 ​ $ 387.20 ​ 213,038 ​ $ 314.25 ​ — ​ $ — Granted 192,237 ​ ​ 396.22 ​ 243,010 ​ ​ 375.81 ​ 216,522 ​ ​ 313.84 Vested (105,678) ​ ​ 352.61 ​ (53,872) ​ ​ — ​ — ​ ​ — Forfeited (29,517) ​ ​ 358.49 ​ (16,896) ​ ​ 307.11 ​ (3,484) ​ ​ 288.92 Non-vested units at December 31 442,322 ​ $ 375.89 ​ 385,280 ​ $ 387.20 ​ 213,038 ​ $ 314.25

Trade and other payables (Table

Trade and other payables (Tables)	12 Months Ended
	Dec. 31, 2023
Trade and other payables.
Schedule of trade and other payables	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Trade payables $ 245,557 $ 188,721 $ 208,850 Short‑term employee benefits ​ 95,104 ​ 84,337 ​ 83,737 Gross-to-net-accruals ​ ​ 55,788 ​ ​ 19,478 ​ ​ — Other ​ ​ 17,564 ​ ​ 3,142 ​ ​ 828 Total trade and other payables $ 414,013 $ 295,679 $ 293,415
Schedule of movement in gross to net accruals	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) ​ ​ Rebates and chargebacks ​ ​ Distribution fees, product returns and other ​ ​ Total Balance at January 1, 2022 ​ $ — ​ $ — ​ $ — Current estimate related to the sales made in the current year ​ ​ 35,426 ​ ​ 10,740 ​ ​ 46,166 (Credits or payments related to sales made during the year) ​ ​ (20,028) ​ ​ (6,661) ​ ​ (26,689) Balance at December 31, 2022 ​ $ 15,398 ​ $ 4,079 ​ $ 19,478 Current estimate related to the sales made in the current year ​ ​ 123,542 ​ ​ 26,427 ​ ​ 149,969 Adjustment for prior year sales ​ ​ (4,041) ​ ​ (883) ​ ​ (4,924) (Credits or payments related to sales made during the year) ​ ​ (78,327) ​ ​ (20,722) ​ ​ (99,049) (Credit or payments related to sales made during prior year) ​ ​ (6,910) ​ ​ (2,775) ​ ​ (9,685) Balance at December 31, 2023 ​ $ 49,662 ​ $ 6,126 ​ $ 55,788 ​

Product net sales (Tables)

Product net sales (Tables)	12 Months Ended
	Dec. 31, 2023
Product net sales.
Product net sales	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) ​ 2023 ​ 2022 2021 Product gross sales ​ $ 1,342,148 ​ ​ 446,923 ​ ​ - Gross to net adjustment ​ ​ (151,365) ​ ​ (46,203) ​ ​ - Product net sales ​ $ 1,190,783 ​ ​ 400,720 ​ ​ -

Collaboration revenue (Tables)

Collaboration revenue (Tables)	12 Months Ended
	Dec. 31, 2023
Collaboration revenue
Schedule of revenue	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, (in thousands of $) ​ 2023 ​ 2022 2021 Zai Lab ​ ​ $ — ​ ​ — ​ ​ J&J ​ ​ — ​ ​ — ​ ​ 292,279 AbbVie ​ ​ — ​ ​ — ​ ​ 121 Upfront payments ​ ​ ​ — ​ ​ — ​ ​ 444,303 Zai Lab ​ ​ ​ — ​ ​ — ​ ​ 25,634 J&J ​ ​ ​ — ​ ​ — ​ ​ 22,865 AbbVie ​ ​ ​ 30,000 ​ ​ — ​ ​ 102 Other ​ ​ ​ — ​ ​ 5,365 ​ ​ 1,214 Milestone payments ​ ​ ​ 30,000 ​ ​ 5,365 ​ ​ 49,815 J&J ​ ​ ​ — ​ ​ — ​ ​ 2,028 Other ​ ​ ​ — ​ ​ 424 ​ ​ 298 Research and development service fees ​ ​ ​ — ​ ​ 424 ​ ​ 2,326 Zai Lab ​ ​ ​ 5,533 ​ ​ 4,238 ​ ​ 833 Other collaboration revenue ​ ​ ​ 5,533 ​ ​ 4,238 ​ ​ 833 Total collaboration revenue ​ ​ $ 35,533 ​ $ 10,026 ​ $ 497,277

Other operating income (Tables)

Other operating income (Tables)	12 Months Ended
	Dec. 31, 2023
Other operating income
Schedule of other operating income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Grants $ 2,538 $ 2,186 $ 4,398 Research and development incentives ​ 27,815 ​ 19,502 ​ 13,970 Payroll tax rebates ​ 11,925 ​ 8,576 ​ 12,621 Change in fair value on non-current financial assets ​ ​ — ​ ​ 4,256 ​ ​ 11,152 Total other operating income $ 42,278 $ 34,520 $ 42,141

Segment reporting (Tables)

Segment reporting (Tables)	12 Months Ended
	Dec. 31, 2023
Segment reporting
Schedule of product net sales by country of sales	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, (in thousands of $) 2023 2022 United States ​ $ 1,046,592 ​ $ 377,659 Japan ​ ​ 56,432 ​ ​ 15,764 EMEA ​ ​ 72,852 ​ ​ 7,297 China ​ ​ 14,907 ​ ​ — Total product net sales $ 1,190,783 $ 400,720
Schedule of collaboration revenue generated by external customers	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended ​ ​ ​ December 31, ​ (in thousands of $) 2023 2022 2021 Denmark $ — $ 5,365 $ 1,389 United States ​ 30,000 ​ — ​ 317,396 China ​ ​ 5,533 ​ ​ 4,238 ​ ​ 178,370 ​ Other ​ — ​ 424 ​ 123 Total collaboration revenue $ 35,533 $ 10,026 $ 497,277
Schedule of external customers geographically location	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-current assets ​ ​ At December 31, (in thousands of $) 2023 2022 2021 Netherlands $ — $ — $ — Belgium ​ 138,252 ​ 186,923 ​ 182,118 United States ​ 6,219 ​ 2,275 ​ 3,091 Japan ​ 2,971 ​ 1,938 ​ 2,319 Germany ​ ​ 461 ​ ​ — ​ ​ — Total $ 147,903 $ 191,136 $ 187,528

Research and development expe_2

Research and development expenses (Tables)	12 Months Ended
	Dec. 31, 2023
Research and development expenses
Schedule of research and development expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 ​ 2021 Personnel expenses $ 226,344 $ 162,010 $ 160,464 External research and development expenses ​ 483,192 ​ 366,955 ​ 382,902 Materials and consumables ​ 4,057 ​ 2,396 ​ 2,735 Depreciation and amortization ​ 105,546 ​ 102,132 ​ 3,742 IT expenses ​ ​ 19,935 ​ ​ 12,678 ​ ​ 7,798 Other expenses ​ 20,418 ​ 17,194 ​ 22,879 Total Research and development expenses $ 859,492 $ 663,366 $ 580,520 ​

Selling, general and administ_2

Selling, general and administrative expenses (Tables)	12 Months Ended
	Dec. 31, 2023
Selling, general and administrative expenses
Schedule of selling, general and administrative expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Personnel expenses $ 303,033 $ 234,740 $ 164,646 Marketing services ​ 202,146 ​ ​ 115,950 ​ 59,968 Professional fees ​ ​ 108,820 ​ ​ 62,620 ​ ​ 42,707 Supervisory board ​ 8,362 ​ 6,912 ​ 12,958 Depreciation and amortization ​ ​ 2,366 ​ ​ 2,211 ​ ​ 2,126 IT expenses ​ ​ 20,408 ​ ​ 17,431 ​ ​ 8,977 Other expenses ​ 66,770 ​ 32,268 ​ 16,263 Total Selling, general and administrative expenses $ 711,905 $ 472,132 $ 307,644 ​

Personnel expenses (Tables)

Personnel expenses (Tables)	12 Months Ended
	Dec. 31, 2023
Personnel expenses
Schedule of personnel expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Short‑term employee benefits—Salaries $ 266,482 $ 216,847 $ 135,676 Short‑term employee benefits—Social Security ​ 19,231 ​ 16,274 ​ 12,785 Post‑employment benefits ​ 7,758 ​ 5,406 ​ 2,864 Termination benefits ​ 1,089 ​ 401 ​ 818 Share‑based payment ​ 226,830 ​ 151,912 ​ 167,965 Employer social security contributions stock options ​ 7,987 ​ 5,910 ​ 5,002 Total personnel expenses $ 529,377 $ 396,750 $ 325,110
Schedule of average number of full-time equivalents employees	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, Average Number of FTE 2023 2022 2021 Research and development ​ 607.3 ​ 474.8 ​ 349.7 Selling, general and administrative ​ 681.2 ​ 442.4 ​ 264.4 ​ ​ 1,288.5 ​ 917.2 ​ 614.1 ​

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases
Schedule of financial position relating to leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ December 31, ​ December 31, In thousands of $ 2023 ​ 2022 ​ 2021 Right-of-use assets ​ ​ ​ ​ ​ ​ ​ ​ Buildings $ 16,798 $ 10,867 $ 9,688 Vehicles ​ ​ 3,191 ​ ​ 1,835 ​ ​ 1,664 Equipment ​ ​ 160 ​ ​ 196 ​ ​ 230 ​ $ 20,149 ​ $ 12,897 ​ $ 11,583 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Lease liabilities ​ ​ ​ ​ ​ ​ ​ ​ Current $ 4,646 $ 3,417 $ 3,509 Non-current ​ ​ 15,354 ​ ​ 9,009 ​ ​ 7,956 ​ $ 20,000 ​ $ 12,426 ​ $ 11,465
Schedule of maturity analysis of the lease liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) Less than 1 year ​ 1-3 years ​ 3-5 years ​ More than 5 years ​ Total contractual cash flows ​ Carrying amount Lease liabilities $ 4,286 $ 8,136 ​ $ 5,754 ​ $ 1,824 ​ $ 20,000 $ 20,000
Schedule of total lease liabilities recognized in our statement of financial position	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, In thousands of $ 2023 2022 ​ 2021 Depreciation charges ​ ​ ​ ​ ​ ​ ​ ​ Buildings $ 2,839 $ 2,179 $ 2,714 Vehicles ​ ​ 971 ​ ​ 735 ​ ​ 651 Equipment ​ ​ 36 ​ ​ 35 ​ ​ 34 ​ $ 3,846 $ 2,949 $ 3,399 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest expense (included in finance cost) ​ $ 693 ​ $ 1,343 ​ $ 412 Expense relating to short-term leases ​ ​ 1,517 ​ ​ 732 ​ ​ 212 Expense relating to leases of low-value assets that are not shown above as short-term leases ​ ​ 40 ​ ​ 21 ​ ​ 7

Financial result and exchange_2

Financial result and exchange gains(losses) (Tables)	12 Months Ended
	Dec. 31, 2023
Financial result and exchange gains/(losses)
Schedule of financial result and exchange gains/(losses)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Interest income $ 92,962 $ 24,741 $ 3,489 Net gain on cash equivalents & current financial assets held at fair value through profit or loss and cash equivalents ​ 14,424 ​ 2,924 ​ 144 Financial income $ 107,386 $ 27,665 $ 3,633 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss on cash equivalents & current financial assets held at fair value through profit or loss and cash equivalents ​ $ (2) ​ $ (1,713) ​ $ (3,482) Other financial expense ​ ​ (904) ​ ​ (2,193) ​ ​ (1,096) Financial expense ​ $ (906) ​ $ (3,906) ​ $ (4,578) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Realized exchange gains/(losses) $ 29 $ (3,743) $ 15 Unrealized exchange gains/(losses) ​ ​ 14,044 ​ ​ (28,989) ​ ​ (50,068) Exchange gains/(losses) $ 14,073 $ (32,732) $ (50,053)

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income taxes
Schedule of income taxes recognized in income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Current year $ (9,592) $ (27,162) $ (15,224) Income tax prior years ​ (2,080) ​ (12) ​ 398 Current tax (expense) / benefit ​ (11,672) ​ (27,174) ​ (14,826) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Originating and reversal of temporary differences ​ ​ 21,115 ​ ​ 46,894 ​ ​ 6,304 Deferred tax (expense) / benefit ​ 21,115 ​ 46,894 ​ 6,304 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total tax (expense) / benefit ​ $ 9,443 ​ $ 19,720 ​ $ (8,522)
Schedule of difference between the provision for income taxes and the amount that would result from applying the Dutch statutory tax rate to income before provision for income taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, (in thousands of $) 2023 2022 2021 Loss before taxes $ 304,496 $ 729,314 $ 399,743 Income tax (expense)/benefit calculated at the Dutch statutory federal income tax rates for applicable tax years (1) ​ 78,560 ​ 188,163 ​ 99,936 Effect of intercompany asset deal / transaction ​ ​ 396 ​ ​ (112,200) ​ ​ — Effect of expenses not deductible in determining taxable results ​ (2,674) ​ (1,570) ​ (4,441) Effect of share based payment expenses that are not deductible in determining taxable results ​ ​ (43,040) ​ ​ (27,043) ​ ​ (29,925) Effect of stock issue expenses that are not taxable in determining taxable results ​ 18,620 ​ 11,412 ​ 14,119 Effect of concessions ​ 87,123 ​ 18,263 ​ 13,413 Effect of change of (de)recognition of deferred tax assets on tax losses ​ ​ (2,282) ​ ​ (194) ​ ​ (44,232) Effect of different tax rates in jurisdictions in which the company operates ​ (3,509) ​ (5,566) ​ (2,084) Effect of change of (de)recognition of deferred tax assets ​ (124,457) ​ (51,320) ​ (50,389) Withholding tax paid ​ ​ (68) ​ ​ — ​ ​ (5,076) (Underprovided)/overprovided in prior years ​ ​ (2,080) ​ ​ (12) ​ ​ 398 Other ​ ​ 2,854 ​ ​ (213) ​ ​ (241) Income tax (expense)/benefit recognized in the consolidated statements of profit or loss $ 9,443 $ 19,720 $ (8,522) (1) Applicable tax rates are 25.8% for 2022 and 2023, and 25.0% for 2021
Schedule of deferred tax assets and liability by type of temporary difference	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2023 (in thousands of $) Assets ​ Liabilities Net Deferred tax assets / (liabilities) ​ ​ ​ ​ ​ ​ ​ ​ ​ Accruals and allowances ​ $ 13,189 ​ $ — ​ $ 13,189 Income tax benefit from excess tax deductions related to share-based payments ​ ​ 23,310 ​ ​ — ​ ​ 23,310 Profit in inventory ​ ​ 52,026 ​ ​ — ​ ​ 52,026 Other tax carryforwards ​ ​ 6,339 ​ ​ — ​ ​ 6,339 Property, plant and equipment ​ ​ 2,136 ​ ​ (1,550) ​ ​ 586 Non-current fixed assets ​ ​ — ​ ​ (5,155) ​ ​ (5,155) Other ​ ​ 1,760 ​ ​ — ​ ​ 1,760 Netting by taxable entity ​ ​ (1,549) ​ ​ 1,550 ​ ​ 1 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net deferred tax assets / (liabilities) $ 97,211 $ (5,155) $ 92,056 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2022 (in thousands of $) Assets ​ Liabilities Net Deferred tax assets / (liabilities) ​ ​ ​ ​ ​ ​ ​ ​ ​ Accruals and allowances ​ $ 8,884 ​ $ — ​ $ 8,884 Income tax benefit from excess tax deductions related to share-based payments ​ ​ 26,887 ​ ​ — ​ ​ 26,887 Profit in inventory ​ ​ 29,711 ​ ​ — ​ ​ 29,711 R&D capitalized expense ​ ​ 11,316 ​ ​ — ​ ​ 11,316 Property, plant and equipment ​ ​ 856 ​ ​ (549) ​ ​ 307 Intangible assets ​ ​ — ​ ​ (3,430) ​ ​ (3,430) Non-current fixed assets ​ ​ — ​ ​ (4,975) ​ ​ (4,975) Other ​ ​ 2,117 ​ ​ — ​ ​ 2,117 Netting by taxable entity ​ ​ (549) ​ ​ 549 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net deferred tax assets / (liabilities) $ 79,222 $ (8,406) $ 70,817 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2021 (in thousands of $) Assets ​ Liabilities Net Deferred tax assets / (liabilities) ​ ​ ​ ​ ​ ​ ​ ​ ​ Accruals and allowances ​ $ 2,858 ​ $ — ​ $ 2,858 Income tax benefit from excess tax deductions related to share-based payments ​ ​ 26,026 ​ ​ — ​ ​ 26,026 Profit in inventory ​ ​ 3,305 ​ ​ — ​ ​ 3,305 Property, plant and equipment ​ ​ 532 ​ ​ (740) ​ ​ (208) Intangible assets ​ ​ — ​ ​ (2,714) ​ ​ (2,714) Non-current fixed assets ​ ​ — ​ ​ (3,725) ​ ​ (3,725) Other ​ ​ 210 ​ ​ — ​ ​ 210 Netting by taxable entity ​ ​ (740) ​ ​ 740 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net deferred tax assets / (liabilities) $ 32,191 $ (6,438) $ 25,753
Schedule of change in net deferred taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) Deferred tax assets Deferred tax liabilities Balance at January 1, 2023 $ 79,222 $ (8,406) Recognized in profit or loss ​ ​ 17,685 ​ ​ 3,430 Recognized in equity ​ ​ 381 ​ ​ — Effects of change in foreign exchange rate ​ ​ (77) ​ ​ (179) Balance at December 31, 2023 ​ $ 97,211 ​ $ (5,155) ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) Deferred tax assets Deferred tax liabilities Balance at January 1, 2022 $ 32,191 $ (6,438) Recognized in profit or loss ​ ​ 49,075 ​ ​ (2,180) Recognized in equity ​ ​ (1,960) ​ ​ — Effects of change in foreign exchange rate ​ ​ (84) ​ ​ 212 Balance at December 31, 2022 ​ $ 79,222 ​ $ (8,406) ​ ​ ​ ​ ​ ​ ​ ​ (in thousands of $) Deferred tax assets Deferred tax liabilities Balance at January 1, 2021 $ 15,038 $ (1,487) Recognized in profit or loss ​ ​ 11,385 ​ ​ (5,082) Recognized in equity ​ ​ 5,494 ​ ​ — Effects of change in foreign exchange rate ​ ​ 274 ​ ​ 131 Balance at December 31, 2021 ​ $ 32,191 ​ $ (6,438)

Loss per share (Tables)

Loss per share (Tables)	12 Months Ended
	Dec. 31, 2023
Loss per share
Schedule of loss per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (in thousands of $) 2023 2022 2021 Loss for the year $ (295,053) $ (709,594) $ (408,265) Weighted average number of shares outstanding ​ 57,169,253 ​ 54,381,371 ​ 51,075,827 Basic and diluted (loss) per share (in $) $ (5.16) $ (13.05) $ (7.99) ​

Financial risk management (Tabl

Financial risk management (Tables)	12 Months Ended
	Dec. 31, 2023
Financial risk management
Schedule of overview of financial instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Measurement category ​ Carrying amount ​ ​ ​ ​ At December 31, (in thousands of $) ​ 2023 ​ 2022 2021 Financial assets — non-current FVTPL $ 21,715 ​ $ 21,715 $ 17,459 Financial assets — non-current ​ FVTOCI ​ ​ 15,528 ​ ​ 17,443 ​ ​ 35,710 Research and development incentive receivables — non-current Amortised cost ​ ​ 76,706 ​ ​ 47,488 ​ 32,707 Restricted cash — non-current Amortised cost ​ ​ 2,419 ​ ​ 1,736 ​ 1,707 Trade and other receivables ​ Amortised cost ​ ​ 496,687 ​ ​ 275,697 ​ 38,221 Financial assets—current ​ FVTPL ​ ​ — ​ ​ 46,162 ​ ​ 73,052 Financial assets—current ​ Amortised cost ​ ​ 1,131,000 ​ ​ 1,345,646 ​ ​ 929,000 Research and development incentive receivables — current ​ Amortised cost ​ ​ 2,584 ​ ​ 1,578 ​ ​ — Cash and bank balances Amortised cost ​ ​ 20,744 ​ ​ 77,477 ​ 242,494 Cash equivalents ​ FVTPL ​ ​ 1,678,100 ​ ​ 669,147 ​ ​ 997,092 Cash equivalents ​ Amortised cost ​ ​ 350,000 ​ ​ 54,116 ​ ​ 95,090 Trade and other payables ​ Amortised cost ​ ​ 414,013 ​ ​ 295,679 ​ 293,415
Schedule of assets at fair value	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2023 (in thousands of $) Level 1 Level 2 Level 3 Non-current financial assets $ 15,528 $ — $ 21,715 Cash and cash equivalents ​ ​ 1,678,100 ​ ​ — ​ ​ — Assets carried at fair value $ 1,693,628 $ — $ 21,715 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2022 (in thousands of $) Level 1 Level 2 Level 3 Non-current financial assets $ 17,443 $ — $ 21,715 Current financial assets ​ 46,162 ​ — ​ — Cash and cash equivalents ​ ​ 669,147 ​ ​ — ​ ​ — Assets carried at fair value $ 732,752 $ — $ 21,715 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, 2021 (in thousands of $) Level 1 Level 2 Level 3 Non-current financial assets $ 35,710 $ — $ 17,459 Current financial assets ​ 73,052 ​ — ​ — Cash and cash equivalents ​ ​ 997,092 ​ ​ — ​ ​ — Assets carried at fair value $ 1,105,854 $ — $ 17,459 ​
Schedule of net exposure exchange differences of the monetary assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At December 31, (in thousands of $) 2023 2022 2021 EUR 923,773 613,866 591,887 JPY ​ 8,232 ​ 5,613 ​ 6,316 GBP 7 59,026 1,237 CHF ​ 193 ​ 3,832 ​ 727 CAD ​ 266 ​ 657 ​ — SEK ​ 1 ​ 7 ​ — DKK 9 6 ​ —

Related party transactions (Tab

Related party transactions (Tables)	12 Months Ended
	Dec. 31, 2023
Related party transactions
Schedule of remuneration of key management personnel	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, (in thousands of $, except for the number of stock options & RSUs) 2023 2022 2021 Remuneration of key management personnel ​ ​ ​ ​ ​ ​ Short-term benefits for senior management members as a group ​ ​ ​ ​ ​ ​ Gross salary ​ $ 4,161 ​ $ 4,199 ​ $ 3,465 Variable pay ​ ​ 2,816 ​ ​ 3,077 ​ ​ 2,020 Employer social security ​ ​ 807 ​ ​ 1,015 ​ ​ 789 Other short term benefits ​ ​ 545 ​ ​ 372 ​ ​ 274 Termination Benefits ​ ​ — ​ ​ — ​ ​ 382 Post-employment benefits for senior management members as a group ​ ​ 167 ​ ​ 104 ​ ​ 150 Cost of stock options granted in the year for senior management members as a group ​ ​ 27,983 ​ ​ 18,393 ​ ​ 15,060 Cost of restricted stock units granted in the year for senior management members as a group ​ ​ 11,694 ​ ​ 9,594 ​ ​ 8,025 Employer social security cost related to stock options ​ ​ (494) ​ ​ 1,101 ​ ​ 4,172 Total benefits for key management personnel ​ ​ 47,679 ​ ​ 37,855 ​ ​ 34,337 Numbers of stock options granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior Management as a group ​ ​ 132,100 ​ ​ 117,600 ​ ​ 101,446 Numbers of restricted stock units granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Senior Management as a group ​ ​ 30,425 ​ ​ 26,500 ​ ​ 22,888 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Remuneration of non-executive directors ​ ​ ​ ​ ​ ​ ​ ​ ​ Board fees and other short-term benefits for non-executive directors ​ ​ 533 ​ ​ 437 ​ ​ 435 Cost of stock options granted in the year for non-executive directors ​ ​ 2,280 ​ ​ 3,643 ​ ​ 3,263 Cost of restricted stock units granted in the year for non-executive directors ​ ​ 1,034 ​ ​ 1,850 ​ ​ 1,731 Total benefits for non-executive board members ​ $ 3,847 ​ $ 5,929 ​ $ 5,429 Numbers of stock options granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-executive directors ​ ​ 12,400 ​ ​ 21,600 ​ ​ 22,950 Numbers of restricted stock units granted in the year ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-executive directors ​ ​ 2,713 ​ ​ 4,800 ​ ​ 5,100

Audit fees (Tables)

Audit fees (Tables)	12 Months Ended
	Dec. 31, 2023
Audit fees
Schedule of auditors' fees expensed in the income statement	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, Fees 2023 2022 2021 ​ ​ in thousands of $ Audit fees (1) $ 1,979 $ 1,394 $ 1,183 Audit-related fees ​ 330 ​ 380 ​ 267 Tax fees (2) ​ — ​ — ​ 79 Total $ 2,309 $ 1,774 $ 1,529 (1) Auditor services performed by Deloitte Accountants B.V. as the external auditor referred to in Section 1 of the Dutch Accounting Firms Oversight Act (Wta) as well as by the Deloitte network. (2) Tax services performed by the Deloitte network .

Overview of consolidation sco_2

Overview of consolidation scope (Tables)	12 Months Ended
	Dec. 31, 2023
Overview of consolidation scope
Schedule of overview of subsidiaries	​ ​ ​ ​ ​ ​ ​ Name Country Participation argenx SE ​ The Netherlands ​ 100.00 % argenx BV Belgium 100.00 % argenx Benelux BV ​ Belgium ​ 100.00 % argenx US, Inc. USA 100.00 % argenx Switzerland, SA ​ Switzerland ​ 100.00 % argenx Japan KK Japan 100.00 % argenx France SAS ​ France ​ 100.00 % argenx Germany GmbH ​ Germany ​ 100.00 % argenx Canada Inc. ​ Canada ​ 100.00 % argenx UK Ltd. ​ United Kingdom ​ 100.00 % argenx Netherlands Services B.V. ​ The Netherlands ​ 100.00 % argenx Italy S.r.l. ​ Italy ​ 100.00 % argenx Spain S.L. ​ Spain ​ 100.00 % ​

Property, plant and equipment_2

Property, plant and equipment (Details) € in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2023 EUR (€)
Property, plant and equipment
Property, plant and equipment at beginning of period	$ 16,234	$ 15,844
Property, plant and equipment at end of period	22,675	16,234	$ 15,844
Commitments to acquire property, plant and equipment	0			€ 0
Assets are pledged as security for liabilities	0
IT, office and lab equipment
Property, plant and equipment
Property, plant and equipment at beginning of period	2,706	3,373
Property, plant and equipment at end of period	$ 2,091	2,706	3,373
IT, office and lab equipment | Minimum
Property, plant and equipment
Estimated useful life	3 years
IT, office and lab equipment | Maximum
Property, plant and equipment
Estimated useful life	5 years
Right-of-use assets Buildings
Property, plant and equipment
Property, plant and equipment at beginning of period	$ 10,867	9,688
Property, plant and equipment at end of period	16,798	10,867	9,688
Right-of-use assets Vehicles
Property, plant and equipment
Property, plant and equipment at beginning of period	1,835	1,664
Property, plant and equipment at end of period	3,191	1,835	1,664
Leasehold improvements
Property, plant and equipment
Property, plant and equipment at beginning of period	631	888
Property, plant and equipment at end of period	436	631	888
Lease equipment
Property, plant and equipment
Property, plant and equipment at beginning of period	196	230
Property, plant and equipment at end of period	$ 160	196	230
IT equipment
Property, plant and equipment
Estimated useful life	3 years
Cost
Property, plant and equipment
Property, plant and equipment at beginning of period	$ 34,282	29,802	20,653
Additions	12,082	5,219	9,430
Disposals	(1,013)	(105)	(217)
Translation differences		(635)	(64)
Property, plant and equipment at end of period	45,350	34,282	29,802
Cost | IT, office and lab equipment
Property, plant and equipment
Property, plant and equipment at beginning of period	8,160	7,938	4,889
Additions	937	962	3,163
Disposals	(202)	(105)	(217)
Translation differences		(635)	104
Property, plant and equipment at end of period	8,895	8,160	7,938
Cost | Right-of-use assets Buildings
Property, plant and equipment
Property, plant and equipment at beginning of period	19,815	16,462	11,721
Additions	8,770	3,353	4,923
Translation differences			(182)
Property, plant and equipment at end of period	28,585	19,815	16,462
Cost | Right-of-use assets Vehicles
Property, plant and equipment
Property, plant and equipment at beginning of period	3,980	3,075	2,273
Additions	2,327	905	802
Disposals	(757)
Property, plant and equipment at end of period	5,550	3,980	3,075
Cost | Leasehold improvements
Property, plant and equipment
Property, plant and equipment at beginning of period	1,981	1,981	1,424
Additions	48		543
Disposals	(54)
Translation differences			14
Property, plant and equipment at end of period	1,975	1,981	1,981
Cost | Lease equipment
Property, plant and equipment
Property, plant and equipment at beginning of period	346	346	346
Property, plant and equipment at end of period	346	346	346
Amortization, Depreciation and impairment
Property, plant and equipment
Property, plant and equipment at beginning of period	(18,047)	(13,958)	(9,071)
Depreciation	(5,574)	(4,593)	(5,055)
Disposals	946	90	158
Translation differences		414	10
Property, plant and equipment at end of period	(22,675)	(18,047)	(13,958)
Amortization, Depreciation and impairment | IT, office and lab equipment
Property, plant and equipment
Property, plant and equipment at beginning of period	(5,454)	(4,565)	(3,642)
Depreciation	(1,539)	(1,388)	(1,118)
Disposals	189	90	158
Translation differences		408	37
Property, plant and equipment at end of period	(6,804)	(5,454)	(4,565)
Amortization, Depreciation and impairment | Right-of-use assets Buildings
Property, plant and equipment
Property, plant and equipment at beginning of period	(8,948)	(6,774)	(4,044)
Depreciation	(2,839)	(2,179)	(2,714)
Translation differences		5	(15)
Property, plant and equipment at end of period	(11,787)	(8,948)	(6,774)
Amortization, Depreciation and impairment | Right-of-use assets Vehicles
Property, plant and equipment
Property, plant and equipment at beginning of period	(2,145)	(1,411)	(760)
Depreciation	(971)	(735)	(651)
Disposals	757
Translation differences		1
Property, plant and equipment at end of period	(2,359)	(2,145)	(1,411)
Amortization, Depreciation and impairment | Leasehold improvements
Property, plant and equipment
Property, plant and equipment at beginning of period	(1,350)	(1,093)	(543)
Depreciation	(189)	(257)	(539)
Translation differences		1	(11)
Property, plant and equipment at end of period	(1,539)	(1,350)	(1,093)
Amortization, Depreciation and impairment | Lease equipment
Property, plant and equipment
Property, plant and equipment at beginning of period	(150)	(116)	(82)
Depreciation	(36)	(35)	(34)
Property, plant and equipment at end of period	$ (186)	$ (150)	$ (116)

Intangible assets (Details)

Intangible assets (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Intangible assets
Intangible assets other than goodwill at beginning of period			$ 174,901	$ 171,684
Derecognition			102,000
Intangible assets other than goodwill at end of period		$ 125,228	125,228	174,901	$ 171,684
Commitments to acquire additional intangible assets		0	0
Intangible assets are pledged as security		0	0
Acquired R&D available for use
Intangible assets
Reclassification	$ 52,900
Intangible assets other than goodwill at end of period		105,539	105,539
Acquired In-Process R&D
Intangible assets
Intangible assets other than goodwill at beginning of period			70,180	70,180
Reclassification	$ (52,900)
Intangible assets other than goodwill at end of period		17,249	17,249	70,180	70,180
Software & databases
Intangible assets
Intangible assets other than goodwill at beginning of period			2,722	2,446
Intangible assets other than goodwill at end of period		2,440	2,440	2,722	2,446
Other Intangibles
Intangible assets
Intangible assets other than goodwill at beginning of period			102,000	99,058
Amortization		(102,000)
Intangible assets other than goodwill at end of period				102,000	99,058
Cost
Intangible assets
Intangible assets other than goodwill at beginning of period			176,519	172,591	167,781
Additions			56,000	102,992	5,000
Translation differences					(190)
Disposals				(5)
Derecognition			(102,000)	(99,058)
Intangible assets other than goodwill at end of period		130,520	130,520	176,519	172,591
Cost | Acquired R&D available for use
Intangible assets
Additions			56,000
Reclassification			52,931
Intangible assets other than goodwill at end of period		108,931	108,931
Cost | Acquired In-Process R&D
Intangible assets
Intangible assets other than goodwill at beginning of period			70,180	70,180	65,180
Additions					5,000
Reclassification			(52,931)
Intangible assets other than goodwill at end of period		17,249	17,249	70,180	70,180
Cost | Software & databases
Intangible assets
Intangible assets other than goodwill at beginning of period			4,340	3,353	3,543
Additions				992
Translation differences					(190)
Disposals				(5)
Intangible assets other than goodwill at end of period		4,340	4,340	4,340	3,353
Cost | Other Intangibles
Intangible assets
Intangible assets other than goodwill at beginning of period			102,000	99,058	99,058
Additions				102,000
Derecognition			(102,000)	(99,058)
Intangible assets other than goodwill at end of period				102,000	99,058
Amortization, Depreciation and impairment
Intangible assets
Intangible assets other than goodwill at beginning of period			(1,618)	(907)	(437)
Derecognition			102,000	99,058
Amortization			(105,674)	(99,768)	(470)
Intangible assets other than goodwill at end of period		(5,292)	(5,292)	(1,618)	(907)
Amortization, Depreciation and impairment | Acquired R&D available for use
Intangible assets
Amortization			(3,392)
Intangible assets other than goodwill at end of period		(3,392)	(3,392)
Amortization, Depreciation and impairment | Software & databases
Intangible assets
Intangible assets other than goodwill at beginning of period			(1,618)	(907)	(437)
Amortization			(282)	(711)	(470)
Intangible assets other than goodwill at end of period		$ (1,900)	(1,900)	(1,618)	$ (907)
Amortization, Depreciation and impairment | Other Intangibles
Intangible assets
Derecognition			102,000	99,058
Amortization			$ (102,000)	$ (99,058)

Other non-current assets - (Det

Other non-current assets - (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other non-current assets,
Non-current restricted cash	$ 2,419	$ 1,736	$ 1,707
Non-current financial assets held at fair value through profit or loss	21,715	21,715	17,459
Non-current financial assets held at fair value through OCI	15,528	17,443	35,710
Total other non-current assets	$ 39,662	$ 40,894	$ 54,876

Other non-current assets - Fair

Other non-current assets - Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other non-current assets..
Cost at beginning	$ 76,659	$ 76,659	$ 1,659
Additions of the year			75,000
Cost at ending	76,659	76,659	76,659
Fair value adjustments at beginning	(37,501)	(23,490)	4,648
Fair value adjustment of the year through profit or loss		4,256	11,152
Fair value adjustment of the year through OCI	(1,915)	(18,267)	(39,290)
Fair value adjustments at ending	(39,416)	(37,501)	(23,490)
Net book value at ending	$ 37,243	$ 39,158	$ 53,169

Other non-current assets - Lice

Other non-current assets - License agreement (Details) $ / shares in Units, € in Millions, $ in Millions		1 Months Ended
	Jan. 01, 2021 $ / shares shares	Oct. 31, 2023 USD ($)	Jun. 30, 2022 EUR (€)	Jun. 30, 2022 USD ($)	Mar. 31, 2021 USD ($) shares	Jan. 31, 2021 $ / shares shares
AgomAb
Financial instruments and financial risk management
Fair value of current financial assets				$ 4.3
AgomAb | Preferred Class B Shares
Financial instruments and financial risk management
Proceeds from issue of shares			€ 38.4		$ 74
Shares issued | shares					286,705
Fair value of non-current financial assets				$ 4.3	$ 11.2
AgomAb | Preferred Class C Shares
Financial instruments and financial risk management
Proceeds from issue of shares		$ 100
Zai Lab
Financial instruments and financial risk management
Number of shares issued | shares	568,182					568,182
Share price | $ / shares	$ 132					$ 132

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Inventories
Raw materials and consumables		$ 240,836	$ 126,046	$ 70,134
Inventories in process		47,074	65,016	37,705
Finished goods		22,640	37,291	1,237
Total inventories		310,550	228,353	$ 109,076
Cost of merchandise sold		101,200	$ 29,400
Decreased in inventory	$ 47,300
Prepaid expenses		47,327
Pre-launch inventory awaiting facility approval
Inventories
Total inventories		$ 101,300

Prepaid expenses (Current) (Det

Prepaid expenses (Current) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Prepaid expenses (Current)
Prepaid inventory	$ 22,460	$ 11,667	$ 10,786
Prepaid research and development expenses	71,201	44,905	39,684
Prepaid advertising expenses	19,933	13,479	2,006
Prepaid software	6,240	4,309	2,272
Other prepaid expenses	14,238	1,662	4,198
Total prepaid expenses	$ 134,072	$ 76,022	$ 58,946

Trade and other receivables (De

Trade and other receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Trade and other receivables.
Trade receivable	$ 417,994	$ 241,228	$ 28,058
Interest receivable	13,126	12,918	1,325
Tax receivables	63,605	20,526	7,974
Other receivable	1,962	1,025	864
Total trade and other receivables	$ 496,687	$ 275,697	$ 38,221

Financial assets - current (Det

Financial assets - current (Details) $ in Thousands, € in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2023 EUR (€)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Total Current Financial Assets
Financial assets	$ 1,131,000	€ 200	$ 1,391,808	$ 1,002,052
EUR
Total Current Financial Assets
Financial assets	$ 221,000
Minimum
Total Current Financial Assets
Maturity Term of Financial Assets	3 months
Maximum
Total Current Financial Assets
Maturity Term of Financial Assets	12 months
Money market funds
Total Current Financial Assets
Financial assets			46,162	73,052
Term accounts
Total Current Financial Assets
Financial assets	$ 1,131,000		$ 1,345,646	$ 929,000

Cash and cash equivalents (Deta

Cash and cash equivalents (Details) $ in Thousands, € in Millions, ¥ in Millions	Dec. 31, 2023 USD ($)	Dec. 31, 2023 EUR (€)	Dec. 31, 2023 JPY (¥)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Disclosure of financial assets [line items]
Money market funds	$ 1,678,100			$ 669,147	$ 997,092
Term accounts	350,000			54,116	95,090
Cash and bank balances	20,744			77,477	242,494
Total cash and cash equivalents	2,048,800	€ 636	¥ 1,164.6	$ 800,740	$ 1,334,676	$ 1,216,803
EUR
Disclosure of financial assets [line items]
Total cash and cash equivalents	702,800
JPY
Disclosure of financial assets [line items]
Total cash and cash equivalents	$ 8,200

Share capital and share premi_3

Share capital and share premium (Details)							12 Months Ended
	Jul. 19, 2023 shares	Jul. 18, 2023 shares	Mar. 29, 2022 shares	Mar. 23, 2022 shares	Feb. 04, 2021 shares	Feb. 02, 2021 shares	Dec. 31, 2023 EquityInstruments shares	Dec. 31, 2022 shares	Dec. 31, 2021 shares
Disclosure of classes of share capital [line items]
Number of shares outstanding at beginning of period							55,395,856	51,668,315	47,571,283
Exercise of stock options							1,137,439	1,024,626	503,282
Vesting of RSUs							79,560	19,581
New shares issued for private placement, initial public offering, public offering and underwriters' over-allotment option			350,000
Number of shares outstanding at end of period							59,194,488	55,395,856	51,668,315
Global Offering
Disclosure of classes of share capital [line items]
New shares issued for private placement, initial public offering, public offering and underwriters' over-allotment option		2,244,899				3,125,000
Underwriters' Over Allotment Option
Disclosure of classes of share capital [line items]
New shares issued for private placement, initial public offering, public offering and underwriters' over-allotment option	336,734			2,333,334	468,750

Share capital and share premi_4

Share capital and share premium - Narrative (Details) $ / shares in Units, $ in Millions				12 Months Ended
	Jul. 19, 2023 USD ($) shares	Jul. 18, 2023 $ / shares shares	May 02, 2023	Dec. 31, 2023 EUR (€) shares	Dec. 31, 2022 shares	Dec. 31, 2021 shares	Dec. 31, 2020 shares
Disclosure of classes of share capital [line items]
Number of shares outstanding				59,194,488	55,395,856	51,668,315	47,571,283
Maximum authorized increase of then outstanding share capital (as a percent)			10%
Period of outstanding share capital			18 months
Maximum authorized increase in share capital | €				€ 202,408.2
Maximum authorized increase in number of shares				2,024,082
Global Offering
Disclosure of classes of share capital [line items]
Number of shares issued		2,244,899
Global Offering | American Depositary Shares
Disclosure of classes of share capital [line items]
Number of shares issued		1,580,981
Share price | $ / shares		$ 490
Global Offering | Ordinary shares
Disclosure of classes of share capital [line items]
Number of shares issued		663,918
Share price | $ / shares		$ 436.37
Underwriters' Over Allotment Option | American Depositary Shares
Disclosure of classes of share capital [line items]
Number of shares issued	336,734
Gross proceeds from issue of shares | $	$ 1,260
Payments of stock issuance costs | $	65.9
Expenses deducted from equity | $	0.8
Net proceeds | $	$ 1,200

Share based payments - Outstand

Share based payments - Outstanding stock options (Details) $ / shares in Units, $ in Millions	1 Months Ended												12 Months Ended
	Dec. 31, 2023 EquityInstruments $ / shares	Oct. 31, 2023 EquityInstruments $ / shares	Jul. 31, 2023 EquityInstruments $ / shares	Apr. 30, 2023 EquityInstruments $ / shares	Dec. 31, 2022 EquityInstruments $ / shares	Oct. 31, 2022 EquityInstruments $ / shares	Jul. 31, 2022 EquityInstruments $ / shares	Apr. 30, 2022 EquityInstruments $ / shares	Dec. 31, 2021 EquityInstruments $ / shares	Oct. 31, 2021 EquityInstruments $ / shares	Jul. 31, 2021 EquityInstruments $ / shares	Apr. 30, 2021 EquityInstruments $ / shares	Dec. 31, 2023 USD ($) EquityInstruments $ / shares shares	Dec. 31, 2022 USD ($) EquityInstruments $ / shares	Dec. 31, 2021 USD ($) EquityInstruments $ / shares	Dec. 31, 2020 EquityInstruments
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 329.26	$ 485.01	$ 387.35	$ 370.34	$ 381.97	$ 359.80	$ 372.69	$ 312.22	$ 349.92	$ 301.02	$ 303.16	$ 275.33	$ 329.26	$ 381.97	$ 349.92
Number of options granted	79,305	74,529	629,121	61,056	508,132	100,118	311,311	102,081	389,588	144,824	280,339	67,833	844,011	1,021,642	882,584
Number of shares on conversion | shares													1
Outstanding stock options	5,118,949				5,511,767				5,619,113				5,118,949	5,511,767	5,619,113	5,365,743
Number of share options granted being used to pay tax by transferring the economic benefits | shares													43,336
Total share based payment expense | $													$ 164	$ 120.2	$ 171.2
2022 | 2.70
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 2.70												$ 2.70
Outstanding stock options									125,339						125,339
2023 | 89.31
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	89.31												89.31
Outstanding stock options					12,111				85,080					12,111	85,080
2023 | 95.38
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	95.38												95.38
Outstanding stock options					124,338				321,473					124,338	321,473
2024 | 2.70
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 2.70												$ 2.70
Outstanding stock options	3,308				19,743				94,088				3,308	19,743	94,088
2024 | 4.36
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 4.36												$ 4.36
Outstanding stock options	532				5,127				6,113				532	5,127	6,113
2024 | 7.92
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 7.92												$ 7.92
Outstanding stock options	81,500				214,800				276,500				81,500	214,800	276,500
2024 | 125.40
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 125.40												$ 125.40
Outstanding stock options	26,171				110,774				111,174				26,171	110,774	111,174
2024 | 150.00
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 150												$ 150
Outstanding stock options	104,176				202,852				203,658				104,176	202,852	203,658
2025 | 12.64
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 12.64												$ 12.64
Outstanding stock options	1,600				2,000				4,500				1,600	2,000	4,500
2025 | 10.46
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 10.46												$ 10.46
Outstanding stock options	99,326				101,861				105,857				99,326	101,861	105,857
2025 | 132.08
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 132.08												$ 132.08
Outstanding stock options	16,712				16,712				16,712				16,712	16,712	16,712
2025 | 216.75
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 216.75												$ 216.75
Outstanding stock options	126,331				127,731				129,711				126,331	127,731	129,711
2025 | 221.24
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 221.24												$ 221.24
Outstanding stock options	31,424				32,100				32,100				31,424	32,100	32,100
2025 | 273.60
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 273.60												$ 273.60
Outstanding stock options	202,205				202,475				203,214				202,205	202,475	203,214
2025 | 341.67
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 341.67												$ 341.67
Outstanding stock options	16,000												16,000
2026 | 12.57
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 12.57												$ 12.57
Outstanding stock options	24,400				30,000				41,000				24,400	30,000	41,000
2026 | 12.67
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 12.67												$ 12.67
Outstanding stock options	97,972				99,772				102,840				97,972	99,772	102,840
2026 | 15.62
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 15.62												$ 15.62
Outstanding stock options	111,811				115,211				117,581				111,811	115,211	117,581
2026 | 259.01
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 259.01												$ 259.01
Outstanding stock options	23,491				23,491				24,366				23,491	23,491	24,366
2026 | 281.89
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 281.89												$ 281.89
Outstanding stock options	59,626				60,890				61,505				59,626	60,890	61,505
2026 | 286.75
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 286.75												$ 286.75
Outstanding stock options	45,228				45,862				48,138				45,228	45,862	48,138
2026 | 341.67
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 341.67												$ 341.67
Outstanding stock options	80,425				80,833				82,430				80,425	80,833	82,430
2027 | 20.34
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 20.34												$ 20.34
Outstanding stock options	38,434				42,509				53,143				38,434	42,509	53,143
2027 | 23.39
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 23.39												$ 23.39
Outstanding stock options	225,852				303,867				361,350				225,852	303,867	361,350
2027 | 312.16
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 312.16												$ 312.16
Outstanding stock options	13,957				14,976								13,957	14,976
2027 | 395.04
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 395.04												$ 395.04
Outstanding stock options	58,091				61,816								58,091	61,816
2027 | 407.19
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 407.19												$ 407.19
Outstanding stock options	13,764				13,764								13,764	13,764
2027 | 397.36
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 397.36												$ 397.36
Outstanding stock options	136,459				137,778								136,459	137,778
2028 | 89.31
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 89.31												$ 89.31
Outstanding stock options	13,890				19,490				39,515				13,890	19,490	39,515
2028 | 95.38
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 95.38												$ 95.38
Outstanding stock options	225,457				264,392				350,631				225,457	264,392	350,631
2028 | 376.47
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 376.47												$ 376.47
Outstanding stock options	15,014												15,014
2028 | 392.72
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 392.72												$ 392.72
Outstanding stock options	127,490												127,490
2028 | 508.96
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 508.96												$ 508.96
Outstanding stock options	2,235												2,235
2029 | 125.40
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 125.40												$ 125.40
Outstanding stock options	71,573				110,756				146,765				71,573	110,756	146,765
2029 | 150.00
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 150												$ 150
Outstanding stock options	370,566				537,110				611,122				370,566	537,110	611,122
2030 | 132.08
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 132.08												$ 132.08
Outstanding stock options	50,801				71,486				102,558				50,801	71,486	102,558
2030 | 216.75
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 216.75												$ 216.75
Outstanding stock options	160,677				223,812				282,475				160,677	223,812	282,475
2030 | 221.24
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 221.24												$ 221.24
Outstanding stock options	78,534				117,790				136,601				78,534	117,790	136,601
2030 | 273.60
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 273.60												$ 273.60
Outstanding stock options	559,173				620,014				692,214				559,173	620,014	692,214
2031 | 259.01
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 259.01												$ 259.01
Outstanding stock options	27,201				35,214				42,282				27,201	35,214	42,282
2031 | 281.89
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 281.89												$ 281.89
Outstanding stock options	128,600				167,406				207,464				128,600	167,406	207,464
2031 | 286.75
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 286.75												$ 286.75
Outstanding stock options	62,138				81,311				92,456				62,138	81,311	92,456
2031 | 341.67
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 341.67												$ 341.67
Outstanding stock options	226,520				286,353				307,158				226,520	286,353	307,158
2032 | 312.16
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 312.16												$ 312.16
Outstanding stock options	58,255				79,155								58,255	79,155
2032 | 395.04
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 395.04												$ 395.04
Outstanding stock options	192,291				238,532								192,291	238,532
2032 | 407.19
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 407.19												$ 407.19
Outstanding stock options	73,288				85,199								73,288	85,199
2032 | 397.36
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 397.36												$ 397.36
Outstanding stock options	347,765				370,354								347,765	370,354
2033 | 376.47
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 376.47												$ 376.47
Outstanding stock options	43,856												43,856
2033 | 392.72
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 392.72												$ 392.72
Outstanding stock options	495,821												495,821
2033 | 508.96
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 508.96												$ 508.96
Outstanding stock options	69,704												69,704
2028-2032 | 330.06
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price | $ / shares	$ 330.06												$ 330.06
Outstanding stock options	79,305												79,305
Tranche One
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage													33%
Tranche Two
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage													4.16%

Share-based payments - Rollforw

Share-based payments - Rollforward (Details)	1 Months Ended												12 Months Ended
	Dec. 31, 2023 EquityInstruments $ / shares	Oct. 31, 2023 EquityInstruments	Jul. 31, 2023 EquityInstruments	Apr. 30, 2023 EquityInstruments	Dec. 31, 2022 EquityInstruments $ / shares	Oct. 31, 2022 EquityInstruments	Jul. 31, 2022 EquityInstruments	Apr. 30, 2022 EquityInstruments	Dec. 31, 2021 EquityInstruments $ / shares	Oct. 31, 2021 EquityInstruments	Jul. 31, 2021 EquityInstruments	Apr. 30, 2021 EquityInstruments	Dec. 31, 2023 EquityInstruments $ / shares	Dec. 31, 2022 EquityInstruments $ / shares	Dec. 31, 2021 EquityInstruments $ / shares
Number of stock options
Total options at beginning of year | EquityInstruments													5,511,767	5,619,113	5,365,743
Number of options granted | EquityInstruments	79,305	74,529	629,121	61,056	508,132	100,118	311,311	102,081	389,588	144,824	280,339	67,833	844,011	1,021,642	882,584
Exercised | EquityInstruments													(1,137,439)	(1,025,780)	(503,282)
Forfeited | EquityInstruments													(99,390)	(103,208)	(125,932)
Total options at end of year | EquityInstruments	5,118,949				5,511,767				5,619,113				5,118,949	5,511,767	5,619,113
Exercisable | EquityInstruments	3,030,486				3,983,960				3,613,371				3,030,486	3,983,960	3,613,371
Weighted average exercise price
Beginning balance													$ 205.02	$ 164.33	$ 142.87
Granted													395.92	375.58	314.99
Exercised													142.31	92.62	64.72
Forfeited													356.57	273.93	234.98
Ending balance	$ 255.41				$ 205.02				$ 164.33				255.41	205.02	164.33
Exercisable	$ 179.22				$ 148.11				$ 106.53				179.22	148.11	106.53
Weighted average share price													$ 456.8	$ 336.5	$ 305.9
Weighted average remaining contractual life													5 years 10 months 24 days	6 years 2 months 12 days	6 years 3 months 18 days

Share-based payments - Overview

Share-based payments - Overview (Details)	1 Months Ended												12 Months Ended
	Dec. 31, 2023 USD ($) EquityInstruments Y $ / shares	Oct. 31, 2023 USD ($) Y EquityInstruments $ / shares	Jul. 31, 2023 USD ($) EquityInstruments Y $ / shares	Apr. 30, 2023 Y EquityInstruments $ / shares	Dec. 31, 2022 EquityInstruments $ / shares	Oct. 31, 2022 Y EquityInstruments $ / shares	Jul. 31, 2022 Y EquityInstruments $ / shares	Apr. 30, 2022 Y EquityInstruments $ / shares	Dec. 31, 2021 EquityInstruments USD ($) $ / shares	Oct. 31, 2021 Y EquityInstruments $ / shares	Jul. 31, 2021 Y EquityInstruments $ / shares	Apr. 30, 2021 Y EquityInstruments $ / shares	Dec. 31, 2023 USD ($) EquityInstruments $ / shares	Dec. 31, 2022 EquityInstruments $ / shares	Dec. 31, 2021 EquityInstruments $ / shares	Dec. 31, 2020 EquityInstruments
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of options granted | EquityInstruments	79,305	74,529	629,121	61,056	508,132	100,118	311,311	102,081	389,588	144,824	280,339	67,833	844,011	1,021,642	882,584
Share price	$ 371.36
Exercise price	$ 329.26	$ 485.01	$ 387.35	$ 370.34	$ 381.97	$ 359.80	$ 372.69	$ 312.22	$ 349.92	$ 301.02	$ 303.16	$ 275.33	$ 329.26	$ 381.97	$ 349.92
Risk-free interest rate	2.40%
Number of stock options | EquityInstruments	5,118,949				5,511,767				5,619,113				5,118,949	5,511,767	5,619,113	5,365,743
Weighted average remaining contractual life													5 years 10 months 24 days	6 years 2 months 12 days	6 years 3 months 18 days
Exercised | EquityInstruments													(1,137,439)	(1,025,780)	(503,282)
Forfeited | EquityInstruments													(99,390)	(103,208)	(125,932)
Exercisable | EquityInstruments	3,030,486				3,983,960				3,613,371				3,030,486	3,983,960	3,613,371
Beginning balance													$ 205.02	$ 164.33	$ 142.87
Granted													395.92	375.58	314.99
Exercised													142.31	92.62	64.72
Forfeited													356.57	273.93	234.98
Ending balance	$ 255.41				$ 205.02				$ 164.33				255.41	205.02	164.33
Exercisable	$ 179.22				148.11				106.53				$ 179.22	$ 148.11	$ 106.53
Belgian taxed beneficiaries
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of options granted | EquityInstruments	8,459
10.46 - 12.64
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of stock options	100,926												100,926
Weighted average remaining contractual life													1 year 11 months 12 days
12.57 - 15.62
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of stock options	234,183												234,183
Weighted average remaining contractual life													2 years 8 months 1 day
20.34 - 23.39
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of stock options	264,286												264,286
Weighted average remaining contractual life													3 years 10 months 20 days
89.31 - 95.38
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of stock options	239,347												239,347
Weighted average remaining contractual life													4 years 11 months 12 days
125.4 - 150
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of stock options	572,486												572,486
Weighted average remaining contractual life													4 years 9 months
132.08 - 273.6
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of stock options	1,225,857												1,225,857
Weighted average remaining contractual life													5 years 3 months 3 days
259.01 - 341.67
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of stock options	669,229												669,229
Weighted average remaining contractual life													6 years 14 days
312.16 - 407.19
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of stock options	893,870												893,870
Weighted average remaining contractual life													7 years 6 months 10 days
330.06 - 508.96
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of stock options	833,425												833,425
Weighted average remaining contractual life													8 years 8 months 8 days
Minimum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Fair value of options | $		$ 123.94	$ 176.44
Share price		$ 439.42	$ 380.81	$ 361.64	$ 368.69	$ 352.97	$ 378.11	$ 320.84	$ 277.72	$ 286.52	$ 300.78	$ 248.9
Expected volatility	36.20%	35.35%	36.22%	41%	39.74%	39.64%	41.30%	39.18%	43.24%	46.01%	45.58%	54.24%
Expected option life (in years)	6.15	4	4	4		4	4	4	4	4	4	4
Risk-free interest rate		2.80%	2.90%	2.96%	3.09%	2.57%	1.77%	1.05%	0.03%	(0.18%)	(0.41%)	(0.41%)
Average fair value per share option	$ 161.88			$ 158.21	$ 127.68	$ 136.66	$ 153.45	$ 111.27	$ 75.03	$ 101.53	$ 131.65	$ 98.96
Time period for beneficiaries to choose contractual term													5 years	5 years
Minimum | Belgian taxed beneficiaries
Disclosure of terms and conditions of share-based payment arrangement [line items]
Fair value of options | $	$ 1,100,000												$ 1,100,000
Time period for beneficiaries to choose contractual term	5 years												5 years
Share options granted (as a percent)	100%
Minimum | 10.46 - 12.64
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	$ 10.46												$ 10.46
Minimum | 12.57 - 15.62
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	12.57												12.57
Minimum | 20.34 - 23.39
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	20.34												20.34
Minimum | 89.31 - 95.38
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	89.31												89.31
Minimum | 125.4 - 150
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	125.4												125.4
Minimum | 132.08 - 273.6
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	132.08												132.08
Minimum | 259.01 - 341.67
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	259.01												259.01
Minimum | 312.16 - 407.19
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	312.16												312.16
Minimum | 330.06 - 508.96
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	$ 330.06												$ 330.06
Maximum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Fair value of options | $	$ 1,400,000	$ 209.04	$ 271.59										$ 1,400,000
Share price		$ 491.75	$ 521.19	$ 401.21	$ 377.61	$ 376.01	$ 397.92	$ 321.06	$ 351.73	$ 304.5	$ 340.95	$ 283.67
Expected volatility	36.21%	36.67%	43.99%	42.18%	40.26%	45.97%	43.10%	40.87%	43.64%	48.46%	47.96%	60.08%
Expected option life (in years)	6.50	6.50	6.50	6.50		6.50	6.50	6.50	6.50	6.50	6.50	6.50
Risk-free interest rate		3.44%	3.03%	3.14%	3.29%	2.80%	2.28%	1.62%	0.67%	(0.05%)	(0.17%)	(0.08%)
Average fair value per share option	$ 165.69			$ 196.18	$ 163.94	$ 169.96	$ 190.53	$ 140.23	$ 145.34	$ 131.80	$ 159.13	$ 154.88
Time period for beneficiaries to choose contractual term													10 years	10 years
Maximum | Belgian taxed beneficiaries
Disclosure of terms and conditions of share-based payment arrangement [line items]
Time period for beneficiaries to choose contractual term	10 years												10 years
Share options granted (as a percent)	100%
Maximum | 10.46 - 12.64
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	$ 12.64												$ 12.64
Maximum | 12.57 - 15.62
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	15.62												15.62
Maximum | 20.34 - 23.39
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	23.39												23.39
Maximum | 89.31 - 95.38
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	95.38												95.38
Maximum | 125.4 - 150
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	150												150
Maximum | 132.08 - 273.6
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	273.6												273.6
Maximum | 259.01 - 341.67
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	341.67												341.67
Maximum | 312.16 - 407.19
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	407.19												407.19
Maximum | 330.06 - 508.96
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price	$ 508.96												$ 508.96

Share-based payments - Range of

Share-based payments - Range of exercise price (Details)

12 Months Ended

Dec. 31, 2023 EquityInstruments $ / shares

Dec. 31, 2022 EquityInstruments $ / shares

Dec. 31, 2021 EquityInstruments $ / shares

Oct. 31, 2023 $ / shares

Jul. 31, 2023 $ / shares

Apr. 30, 2023 $ / shares

Oct. 31, 2022 $ / shares

Jul. 31, 2022 $ / shares

Apr. 30, 2022 $ / shares

Oct. 31, 2021 $ / shares

Jul. 31, 2021 $ / shares

Apr. 30, 2021 $ / shares

Dec. 31, 2020 EquityInstruments

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

$ 329.26

$ 381.97

$ 349.92

$ 485.01

$ 387.35

$ 370.34

$ 359.80

$ 372.69

$ 312.22

$ 301.02

$ 303.16

$ 275.33

Number of stock options | EquityInstruments

5,118,949

5,511,767

5,619,113

5,365,743

Weighted average remaining contractual life

5 years 10 months 24 days

6 years 2 months 12 days

6 years 3 months 18 days

2.7 - 7.92

Disclosure of terms and conditions of share-based payment arrangement [line items]

Number of stock options

85,340

Weighted average remaining contractual life

11 months 15 days

10.46 - 12.64

Disclosure of terms and conditions of share-based payment arrangement [line items]

Number of stock options

100,926

Weighted average remaining contractual life

1 year 11 months 12 days

12.57 - 15.62

Disclosure of terms and conditions of share-based payment arrangement [line items]

Number of stock options

234,183

Weighted average remaining contractual life

2 years 8 months 1 day

20.34 - 23.39

Disclosure of terms and conditions of share-based payment arrangement [line items]

Number of stock options

264,286

Weighted average remaining contractual life

3 years 10 months 20 days

89.31 - 95.38

Disclosure of terms and conditions of share-based payment arrangement [line items]

Number of stock options

239,347

Weighted average remaining contractual life

4 years 11 months 12 days

125.4 - 150

Disclosure of terms and conditions of share-based payment arrangement [line items]

Number of stock options

572,486

Weighted average remaining contractual life

4 years 9 months

132.08 - 273.6

Disclosure of terms and conditions of share-based payment arrangement [line items]

Number of stock options

1,225,857

Weighted average remaining contractual life

5 years 3 months 3 days

259.01 - 341.67

Disclosure of terms and conditions of share-based payment arrangement [line items]

Number of stock options

669,229

Weighted average remaining contractual life

6 years 14 days

312.16 - 407.19

Disclosure of terms and conditions of share-based payment arrangement [line items]

Number of stock options

893,870

Weighted average remaining contractual life

7 years 6 months 10 days

330.06 - 508.96

Disclosure of terms and conditions of share-based payment arrangement [line items]

Number of stock options

833,425

Weighted average remaining contractual life

8 years 8 months 8 days

Minimum | 2.7 - 7.92

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

$ 2.7

Minimum | 10.46 - 12.64

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

10.46

Minimum | 12.57 - 15.62

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

12.57

Minimum | 20.34 - 23.39

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

20.34

Minimum | 89.31 - 95.38

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

89.31

Minimum | 125.4 - 150

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

125.4

Minimum | 132.08 - 273.6

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

132.08

Minimum | 259.01 - 341.67

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

259.01

Minimum | 312.16 - 407.19

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

312.16

Minimum | 330.06 - 508.96

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

330.06

Maximum | 2.7 - 7.92

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

7.92

Maximum | 10.46 - 12.64

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

12.64

Maximum | 12.57 - 15.62

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

15.62

Maximum | 20.34 - 23.39

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

23.39

Maximum | 89.31 - 95.38

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

95.38

Maximum | 125.4 - 150

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

150

Maximum | 132.08 - 273.6

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

273.6

Maximum | 259.01 - 341.67

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

341.67

Maximum | 312.16 - 407.19

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

407.19

Maximum | 330.06 - 508.96

Disclosure of terms and conditions of share-based payment arrangement [line items]

Exercise price

$ 508.96

Share-based payments - Restrict

Share-based payments - Restricted Stock Units (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) EquityInstruments $ / shares shares	Dec. 31, 2022 USD ($) EquityInstruments shares $ / shares	Dec. 31, 2021 USD ($) EquityInstruments $ / shares
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting of RSUs	(79,560)	(19,581)
Number of shares on conversion | shares	1
Total share based payment expense | $	$ 164	$ 120.2	$ 171.2
Restricted Stock Units (RSUs)
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of RSUs - January 1 | EquityInstruments	385,280	213,038
Number of RSUs - Granted | EquityInstruments	192,237	243,010	216,522
Vesting of RSUs | EquityInstruments	(105,678)	(53,872)
Number of RSUs - Forfeited | EquityInstruments	(29,517)	(16,896)	(3,484)
Number of RSUs - December 31 | EquityInstruments	442,322	385,280	213,038
Weighted average Grand Date Fair Value - January 1 | $ / shares	$ 387.20	$ 314.25
Weighted average Grand Date Fair Value - Granted | $ / shares	396.22	375.81	$ 313.84
Weighted average Grand Date Fair Value - Vested | $ / shares	352.61
Weighted average Grand Date Fair Value - Forfeited | $ / shares	358.49	307.11	288.92
Weighted average Grand Date Fair Value - December 31 | $ / shares	$ 375.89	$ 387.20	$ 314.25
Number of shares on conversion | shares	1
Vesting period	4 years
Vesting percentage	25%
Total share based payment expense | $	$ 69	$ 36.9	$ 8.1

Trade and other payables (Detai

Trade and other payables (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Trade and other payables.
Trade payables	$ 245,557	$ 188,721	$ 208,850
Short term employee benefits	95,104	84,337	83,737
Gross-to-net accruals	55,788	19,478
Other	17,564	3,142	828
Total trade and other payables	$ 414,013	$ 295,679	$ 293,415

Trade and other payables - Move

Trade and other payables - Movement in net accruals (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disclosure of subsidiaries [line items]
Gross-to-net accruals	$ 19,478
Current estimate related to the sales made in the current year	149,969	$ 46,166
Adjustment for prior year sales	(4,924)
(Credits or payments related to sales made during the year)	(99,049)	(26,689)
(Credits or payments related to sales made during the prior year)	(9,685)
Gross-to-net accruals	55,788	19,478
Rebates and charge backs
Disclosure of subsidiaries [line items]
Gross-to-net accruals	15,398
Current estimate related to the sales made in the current year	123,542	35,426
Adjustment for prior year sales	(4,041)
(Credits or payments related to sales made during the year)	(78,327)	(20,028)
(Credits or payments related to sales made during the prior year)	(6,910)
Gross-to-net accruals	49,662	15,398
Distribution fees, product returns and other
Disclosure of subsidiaries [line items]
Gross-to-net accruals	4,079
Current estimate related to the sales made in the current year	26,427	10,740
Adjustment for prior year sales	(883)
(Credits or payments related to sales made during the year)	(20,722)	(6,661)
(Credits or payments related to sales made during the prior year)	(2,775)
Gross-to-net accruals	$ 6,126	$ 4,079

Product net sales - (Details)

Product net sales - (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Product net sales.
Product gross sales	$ 1,342,148	$ 446,923
Gross to net adjustment	(151,365)	(46,203)
Product net sales	$ 1,190,783	$ 400,720

Collaboration revenue (Details)

Collaboration revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Collaboration revenue
Upfront payments			$ 444,303
Milestone payments	$ 30,000	$ 5,365	49,815
Research and development service fees		424	2,326
Total collaboration revenue	35,533	10,026	497,277
Collaboration revenue	35,533	10,026	497,277
Zai Lab
Collaboration revenue
Upfront payments			151,903
Milestone payments			25,634
Other collaboration revenue	5,533	4,238	833
J&J
Collaboration revenue
Upfront payments			292,279
Milestone payments			22,865
Research and development service fees			2,028
AbbVie
Collaboration revenue
Upfront payments			121
Milestone payments	30,000		102
Other
Collaboration revenue
Milestone payments		5,365	1,214
Research and development service fees		424	298
Other collaboration revenue	$ 5,533	$ 4,238	$ 833

Collaboration revenue - Additio

Collaboration revenue - Additional Information (Details) $ / shares in Units, $ in Millions		1 Months Ended
	Jan. 06, 2021 USD ($) item $ / shares shares	Oct. 31, 2023 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2021 USD ($)
Zai Lab
Collaboration revenue
Number of shares issued | shares	568,182
Share price | $ / shares	$ 132
Zai Lab | Collaboration and license agreement
Collaboration revenue
License payment committed	$ 175
Upfront payments	75
Collaborative Arrangement Upfront Non-refundable non-creditable payment received	75
Collaborative arrangement maximum additional milestone, contingent payments to be received	$ 25
Number of performance obligation | item	2
Collaborative arrangements number of preclinical milestones achieved | item	2
Transaction price allocated to remaining performance obligations	$ 25
J&J | Collaboration and license agreement
Collaboration revenue
Transaction price allocated to remaining performance obligations				$ 315.1
AbbVie
Collaboration revenue
Collaborative arrangements amount of preclinical milestones payment received		$ 30
Collaborative arrangement maximum additional development milestone payments to be received on exercise of option			$ 50
Collaborative arrangement maximum regulatory milestone payments to be received on exercise of option			190
Collaborative arrangement maximum commercial Milestone payments to be received on exercise of Option			$ 325

Other operating income (Details

Other operating income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other operating income
Grants	$ 2,538	$ 2,186	$ 4,398
Research and development incentives	27,815	19,502	13,970
Payroll tax rebates	11,925	8,576	12,621
Change in fair value on non-current financial assets		4,256	11,152
Total other operating income	$ 42,278	$ 34,520	$ 42,141

Other operating income - Other

Other operating income - Other Incentives (Details)	12 Months Ended
	Dec. 31, 2023
Other operating income
Incentive refund period	5 years

Segment reporting - Product net

Segment reporting - Product net sales by country of sales (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Segment reporting
Total product net sales	$ 1,190,783	$ 400,720
United States
Segment reporting
Total product net sales	1,046,592	377,659
Japan
Segment reporting
Total product net sales	56,432	15,764
EMEA
Segment reporting
Total product net sales	72,852	$ 7,297
China
Segment reporting
Total product net sales	$ 14,907

Segment reporting - Major distr

Segment reporting - Major distributor or whole sellers (Details)	12 Months Ended
	Dec. 31, 2023 customer item	Dec. 31, 2022
Segment reporting
Number of operating segments | item	1
Number of major customers from U.S. | customer	4
Percentage of product net sales from major customers from United States	86%	91%

Segment reporting (Details)

Segment reporting (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment reporting
Revenue from external customers	$ 35,533	$ 10,026	$ 497,277
Denmark
Segment reporting
Revenue from external customers		5,365	1,389
United States
Segment reporting
Revenue from external customers	30,000		317,396
China
Segment reporting
Revenue from external customers	$ 5,533	4,238	178,370
Other
Segment reporting
Revenue from external customers		$ 424	$ 123

Segment reporting - Noncurrent

Segment reporting - Noncurrent assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment reporting
Non current Assets exclude deferred tax assets	$ 147,903	$ 191,136	$ 187,528
Belgium
Segment reporting
Non current Assets exclude deferred tax assets	138,252	186,923	182,118
United States
Segment reporting
Non current Assets exclude deferred tax assets	6,219	2,275	3,091
Japan
Segment reporting
Non current Assets exclude deferred tax assets	2,971	$ 1,938	$ 2,319
Germany
Segment reporting
Non current Assets exclude deferred tax assets	$ 461

Research and development expe_3

Research and development expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Research and development expenses
Personnel expenses	$ 226,344	$ 162,010	$ 160,464
External research and development expenses	483,192	366,955	382,902
Materials and consumables	4,057	2,396	2,735
Depreciation and amortization	105,546	102,132	3,742
IT expenses	19,935	12,678	7,798
Other expenses	20,418	17,194	22,879
Total research and development expenses	$ 859,492	$ 663,366	$ 580,520

Selling, general and administ_3

Selling, general and administrative expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Selling, general and administrative expenses
Personnel expenses	$ 303,033	$ 234,740	$ 164,646
Marketing services	202,146	115,950	59,968
Professional fees	108,820	62,620	42,707
Supervisory board	8,362	6,912	12,958
Depreciation and amortization	2,366	2,211	2,126
IT expenses	20,408	17,431	8,977
Other expenses	66,770	32,268	16,263
Total Selling, general and administrative expenses	$ 711,905	$ 472,132	$ 307,644

Personnel expenses (Details)

Personnel expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Personnel expenses
Shortterm employee benefits-Salaries	$ 266,482	$ 216,847	$ 135,676
Shortterm employee benefits-Social Security	19,231	16,274	12,785
Postemployment benefits	7,758	5,406	2,864
Termination benefits	1,089	401	818
Sharebased payment	226,830	151,912	167,965
Employer social security contributions stock options	7,987	5,910	5,002
Total personnel expenses	$ 529,377	$ 396,750	$ 325,110

Personnel expenses - FTE (Detai

Personnel expenses - FTE (Details) - employee	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Personnel expenses
Research and development	607.3	474.8	349.7
Selling, general and administrative	681.2	442.4	264.4
Number of FTE	1,288.5	917.2	614.1

Leases - Financial position rel

Leases - Financial position relating to leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disclosure of quantitative information about right-of-use assets
Right-of-use assets	$ 20,149	$ 12,897	$ 11,583
Additions to right-of-use assets	11,100	4,200	5,700
Lease liabilities
Current	4,646	3,417	3,509
Non-current	15,354	9,009	7,956
Lease liabilities	20,000	12,426	11,465
Buildings
Disclosure of quantitative information about right-of-use assets
Right-of-use assets	16,798	10,867	9,688
Vehicles
Disclosure of quantitative information about right-of-use assets
Right-of-use assets	3,191	1,835	1,664
Equipment
Disclosure of quantitative information about right-of-use assets
Right-of-use assets	$ 160	$ 196	$ 230

Leases - Total contractual cash

Leases - Total contractual cash flow carrying amount (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disclosure of maturity analysis of finance lease payments receivable [line items]
Total contractual cash flow	$ 20,000
Lease liabilities	20,000	$ 12,426	$ 11,465
Less than 1 year
Disclosure of maturity analysis of finance lease payments receivable [line items]
Total contractual cash flow	4,286
1-3 years
Disclosure of maturity analysis of finance lease payments receivable [line items]
Total contractual cash flow	8,136
3-5 years
Disclosure of maturity analysis of finance lease payments receivable [line items]
Total contractual cash flow	5,754
More than 5 years
Disclosure of maturity analysis of finance lease payments receivable [line items]
Total contractual cash flow	$ 1,824

Leases - Statement of profit or

Leases - Statement of profit or loss and other comprehensive income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financial position relating to leases
Depreciation, right-of-use assets	$ 3,846	$ 2,949	$ 3,399
Interest expense (included in finance cost)	693	1,343	412
Expense relating to short-term leases	1,517	732	212
Expense relating to leases of low-value assets that are not shown above as short-term leases	40	21	7
Cash outflow for leases	3,800	4,200	4,500
Buildings
Financial position relating to leases
Depreciation, right-of-use assets	2,839	2,179	2,714
Vehicles
Financial position relating to leases
Depreciation, right-of-use assets	971	735	651
Equipment
Financial position relating to leases
Depreciation, right-of-use assets	$ 36	$ 35	$ 34

Financial result and exchange_3

Financial result and exchange gains(losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financial result and exchange gains/(losses)
Interest income	$ 92,962	$ 24,741	$ 3,489
Net gain on cash equivalents & current financial assets held at fair value through profit or loss and cash equivalents	14,424	2,924	144
Financial income	107,386	27,665	3,633
Net loss on cash equivalents & current financial assets held at fair value through profit or loss and cash equivalents	(2)	(1,713)	(3,482)
Other financial expense	(904)	(2,193)	(1,096)
Financial expense	(906)	(3,906)	(4,578)
Realized exchange gains/(losses)	29	(3,743)	15
Unrealized exchange gains/(losses)	14,044	(28,989)	(50,068)
Exchange gains/(losses)	$ 14,073	$ (32,732)	$ (50,053)

Income taxes - Tax expense (Det

Income taxes - Tax expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income taxes
Current year	$ (9,592)	$ (27,162)	$ (15,224)
Income tax prior years	(2,080)	(12)	398
Current tax (expense) / benefit	(11,672)	(27,174)	(14,826)
Originating and reversal of temporary differences	21,115	46,894	6,304
Deferred tax (expense) / benefit	21,115	46,894	6,304
Total tax (expense) / benefit	$ 9,443	$ 19,720	$ (8,522)

Income taxes - Provision for in

Income taxes - Provision for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income taxes
Loss before taxes	$ 304,496	$ 729,314	$ 399,743
Income tax (expense)/benefit calculated at the Dutch statutory federal income tax rates for applicable tax years (1)	78,560	188,163	99,936
Effect of intercompany asset deal / transaction	396	(112,200)
Effect of expenses not deductible in determining taxable results	(2,674)	(1,570)	(4,441)
Effect of share based payment expenses that are not deductible in determining taxable results	(43,040)	(27,043)	(29,925)
Effect of stock issue expenses that are not taxable in determining taxable results	18,620	11,412	14,119
Effect of concessions	87,123	18,263	13,413
Effect of change of (de)recognition of deferred tax assets on tax losses	(2,282)	(194)	(44,232)
Effect of different tax rates in jurisdictions in which the company operates	(3,509)	(5,566)	(2,084)
Effect of change of (de)recognition of deferred tax assets	(124,457)	(51,320)	(50,389)
Withholding tax paid	(68)		(5,076)
(Underprovided)/overprovided in prior years	(2,080)	(12)	398
Other	2,854	(213)	(241)
Total tax (expense) / benefit	$ 9,443	$ 19,720	$ (8,522)
Applicable tax rate	25.80%	25.80%	25%

Income taxes - Deferred tax ass

Income taxes - Deferred tax assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income taxes - Deferred tax assets
Deferred tax assets	$ 97,211	$ 79,222	$ 32,191
Deferred tax liabilities	(5,155)	(8,406)	(6,438)
Net deferred tax assets / (liabilities)	92,056	70,817	25,753
Unused tax losses for which no deferred tax asset recognized	783,300	756,100	789,600
Temporary differences and unused tax losses
Income taxes - Deferred tax assets
Deferred tax assets	196,100	189,300	203,800
Accruals and allowances
Income taxes - Deferred tax assets
Deferred tax assets	13,189	8,884	2,858
Net deferred tax assets / (liabilities)	13,189	8,884	2,858
Income tax benefit from excess tax deductions related to share-based payments
Income taxes - Deferred tax assets
Deferred tax assets	23,310	26,887	26,026
Net deferred tax assets / (liabilities)	23,310	26,887	26,026
Profit in inventory
Income taxes - Deferred tax assets
Deferred tax assets	52,026	29,711	3,305
Net deferred tax assets / (liabilities)	52,026	29,711	3,305
Other tax carryforwards
Income taxes - Deferred tax assets
Deferred tax assets	6,339
Net deferred tax assets / (liabilities)	6,339
R&D capitalized expense
Income taxes - Deferred tax assets
Deferred tax assets		11,316
Net deferred tax assets / (liabilities)		11,316
Property, plant and equipment
Income taxes - Deferred tax assets
Deferred tax assets	2,136	856	532
Deferred tax liabilities	(1,550)	(549)	(740)
Net deferred tax assets / (liabilities)	586	307	(208)
Intangible assets
Income taxes - Deferred tax assets
Deferred tax liabilities		(3,430)	(2,714)
Net deferred tax assets / (liabilities)		(3,430)	(2,714)
Non-current fixed assets
Income taxes - Deferred tax assets
Deferred tax liabilities	(5,155)	(4,975)	(3,725)
Net deferred tax assets / (liabilities)	(5,155)	(4,975)	(3,725)
Netting by taxable entity
Income taxes - Deferred tax assets
Deferred tax assets	1,550	549	740
Deferred tax liabilities	(1,549)	(549)	(740)
Net deferred tax assets / (liabilities)	1
Other
Income taxes - Deferred tax assets
Deferred tax assets	1,760	2,117	210
Net deferred tax assets / (liabilities)	1,760	2,117	210
Carried forward Netherlands
Income taxes - Deferred tax assets
Unused tax losses for which no deferred tax asset recognized	33,200	35,400	24,900
Belgium
Income taxes - Deferred tax assets
Unrecognized deferred tax asset on IID	163,700	107,200	53,400
IID carry-forwarded	654,900	428,800	213,600
Belgium | Argenx BV
Income taxes - Deferred tax assets
Unused tax losses for which no deferred tax asset recognized	750,100	720,700	764,700
Unrecognized Deferred tax asset on future amortizations on intellectual property	106,300	112,200
Unrecognized deferred tax asset on excess depreciation on R&D	$ 278,200	$ 204,700	$ 166,300

Income taxes - Change in net de

Income taxes - Change in net deferred taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets
Balance at beginning of period	$ 79,222	$ 32,191	$ 15,038
Recognized in profit or loss	17,685	49,075	11,385
Recognized in equity	381	(1,960)	5,494
Effects of change in foreign exchange rate	(77)	(84)	274
Balance at end of period	97,211	79,222	32,191
Deferred tax liabilities
Balance at beginning of period	(8,406)	(6,438)	(1,487)
Recognized in profit or loss	3,430	(2,180)	(5,082)
Effects of change in foreign exchange rate	(179)	212	131
Balance at end of period	$ (5,155)	$ (8,406)	$ (6,438)

Income taxes - Additional infor

Income taxes - Additional information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income taxes - Deferred tax assets
Tax rate applicable	25.80%	25.80%	25%
Asset deal consideration		$ 449
Estimated undistributed earnings for which no provision for deferred tax liabilities recognized	$ 127.9
Belgium | Argenx BV
Income taxes - Deferred tax assets
Unrecognized deferred tax asset	$ 106.3	$ 112.2

Loss per share (Details)

Loss per share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Loss per share
Loss for the year	$ (295,053)	$ (709,594)	$ (408,265)
Weighted average number of shares outstanding	57,169,253	54,381,371	51,075,827
Basic (loss) per share (in $)	$ (5.16)	$ (13.05)	$ (7.99)
Diluted (loss) per share (in $)	$ (5.16)	$ (13.05)	$ (7.99)

Financial risk management (Deta

Financial risk management (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Amortised cost | Trade and other payables
Disclosure of financial assets [line items]
Carrying amount of liabilities under IFRS 9	$ 414,013	$ 295,679	$ 293,415
FVTPL | Financial assets - non-current
Disclosure of financial assets [line items]
Carrying amount of assets under IFRS 9	21,715	21,715	17,459
FVTPL | Financial assets - current
Disclosure of financial assets [line items]
Carrying amount of assets under IFRS 9		46,162	73,052
FVTPL | Cash equivalents
Disclosure of financial assets [line items]
Carrying amount of assets under IFRS 9	1,678,100	669,147	997,092
FVTOCI | Financial assets - non-current
Disclosure of financial assets [line items]
Carrying amount of assets under IFRS 9	15,528	17,443	35,710
Amortised costs | Research and development incentive receivables - non-current member
Disclosure of financial assets [line items]
Carrying amount of assets under IFRS 9	76,706	47,488	32,707
Amortised costs | Noncurrent restricted cash
Disclosure of financial assets [line items]
Carrying amount of assets under IFRS 9	2,419	1,736	1,707
Amortised costs | Trade and other receivables
Disclosure of financial assets [line items]
Carrying amount of assets under IFRS 9	496,687	275,697	38,221
Amortised costs | Financial assets - current
Disclosure of financial assets [line items]
Carrying amount of assets under IFRS 9	1,131,000	1,345,646	929,000
Amortised costs | Research and development incentive receivables - current
Disclosure of financial assets [line items]
Carrying amount of assets under IFRS 9	2,584	1,578
Amortised costs | Cash and cash equivalents
Disclosure of financial assets [line items]
Carrying amount of assets under IFRS 9	20,744	77,477	242,494
Amortised costs | Cash equivalents
Disclosure of financial assets [line items]
Carrying amount of assets under IFRS 9	$ 350,000	$ 54,116	$ 95,090

Financial risk management - Fai

Financial risk management - Fair value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financial instruments and financial risk management
Current financial assets	$ 1,131,000
Transfers out of Level 1 to Level 2 assets	0	$ 0	$ 0
Transfers out of Level 1 to Level 2 liabilities	0	0	0
Transfers out of Level 2 to Level 1 assets	0	0	0
Transfers out of Level 2 to Level 1 liabilities	0	0	0
Transfer into level 3 assets	0	0	0
Transfer out of level 3 assets	0	0	0
Transfer into level 3 liabilities	0	0	0
Transfer out of level 3 liabilities	0	0	0
Level 1
Financial instruments and financial risk management
Non-current financial assets	15,528	17,443	35,710
Current financial assets		46,162	73,052
Cash equivalents	1,678,100	669,147	997,092
Assets carried at fair value	1,693,628	732,752	1,105,854
Level 3
Financial instruments and financial risk management
Non-current financial assets	21,715	21,715	17,459
Assets carried at fair value	$ 21,715	$ 21,715	$ 17,459

Financial risk management - Lic

Financial risk management - License agreement (Details) $ / shares in Units, € in Millions, $ in Millions		1 Months Ended
	Jan. 01, 2021 $ / shares shares	Oct. 31, 2023 USD ($)	Jun. 30, 2022 EUR (€)	Jun. 30, 2022 USD ($)	Mar. 31, 2021 USD ($) shares	Jan. 31, 2021 $ / shares shares
AgomAb
Financial instruments and financial risk management
Fair value of current financial assets				$ 4.3
AgomAb | Preferred Class B Shares
Financial instruments and financial risk management
Proceeds from issue of shares			€ 38.4		$ 74
Shares issued | shares					286,705
Fair value of non-current financial assets				$ 4.3	$ 11.2
AgomAb | Preferred Class C Shares
Financial instruments and financial risk management
Proceeds from issue of shares		$ 100
Zai Lab
Financial instruments and financial risk management
Number of shares issued | shares	568,182					568,182
Share price | $ / shares	$ 132					$ 132

Financial risk management - Cap

Financial risk management - Capital risk (Details) $ in Thousands, € in Millions, ¥ in Millions	Dec. 31, 2023 USD ($)	Dec. 31, 2023 EUR (€)	Dec. 31, 2023 JPY (¥)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Financial risk management
Cash and cash equivalents	$ 2,048,800	€ 636	¥ 1,164.6	$ 800,740	$ 1,334,676	$ 1,216,803
Financial assets	1,131,000	€ 200		$ 1,391,808	$ 1,002,052
Total capital	$ 5,658,600

Financial risk management - Cre

Financial risk management - Credit risk (Details)	12 Months Ended
	Dec. 31, 2023
Credit risk | Maximum
Disclosure of financial assets that are either past due or impaired [line items]
Recommended maturity term for short term investment	6 months

Financial risk management - Int

Financial risk management - Interest rate risk (Details) - Interest rate risk € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023 EUR (€)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Disclosure of risk management strategy related to hedge accounting [line items]
Increase decrease in basis points	0.25%
Positive/negative impact	€ 7.9	$ 6.2	$ 0.9

Financial risk management - For

Financial risk management - Foreign exchange risk (Details) - Currency risk € in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2023 EUR (€)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
EUR
Disclosure of risk management strategy related to hedge accounting [line items]
Net exposure to exchange differences of the monetary assets	$ 923,773		$ 613,866	$ 591,887
Percentage of reasonably possible increase in risk assumption	10%	10%
Percentage of reasonably possible decrease in risk assumption	10%
Increase (decrease) in financial instrument due to reasonably possible increase in designated risk component	$ (92,300)		(61,400)	(53,800)
Increase (decrease) in financial instrument due to reasonably possible decrease in designated risk component	92,300		61,400	53,800
JPY
Disclosure of risk management strategy related to hedge accounting [line items]
Net exposure to exchange differences of the monetary assets	8,232		5,613	6,316
GBP
Disclosure of risk management strategy related to hedge accounting [line items]
Net exposure to exchange differences of the monetary assets	7		59,026	1,237
CHF
Disclosure of risk management strategy related to hedge accounting [line items]
Net exposure to exchange differences of the monetary assets	193		3,832	$ 727
CAD
Disclosure of risk management strategy related to hedge accounting [line items]
Net exposure to exchange differences of the monetary assets	266		657
SEK
Disclosure of risk management strategy related to hedge accounting [line items]
Net exposure to exchange differences of the monetary assets	1		7
DKK
Disclosure of risk management strategy related to hedge accounting [line items]
Net exposure to exchange differences of the monetary assets	$ 9		$ 6
Other currencies
Disclosure of risk management strategy related to hedge accounting [line items]
Percentage of reasonably possible increase in risk assumption	10%	10%
Percentage of reasonably possible decrease in risk assumption	10%
Increase (decrease) in financial instrument due to reasonably possible increase in designated risk component | €		€ 0
Increase (decrease) in financial instrument due to reasonably possible decrease in designated risk component | €		€ 0

Related party transactions - Co

Related party transactions - Compensation (Details) $ in Thousands	1 Months Ended												12 Months Ended
	Dec. 31, 2023 USD ($) EquityInstruments	Oct. 31, 2023 EquityInstruments	Jul. 31, 2023 EquityInstruments	Apr. 30, 2023 EquityInstruments	Dec. 31, 2022 EquityInstruments	Oct. 31, 2022 EquityInstruments	Jul. 31, 2022 USD ($) EquityInstruments	Apr. 30, 2022 EquityInstruments	Dec. 31, 2021 EquityInstruments	Oct. 31, 2021 EquityInstruments	Jul. 31, 2021 EquityInstruments	Apr. 30, 2021 EquityInstruments	Dec. 31, 2023 USD ($) EquityInstruments shares	Dec. 31, 2022 USD ($) shares EquityInstruments	Dec. 31, 2021 USD ($) shares EquityInstruments
Compensation of key management personnel
Numbers of stock options granted in the year | EquityInstruments	79,305	74,529	629,121	61,056	508,132	100,118	311,311	102,081	389,588	144,824	280,339	67,833	844,011	1,021,642	882,584
Investment in joint venture							$ 2,000						$ 13,000	$ 2,000
Onco Verity Inc. Joint Venture
Compensation of key management personnel
Contractual capital commitments	$ 13,000												13,000
Senior management
Compensation of key management personnel
Gross salary													4,161	4,199	$ 3,465
Variable pay													2,816	3,077	2,020
Employer social security													807	1,015	789
Other short term benefits													545	372	274
Termination benefits															382
Post-employment benefits for senior management members as a group													167	104	150
Cost of stock options granted in the year													27,983	18,393	15,060
Cost of restricted stock units granted in the year													11,694	9,594	8,025
Employer social security contributions stock options													(494)	1,101	4,172
Total benefits													$ 47,679	$ 37,855	$ 34,337
Numbers of stock options granted in the year | shares													132,100	117,600	101,446
Numbers of restricted stock units granted in the year | shares													30,425	26,500	22,888
Non-executive Directors
Compensation of key management personnel
Board fees and other short-term benefits for non-executive directors													$ 533	$ 437	$ 435
Cost of stock options granted in the year													2,280	3,643	3,263
Cost of restricted stock units granted in the year													1,034	1,850	1,731
Total benefits													$ 3,847	$ 5,929	$ 5,429
Numbers of stock options granted in the year | shares													12,400	21,600	22,950
Numbers of restricted stock units granted in the year | shares													2,713	4,800	5,100

Commitments (Details)

Commitments (Details) € in Thousands, $ in Thousands	Feb. 28, 2019 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2023 EUR (€)	Dec. 31, 2022 USD ($)
Commitments [Line Items]
Commitments to acquire property, plant and equipment		$ 0	€ 0
Borrowings		7,200	€ 6,500
Efgartigimod
Commitments [Line Items]
Outstanding commitment		$ 361,800
Contractual obligations				$ 13,300
Halozyme | Global Collaboration and License Agreement
Commitments [Line Items]
Outstanding commitment	$ 124,000
Payment for each future target	12,500
Future milestone payments	160,000
Payment for additional milestones	$ 40,000

Audit fees (Details)

Audit fees (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Audit fees
Audit fees (1)	$ 1,979	$ 1,394	$ 1,183
Audit-related fees	330	380	267
Tax fees (2)			79
Total	$ 2,309	$ 1,774	$ 1,529

Overview of consolidation sco_3

Overview of consolidation scope (Details)	12 Months Ended
	Dec. 31, 2023 subsidiary
ARGENX SE | Netherlands
Overview of consolidation scope
Participation ( as a percent)	100%
ARGENX BV | Belgium
Overview of consolidation scope
Number of subsidiaries	2
Participation ( as a percent)	100%
IIP BV | Belgium
Overview of consolidation scope
Participation ( as a percent)	100%
ARGENX US INC | United States
Overview of consolidation scope
Number of subsidiaries	10
Participation ( as a percent)	100%
ARGENX SWITZERLAND, SA | Switzerland
Overview of consolidation scope
Participation ( as a percent)	100%
ARGENX JAPAN KK | Japan
Overview of consolidation scope
Participation ( as a percent)	100%
ARGENX FRANCE SAS | France
Overview of consolidation scope
Participation ( as a percent)	100%
ARGENX GERMANY GMBH | Germany
Overview of consolidation scope
Participation ( as a percent)	100%
ARGENX CANADA INC [Member] | CANADA
Overview of consolidation scope
Participation ( as a percent)	100%
ARGENX UK LTD [Member] | UNITED KINGDOM
Overview of consolidation scope
Participation ( as a percent)	100%
ARGENX NETHERLANDS B.V [Member] | Netherlands
Overview of consolidation scope
Participation ( as a percent)	100%
ARGENX ITALY [Member] | ITALY
Overview of consolidation scope
Participation ( as a percent)	100%
Argenx Spain S.L. [Member] | SPAIN
Overview of consolidation scope
Participation ( as a percent)	100%