argenx SE (ARGX) 6-K 1 Aug 19 2019 H1 First of two registration trials from Phase 3 program of efgartigimod in primary immune thrombocytopenia (ITP) patients expected to start in 2H19 Financial data

Document and Entity Information

Document and Entity Information	6 Months Ended
	Jun. 30, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	ARGENX SE
Entity Central Index Key	0001697862
Document Type	6-K
Document Period End Date	Jun. 30, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	H1

CONSOLIDATED STATEMENT OF FINAN

CONSOLIDATED STATEMENT OF FINANCIAL POSITION - EUR (€) € in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	€ 167,793	€ 281,040
Restricted cash - current	1,692	1,692
Research and development incentive receivables - current	301	301
Financial assets - current	776,490	283,529
Prepaid expenses	8,326	2,995
Trade and other receivables	5,277	2,886
Total current assets	959,879	572,443
Noncurrent assets
Restricted cash - non-current	356	251
Research and development incentive receivables - non-current	6,047	4,883
Financial assets - non-current	1,499	1
Property, plant and equipment	5,887	824
Intangible assets	35,474	56
Total non-current assets	49,263	6,015
TOTAL ASSETS	1,009,142	578,458
Equity
Share capital	3,810	3,597
Share premium	828,162	673,454
Accumulated losses	(214,724)	(169,603)
Other reserves	48,146	30,947
Total equity	665,394	538,395
Non-current liabilities	241,360	7
Provisions for employee benefits	7	7
Non-current lease liabilities	3,686
Deferred revenue - non-current	237,667
Current liabilities	102,388	40,056
Current lease liabilities	1,078
Trade and other payables	55,068	37,072
Tax liabilities	378	823
Deferred revenue - current	45,864	2,161
Total liabilities	343,748	40,063
TOTAL EQUITY AND LIABILITIES	€ 1,009,142	€ 578,458

CONSOLIDATED STATEMENT OF PROFI

CONSOLIDATED STATEMENT OF PROFIT AND LOSS AND OTHER COMPREHENSIVE INCOME - EUR (€) € in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
CONSOLIDATED STATEMENT OF PROFIT AND LOSS AND OTHER COMPREHENSIVE INCOME
Revenue	€ 43,532	€ 17,910
Other operating income	7,767	2,588
Total operating income	51,299	20,498
Research and development expenses	(78,304)	(34,371)
Selling, general and administrative expenses	(27,462)	(11,514)
Operating loss	(54,467)	(25,387)
Financial income	7,210	1,256
Exchange gains	2,486	4,024
Loss before taxes	(44,771)	(20,107)
Income tax (expense)/benefit	(350)	31
Loss for the year and total comprehensive loss	€ (45,121)	€ (20,076)
Weighted average number of shares outstanding	37,764,237	32,375,133
Basic and diluted loss per share	€ (1.19)	€ (0.62)

CONSOLIDATED STATEMENT OF CASH

CONSOLIDATED STATEMENT OF CASH FLOWS - EUR (€) € in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
CASH FLOWS (USED IN) / FROM OPERATING ACTIVITIES
Operating result	€ (54,467)	€ (25,387)
Adjustments for non-cash items
Amortization of intangible assets	12	5
Depreciation of property, plant and equipment	915	215
Expense recognized in respect of share-based payments	17,199	8,824
Adjustments for non-cash items	(36,341)	(16,343)
Movements in current assets/liabilities
(Increase)/decrease in trade and other receivables	(179)	(7,356)
(Increase)/decrease in other current assets	(5,331)	(2,268)
Increase/(decrease) in trade and other payables	17,996	6,274
Increase/(decrease) in deferred revenue - current	38,657	(7,810)
Movements in non-current assets/liabilities
Increase)/decrease in other- noncurrent assets	(2,767)	(84)
Increase/(decrease) in deferred revenue - non-current	217,143
Cash flows (used in)/from operating activities	229,178	(27,587)
Income taxes paid	(794)
NET CASH FLOWS (USED IN) / FROM OPERATING ACTIVITIES	228,384	(27,587)
CASH FLOWS (USED IN) / FROM INVESTING ACTIVITIES
Purchase of intangible assets	(35,429)
Purchase of property, plant and equipment	(678)	(292)
(Increase)/decrease in financial assets - current	(488,534)	(29,075)
Interest paid	(47)
Interest received	1,384	1,256
NET CASH FLOWS (USED IN) / FROM INVESTING ACTIVITIES	(523,304)	(28,111)
CASH FLOWS (USED IN) / FROM FINANCING ACTIVITIES
Payment of lease liabilities	(536)
Proceeds from issue of new shares, gross amount	176,725
Proceeds from exercise of stock options	3,144	1,676
NET CASH FLOWS (USED IN) / FROM FINANCING ACTIVITIES	179,333	1,676
NET INCREASE (DECREASE) IN CASH & CASH EQUIVALENTS	(115,587)	(54,022)
Cash and cash equivalents at the beginning of the period	281,040	190,867
Exchange gains/(losses) on cash & cash equivalents	2,340	4,024
Cash and cash equivalents at the end of the period	€ 167,793	€ 140,869

CONSOLIDATED STATEMENT OF CHANG

CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - EUR (€) € in Thousands	Share capital	Share premium	Accumulated losses	Other reserves Equity-settled share-based payment reserve	Total equity attributable to owners of the parent	Total
Adoption of IFRS 15 (modified retrospective approach)			€ (2,395)		€ (2,395)	€ (2,395)
Equity at beginning of period at Dec. 31, 2017	€ 3,217	€ 430,518	(100,568)	€ 11,764	344,931	344,931
Total comprehensive loss of the period						(20,076)
Equity at end of period (Balances without adoption of IFRS 15) at Jun. 30, 2018	3,245	432,166	(123,039)	20,588	332,960	332,960
Equity at beginning of period at Dec. 31, 2017	3,217	430,518	(100,568)	11,764	344,931	344,931
Equity at end of period at Dec. 31, 2018	3,597	673,454	(169,603)	30,947	538,395	538,395
Equity at beginning of period at Jan. 01, 2018	3,217	430,518	(102,963)	11,764	342,536	342,536
Total comprehensive loss of the period			(20,076)		(20,076)	(20,076)
Share-based payment				8,824	8,824	8,824
Exercise of stock options	28	1,648			1,676	1,676
Equity at end of period (Balances without adoption of IFRS 15) at Jun. 30, 2018	3,245	432,166	(123,039)	20,588	332,960	332,960
Equity at beginning of period at Dec. 31, 2018	3,597	673,454	(169,603)	30,947	538,395	538,395
Total comprehensive loss of the period			(45,121)		(45,121)	(45,121)
Share-based payment				17,199	17,199	17,199
Issue of new shares	177	176,548			176,725	176,725
Accounting treatment of the share subscription agreement		(24,948)			(24,948)	(24,948)
Exercise of stock options	36	3,108			3,144	3,144
Equity at end of period at Jun. 30, 2019	€ 3,810	€ 828,162	€ (214,724)	€ 48,146	€ 665,394	€ 665,394

General information about the c

General information about the company	6 Months Ended
	Jun. 30, 2019
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 Willemstraat 5, 4811 AH, Breda, the Netherlands. An overview of the company and its subsidiaries (the Company) is described in note 17. 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.

Significant accounting policies

Significant accounting policies	6 Months Ended
	Jun. 30, 2019
Significant accounting policies
Significant accounting policies	2. Significant accounting policies The unaudited condensed consolidated interim financial statements for the six months ended June 30, 2019 have been prepared in accordance with International Accounting Standard 34 ‘Interim financial reporting’ (IAS 34) as issued by the IASB and IAS 34 as adopted by the European Union (EU). The unaudited condensed consolidated interim financial statements should be read in conjunction with the annual financial statements for the year ended December 31, 2018, which have been prepared in accordance with the International Financial Reporting Standards (IFRS), as issued by the International Accounting Standards Board (IASB) and as adopted by the EU. All amounts herein are presented in thousands of €, unless otherwise indicated, rounded to the nearest € ‘000. The unaudited condensed consolidated financial statements have been approved for issue by the Company’s Board of Directors (the Board) on July 31, 2019. The accounting policies applied in the preparation of the unaudited condensed consolidated interim financial statements are consistent with those applied in the financial statements for the year ended December 31, 2018, other than the adoption of IFRS 16 Leases (IFRS 16). Other new standards or interpretations applicable from January 1, 2019 do not have any significant impact on the unaudited condensed consolidated interim financial statements. The Company has adopted IFRS 16 on January 1, 2019. The Company elected the modified retrospective approach for the transition, which foresees that prior period figures remain as reported under the previous standard IAS 17, and the cumulative effect of applying IFRS 16 is recognized as an adjustment to the opening balance of equity as of the date of initial application (i.e., the beginning of the year 2019). On adoption of IFRS 16, the Company recognized lease liabilities in relation to leases which had previously been classified as ‘operating leases’ under IAS 17. These liabilities were measured at the present value of the remaining lease payments and discounted using the Company’s incremental borrowing rate as of January 1, 2019. The Company’s weighted average incremental borrowing rate applied to these lease liabilities on January 1, 2019 was 1.32%. The differences between our total operating lease commitments as reported in note 5.7 of our consolidated financial statements of December 31, 2018 and the total lease liabilities recognized in our statement of financial position as at January 1, 2019 are summarized below. (in thousands of €) Operating lease commitments disclosed as at December 31, 2018 € 3,004 Less: discounting effect using the lessee's incremental borrowing rate of the date of initial application € (126) Less: short-term leases recognized on a straight-line basis as expense € (88) Lease liability recognized as at January 1, 2019 € 2,790 of which are: Current lease liabilities € 1,078 Non-current lease liabilities € 1,712 The cumulative effect of adopting IFRS 16 to the unaudited condensed consolidated interim statement of financial position as of January 1, 2019 is as follows: (in thousands of €) Property, plant and equipment (right-of-use assets) € 2,790 Effect on total assets € 2,790 Lease liabilities (current and non-current) € 2,790 Effect on total equity and liabilities € 2,790 The adoption of IFRS 16 does not have a significant impact on the metrics used to measure financial performance. In applying IFRS 16 for the first time, the Company has used the following practical expedients permitted by the standard: - the use of a single discount rate to a portfolio of leases with reasonably similar characteristics; - reliance on previous assessments on whether leases are onerous; - the accounting for operating leases with a remaining lease term of less than 12 months as at January 1, 2019 as short-term leases; and - the use of hindsight in determining the lease term where the contract contains options to extend or terminate the lease. The Company has also elected not to reassess whether a contract is, or contains, a lease at the date of initial application. Instead, for contracts entered into before the transition date, the Company relied on its assessment made applying IAS 17 and IFRIC 4 Determining whether an Arrangement contains a Lease . Other new standards and interpretations applicable for the first time for the financial year beginning January 1, 2019 did not have any impact on our unaudited condensed consolidated interim financial statements. The Company has not early adopted any other standard, interpretation or amendment that has been issued but is not yet effective. Change in accounting policies with effect as from January 1, 2019 as a result of the adoption of IFRS 16. Until December 31, 2018, leases of property, plant and equipment were classified as either finance or operating leases. Payments made under operating leases were charged to profit and loss on a straight-line basis over the period of the lease. As from January 1, 2019, leases are recognized as a right-of-use asset and a corresponding liability at the date at which the leased asset is available for use by the Company. Each lease payment is allocated between the liability and finance cost. The finance cost is charged to profit and loss over the lease period so as to produce a constant periodic rate of interest on the remaining balance of the liability for each period. The right-of-use asset is depreciated over the shorter of the asset’s useful life and the lease term on a straight-line basis. Assets and liabilities arising from a lease are initially measured on a present value basis. The lease payments are discounted using the interest rate implicit in the lease. If that rate cannot be determined, the lessee’s incremental borrowing rate is used. The right-of-use assets are presented in the statement of financial position under the caption “Property, plant and equipment” and the lease liabilities are presented as current and non-current lease liabilities.

Critical accounting judgements

Critical accounting judgements and key sources of estimation uncertainty	6 Months Ended
	Jun. 30, 2019
Critical accounting judgements and key sources of estimation uncertainty
Critical accounting judgements and key sources of estimation uncertainty	3. Critical accounting judgements and key sources of estimation uncertainty In the application of the Company’s accounting policies, 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. The following areas are areas where key assumptions concerning the future, and other key sources of estimation uncertainty at the end of the reporting period, have a significant risk of causing a material adjustment to the carrying amounts of assets and liabilities within the next financial year. Critical judgements in applying accounting policies Revenue recognition Revenue from certain arrangements is recognized as the Company satisfies a single performance obligation. The Company recognizes upfront payments and milestone payments, allocated to a combined performance obligation over the estimated service period based on a pattern that reflects the transfer of the services. The revenue recognized would reflect the level of service during each period. In this case, the Company would use an input model that considers estimates of the percentage of total research and development service costs that are completed each period compared to the total estimated services costs (percentage of completion method). Research and development service fees are recognized as revenue when costs are incurred and agreed by the parties as the Company is acting as a principal in the scope of its stake in the research and development activities of its ongoing license and collaboration agreements. Research and development cost accruals Research and development costs are charged to expense as incurred and are typically made up of payroll costs, clinical and preclinical activities, drug development and manufacturing costs, including costs for clinical research organizations and investigative sites. Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as information provided by vendors on their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the financial statements as prepaid expenses. Critical accounting estimates Going concern The Company has incurred net losses since its inception and for the six months ended June 30, 2019, its unaudited condensed consolidated interim statement of profit and loss and other comprehensive income reflects a net loss, and its unaudited condensed consolidated interim statement of financial position includes a loss carried forward. On July 31, 2019, the Board reviewed and approved the unaudited condensed consolidated interim financial statements and accounting standards. Taking into account the cash and cash equivalents and current financial asset position of €944.3 million on June 30, 2019, the Board is of the opinion that the Company can submit its unaudited condensed consolidated financial statements on a going concern basis. Whilst the current cash position is sufficient for the Company’s immediate and mid‑term needs, the Board pointed out that if the research and development activities continue to deliver added value, the Company may seek additional funding to support the continuing development of its portfolio of products or to be able to execute other business opportunities. Measurement of share‑based payments In accordance with IFRS 2— Share‑based Payment , the fair value of the options at grant date is recognized as an expense in the statement of profit and loss and other comprehensive income over the vesting period. Subsequently, the fair value recognized in equity is not re‑measured. The fair value of each stock option granted during the year is calculated using the Black‑Scholes pricing model. This pricing model requires the input of subjective assumptions, which are detailed in note 10. Recognition of deferred tax assets Deferred tax assets are recognized only if management assesses that these tax assets can be offset against positive taxable income within a foreseeable future. This judgment is made by management on an ongoing basis and is based on budgets and business plans for the coming years, including planned commercial initiatives. These budgets and business plans are reviewed and approved by the Board. Since inception, the Company has reported losses, and consequently, the Company has unused tax losses. The deferred tax assets are currently not deemed to meet the criteria for recognition as management is not able to provide any convincing positive evidence that deferred tax assets should be recognized. Therefore, management has concluded that deferred tax assets should not be recognized as of June 30, 2019.

Cash and cash equivalents

Cash and cash equivalents	6 Months Ended
	Jun. 30, 2019
Cash and cash equivalents
Cash and cash equivalents	4. Cash and cash equivalents Six Months Ended Year Ended June 30, December 31, (in thousands of €) 2019 2018 Cash equivalents € 113,505 € 217,626 Cash and bank balances 54,288 63,414 € 167,793 € 281,040 On June 30, 2019, cash and cash equivalents amounted to €167.8 million, compared to €281.0 million on December 31, 2018 and included cash equivalents and cash and bank balances held in different financial institutions. Cash positions are invested with selected financial institutions, which are considered to be high-quality financial institutions with sound credit ratings, or in highly-rated money market funds. Policies are in place that limit the amount of credit exposure to any specific financial institution.

Current financial assets

Current financial assets	6 Months Ended
	Jun. 30, 2019
Current financial assets
Current financial assets	5. Current financial assets On June 30, 2019, the current financial assets amounted to €776.5 million, compared to €283.5 million on December 31, 2018. These current financial assets relate to: · Financial instruments in the form of money market funds with a recommended investment horizon of six months. These funds are highly liquid investments and can be readily converted into a known amount of cash, but because of their historical volatility these funds cannot be classified as cash and cash equivalents. Amounts recorded are measured at fair value. · USD term accounts with an original maturity of six months. Please also refer to note 16 for more information on the financial instruments.

Prepaid expenses

Prepaid expenses	6 Months Ended
	Jun. 30, 2019
Prepaid expenses
Prepaid expenses	6. Prepaid expenses Prepaid expenses on June 30, 2019 amounted to €8.3 million, compared to €3.0 million on December 31, 2018. The increase in prepaid expenses is mainly driven by upfront fees paid in the first six months of 2019 to a third-party drug product manufacturer as the Company is further advancing its clinical development and manufacturing activities of efgartigimod.

Trade and other receivables

Trade and other receivables	6 Months Ended
	Jun. 30, 2019
Trade and other receivables
Trade and other receivables	7. Trade and other receivables Trade and other receivables are composed of receivables which are detailed below: Six Months Ended Year Ended June 30, December 31, (in thousands of €) 2019 2018 VAT receivable € 607 € 496 Trade receivables 120 214 Other receivables 260 455 Interest receivable 2,656 556 VLAIO grant receivable 1,634 1,165 € 5,277 € 2,886 The nominal amounts of all trade and other receivables approximate their respective fair values. The VAT receivable relates to VAT amounts to be recovered in the second half of 2019. Trade receivables correspond to amounts invoiced to the collaborators or strategic allies of the Company. No bad debt allowance was recorded, nor were any trade receivables impaired on June 30, 2019 and December 31, 2018. The Flanders Innovation and Entrepreneurship Agency (VLAIO) grant receivable consists of earned income from government grants for which no payments have been received but for which the relating expenditures have been incurred. For more information on the Flanders Innovation and Entrepreneurship Agency grants, see note 12.

Intangible assets

Intangible assets	6 Months Ended
	Jun. 30, 2019
Intangible assets
Intangible assets	8 Intangible assets The intangibles assets held by the Company increased substantially as a result of the in-licensing of the ENHANZE® drug delivery technology from Halozyme. Under the terms of the agreement, the Company paid an upfront payment of $30 million and exercised the option to nominate an additional target, triggering a $10 million development milestone payment. In line with its accounting policies, the Company has capitalized this upfront payment upon commencement of the in-license agreement. The development milestone payment has been capitalized when the development milestone was triggered. These intangible assets relating to products in development that are not yet available for use are not amortized. These intangible assets are assessed for impairment on an annual basis, or more frequently if indicators of a potential impairment exist. An impairment is recorded if the carrying value exceeds the recoverable amount of the intangible assets. Intangible assets relating to products which fail during development, or for which development ceases for any reason are written down to their recoverable amount, which is typically nil. If and when the Company obtains approval for the commercial application of a product in development, the related in-process research and development assets will be reclassified to intangible assets associated with products and amortized over its estimated useful life from marketing approval.

Shareholders' capital

Shareholders' capital	6 Months Ended
	Jun. 30, 2019
Shareholders' capital
Shareholders' capital	9 Shareholders’ capital Roll forward of number of shares outstanding: Number of shares outstanding on December 31, 2017 32,180,641 Exercise of options in January 2018 111,727 Exercise of options in March 2018 113,075 Exercise of options in April 2018 34,039 Exercise of options in May 2018 5,900 Exercise of options in June 2018 5,393 Exercise of options in July 2018 469 Exercise of options in August 2018 2,300 Exercise of options in September 2018 5,913 U.S. third public offering on Nasdaq on September 18, 2018 3,475,000 Exercise of options in October 2018 556 Exercise of options in November 2018 9,768 Exercise of options in December 2018 30,531 Number of shares outstanding on December 31, 2018 35,975,312 Exercise of options in January 2019 163,170 Share subscription from Johnson & Johnson Innovation Inc. 1,766,899 Exercise of options in February 2019 13,393 Exercise of options in March 2019 73,005 Exercise of options in April 2019 13,729 Exercise of options in May 2019 35,054 Exercise of options in June 2019 66,965 Number of shares outstanding on June 30, 2019 38,107,527 New shares issued during 2019 1,766,899 new shares were issued to Johnson & Johnson Innovation Inc., following the closing of the exclusive, global collaboration and license agreement for cusatuzumab (ARGX-110) with Cilag GmbH International, an affiliate of the Janssen Pharmaceutical Companies of Johnson & Johnson (see note 11). 365,316 new shares were issued in the six months ended June 30, 2019 as a result of the exercise of stock options during this period under the argenx Employee Stock Option Plan. This resulted in a total of 38,107,527 ordinary shares with a nominal value of €0.10 per share, on June 30, 2019. On May 7, 2019, at the annual general meeting, the shareholders of the Company renewed the authorization to the Board to issue up to a maximum of 20% of the then-outstanding share capital for a period of 18 months, or up to a capital increase of €760,110 represented by 7,601,101 shares.

Share based payments

Share based payments	6 Months Ended
	Jun. 30, 2019
Share based payments
Share based payments	10 Share‑based payments The Company has a stock options scheme for the employees of the Company and its subsidiaries. In accordance with the terms of the plan, as approved by shareholders, employees may be granted options to purchase ordinary shares at an exercise price as mentioned below per ordinary share, as set forth below. The stock options can be granted to employees, consultants or directors of the Company and its subsidiaries. The stock options have been granted free of charge. Each employee’s stock option converts into one ordinary share of the Company upon exercise. No amounts are paid or payable by the recipient on receipt of the option. The options carry neither rights to dividends nor voting rights. 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 stock options granted will vest on the first anniversary of the granting of the stock options, and · 1/24th of the remaining 2/3rd of the stock options granted will vest on the last day of each of the 24 months following the month of the first anniversary of the granting of the stock options. No other conditions are attached to the stock options. The following share‑based payment arrangements were in existence during the current and prior years: Exercise price Outstanding Outstanding per stock stock options on stock options on options June 30, December 31, Expiry date (in €) 2019 2018 2020 € 3.95 15,200 18,200 2021 3.95 — — 2023 2.44 215,519 294,400 2024 2.44 96,696 117,733 2024 3.95 6,238 6,895 2024 7.17 337,100 407,061 2024 2.44 6,000 26,970 2025 11.44 39,000 39,000 2025 10.34 3,000 3,000 2025 9.47 188,590 226,323 2026 11.38 49,995 50,415 2026 11.47 225,874 257,616 2026 14.13 268,371 315,102 2027 18.41 111,389 114,019 2027 21.17 569,871 628,292 2023 80.82 94,100 94,600 2028 80.82 75,450 75,450 2023 86.32 367,760 369,760 2028 86.32 433,365 491,815 2024/2029 (1) € 113.49 423,487 3,527,005 3,536,651 (1) On June 28, 2019, the Company granted a total of 423,487 stock options. The beneficiary can choose between a contractual term of five or ten years. The fair market value of the stock options has been determined based on the Black and Scholes model. The expected volatility in the model is based on the historical volatility of peer companies and historical volatility of the Company since its initial public offering. On June 28, 2019, the Company granted a total of 423,487 stock options to certain of its employees, Board members and consultants. Below is an overview of the parameters used in relation to the new grant during 2019: Stock options granted in June 2019 Number of options granted 423,487 Average fair value of options (in EUR) € 67.35 Share price (in EUR) € 123.20 Exercise price (in EUR) € 113.49 Expected volatility 45.3 % Average expected option life (in years) (1) 10.00 Risk‑free interest rate 0.07 % Expected dividends — % (1) The beneficiary can choose between a contractual term of five or ten years. The average expected option life is currently estimated at ten 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 would range from €26.3 million (100% of the stock options at an expected option life of five years) to €28.5 million (100% of the stock options at an expected option life of ten years). The total share‑based payment expense recognized in the unaudited condensed consolidated statement of profit and loss and other comprehensive income totaled €17.2 million for the six months ended June 30, 2019 compared to €8.8 million for the six months ended June 30, 2018. The total number of stock options outstanding on June 30, 2019 totaled 3,527,005, compared to 3,536,651 outstanding on December 31, 2018. No stock options expired in the six months ended June 30, 2019 or in the year ended December 31, 2018. 365,316 stock options have been exercised in the six months ended June 30, 2019, compared to 319,671 in the year ended December 31, 2018. A total of 67,817 stock options have been forfeited in the six months ended June 30, 2019, compared to 46,369 in the year ended December 31, 2018.

Revenue

Revenue	6 Months Ended
	Jun. 30, 2019
Revenue
Revenue	11 Six Months Ended June 30, (in thousands of €) 2019 2018 Upfront payments € 8,615 € 6,812 Milestone payments 26,135 10,132 Research and development service fees 8,782 966 € 43,532 € 17,910 For the six months ended June 30, 2019, the majority of the revenue was generated under the collaboration agreements signed with AbbVie and Janssen. These agreements comprise elements of upfront payments, milestone payments based on development criteria and research and development service fees. For the six months ended June 30, 2019, €26.6 million related to the collaboration and license agreement with AbbVie was recognized in revenue on the basis of costs incurred for this program. Revenue recognized consisted of (i) €0.5 million related to the upfront payment received, (ii) €0.2 million related to development milestone payments received in previous years and (iii) €25.9 million related to a milestone achieved in the six months ended June 30, 2019. The outstanding balance of deferred revenue amounts to €2.0 million of which €1.3 million is recognized as deferred revenue — current and €0.7 as deferred revenue — non-current. For the six months ended June 30, 2019, €6.6 million related to the collaboration and license agreement with Janssen was recognized in revenue on the basis of costs incurred for this program. Revenue recognized consisted of (i) €6.0 million related to the upfront payment received and (ii) €0.6 million related to the revenue recognition of deferred income triggered by the accounting treatment of the share subscription agreement at the time of signing of the agreement in December 2018. The outstanding balance of deferred revenue amounts to €281.4 million of which €44.5 million is recognized as deferred revenue — current and €236.9 as deferred revenue — non-current. Research and development service fees increased by €7.8 million to €8.8 million for the six months ended June 30, 2019 due to the research and development service fees recognized under the Janssen collaboration and license agreement. In December 2018, the Company entered into a collaboration agreement with Cilag GmbH International, an affiliate of Janssen, to jointly develop and commercialize cusatuzumab. The Company has granted Janssen a license to the cusatuzumab program to develop, manufacture and commercialize products. For the U.S., the granted commercialization license is co-exclusive with argenx, while outside the U.S., the granted license is exclusive. Janssen and argenx will assume certain development obligations, and will be jointly responsible for all research, development and regulatory costs relating to the products. argenx will be eligible to receive potentially up to $1.3 billion in development, regulatory and sales milestones, in addition to tiered royalties, ranging from the low double digits to the high teens. Janssen will be responsible for commercialization worldwide. argenx retains the option to participate in commercialization efforts in the US, where the companies have agreed to share royalties on a 50/50 basis, and outside the U.S., Janssen will pay sales royalties ranging from the low double digits to the high teens to argenx. Under the terms of the agreement, Janssen committed to an upfront payment of $500 million consisting of a license payment of $300 million and a $200 million equity investment in the Company by subscribing to 1,766,899 new shares at a price of €100.02 per share, including an issuance premium. The agreement became effective in January 2019 following expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act. With regard to this collaboration with Janssen, the Company concluded as follows: · There is one single performance obligation under IFRS 15, that being the transfer of a license combined with performance of research and development activities. The Company concluded that the license is not distinct in the context of the contract. Moreover, the Company concluded that the share premium that Janssen paid above the closing price on the day of entering into the investment agreement (being December 2, 2018) was paid because of the existing obligations to deliver development services under the terms of the collaboration agreement, and is therefore to be allocated to the single performance obligation. · The transaction price of this agreement is currently composed of a fixed part, that being an upfront license fee and the share premium, and a variable part, that being milestone payments and cost reimbursements of research and development activities delivered. Milestone payments are included in the transaction price of the arrangement only when achieved. Sales-based milestones and sales-based royalties are a part of the Company’s arrangements but are not yet included in its revenues, as its programs with AbbVie and Janssen are still in the development phase. · The transaction price has been allocated to the single performance obligation, and revenues have been recognized over the estimated service period based on a pattern that reflects the transfer of the license and progress to complete satisfaction of the research and development activities. This is because the transfer of the license is considered to be combined with the performance of research and development activities. Therefore, research and development milestone payments are variable considerations that are entirely allocated to the single performance obligation. · The Company has chosen an input model to measure the satisfaction of the single performance obligation that considers percentage of costs incurred for these programs (percentage of completion method). · Cost reimbursements received are recognized in revenues when costs are incurred and agreed by the parties, as the Company is acting as a principal in the scope of its stake of the research and development activities of its ongoing license and collaboration agreements.

Other operating income

Other operating income	6 Months Ended
	Jun. 30, 2019
Other operating income
Other operating income	12 Other operating income Six Months Ended June 30, (in thousands of €) 2019 2018 Grants € 1,178 € 553 Research and development incentives 1,164 503 Payroll tax rebates 5,425 1,532 € 7,767 € 2,588 Grants The Flanders Innovation and Entrepreneurship Agency provided the Company with several grants. On June 30, 2019, the grants received by the Company reflected the expenses incurred by the Company in the various research and development projects sponsored by Flanders Innovation and Entrepreneurship Agency. No conditions related to the above government grants were unfulfilled, nor were there any contingencies related thereon at the date of the approval of these financial statements. Other incentives Research and development incentives The Company has accounted for a tax receivable of €1.2 million in the six months ended June 30, 2019, compared to €0.5 million in the six months ended June 30, 2018, 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. Payroll tax rebates The Company accounted for €5.4 million payroll tax rebates in the six months ended June 30, 2019, compared to €1.5 million in the six months ended June 30, 2018, as a reduction in withholding income taxes for its highly‑qualified personnel employed in its research and development department.

Segment reporting

Segment reporting	6 Months Ended
	Jun. 30, 2019
Segment reporting
Segment reporting	13 Segment reporting The Company operates from the Netherlands, Belgium, the United States and Japan. Revenues are invoiced by the subsidiary in Belgium and are generated by external customers geographically located as shown in the table below. Revenue from External Customers Six Months Ended June 30, (in thousands of €) 2019 2018 Netherlands € — € 214 Denmark 128 859 Belgium 1,498 — Switzerland 15,310 527 United States — — Luxembourg 26,596 16,310 Total € 43,532 € 17,910 Information about major clients: The Company received €43.5 million of revenue from its external customers in the six months ended June 30, 2019, compared to €17.9 million over the six months ended June 30, 2018, of which in the six monhs ended June 30, 2019 €26.6 million came from the Company’s largest client, €15.3 million from its second-largest client and €1.5 million from its third-largest client, compared to, respectively, €16.3 million, €0.9 million and €0.5 million in the six months ended June 30, 2018.

Research and development expens

Research and development expenses	6 Months Ended
	Jun. 30, 2019
Research and development expenses
Research and development expenses	14 Research and development expenses Six Months Ended June 30, (in thousands of €) 2019 2018 Personnel expense € 22,887 € 12,284 External research and development expenses 46,780 17,313 Materials and consumables 878 785 Depreciation and amortization 932 220 Other expenses 6,827 3,769 € 78,304 € 34,371

Selling, general and administra

Selling, general and administrative expenses	6 Months Ended
	Jun. 30, 2019
Selling, general and administrative expenses
Selling, general and administrative expenses	15 Selling, general and administrative expenses Six Months Ended June 30, (in thousands of €) 2019 2018 Personnel expense € 17,132 € 8,361 Consulting fees 6,795 1,299 Supervisory board 1,424 477 Office costs 2,111 1,377 € 27,462 € 11,514

Financial instruments and finan

Financial instruments and financial risk management	6 Months Ended
	Jun. 30, 2019
Financial instruments and financial risk management
Financial instruments and financial risk management	16 Overview of financial instruments (in thousands of €) Measurement Category Carrying Amount Financial assets — non-current FVTPL € 1,499 Research and development incentive receivables — non-current Amortized cost 6,047 Restricted cash — non-current Amortized cost 356 Trade and other receivables Amortized cost 5,277 Prepaid expenses Amortized cost 8,326 Financial assets—current FVTPL 776,490 Research and development incentive receivables — current Amortized cost 301 Restricted cash — current Amortized cost 1,692 Cash and cash equivalents Amortized cost 167,793 Trade and other payables Amortized cost 55,068 Current financial assets included collective investment funds nominated in € and $ that are not considered as cash equivalents and of which the underlying investments include bonds and other international debt securities. The average credit rating of the underlying instruments is BBB or higher. The maximum exposure to credit risk is the carrying value at reporting date. These investment funds are recognized at fair value in the Company’s consolidated financial statements (level 1). The fair value corresponds to the quoted market price and can therefore be classified as a level 1 fair value measurement. The net asset value (NAV) of the funds is available on a daily basis. Any difference between amounts invested and fair value at reporting date is booked in Profit & Loss. Due to the current nature of the financial liabilities and financial assets at amortized cost, the nominal value of those financial liabilities and financial assets presented above approximates their fair value. The Company carried the following assets at fair value on June 30, 2019 and December 31, 2018 respectively: At June 30, 2019 (in thousands of €) Level 1 Level 2 Level 3 Non-current financial assets € € € 1,499 Current financial assets 776,490 Assets carried at fair value € 776,490 € — € 1,499 At December 31, 2018 (in thousands of €) Level 1 Level 2 Level 3 Non-current financial assets € € € 1 Current financial assets 283,529 Assets carried at fair value € 283,529 € — € 1 During the disclosed six month period, no transfers occurred between the applicable categories. 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 Innovative Access Program. In exchange for granting this license, the Company received a profit share in AgomAb Therapeutics NV. The Company assessed the accounting treatment and concluded that the license agreement is in scope of IFRS 15 and that any revenue should be recognized at once at the effective date of the agreement. The profit share has been designated as a non-current financial asset held at fair value 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 March 2019, AgomAb Therapeutics NV secured €21.0 million in a Series A financing round. The Company used the post-money valuation of this Series A financing round and the number of outstanding shares in determining the fair value of the profit sharing instrument. Risks The Company’s activities expose it to a variety of financial risks: market risk (including currency, fair value interest rate risk, cash flow interest rate risk and price risk), credit risk and liquidity risk. The unaudited condensed consolidated interim financial statements do not include all financial risk management information and disclosures required in the annual financial statements, and should be read in conjunction with the Annual Report of the Company for the year ended December 31, 2018. During the six months ended June 30, 2019, there have been no significant changes in the risk profile of the Company, nor is the risk profile of the Company expected to change significantly in the second half of 2019, other than as referred to in Sections 3 and 4 of the Management Report in “Risk Factors and Forward-Looking Statements” and “Operational and Financial Outlook”. However, the Company’s actual results may differ materially from those predicted as a result of various important factors, including its expectations regarding the inherent uncertainties associated with competitive developments, preclinical and clinical trial and product development activities and regulatory approval requirements; its reliance on collaborations with third parties; estimating the commercial potential of its drug candidates; its ability to obtain and maintain protection of intellectual property for its technologies and drugs; its limited operating history and its ability to obtain additional funding for operations and to complete the development and commercialization of its product candidates.

Other disclosures

Other disclosures	6 Months Ended
	Jun. 30, 2019
Other disclosures
Other disclosures	17 Related party transactions Amongst the shareholders of the Company, there are minority investors and venture capital funds which individually do not hold a significant influence on the Company. Balances and transactions between the Company and its subsidiaries, which are related parties of the Company, have been eliminated through consolidation and are not disclosed in this note. There were no significant transactions with related parties during the six months ended June 30, 2019, other than compensation of key management personnel. The unaudited condensed consolidated interim financial statements do not include all related party disclosures required in the annual financial statements, and should be read in conjunction with the Annual Report of the Company for the year ended December 31, 2018. Contingencies The Company is currently not facing any outstanding claims or litigations that may have a significant adverse impact on the Company’s financial position. As described in note 12, the Company has received several types of government grants which are granted subject to a certain number of conditions that need to be met at the grant date and in the future. The Company recognizes grant income from Belgian and Flemish grant bodies when all contractual conditions are met. These government institutions may however subsequently perform an audit which may result in a (partial) claw back of the grant. The Company deems that the claw back risk is remote in view of the continuous monitoring of the contractual conditions. Currently, the Company has fulfilled all the existing conditions relating to the recognition of its grant income. Contracts with these grant bodies also typically include clauses that define the need for future validation of the project results after completion of the initial grant term during which the subsidized expenses or investments have been incurred and for which the grant was earned. Should this validation not occur or be deemed inadequate, the grant bodies have the right to reclaim funds previously granted. As described in note 10, on June 28, 2019, the Company granted a total of 423,487 stock options to certain of its employees, Board members and consultants. As part of the grant of these stock options, the Company has undertaken to compensate Belgian taxes that are paid upon the grant of these stock options if and when at the end of the exercise period, the stock price would be lower than the exercise price, as increased with these taxes. The Company has applied for a tax ruling on this subject that would cover the stock option grants as from June 28, 2018. The exposure that the Company could face at the end of the exercise period for the stock options granted as from June 28, 2018 ranges from €3.7 million to €3.9 million. Contractual obligations and commitments As a consequence of the adoption of IFRS 16 ‘Leases’ on January 1, 2019, lease obligations in the scope of the new standard are presented as lease liabilities in the statements of financial position and are therefore no longer disclosed separately as off-balance sheet commitments. The Company’s manufacturing commitments with its drug substance manufacturing contractor Lonza relate to the ongoing execution of the biologic license application (BLA) services for efgartigimod and the ongoing manufacturing activities related to the start-up of Lonza Singapore as a potential future commercial manufacturing site. 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. The total commitment under this commercial supply agreement amounts to a minimum commitment of £25.3 million over a period of five years starting from 2020. In the aggregate, the Company has outstanding commitments for efgartigimod of approximately €40.7 million. In addition, the Company also has contractual obligations for cusatuzumab of approximately €8.4 million and for ARGX-117 of approximately €3.1 million. Overview of consolidation scope The parent company argenx SE is domiciled in the Netherlands. argenx SE has two subsidiaries, argenx BVBA, based in Belgium, and argenx US, Inc., based in the United States. Since May 2019, argenx BVBA also has one subsidiary, argenx Japan KK, based in Japan. Details of the Company’s consolidated entities at the end of the six months ended June 30, 2019 are as follows: List of consolidated companies. Name Registration number Country Participation Main activity argenx SE COC 24435214 The Netherlands 100.00 % Holding company argenx BVBA Belgium 100.00 % Biotechnical research on drugs and pharma processes argenx US, Inc. 36-4880497 USA 100.00 % Pharmaceuticals and pharmacy supplies merchant wholesalers argenx Japan KK 0104-01-145183 Japan 100.00 % Pharmaceuticals and pharmacy supplies merchant wholesalers

Events after the balance sheet

Events after the balance sheet date	6 Months Ended
	Jun. 30, 2019
Events after the balance sheet date
Events after the balance sheet date	18 On July 17, 2019, the Company dosed the first subject in a Phase 1 clinical trial evaluating the safety, pharmacokinetics and pharmacodynamics of efgartigimod, using Halozyme's proprietary ENHANZE® drug delivery technology. Initiation of this study triggered a $5 million milestone payment obligation to Halozyme during the third quarter of 2019 under the global collaboration and license agreement between the two companies.

Significant accounting polici_2

Significant accounting policies (Policies)	6 Months Ended
	Jun. 30, 2019
Significant accounting policies
Revenue recognition	Revenue recognition Revenue from certain arrangements is recognized as the Company satisfies a single performance obligation. The Company recognizes upfront payments and milestone payments, allocated to a combined performance obligation over the estimated service period based on a pattern that reflects the transfer of the services. The revenue recognized would reflect the level of service during each period. In this case, the Company would use an input model that considers estimates of the percentage of total research and development service costs that are completed each period compared to the total estimated services costs (percentage of completion method). Research and development service fees are recognized as revenue when costs are incurred and agreed by the parties as the Company is acting as a principal in the scope of its stake in the research and development activities of its ongoing license and collaboration agreements.
Research and development cost accruals	Research and development cost accruals Research and development costs are charged to expense as incurred and are typically made up of payroll costs, clinical and preclinical activities, drug development and manufacturing costs, including costs for clinical research organizations and investigative sites. Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as information provided by vendors on their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the financial statements as prepaid expenses.
Going concern	Going concern The Company has incurred net losses since its inception and for the six months ended June 30, 2019, its unaudited condensed consolidated interim statement of profit and loss and other comprehensive income reflects a net loss, and its unaudited condensed consolidated interim statement of financial position includes a loss carried forward. On July 31, 2019, the Board reviewed and approved the unaudited condensed consolidated interim financial statements and accounting standards. Taking into account the cash and cash equivalents and current financial asset position of €944.3 million on June 30, 2019, the Board is of the opinion that the Company can submit its unaudited condensed consolidated financial statements on a going concern basis. Whilst the current cash position is sufficient for the Company’s immediate and mid‑term needs, the Board pointed out that if the research and development activities continue to deliver added value, the Company may seek additional funding to support the continuing development of its portfolio of products or to be able to execute other business opportunities.
Measurement of share based payments	Measurement of share‑based payments In accordance with IFRS 2— Share‑based Payment , the fair value of the options at grant date is recognized as an expense in the statement of profit and loss and other comprehensive income over the vesting period. Subsequently, the fair value recognized in equity is not re‑measured. The fair value of each stock option granted during the year is calculated using the Black‑Scholes pricing model. This pricing model requires the input of subjective assumptions, which are detailed in note 10.
Recognition of deferred tax assets	Recognition of deferred tax assets Deferred tax assets are recognized only if management assesses that these tax assets can be offset against positive taxable income within a foreseeable future. This judgment is made by management on an ongoing basis and is based on budgets and business plans for the coming years, including planned commercial initiatives. These budgets and business plans are reviewed and approved by the Board. Since inception, the Company has reported losses, and consequently, the Company has unused tax losses. The deferred tax assets are currently not deemed to meet the criteria for recognition as management is not able to provide any convincing positive evidence that deferred tax assets should be recognized. Therefore, management has concluded that deferred tax assets should not be recognized as of June 30, 2019.

Significant accounting polici_3

Significant accounting policies (Tables)	6 Months Ended
	Jun. 30, 2019
Significant accounting policies
Summary of total lease liabilities recognized in our statement of financial position	(in thousands of €) Operating lease commitments disclosed as at December 31, 2018 € 3,004 Less: discounting effect using the lessee's incremental borrowing rate of the date of initial application € (126) Less: short-term leases recognized on a straight-line basis as expense € (88) Lease liability recognized as at January 1, 2019 € 2,790 of which are: Current lease liabilities € 1,078 Non-current lease liabilities € 1,712
Schedule of cumulative effect of adoption	(in thousands of €) Property, plant and equipment (right-of-use assets) € 2,790 Effect on total assets € 2,790 Lease liabilities (current and non-current) € 2,790 Effect on total equity and liabilities € 2,790

Cash and cash equivalents (Tabl

Cash and cash equivalents (Tables)	6 Months Ended
	Jun. 30, 2019
Cash and cash equivalents
Schedule of cash and cash equivalents	Six Months Ended Year Ended June 30, December 31, (in thousands of €) 2019 2018 Cash equivalents € 113,505 € 217,626 Cash and bank balances 54,288 63,414 € 167,793 € 281,040

Trade and other receivables (Ta

Trade and other receivables (Tables)	6 Months Ended
	Jun. 30, 2019
Trade and other receivables
Schedule of trade and other receivables	Six Months Ended Year Ended June 30, December 31, (in thousands of €) 2019 2018 VAT receivable € 607 € 496 Trade receivables 120 214 Other receivables 260 455 Interest receivable 2,656 556 VLAIO grant receivable 1,634 1,165 € 5,277 € 2,886

Shareholders' capital (Tables)

Shareholders' capital (Tables)	6 Months Ended
	Jun. 30, 2019
Shareholders' capital
Schedule of number of share outstanding	Number of shares outstanding on December 31, 2017 32,180,641 Exercise of options in January 2018 111,727 Exercise of options in March 2018 113,075 Exercise of options in April 2018 34,039 Exercise of options in May 2018 5,900 Exercise of options in June 2018 5,393 Exercise of options in July 2018 469 Exercise of options in August 2018 2,300 Exercise of options in September 2018 5,913 U.S. third public offering on Nasdaq on September 18, 2018 3,475,000 Exercise of options in October 2018 556 Exercise of options in November 2018 9,768 Exercise of options in December 2018 30,531 Number of shares outstanding on December 31, 2018 35,975,312 Exercise of options in January 2019 163,170 Share subscription from Johnson & Johnson Innovation Inc. 1,766,899 Exercise of options in February 2019 13,393 Exercise of options in March 2019 73,005 Exercise of options in April 2019 13,729 Exercise of options in May 2019 35,054 Exercise of options in June 2019 66,965 Number of shares outstanding on June 30, 2019 38,107,527

Sharebased payments (Tables)

Sharebased payments (Tables)	6 Months Ended
	Jun. 30, 2019
Share based payments
Schedule of share-based payments arrangements	Exercise price Outstanding Outstanding per stock stock options on stock options on options June 30, December 31, Expiry date (in €) 2019 2018 2020 € 3.95 15,200 18,200 2021 3.95 — — 2023 2.44 215,519 294,400 2024 2.44 96,696 117,733 2024 3.95 6,238 6,895 2024 7.17 337,100 407,061 2024 2.44 6,000 26,970 2025 11.44 39,000 39,000 2025 10.34 3,000 3,000 2025 9.47 188,590 226,323 2026 11.38 49,995 50,415 2026 11.47 225,874 257,616 2026 14.13 268,371 315,102 2027 18.41 111,389 114,019 2027 21.17 569,871 628,292 2023 80.82 94,100 94,600 2028 80.82 75,450 75,450 2023 86.32 367,760 369,760 2028 86.32 433,365 491,815 2024/2029 (1) € 113.49 423,487 3,527,005 3,536,651 (1) On June 28, 2019, the Company granted a total of 423,487 stock options. The beneficiary can choose between a contractual term of five or ten years.
Schedule of parameters used in relation to the new grants	Stock options granted in June 2019 Number of options granted 423,487 Average fair value of options (in EUR) € 67.35 Share price (in EUR) € 123.20 Exercise price (in EUR) € 113.49 Expected volatility 45.3 % Average expected option life (in years) (1) 10.00 Risk‑free interest rate 0.07 % Expected dividends — % (1) The beneficiary can choose between a contractual term of five or ten years. The average expected option life is currently estimated at ten 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 would range from €26.3 million (100% of the stock options at an expected option life of five years) to €28.5 million (100% of the stock options at an expected option life of ten years).

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue
Schedule of Revenue	Six Months Ended June 30, (in thousands of €) 2019 2018 Upfront payments € 8,615 € 6,812 Milestone payments 26,135 10,132 Research and development service fees 8,782 966 € 43,532 € 17,910

Other operating income (Tables)

Other operating income (Tables)	6 Months Ended
	Jun. 30, 2019
Other operating income
Schedule of other operating income	Six Months Ended June 30, (in thousands of €) 2019 2018 Grants € 1,178 € 553 Research and development incentives 1,164 503 Payroll tax rebates 5,425 1,532 € 7,767 € 2,588

Segment reporting (Tables)

Segment reporting (Tables)	6 Months Ended
	Jun. 30, 2019
Segment reporting
Schedule of external customers geographically location	Revenue from External Customers Six Months Ended June 30, (in thousands of €) 2019 2018 Netherlands € — € 214 Denmark 128 859 Belgium 1,498 — Switzerland 15,310 527 United States — — Luxembourg 26,596 16,310 Total € 43,532 € 17,910

Research and development expe_2

Research and development expenses (Tables)	6 Months Ended
	Jun. 30, 2019
Research and development expenses
Schedule of research and development expenses	Six Months Ended June 30, (in thousands of €) 2019 2018 Personnel expense € 22,887 € 12,284 External research and development expenses 46,780 17,313 Materials and consumables 878 785 Depreciation and amortization 932 220 Other expenses 6,827 3,769 € 78,304 € 34,371

Selling, general and administ_2

Selling, general and administrative expenses (Tables)	6 Months Ended
	Jun. 30, 2019
Selling, general and administrative expenses
Schedule of selling, general and administrative expenses	Six Months Ended June 30, (in thousands of €) 2019 2018 Personnel expense € 17,132 € 8,361 Consulting fees 6,795 1,299 Supervisory board 1,424 477 Office costs 2,111 1,377 € 27,462 € 11,514

Financial instruments and fin_2

Financial instruments and financial risk management (Tables)	6 Months Ended
	Jun. 30, 2019
Financial instruments and financial risk management
Schedule of overview of financial instruments	(in thousands of €) Measurement Category Carrying Amount Financial assets — non-current FVTPL € 1,499 Research and development incentive receivables — non-current Amortized cost 6,047 Restricted cash — non-current Amortized cost 356 Trade and other receivables Amortized cost 5,277 Prepaid expenses Amortized cost 8,326 Financial assets—current FVTPL 776,490 Research and development incentive receivables — current Amortized cost 301 Restricted cash — current Amortized cost 1,692 Cash and cash equivalents Amortized cost 167,793 Trade and other payables Amortized cost 55,068
Schedule of assets at fair value	At June 30, 2019 (in thousands of €) Level 1 Level 2 Level 3 Non-current financial assets € € € 1,499 Current financial assets 776,490 Assets carried at fair value € 776,490 € — € 1,499 At December 31, 2018 (in thousands of €) Level 1 Level 2 Level 3 Non-current financial assets € € € 1 Current financial assets 283,529 Assets carried at fair value € 283,529 € — € 1

Other disclosures (Tables)

Other disclosures (Tables)	6 Months Ended
	Jun. 30, 2019
Other disclosures
Schedule of overview of subsidiaries	Name Registration number Country Participation Main activity argenx SE COC 24435214 The Netherlands 100.00 % Holding company argenx BVBA Belgium 100.00 % Biotechnical research on drugs and pharma processes argenx US, Inc. 36-4880497 USA 100.00 % Pharmaceuticals and pharmacy supplies merchant wholesalers argenx Japan KK 0104-01-145183 Japan 100.00 % Pharmaceuticals and pharmacy supplies merchant wholesalers

Significant accounting polici_4

Significant accounting policies - Lease Liabilities (Details) - EUR (€) € in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Significant accounting policies
Weighted average incremental borrowing rate		1.32%
Operating lease commitments disclosed as at December 31, 2018			€ 3,004
Less: discounting effect using the lessee's incremental borrowing rate of the date of initial application			(126)
Less: short-term leases recognised on a straight-line basis as expense			€ (88)
Lease liability recognized as at January 1, 2019		€ 2,790
Current lease liabilities	€ 1,078	1,078
Non-current lease liabilities	€ 3,686	€ 1,712

Significant accounting polici_5

Significant accounting policies - Cumulative of adopting IFRS 16 (Details) - EUR (€) € in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Disclosure of initial application of standards or interpretations [line items]
Lease liabilities (current and non-current)		€ 2,790
Effect on total equity and liabilities	€ 1,009,142		€ 578,458
Increase (decrease) due to application of IFRS 16
Disclosure of initial application of standards or interpretations [line items]
Property, plant and equipment (right-of-use assets)		2,790
Effect on total assets		2,790
Lease liabilities (current and non-current)		2,790
Effect on total equity and liabilities		€ 2,790

Critical accounting judgement_2

Critical accounting judgements and key sources of estimation uncertainty - (Details) € in Millions	Jun. 30, 2019EUR (€)
Critical accounting judgements and key sources of estimation uncertainty
Cash and cash equivalents and current financial assets	€ 944.3

Cash and cash equivalents (Deta

Cash and cash equivalents (Details) - EUR (€) € in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Cash and cash equivalents
Cash equivalents	€ 113,505	€ 217,626
Cash and bank balances	54,288	63,414
Total cash and cash equivalents	€ 167,793	€ 281,040	€ 140,869	€ 190,867

Current financial assets (Detai

Current financial assets (Details) - EUR (€) € in Thousands	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Other current financial assets
Financial assets - current	€ 776,490	€ 283,529
Maturity Term	6 months

Prepaid expenses (Details)

Prepaid expenses (Details) - EUR (€) € in Thousands	Jun. 30, 2019	Dec. 31, 2018
Prepaid expenses
Prepaid expenses	€ 8,326	€ 2,995

Trade and other receivables (De

Trade and other receivables (Details) - EUR (€) € in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Trade and other receivables
VAT receivable	€ 607		€ 496
Trade receivables	120		214
Other receivables	260		455
Interest receivable	2,656		556
VLAIO grant receivable	1,634		1,165
Total trade and other current receivables	5,277		€ 2,886
Government grant received from Flanders Innovation and Entrepreneurship Agency	1,178	€ 553
Flanders Innovation and Entrepreneurship Agency
Trade and other receivables
Government grant received from Flanders Innovation and Entrepreneurship Agency	€ 0

Intangible assets (Details)

Intangible assets (Details) € in Millions	6 Months Ended
	Jun. 30, 2019EUR (€)
Intangible assets
Upfront payment	€ 30
Development milestone payment	€ 10

Shareholders' capital (Details)

Shareholders' capital (Details) - EUR (€)	May 07, 2019	Sep. 18, 2018	Jun. 30, 2019	May 31, 2019	Apr. 30, 2019	Mar. 31, 2019	Feb. 28, 2019	Jan. 31, 2019	Dec. 31, 2018	Nov. 30, 2018	Oct. 31, 2018	Sep. 30, 2018	Aug. 31, 2018	Jul. 31, 2018	Jun. 30, 2018	May 31, 2018	Apr. 30, 2018	Mar. 31, 2018	Jan. 31, 2018	Jun. 30, 2019	Dec. 31, 2018
Disclosure of classes of share capital [line items]
Number of shares outstanding at beginning of period																			32,180,641		32,180,641
Exercise of Options			66,965	35,054	13,729	73,005	13,393	163,170	30,531	9,768	556	5,913	2,300	469	5,393	5,900	34,039	113,075	111,727		35,975,312
New shares issued for private placement, initial public offering, public offering and underwriters' over-allotment option		3,475,000																		38,107,527
Number of shares outstanding at end of period			38,107,527																	38,107,527
Par value per share			€ 0.1																	€ 0.1
Maximum authorized increase of then outstanding share capital (as a percent)	20.00%
Period of outstanding share capital	18 months
Maximum authorized increase in share capital	€ 760,110
Maximum authorized increase in number of shares	7,601,101
Johnson & Johnson Innovation Inc
Disclosure of classes of share capital [line items]
Share subscription																				1,766,899
IFRS Employee Stock Option [Member]
Disclosure of classes of share capital [line items]
Exercise of Options																				365,316

Share based payments - Outstand

Share based payments - Outstanding stock options (Details)	Jun. 28, 2019EquityInstrumentsY	Jun. 30, 2019USD ($)Yitemshares	Jun. 30, 2019EUR (€)EquityInstruments	Dec. 31, 2018EquityInstrumentsEUR (€)
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of shares on conversion | shares		1
Amounts are paid or payable by the recipient on receipt of the option | $		$ 0
Other conditions attached to options | item		0
Vesting period		24 months
Exercise price per stock options			€ 113.49
Outstanding stock options			3,527,005	3,536,651
Option life (in years) | Y		10
2020 | 3.95
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 3.95
Outstanding stock options | EquityInstruments			15,200	18,200
2021 | 3.95
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 3.95
2023 | 2.44
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 2.44
Outstanding stock options | EquityInstruments			215,519	294,400
2023 | 80.82
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 80.82
Outstanding stock options | EquityInstruments			94,100	94,600
2023 | 86.32
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 86.32
Outstanding stock options | EquityInstruments			367,760	369,760
2024 | 3.95
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 3.95
Outstanding stock options | EquityInstruments			6,238	6,895
2024 | 2.44
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 2.44
Outstanding stock options | EquityInstruments			96,696	117,733
2024 | 2.44 - Expiry date 2024 option 1
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 2.44
Outstanding stock options | EquityInstruments			6,000	26,970
2024 | 7.17
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 7.17
Outstanding stock options | EquityInstruments			337,100	407,061
2025 | 11.44
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 11.44
Outstanding stock options | EquityInstruments			39,000	39,000
2025 | 10.34
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 10.34
Outstanding stock options | EquityInstruments			3,000	3,000
2025 | 9.47
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 9.47
Outstanding stock options | EquityInstruments			188,590	226,323
2026 | 11.38
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 11.38
Outstanding stock options | EquityInstruments			49,995	50,415
2026 | 11.47
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 11.47
Outstanding stock options | EquityInstruments			225,874	257,616
2026 | 14.13
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 14.13
Outstanding stock options | EquityInstruments			268,371	315,102
2027 | 18.41
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 18.41
Outstanding stock options | EquityInstruments			111,389	114,019
2027 | 21.17
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 21.17
Outstanding stock options | EquityInstruments			569,871	628,292
2028 | 80.82
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 80.82
Outstanding stock options | EquityInstruments			75,450	75,450
2028 | 86.32
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 86.32
Outstanding stock options | EquityInstruments			433,365	491,815
2024/2029 | 113.49
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price per stock options			€ 113.49
Outstanding stock options | EquityInstruments	423,487		423,487
Tranche One
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage		0.33%
Tranche Two
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage		0.04%
Percentage of stock options granted		0.67%
Maximum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage	100.00%
Vesting period	10 years
Option life (in years) | Y	10
Maximum | 2024/2029 | 113.49
Disclosure of terms and conditions of share-based payment arrangement [line items]
Option life (in years) | Y	10
Minimum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage	100.00%
Vesting period	5 years
Option life (in years) | Y	5
Minimum | 2024/2029 | 113.49
Disclosure of terms and conditions of share-based payment arrangement [line items]
Option life (in years) | Y	5

Share based payments - Overview

Share based payments - Overview (Details)	Jun. 28, 2019EUR (€)Y	Jun. 30, 2019EUR (€)EquityInstrumentsY	Jun. 30, 2018EUR (€)	Dec. 31, 2018EquityInstrumentsEUR (€)
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of options granted | EquityInstruments		423,487
Average fair value of options		€ 67.35
Share price		123.20
Exercise price		€ 113.49
Expected volatility		45.30%
Average expected option life (in years) | Y		10
Riskfree interest rate		0.07%
Time period for beneficiaries to choose contractual term (in days)	60 years
Total share based payment expense		€ 17,200,000	€ 8,800,000
Outstanding stock options		3,527,005		3,536,651
Options expired | EquityInstruments		0		0
Exercised		365,316		319,671
Forfeited		67,817		46,369
Tranche One
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage		0.33%
Tranche Two
Disclosure of terms and conditions of share-based payment arrangement [line items]
Vesting percentage		0.04%
Maximum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Average fair value of options	€ 28,500,000
Average expected option life (in years) | Y	10
Vesting percentage	100.00%
Minimum
Disclosure of terms and conditions of share-based payment arrangement [line items]
Average fair value of options	€ 26,300,000
Average expected option life (in years) | Y	5
Vesting percentage	100.00%

Revenue (Details)

Revenue (Details) - EUR (€) € in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Revenue
Upfront payments	€ 8,615	€ 6,812
Milestone payments	26,135	10,132
Research and development service fees (FTE)	8,782	966
Total revenue	€ 43,532	€ 17,910

Revenue - Additional Informatio

Revenue - Additional Information (Details) € / shares in Units, € in Thousands, $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2019EUR (€)	Jun. 30, 2018EUR (€)	Dec. 31, 2018USD ($)shares	Dec. 31, 2018EUR (€)€ / sharesshares	Dec. 31, 2018EUR (€)
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	€ 43,532	€ 17,910
Upfront payments	8,615	6,812
Research and development service fees (FTE)	8,782	966
Milestone payments	26,135	€ 10,132
Deferred revenue - current	45,864				€ 2,161
Deferred revenue - non-current	237,667
Equity investment	176,725
AbbVie | Collaboration and license agreement
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	26,600
Upfront payments	500
Research and development service fees (FTE)	200
Milestone payments	25,900
Deferred revenue	2,000
Deferred revenue - current	1,300
Deferred revenue - non-current	700
Janssen
Disclosure of disaggregation of revenue from contracts with customers [line items]
Increase in research and development service fees	7,800
Milestone payment to be received					€ 1,300
Percentage share of royalties			50.00%		50.00%
Upfront payment committed | $			$ 500
License payment committed | $			300
Equity investment | $			$ 200
Shares issued | shares			1,766,899	1,766,899
Share price | € / shares				€ 100.02
Janssen | Collaboration and license agreement
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	6,600
Upfront payments	6,000
Research and development service fees (FTE)	600
Deferred revenue - current	44,500
Deferred revenue - non-current	236,900
Revenue recognition of deferred income	€ 281,400
Increase in research and development service fees				€ 8,800

Other operating income (Details

Other operating income (Details) - EUR (€) € in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Other operating income
Grants	€ 1,178	€ 553
Research and development incentives	1,164	503
Payroll tax rebates	5,425	1,532
Total	€ 7,767	€ 2,588

Other operating income - Grants

Other operating income - Grants, Research and development incentives and Payroll tax rebates (Details) € in Thousands	6 Months Ended
	Jun. 30, 2019EUR (€)item	Jun. 30, 2018EUR (€)
Other operating income
Number of conditions related to government grants that are unfulfilled | item	0
Research and development incentive receivables	€ 1,200	€ 500
Minimum refund period of research and development incentive receivables.	5 years	5 years
Payroll tax rebates	€ 5,425	€ 1,532

Segment reporting - Revenue fro

Segment reporting - Revenue from external customers (Details) - EUR (€) € in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Disclosure of geographical areas [line items]
Revenue from external customers	€ 43,532	€ 17,910
Netherlands
Disclosure of geographical areas [line items]
Revenue from external customers		214
Denmark
Disclosure of geographical areas [line items]
Revenue from external customers	128	859
Belgium
Disclosure of geographical areas [line items]
Revenue from external customers	1,498
Switzerland
Disclosure of geographical areas [line items]
Revenue from external customers	15,310	527
Luxembourg
Disclosure of geographical areas [line items]
Revenue from external customers	€ 26,596	€ 16,310

Segment reporting - Information

Segment reporting - Information about major clients (Details) - EUR (€) € in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Disclosure of major customers [line items]
Revenue	€ 43,532	€ 17,910
Largest client
Disclosure of major customers [line items]
Revenue	26,600	16,300
Second largest client
Disclosure of major customers [line items]
Revenue	15,300	900
Third largest client
Disclosure of major customers [line items]
Revenue	€ 1,500	€ 500

Research and development expe_3

Research and development expenses (Details) - EUR (€) € in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Research and development expenses
Personnel expenses	€ 22,887	€ 12,284
External research and development expenses	46,780	17,313
Materials and consumables	878	785
Depreciation and amortisation	932	220
Other expenses	6,827	3,769
Research and development expenses	€ 78,304	€ 34,371

Selling, general and administ_3

Selling, general and administrative expenses (Details) - EUR (€) € in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Selling, general and administrative expenses
Personnel expenses	€ 17,132	€ 8,361
Consulting fees	6,795	1,299
Supervisory board	1,424	477
Office costs	2,111	1,377
Total	€ 27,462	€ 11,514

Financial instruments and fin_3

Financial instruments and financial risk management (Details) € in Thousands	Jun. 30, 2019EUR (€)
Amortised cost | Trade and other payables
Disclosure of financial assets [line items]
Carrying amount	€ 55,068
Amortised cost | Research and development incentive receivables - non-current member
Disclosure of financial assets [line items]
Carrying amount	6,047
Amortised cost | Restricted cash - non-current
Disclosure of financial assets [line items]
Carrying amount	356
Amortised cost | Trade and other receivables
Disclosure of financial assets [line items]
Carrying amount	5,277
Amortised cost | Prepaid expenses
Disclosure of financial assets [line items]
Carrying amount	8,326
Amortised cost | Research and development incentive receivables - current
Disclosure of financial assets [line items]
Carrying amount	301
Amortised cost | Restricted cash - current
Disclosure of financial assets [line items]
Carrying amount	1,692
Amortised cost | Cash and cash equivalents
Disclosure of financial assets [line items]
Carrying amount	167,793
FVTPL | Financial assets - non-current
Disclosure of financial assets [line items]
Carrying amount	1,499
FVTPL | Financial assets-current
Disclosure of financial assets [line items]
Carrying amount	€ 776,490

Financial instruments and fin_4

Financial instruments and financial risk management - Fair value (Details) - EUR (€) € in Thousands	6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Fair value hierarchy
Transfers out of Level 1 to Level 2 assets	€ 0
Transfers out of Level 1 to Level 2 liabilities	0
Transfers out of Level 2 to Level 1 assets	0
Transfers out of Level 2 to Level 1 liabilities	0
Transfer into level 3 assets	0
Transfer out of level 3 assets	0
Transfer into level 3 liabilities	0
Transfer out of level 3 liabilities	0
AgomAb Therapeutics
Fair value hierarchy
Secured Series A Financing		€ 21,000
Level 1
Fair value hierarchy
Current financial assets	776,490		€ 283,529
Assets carried at fair value	776,490		283,529
Level 3
Fair value hierarchy
Non-current financial assets	1,499		1
Assets carried at fair value	€ 1,499		€ 1

Other disclosures - Commitments

Other disclosures - Commitments (Details) € in Millions	1 Months Ended	6 Months Ended
	Dec. 31, 2018EUR (€)	Jun. 30, 2019EUR (€)EquityInstruments
Commitments [Line Items]
Number of options granted | EquityInstruments		423,487
Outstanding commitment		€ 40.7
ARGX-110
Commitments [Line Items]
Contractual obligations		8.4
ARGX-117
Commitments [Line Items]
Contractual obligations		3.1
Lonza Sales AG
Commitments [Line Items]
Contractual obligations	€ 25.3
Contractual period	5 years
Minimum
Commitments [Line Items]
Estimated exposure of stock option		3.7
Maximum
Commitments [Line Items]
Estimated exposure of stock option		€ 3.9

Other disclosures - Overview of

Other disclosures - Overview of Subsidiaries and Subsequent Events (Details) € in Thousands	Sep. 18, 2018shares	Jun. 30, 2019subsidiaryshares	Dec. 31, 2018EUR (€)
Subsequent Events
Future lease commitments | €			€ 3,004
New shares issued for private placement, initial public offering, public offering and underwriters' over-allotment option | shares	3,475,000	38,107,527
Netherlands
Overview of consolidation scope
Participation ( as a percent)		100.00%
ARGENX BVBA | Belgium
Overview of consolidation scope
Number of subsidiaries		2
Participation ( as a percent)		100.00%
ARGENX US INC | United States
Overview of consolidation scope
Number of subsidiaries		1
Participation ( as a percent)		100.00%

Events after the balance shee_2

Events after the balance sheet date (Details) $ in Millions	Jul. 17, 2019USD ($)
Halozyme | Global Collaboration and License Agreement
Disclosure of non-adjusting events after reporting period [line items]
Milestone payments	$ 5