ADC Therapeutics (ADCT) 10-Q 6 May 24 2024 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2024	May 01, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-39071
Entity Registrant Name	ADC Therapeutics SA
Entity Incorporation, State or Country Code	V8
Entity Address, Address Line One	Biopôle
Entity Address, Address Line Two	Route de la Corniche 3B
Entity Address, Postal Zip Code	1066
Entity Address, City or Town	Epalinges
Entity Address, Country	CH
Country Region	41
City Area Code	21 653
Local Phone Number	02 00
Title of 12(g) Security	Common Shares, par value CHF 0.08 per share
Trading Symbol	ADCT
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		82,814,000
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001771910
Current Fiscal Year End Date	--12-31

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets
Cash and cash equivalents	$ 234,285	$ 278,598
Accounts receivable, net	23,186	25,182
Inventory	15,997	16,177
Prepaid expenses and other current assets	16,738	16,334
Total current assets	290,206	336,291
Property and equipment, net	5,785	5,622
Operating lease right-of-use assets	10,059	10,511
Interest in joint venture	930	1,647
Other long-term assets	986	711
Total assets	307,966	354,782
Current liabilities
Accounts payable	14,315	15,569
Accrued expenses and other current liabilities	48,670	52,101
Total current liabilities	62,985	67,670
Deferred royalty obligation	310,010	303,572
Senior secured term loans	113,234	112,730
Operating lease liabilities, long-term	9,662	10,180
Other long-term liabilities	6,524	8,879
Total liabilities	502,415	503,031
Commitments and contingencies (See Note 13)
Shareholders’ equity
Common shares, at CHF 0.08 par value	7,312	7,312
Additional paid-in capital	1,181,020	1,180,545
Treasury shares	(502)	(541)
Accumulated other comprehensive loss	(201)	(93)
Accumulated deficit	(1,382,078)	(1,335,472)
Total shareholders’ (deficit) equity	(194,449)	(148,249)
Total liabilities and shareholders’ equity	$ 307,966	$ 354,782

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - SFr / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Common shares, par value (in CHF per share)	SFr 0.08	SFr 0.08
Common shares issued (in shares)	89,041,946	89,041,946
Common shares outstanding (in shares)	82,777,226	82,293,137
Treasury shares (in shares)	6,264,720	6,748,809

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATION - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue
Product revenues, net	$ 17,848	$ 18,953
License revenues and royalties	205	39
Total revenue, net	18,053	18,992
Operating expense
Cost of product sales	(2,510)	27
Research and development	(25,735)	(38,375)
Selling and marketing	(11,390)	(15,351)
General and administrative	(12,031)	(15,503)
Total operating expense	(51,666)	(69,202)
Loss from operations	(33,613)	(50,210)
Other income (expense)
Interest income	2,948	2,175
Interest expense	(12,496)	(10,291)
Other, net	(2,595)	833
Total other expense	(12,143)	(7,283)
Loss before income taxes	(45,756)	(57,493)
Income tax expense	(163)	(518)
Loss before equity in net losses of joint venture	(45,919)	(58,011)
Equity in net losses of joint venture	(687)	(1,363)
Net loss	$ (46,606)	$ (59,374)
Net loss per share
Net loss per share, basic (in dollars per share)	$ (0.56)	$ (0.73)
Net loss per share, diluted (in dollars per share)	$ (0.56)	$ (0.73)
Weighted average shares outstanding, basic (in shares)	82,552,322	80,805,770
Weighted average shares outstanding, diluted (in shares)	82,552,322	80,805,770

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (46,606)	$ (59,374)
Other comprehensive (loss) income:
Remeasurement of defined benefit plan	0	(39)
Foreign currency translation adjustment	(78)	141
Other comprehensive (loss) income before share of other comprehensive loss in joint venture	(78)	102
Share of other comprehensive loss in joint venture	(30)	(256)
Other comprehensive loss	(108)	(154)
Total comprehensive loss	$ (46,714)	$ (59,528)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS’ EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Treasury stock	Accumulated other comprehensive (loss) income	Accumulated deficit
Beginning balance (in shares) at Dec. 31, 2022		89,041,946
Beginning balance at Dec. 31, 2022	$ 79,451	$ 7,312	$ 1,166,414	$ (679)	$ 1,823	$ (1,095,419)
Treasury stock, beginning balance (in shares) at Dec. 31, 2022				(8,399,419)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(59,374)					(59,374)
Remeasurement of defined benefit plan	(39)				(39)
Foreign currency translation adjustment	141				141
Other comprehensive (loss) income before share of other comprehensive loss in joint venture	102				102
Share of other comprehensive loss in joint venture	(256)				(256)
Other comprehensive loss	(154)				(154)	0
Total comprehensive loss	(59,528)				(154)	(59,374)
Vestings of RSUs	0		(23)	$ 23
Vestings of RSUs (in shares)				254,891
Issuance of shares, 2022 Employee Stock Purchase Plan	425		414	$ 11
Issuance of shares, 2022 Employee Stock Purchase Plan (in shares)				130,348
Share-based compensation expense	8,074		8,074
Common stock, increase (decrease) (in shares)		0		385,239
Stockholders' equity, excluding OCI, increase (decrease)	8,499	$ 0	8,465	$ 34
Ending balance (in shares) at Mar. 31, 2023		89,041,946
Ending balance at Mar. 31, 2023	28,422	$ 7,312	1,174,879	$ (645)	1,669	(1,154,793)
Treasury stock, ending balance (in shares) at Mar. 31, 2023				(8,014,180)
Beginning balance (in shares) at Dec. 31, 2022		89,041,946
Beginning balance at Dec. 31, 2022	$ 79,451	$ 7,312	1,166,414	$ (679)	1,823	(1,095,419)
Treasury stock, beginning balance (in shares) at Dec. 31, 2022				(8,399,419)
Ending balance (in shares) at Dec. 31, 2023	82,293,137	89,041,946
Ending balance at Dec. 31, 2023	$ (148,249)	$ 7,312	1,180,545	$ (541)	(93)	(1,335,472)
Treasury stock, ending balance (in shares) at Dec. 31, 2023	(6,748,809)			(6,748,809)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (46,606)					(46,606)
Remeasurement of defined benefit plan	0
Foreign currency translation adjustment	(78)				(78)
Other comprehensive (loss) income before share of other comprehensive loss in joint venture	(78)				(78)
Share of other comprehensive loss in joint venture	(30)				(30)
Other comprehensive loss	(108)				(108)	0
Total comprehensive loss	(46,714)				(108)	(46,606)
Vestings of RSUs	0		(20)	$ 20
Vestings of RSUs (in shares)				248,030
Exercise of options	$ 33		32	$ 1
Exercise of options (in shares)	6,384			6,384
Issuance of shares, 2022 Employee Stock Purchase Plan	$ 323		305	$ 18
Issuance of shares, 2022 Employee Stock Purchase Plan (in shares)				229,675
Share-based compensation expense	158		158
Common stock, increase (decrease) (in shares)		0		484,089
Stockholders' equity, excluding OCI, increase (decrease)	$ 514	$ 0	475	$ 39
Ending balance (in shares) at Mar. 31, 2024	82,777,226	89,041,946
Ending balance at Mar. 31, 2024	$ (194,449)	$ 7,312	$ 1,181,020	$ (502)	$ (201)	$ (1,382,078)
Treasury stock, ending balance (in shares) at Mar. 31, 2024	(6,264,720)			(6,264,720)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash used in operating activities
Net loss	$ (46,606)	$ (59,374)
Adjustments to reconcile net loss to net cash used in operations:
Deferred income taxes	0	(69)
Share-based compensation expense	158	8,074
Accretion expense of deferred royalty obligation	6,864	861
Amortization of debt discount, senior secured term loan	503	830
Cumulative catch-up adjustment, deferred royalty obligation	(263)	(129)
Write-downs of inventory	748	53
Depreciation	331	263
Amortization of operating lease right-of-use assets	512	460
Equity in net losses of joint venture	687	1,363
Warrant obligations, increase (decrease) in fair value	3,068	(616)
Other	(174)	(19)
Changes in operating assets and liabilities:
Accounts receivable, net	1,995	48,901
Inventory	(568)	(348)
Other current assets	(420)	643
Other long-term assets	(281)	0
Accounts payable	(1,247)	(3,663)
Accrued expenses and other short-term liabilities	(3,543)	(12,300)
Operating lease liabilities	(514)	(322)
Other long-term liabilities	(5,345)	0
Net cash used in operating activities	(44,095)	(15,392)
Cash flows from investing activities
Payment for purchases of property and equipment	(531)	(1,016)
Net cash used in investing activities	(531)	(1,016)
Cash flows provided by financing activities
Proceeds from share issuance under stock purchase plan	323	425
Proceeds from the exercise of stock options	33	0
Net cash provided by financing activities	356	425
Net decrease in cash and cash equivalents	(44,270)	(15,983)
Exchange gains/(losses) on cash and cash equivalents	(43)	89
Cash and cash equivalents at beginning of period	278,598	326,441
Cash and cash equivalents at end of period	234,285	310,547
Supplemental Cash Flow Information:
Interest paid	3,900	3,714
Interest received	4,382	2,795
Payments made under royalty financing transaction	1,229	4,885
Supplemental Non-Cash Investing Activities:
Capital expenditures recorded in Accounts payable and Accrued expenses and other current liabilities	$ 9	$ 411

Description of Business and Org

Description of Business and Organization	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Organization	Description of Business and Organization ADC Therapeutics is a leading, commercial-stage global pioneer in the field of antibody drug conjugates (“ADCs”) committed to advancing its proprietary ADC technology platform to transform the treatment paradigm for patients with hematologic malignancies and solid tumors. Since its inception, the Company has devoted its resources to developing a validated and differentiated technology platform with multiple payloads and targets, a robust next-generation research and development toolbox, and specialized end-to-end capabilities. The Company generates sales from its flagship product, ZYNLONTA, which is currently approved in the U.S. for the treatment of relapsed or refractory diffuse large B-cell lymphoma (“DLBCL”) in the third-line setting and has also been granted conditional marketing authorization in Europe. Additionally, the Company is seeking to expand ZYNLONTA into earlier lines of therapy and indolent lymphomas, and is committed to advancing its portfolio and pipeline through its continued research, development, regulatory and commercialization activities. The Company was incorporated on June 6, 2011 under the laws of Switzerland, with its registered office located at Route de la Corniche 3B, 1066 Epalinges, Switzerland. The Company has three wholly-owned subsidiaries: ADC Therapeutics America, Inc. (“ADCT America”), which is incorporated in Delaware, USA on December 10, 2014. ADC Therapeutics (UK) Ltd (“ADCT UK”), incorporated in England on December 12, 2014 and ADC Therapeutics (NL) B.V. which was incorporated in the Netherlands on February 25, 2022. The Company and its three subsidiaries form the ADCT Group (the “Group”). All references to “ADC Therapeutics,” “the Company", “we,” “us,” and “our” refer to ADC Therapeutics SA and its unaudited condensed consolidated subsidiaries unless otherwise indicated.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of preparation and principles of consolidation These accompanying unaudited condensed consolidated financial statements, which include the accounts of the Company and its wholly-owned subsidiaries, have been prepared following the requirements of the U.S. Securities and Exchange Commission for interim reporting. As permitted under those rules, certain footnotes and other financial information that are normally required by U.S. generally accepted accounting principles, or U.S. GAAP, can be condensed or omitted. All intercompany transactions and balances have been eliminated in consolidation. The information included in this Quarterly Report on Form 10‑Q should be read in conjunction with our annual audited consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10‑K for the year ended December 31, 2023. In the opinion of management, these condensed consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements and include all adjustments, consisting only of normal recurring adjustments, considered necessary for the fair statement of our financial position and operating results. The results for the three months ended March 31, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024, for any other interim period or for any future period. The Company’s significant accounting policies have not changed substantially from those previously described in the Company’s Annual Report on Form 10‑K for the year ended December 31, 2023. The Company is managed and operated as one business segment, focused on the global development and commercialization of targeted ADC cancer therapies. A single management team that reports to the chief operating decision-maker, the Chief Executive Officer, comprehensively manages and allocates resources at the global corporate level. Accordingly, the Company views its business and manages its operations as a single operating segment. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosures in the unaudited condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and on assumptions believed to be reasonable under the circumstances. Actual results could differ materially from those estimates. Going Concern We are responsible for evaluating, and providing disclosure of uncertainties about, our ability to continue as a going concern. As of March 31, 2024, we had cash and cash equivalents of $234.3 million. Based on our evaluation, we concluded there is no substantial doubt about our ability to continue as a going concern within one year from the date the unaudited condensed consolidated financial statements were issued. Recent Accounting Pronouncements New accounting pronouncements which have been adopted There are no accounting pronouncements that the Company has recently adopted. Issued but not yet adopted In November 2023, the FASB amended guidance in ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. The revised guidance requires that a public entity disclose significant segment expenses regularly reviewed by the chief operating decision maker (CODM), including public entities with a single reportable segment. The amended guidance is effective for fiscal years beginning in January 2024 and interim periods beginning January 2025 on a retrospective basis. Early adoption is permitted. The Company is currently evaluating the effect that adoption of ASU 2023-07 will have on its consolidated financial statements. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. The ASU requires the annual financial statements to include consistent categories and greater disaggregation of information in the rate reconciliation, and income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for the Company’s annual reporting periods beginning in January 2025. Adoption is either with a prospective method or a fully retrospective method of transition. Early adoption is permitted. The Company is currently evaluating the effect that adoption of ASU 2023-09 will have on its consolidated financial statements.

Fair value measurements

Fair value measurements	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements The carrying amount of Cash and cash equivalents, Accounts Receivable, net and Accounts payable is a reasonable approximation of fair value due to the short-term nature of these assets and liabilities. Financial liabilities that are not measured at fair value on a recurring basis include our senior secured term loan. The estimated fair value of debt is based on Level 2 inputs, including our understanding of current market rates we could obtain for similar loans. The Deerfield warrants, which are measured at fair value on a recurring basis, were as follows as of March 31, 2024 and December 31, 2023: (in thousands) Total Quoted prices in active markets for identical assets and liabilities (Level 1) Other observable inputs (Level 2) Significant unobservable inputs (Level 3) March 31, 2024: Deerfield warrant obligation $ 3,364 $ — $ 3,364 $ — Total $ 3,364 $ — $ 3,364 $ — (in thousands) Total Quoted prices in active markets for identical assets and liabilities (Level 1) Other observable inputs (Level 2) Significant unobservable inputs (Level 3) December 31, 2023: Deerfield warrant obligation $ 296 $ — $ 296 $ — Total $ 296 $ — $ 296 $ — Fair values must be estimated at the end of each reporting period with regard to the Deerfield warrants. The approach to valuation follows the fair value principle, and the key input factors are described for the Deerfield warrants in note 10, "Deerfield warrants." A Black-Scholes model was used to calculate the fair values. There were no transfers between the respective levels during the period.

Inventory

Inventory	3 Months Ended
	Mar. 31, 2024
Inventory Disclosure [Abstract]
Inventory	Inventory As of March 31, 2024 and December 31, 2023 inventory consisted of the following: (in thousands) March 31, 2024 December 31, 2023 Work in progress $ 15,944 $ 16,095 Finished goods 53 82 Total inventory, net $ 15,997 $ 16,177

Property and equipment

Property and equipment	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Property and equipment	Property and equipment Property and equipment as of March 31, 2024 and December 31, 2023 consisted of the following: (in thousands) March 31, 2024 December 31, 2023 Leasehold improvements $ 3,940 $ 3,953 Laboratory equipment 4,131 3,652 Office equipment 1,122 1,119 Hardware and computer software 1,172 1,173 10,365 9,897 Less: accumulated depreciation (4,580) (4,275) Property and equipment, net $ 5,785 $ 5,622 Depreciation expense for the three months ended March 31, 2024 and 2023 was $331 and $263, respectively.

Interest in joint ventures

Interest in joint ventures	3 Months Ended
	Mar. 31, 2024
Equity Method Investments and Joint Ventures [Abstract]
Interest in joint ventures	Interest in joint venture On December 14, 2020, the Company formed a new joint venture company, Overland ADCT BioPharma, with Overland Pharmaceuticals (“Overland”) to develop and commercialize ZYNLONTA, and three of the Company’s ADC product candidates, ADCT-601, ADCT-602 and ADCT-901 (collectively, the “Licensed Products”), in greater China and Singapore (the “Territory”). The table below provides a rollforward of the Company’s interest in Overland ADCT BioPharma as of March 31, 2024 and December 31, 2023. (in thousands) Interest in joint venture January 1, 2023 $ 7,613 Share of comprehensive loss in joint venture (5,966) December 31, 2023 $ 1,647 Share of comprehensive loss in joint venture (717) March 31, 2024 $ 930

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income taxes

Accrued expenses and other curr

Accrued expenses and other current liabilities	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued expenses and other current liabilities	Accrued expenses and other current liabilities Accrued expenses and other current liabilities consist of the following: (in thousands) March 31, 2024 December 31, 2023 Accrued R&D costs $ 20,709 $ 24,902 Accrued payroll and benefits 6,029 12,693 GTN sales adjustments 8,804 1,543 Operating lease liabilities, short-term 1,432 1,467 Other 11,696 11,496 $ 48,670 $ 52,101

Senior secured term loan facili

Senior secured term loan facility	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Senior secured term loan facility	Senior secured term loan facility On August 15, 2022, the Company, ADCT UK and ADCT America entered into the Loan Agreement, pursuant to which the Company may borrow up to $175.0 million principal amount of secured term loans, including (i) a First Tranche and (ii) Future Tranches. On August 15, 2022, the Company drew down $120.0 million principal amount of term loans under the Loan Agreement. On August 15, 2022, the Company also issued to the lenders under the Loan Agreement warrants to purchase an aggregate of 527,295 common shares, which warrants have an exercise price of $8.30 per share. Each warrant is exercisable, on a cash or a cashless basis, at the option of the holder at any time on or prior to August 15, 2032. The warrants are freestanding financial instruments that are indexed to the Company’s common stock and meet all other conditions for equity classification under ASC 480 and ASC 815. Accordingly, these warrants are recognized in equity and accounted for as a component of additional paid-in capital at the time of issuance. On August 15, 2022, the Company also entered into the Share Purchase Agreement with the lenders under the Loan Agreement to purchase 733,568 common shares of the Company. For the three months ended March 31, 2024 and 2023, the Company recorded interest expense on the senior secured term loan in the amount of $4,403 and $4,540, respectively, which was recorded in interest expense in the unaudited condensed consolidated statement of operations. The EIR at March 31, 2024 was 16.81%. The following table provides a summary of the interest expense for the Company’s senior secured term loan for the three months ended March 31, 2024 and 2023: Three months ended March 31, 2024 2023 Contractual interest expense $ 3,900 $ 3,710 Amortization of debt discount 503 830 Total $ 4,403 $ 4,540 The amount at which the senior secured term loan is presented as a liability in the unaudited condensed consolidated balance sheet represents the net present value of all future cash outflows associated with the loan discounted at the EIR. The carrying value of the senior secured term loan is $113.2 million and $112.7 million as of March 31, 2024 and December 31, 2023, respectively. Contractual payments due under our senior secured term loans, including exit fees are as follows (in thousands): 2024 (remainder) $ — 2025 — 2026 3,090 2027 9,330 2028 12,480 Thereafter 99,840 Total $ 124,740

Deerfield warrants

Deerfield warrants	3 Months Ended
	Mar. 31, 2024
Other Liabilities Disclosure [Abstract]
Deerfield warrants	Deerfield warrants Pursuant to the Exchange Agreement with Deerfield entered into on August 15, 2022, the Company issued warrants to purchase an aggregate of 4,412,840 common shares. The warrants consist of warrants to purchase an aggregate of 2,631,578 common shares at an exercise price of $24.70 per share and warrants to purchase an aggregate of 1,781,262 common shares at an exercise price of $28.07 per share. Each warrant is exercisable, on a cash or a cashless basis, at the option of the holder, at any time on or prior to May 19, 2025. The warrant obligation is remeasured to fair value at the end of each reporting period. Changes in the fair value (gains or losses) of the warrant obligation at the end of each period are recorded in the unaudited condensed consolidated statement of operations. During the three months ended March 31, 2024 and 2023, the Company recognized (expense) income of $(3,068) and $616, respectively, as a result of changes in the fair value of the warrant obligation. The fair value of the warrant obligation as of March 31, 2024 and December 31, 2023 was $3,364 and $296, respectively. The increase in fair value of the warrant obligation from December 31, 2023 to March 31, 2024 was primarily due to the increase in the fair value of the underlying shares during the respective period. This amount was recorded to Other, net in the unaudited condensed consolidated statement of operations. See note 15, "Other income (expense)" for further information. The Company used a third party valuation firm to assist in calculating the fair value of the Deerfield warrant obligation, using the Black-Scholes option-pricing model. Key inputs for the valuation of the warrant obligation as of March 31, 2024 and December 31, 2023 were as follows: As of As of March 31, 2024 December 31, 2023 Exercise price in $ 24.70 and 28.07 24.70 and 28.07 Share price in $ 4.49 1.66 Risk-free interest rate 5.0 % 4.6 % Expected volatility 136.2 % 116.0 % Expected term (months) 13.7 months 16.7 months Dividend yield — — Black-Scholes value in $ 0.80 and 0.71 0.07 and 0.06

Deferred royalty obligation

Deferred royalty obligation	3 Months Ended
	Mar. 31, 2024
Other Liabilities Disclosure [Abstract]
Deferred royalty obligation	Deferred royalty obligation On August 25, 2021, the Company entered into a royalty purchase agreement with certain entities managed by HCR for up to $325.0 million. Under the terms of the agreement, the Company received gross proceeds of $225.0 million upon closing (the “First Investment Amount”) and received an additional $75.0 million during the year ended December 31, 2023 upon the first commercial sale of ZYNLONTA in the United Kingdom or any European Union country (the “Second Investment Amount”) and together with the First Investment Amount, the “Investment Amount”). The table below provides a rollforward of the Company’s debt obligation relating to the royalty purchase agreement. (in thousands) Liability balance at January 1, 2023 $ 222,277 Plus: Additional proceeds from the sale of future royalties 75,000 Less: Transaction costs 1,898 Less: royalty payments 8,709 Plus: interest expense 27,915 Less: cumulative catch-up adjustment, Other, net 4,972 Liability balance at December 31, 2023 309,613 Less: royalty payments 1,229 Plus: interest expense 8,093 Less: cumulative catch-up adjustment, Other, net 263 Liability balance at March 31, 2024 $ 316,214

Pension obligations

Pension obligations	3 Months Ended
	Mar. 31, 2024
Retirement Benefits [Abstract]
Pension obligations	Pension and post-retirement benefit obligations The pension plan for Swiss employees is a defined benefit pension plan. The Company contracted with the Swiss Life Collective BVG Foundation based in Zurich for the provision of occupational benefits. All benefits in accordance with the regulations are reinsured in their entirety with Swiss Life SA within the framework of the corresponding contract. This pension solution fully reinsures the risks of disability, death and longevity with Swiss Life. Swiss Life invests the vested pension capital and provides a 100% capital and interest guarantee. The pension plan is entitled to an annual bonus from Swiss Life comprising the effective savings, risk and cost results. Although, as is the case with many Swiss pension plans, the amount of ultimate pension benefit is not defined, certain legal obligations of the plan create constructive obligations on the employer to pay further contributions to fund an eventual deficit; this results in the plan nevertheless being accounted for as a defined benefit plan. The net periodic benefit cost for the three months ended March 31, 2024 and 2023 is as follows: (in thousands) 2024 2023 Net periodic benefit cost: Service cost $ 164 $ 172 Interest cost 38 74 Expected return on plan assets (59) (82) Amortization of prior service cost (41) (39) Net periodic benefit cost $ 102 $ 125 The components of net periodic benefit cost are included in operating expense on the unaudited condensed consolidated statement of operation.

Commitment and contingencies

Commitment and contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies Manufacturing Commitments Some of our inventory components require long lead times to manufacture. Therefore, we make long-term investments in our supply chain in order to ensure we have enough drug product to meet current and future revenue forecasts. Third party manufacturing agreements include non-cancelable obligations related to the supply of ZYNLONTA and the company’s product candidates. There have been no material changes related to our non-cancelable obligations under these arrangements as disclosed in our Annual Report on Form 10-K for the year ended December 31, 2023. Contingent liabilities From time to time, we may be involved in various legal matters generally incidental to our business. Although the results of litigation and claims cannot be predicted with certainty, after discussion with legal counsel, we are not aware

Revenue

Revenue	3 Months Ended
	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The table below provides a disaggregation of revenues by type and customer location for the three months ended March 31, 2024 and 2023: (in thousands) 2024 2023 Types of goods and services Product revenue, net $ 17,848 $ 18,953 Royalties 205 39 Total revenue $ 18,053 $ 18,992 Customer Location U.S. $ 17,848 $ 18,953 EMEA (1) 205 39 Total revenue $ 18,053 $ 18,992 (1) Europe, the Middle East and Africa Product revenue, net The table below provides a rollforward of the Company’s accruals related to the GTN sales adjustments for the three months ended March 31, 2024 and 2023. (in thousands) Discarded Drug Rebate Other Adjustments Total Balance as of January 1, 2023 $ — $ 3,746 $ 3,746 GTN accruals for current period 1,316 4,300 5,616 Prior period adjustments — (648) (648) Credits, payments and reclassifications — (4,352) (4,352) Balance as of March 31, 2023 $ 1,316 $ 3,046 $ 4,362 Balance as of January 1, 2024 $ 7,391 $ 3,946 $ 11,337 GTN accruals for current period 2,046 4,458 6,504 Prior period adjustments (44) (229) (273) Credits, payments and reclassifications — (4,407) (4,407) Balance as of March 31, 2024 $ 9,393 $ 3,768 $ 13,161 The table below provides the classification of the accruals related to the GTN sales adjustment included in the Company’s unaudited condensed consolidated balance sheet as of March 31, 2024 and December 31, 2023. (in thousands) March 31, 2024 December 31, 2023 Accounts receivable, net $ 2,310 $ 2,403 Other current and non-current liabilities 10,851 8,934 $ 13,161 $ 11,337 Customers from which we derive more than 10% of our total product revenues for the three months ended March 31, 2024 and 2023 are as follows: 2024 2023 McKesson 43.0 % 39.0 % AmerisourceBergen Corporation 38.0 % 36.0 % Cardinal Health 19.0 % 25.0 %

Other income (expense)

Other income (expense)	3 Months Ended
	Mar. 31, 2024
Other Income and Expenses [Abstract]
Other income (expense)	Other income (expense) Interest Income Interest income includes interest received from banks on our cash balances. Interest income was $2.9 million and $2.2 million for the three months ended March 31, 2024 and 2023, respectively. Interest Expense The components of Interest expense for the three months ended March 31, 2024 and 2023 are as follows: (in thousands) 2024 2023 Deferred royalty obligation interest expense $ 8,093 $ 5,746 Effective interest expense on senior secured term loan facility 4,403 4,540 Other interest expense — 5 Interest expense $ 12,496 $ 10,291 Other, net The components of Other, net for the three months ended March 31, 2024 and 2023 are as follows: (in thousands) 2024 2023 Deerfield warrant obligation, change in fair value (expense) income $ (3,068) $ 616 Cumulative catch-up adjustment, deferred royalty obligation 263 129 Exchange differences loss (37) (52) R&D tax credit 247 140 Other, net $ (2,595) $ 833

Share-based compensation

Share-based compensation	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Share-based compensation	Share-based compensation The Company has adopted various share-based compensation incentive plans. Under these plans the Company may at its discretion grant to the plan participants, such as directors, certain employees, and service providers awards in the form of restricted shares and restricted share units (“RSUs”), share options, share appreciation rights, performance awards and other share-based awards. The 2019 Equity Incentive Plan was adopted in November 2019 while the Conditional Share Capital Plan and the Inducement Plan were adopted in December 2023. 2019 Equity Incentive Plan In November 2019, the Company adopted the 2019 Equity Incentive Plan. Under the 2019 Equity Incentive Plan, the Company may at its discretion grant to plan participants, such as directors, certain employees and service providers, awards in the form of restricted shares and RSUs, share options, share appreciation rights, performance awards and other share-based awards. The Company has reserved 17,741,355 common shares for future issuance under the 2019 Equity Incentive Plan (including share-based equity awards granted to date less awards forfeited). As of March 31, 2024, the Company has 4,076,361 common shares available for the future issuance of share-based equity awards. As of March 31, 2024 and December 31, 2023, the cumulative amount recorded as a net increase to additional paid-in capital within equity on the unaudited condensed consolidated balance sheet in respect of the 2019 Equity Incentive Plan was $156,925 and $157,906, respectively. The amounts of expense (reversal) recognized for all awards for services received during the three months ended March 31, 2024 and 2023 were $(981) and $7,977, respectively. Conditional Share Capital Plan In December 2023, the Company adopted the Conditional Share Capital Plan. Under the Conditional Share Capital Plan, the Company may at its discretion grant to plan participants, such as directors, certain employees and service providers, awards in the form of restricted shares and RSUs, share options, share appreciation rights, performance awards and other share-based awards. The Company has reserved 8,000,000 common shares for future issuance under this plan. As of March 31, 2024, the Company has 2,614,409 common shares available for the future issuance of share-based equity awards. As of March 31, 2024, the cumulative amount recorded as a net increase to additional paid-in capital within equity on the unaudited condensed consolidated balance sheet in respect of the Conditional Share Capital Plan was $1,382. The amounts of expense for all awards recognized for services received during the three months ended March 31, 2024 was $1,063. Inducement Plan In December 2023, the Company adopted the Inducement Plan. Under the Inducement Plan, the Company may at its discretion grant to any employee who is eligible to receive an employment inducement grant in accordance with NYSE Listed Company Manual 303A.08. The maximum number of common shares in respect of which awards may be granted under the Inducement Plan is 1,000,000 common shares (including share-based equity awards granted to date, less awards forfeited), subject to adjustment in the event of certain corporate transactions or events if necessary to prevent dilution or enlargement of the benefits made available under the plan. Equity incentive awards under the Inducement Plan may be granted in the form of options, share appreciation rights, restricted shares, restricted share units, performance awards or other share-based awards but not “incentive stock options” for purposes of U.S. tax laws. There have been no awards issued in connection with the Inducement Plan for the three months ended March 31, 2024. Share Options Pursuant to the 2019 Equity Incentive Plan, the Company may grant share options to its directors, certain employees and service providers working for the benefit of the Company at the time. The exercise price per share option is set by the Company at the fair market value of the underlying common shares on the date of grant, as determined by the Company, which is generally the closing share price of the Company’s common shares traded on the NYSE. The awards generally vest 25% on the first anniversary of the date of grant, and thereafter evenly on a monthly basis over the subsequent three years. The contractual term of each share option award granted is ten years. Under the grant, the options may be settled only in common shares of the Company. Therefore, the grants of share options under the 2019 Equity Incentive Plan have been accounted for as equity-settled under US GAAP. As such, the Company records a charge for the vested portion of award grants and for partially earned but non-vested portions of award grants. This results in a front-loaded charge to the Company’s unaudited condensed consolidated statement of operation and a corresponding increase to additional paid-in capital within equity on the unaudited condensed consolidated balance sheet. The expense (reversal) recognized for services received during the three months ended March 31, 2024 and 2023 is $(1,434) and $4,781, respectively. Movements in the number of awards outstanding under the Plans described above and their related weighted average strike prices are as follows: Weighted average strike price per share (in $ per share) Number of awards Weighted average remaining life in years Aggregate Intrinsic Value (in $ thousands) Outstanding as of December 31, 2023 $11.00 10,744,406 8.14 $ — Granted 3.41 154,200 Forfeited 12.67 (277,331) Expired 15.01 (7,886) Exercised 5.00 (6,384) Outstanding as of March 31, 2024 $11.21 10,607,005 7.33 $ — As of March 31, 2024, 5,046,977 awards are vested and exercisable out of the total outstanding awards of 10,607,005 common shares. As of March 31, 2024, the weighted average strike price and weighted average remaining life for vested and exercisable awards is $18.64 and 6.00 years, respectively. Awards outstanding as of March 31, 2024 have expiration dates through 2034. The weighted average grant date fair value of the awards granted during the three months ended March 31, 2024 was $2.68. The aggregate intrinsic value of vested and exercisable options was zero. As of March 31, 2024, the unrecognized compensation cost related to 5,560,028 unvested share options expected to vest was $11.1 million. This unrecognized cost will be recognized over an estimated weighted-average amortization period of 1.55. The fair values of the options granted under the Equity Incentive Plan 2019 were determined on the date of the grant using the Black-Scholes option-pricing model. The Company used a third-party valuation firm to assist in calculating the fair value of the award grants per participant. The fair values of the options granted during the three months ended March 31, 2024 and 2023 were determined on the date of grant using the following assumptions: For the Three Months Ended March 31, 2024 2023 Share price, in $ 1.69-4.86 1.99-5.45 Strike price, in $ 1.69-4.86 1.99-5.45 Expected volatility, in % 95 75-80 Award life, in years 6.08 6.08 Expected dividends — — Risk-free interest rate, in % 3.75-4.10 3.39-4.13 During the three months ended March 31, 2023, the expected volatility was based on the Company’s historical volatility and selected volatility determined by median values observed among other comparable public companies. Beginning in the third quarter of 2023, the Company’s expected volatility is no longer determined by values observed among other comparable companies and is now based on the Company’s historical volatility. The award life for options granted was based on the time interval between the date of grant and the date during the ten-year life after which, when making the grant, the Company expected on average that participants would exercise their options. RSUs Pursuant to the 2019 Equity Incentive Plan and Conditional Share Capital Plan, the Company may grant RSUs to its directors, certain employees and service providers working for the benefit of the Company at the time. The awards generally vest annually over a period of two March 31, 2024 and 2023 is $1,516 and $3,196, respectively. Number of awards Weighted average grant date fair value (in $ per share) December 31, 2023 6,533,843 $2.03 Vested (248,030) 12.06 Forfeited (279,422) 3.31 March 31, 2024 (1) 6,006,391 $1.55 (1) Includes 5,385,591 RSUs outstanding in connection with the Conditional Share Capital Pan. The total fair value of RSU awards vested (as measured on the date of vesting) during the three months ended March 31, 2024 was $1.3 million. Employee Stock Purchase Plan In June 2022, the Company adopted the 2022 Employee Stock Purchase Plan (“ESPP”), which allows eligible employees to purchase designated shares of the Company's common shares at a discount, over a series of offering periods through accumulated payroll deductions. The Company offers the ESPP to employees twice a year with each having a six-month offering period. The first offering period is generally from January 1st through June 30th and the second offering period is from July 1st through December 31st. The grant date is the first day of each offering period.

Loss per share

Loss per share	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Loss per share	Loss per share The basic loss per share is calculated by dividing the net loss attributable to shareholders by the weighted average number of shares in issue during the period, excluding common shares owned by the Company and held as treasury shares, as follows: For the Three Months Ended March 31, (in thousands, except per share amounts) 2024 2023 Net loss $ (46,606) $ (59,374) Weighted average number of shares outstanding 82,552,322 80,805,770 Basic and diluted loss per share $ (0.56) $ (0.73) For the three months ended March 31, 2024 and 2023, basic and diluted loss per share are calculated on the weighted average number of shares issued and outstanding and exclude shares to be issued under the Equity Incentive Plan 2019, Conditional Share Capital Plan, the Company’s warrant agreements and 2022 ESPP as the effect of including those shares would be anti-dilutive. See note 9, “Senior secured term loan facility,” note 10, “Deerfield warrants” and note 16, “Share-based compensation expense,” for further information. Potentially dilutive securities that were not included in the diluted per share calculations because the effect of including them would be anti-dilutive were as follows: For the Three Months Ended March 31, 2024 2023 2019 Equity Incentive Plan - Share Options 10,607,005 13,118,656 2019 Equity Incentive Plan - RSUs 620,800 2,110,222 Conditional Share Capital Plan - RSUs 5,385,591 — Outstanding warrants 4,940,135 4,940,135 21,553,531 20,169,013

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net loss	$ (46,606)	$ (59,374)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of preparation and principles of consolidation	Basis of preparation and principles of consolidation These accompanying unaudited condensed consolidated financial statements, which include the accounts of the Company and its wholly-owned subsidiaries, have been prepared following the requirements of the U.S. Securities and Exchange Commission for interim reporting. As permitted under those rules, certain footnotes and other financial information that are normally required by U.S. generally accepted accounting principles, or U.S. GAAP, can be condensed or omitted. All intercompany transactions and balances have been eliminated in consolidation. The information included in this Quarterly Report on Form 10‑Q should be read in conjunction with our annual audited consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10‑K for the year ended December 31, 2023. In the opinion of management, these condensed consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements and include all adjustments, consisting only of normal recurring adjustments, considered necessary for the fair statement of our financial position and operating results. The results for the three months ended March 31, 2024 are not necessarily indicative of the results to be expected for the year ending December 31, 2024, for any other interim period or for any future period. The Company’s significant accounting policies have not changed substantially from those previously described in the Company’s Annual Report on Form 10‑K for the year ended December 31, 2023.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosures in the unaudited condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and on assumptions believed to be reasonable under the circumstances. Actual results could differ materially from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements New accounting pronouncements which have been adopted There are no accounting pronouncements that the Company has recently adopted. Issued but not yet adopted In November 2023, the FASB amended guidance in ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. The revised guidance requires that a public entity disclose significant segment expenses regularly reviewed by the chief operating decision maker (CODM), including public entities with a single reportable segment. The amended guidance is effective for fiscal years beginning in January 2024 and interim periods beginning January 2025 on a retrospective basis. Early adoption is permitted. The Company is currently evaluating the effect that adoption of ASU 2023-07 will have on its consolidated financial statements. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. The ASU requires the annual financial statements to include consistent categories and greater disaggregation of information in the rate reconciliation, and income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for the Company’s annual reporting periods beginning in January 2025. Adoption is either with a prospective method or a fully retrospective method of transition. Early adoption is permitted. The Company is currently evaluating the effect that adoption of ASU 2023-09 will have on its consolidated financial statements.

Fair value measurements (Tables

Fair value measurements (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value, Liabilities Measured on Recurring Basis	The Deerfield warrants, which are measured at fair value on a recurring basis, were as follows as of March 31, 2024 and December 31, 2023: (in thousands) Total Quoted prices in active markets for identical assets and liabilities (Level 1) Other observable inputs (Level 2) Significant unobservable inputs (Level 3) March 31, 2024: Deerfield warrant obligation $ 3,364 $ — $ 3,364 $ — Total $ 3,364 $ — $ 3,364 $ — (in thousands) Total Quoted prices in active markets for identical assets and liabilities (Level 1) Other observable inputs (Level 2) Significant unobservable inputs (Level 3) December 31, 2023: Deerfield warrant obligation $ 296 $ — $ 296 $ — Total $ 296 $ — $ 296 $ —

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Mar. 31, 2024
Inventory Disclosure [Abstract]
Schedule of Inventory	As of March 31, 2024 and December 31, 2023 inventory consisted of the following: (in thousands) March 31, 2024 December 31, 2023 Work in progress $ 15,944 $ 16,095 Finished goods 53 82 Total inventory, net $ 15,997 $ 16,177

Property and equipment (Tables)

Property and equipment (Tables)	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property and equipment as of March 31, 2024 and December 31, 2023 consisted of the following: (in thousands) March 31, 2024 December 31, 2023 Leasehold improvements $ 3,940 $ 3,953 Laboratory equipment 4,131 3,652 Office equipment 1,122 1,119 Hardware and computer software 1,172 1,173 10,365 9,897 Less: accumulated depreciation (4,580) (4,275) Property and equipment, net $ 5,785 $ 5,622

Interest in joint ventures (Tab

Interest in joint ventures (Tables)	3 Months Ended
	Mar. 31, 2024
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	The table below provides a rollforward of the Company’s interest in Overland ADCT BioPharma as of March 31, 2024 and December 31, 2023. (in thousands) Interest in joint venture January 1, 2023 $ 7,613 Share of comprehensive loss in joint venture (5,966) December 31, 2023 $ 1,647 Share of comprehensive loss in joint venture (717) March 31, 2024 $ 930

Accrued expenses and other cu_2

Accrued expenses and other current liabilities (Tables)	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following: (in thousands) March 31, 2024 December 31, 2023 Accrued R&D costs $ 20,709 $ 24,902 Accrued payroll and benefits 6,029 12,693 GTN sales adjustments 8,804 1,543 Operating lease liabilities, short-term 1,432 1,467 Other 11,696 11,496 $ 48,670 $ 52,101

Senior secured term loan faci_2

Senior secured term loan facility (Tables)	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Schedule of Long-Term Debt Instruments	The following table provides a summary of the interest expense for the Company’s senior secured term loan for the three months ended March 31, 2024 and 2023: Three months ended March 31, 2024 2023 Contractual interest expense $ 3,900 $ 3,710 Amortization of debt discount 503 830 Total $ 4,403 $ 4,540
Schedule of Maturities of Long-Term Debt	Contractual payments due under our senior secured term loans, including exit fees are as follows (in thousands): 2024 (remainder) $ — 2025 — 2026 3,090 2027 9,330 2028 12,480 Thereafter 99,840 Total $ 124,740

Deerfield warrants (Tables)

Deerfield warrants (Tables)	3 Months Ended
	Mar. 31, 2024
Other Liabilities Disclosure [Abstract]
Fair Value Measurement Inputs and Valuation Techniques	Key inputs for the valuation of the warrant obligation as of March 31, 2024 and December 31, 2023 were as follows: As of As of March 31, 2024 December 31, 2023 Exercise price in $ 24.70 and 28.07 24.70 and 28.07 Share price in $ 4.49 1.66 Risk-free interest rate 5.0 % 4.6 % Expected volatility 136.2 % 116.0 % Expected term (months) 13.7 months 16.7 months Dividend yield — — Black-Scholes value in $ 0.80 and 0.71 0.07 and 0.06

Deferred royalty obligation (Ta

Deferred royalty obligation (Tables)	3 Months Ended
	Mar. 31, 2024
Other Liabilities Disclosure [Abstract]
Schedule Of Royalty Purchase Obligation	The table below provides a rollforward of the Company’s debt obligation relating to the royalty purchase agreement. (in thousands) Liability balance at January 1, 2023 $ 222,277 Plus: Additional proceeds from the sale of future royalties 75,000 Less: Transaction costs 1,898 Less: royalty payments 8,709 Plus: interest expense 27,915 Less: cumulative catch-up adjustment, Other, net 4,972 Liability balance at December 31, 2023 309,613 Less: royalty payments 1,229 Plus: interest expense 8,093 Less: cumulative catch-up adjustment, Other, net 263 Liability balance at March 31, 2024 $ 316,214

Pension obligations (Tables)

Pension obligations (Tables)	3 Months Ended
	Mar. 31, 2024
Retirement Benefits [Abstract]
Schedule of Net Benefit Costs	The net periodic benefit cost for the three months ended March 31, 2024 and 2023 is as follows: (in thousands) 2024 2023 Net periodic benefit cost: Service cost $ 164 $ 172 Interest cost 38 74 Expected return on plan assets (59) (82) Amortization of prior service cost (41) (39) Net periodic benefit cost $ 102 $ 125

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The table below provides a disaggregation of revenues by type and customer location for the three months ended March 31, 2024 and 2023: (in thousands) 2024 2023 Types of goods and services Product revenue, net $ 17,848 $ 18,953 Royalties 205 39 Total revenue $ 18,053 $ 18,992 Customer Location U.S. $ 17,848 $ 18,953 EMEA (1) 205 39 Total revenue $ 18,053 $ 18,992 (1) Europe, the Middle East and Africa The table below provides a rollforward of the Company’s accruals related to the GTN sales adjustments for the three months ended March 31, 2024 and 2023. (in thousands) Discarded Drug Rebate Other Adjustments Total Balance as of January 1, 2023 $ — $ 3,746 $ 3,746 GTN accruals for current period 1,316 4,300 5,616 Prior period adjustments — (648) (648) Credits, payments and reclassifications — (4,352) (4,352) Balance as of March 31, 2023 $ 1,316 $ 3,046 $ 4,362 Balance as of January 1, 2024 $ 7,391 $ 3,946 $ 11,337 GTN accruals for current period 2,046 4,458 6,504 Prior period adjustments (44) (229) (273) Credits, payments and reclassifications — (4,407) (4,407) Balance as of March 31, 2024 $ 9,393 $ 3,768 $ 13,161 The table below provides the classification of the accruals related to the GTN sales adjustment included in the Company’s unaudited condensed consolidated balance sheet as of March 31, 2024 and December 31, 2023. (in thousands) March 31, 2024 December 31, 2023 Accounts receivable, net $ 2,310 $ 2,403 Other current and non-current liabilities 10,851 8,934 $ 13,161 $ 11,337
Schedule of Product Revenue by Customer	Customers from which we derive more than 10% of our total product revenues for the three months ended March 31, 2024 and 2023 are as follows: 2024 2023 McKesson 43.0 % 39.0 % AmerisourceBergen Corporation 38.0 % 36.0 % Cardinal Health 19.0 % 25.0 %

Other income (expense) (Tables)

Other income (expense) (Tables)	3 Months Ended
	Mar. 31, 2024
Other Income and Expenses [Abstract]
Schedule of Interest Expense	Interest Expense The components of Interest expense for the three months ended March 31, 2024 and 2023 are as follows: (in thousands) 2024 2023 Deferred royalty obligation interest expense $ 8,093 $ 5,746 Effective interest expense on senior secured term loan facility 4,403 4,540 Other interest expense — 5 Interest expense $ 12,496 $ 10,291
Schedule of Other, Net	The components of Other, net for the three months ended March 31, 2024 and 2023 are as follows: (in thousands) 2024 2023 Deerfield warrant obligation, change in fair value (expense) income $ (3,068) $ 616 Cumulative catch-up adjustment, deferred royalty obligation 263 129 Exchange differences loss (37) (52) R&D tax credit 247 140 Other, net $ (2,595) $ 833

Share-based compensation (Table

Share-based compensation (Tables)	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Share-Based Payment Arrangement, Option, Activity	Movements in the number of awards outstanding under the Plans described above and their related weighted average strike prices are as follows: Weighted average strike price per share (in $ per share) Number of awards Weighted average remaining life in years Aggregate Intrinsic Value (in $ thousands) Outstanding as of December 31, 2023 $11.00 10,744,406 8.14 $ — Granted 3.41 154,200 Forfeited 12.67 (277,331) Expired 15.01 (7,886) Exercised 5.00 (6,384) Outstanding as of March 31, 2024 $11.21 10,607,005 7.33 $ —
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions	The fair values of the options granted during the three months ended March 31, 2024 and 2023 were determined on the date of grant using the following assumptions: For the Three Months Ended March 31, 2024 2023 Share price, in $ 1.69-4.86 1.99-5.45 Strike price, in $ 1.69-4.86 1.99-5.45 Expected volatility, in % 95 75-80 Award life, in years 6.08 6.08 Expected dividends — — Risk-free interest rate, in % 3.75-4.10 3.39-4.13
Share-Based Payment Arrangement, Restricted Stock Unit, Activity	Number of awards Weighted average grant date fair value (in $ per share) December 31, 2023 6,533,843 $2.03 Vested (248,030) 12.06 Forfeited (279,422) 3.31 March 31, 2024 (1) 6,006,391 $1.55 (1) Includes 5,385,591 RSUs outstanding in connection with the Conditional Share Capital Pan.

Loss per share (Tables)

Loss per share (Tables)	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Schedule of Loss per Share	The basic loss per share is calculated by dividing the net loss attributable to shareholders by the weighted average number of shares in issue during the period, excluding common shares owned by the Company and held as treasury shares, as follows: For the Three Months Ended March 31, (in thousands, except per share amounts) 2024 2023 Net loss $ (46,606) $ (59,374) Weighted average number of shares outstanding 82,552,322 80,805,770 Basic and diluted loss per share $ (0.56) $ (0.73)
Schedule of Potentially Dilutive Securities Excluded from Earnings Per Share Calculation	Potentially dilutive securities that were not included in the diluted per share calculations because the effect of including them would be anti-dilutive were as follows: For the Three Months Ended March 31, 2024 2023 2019 Equity Incentive Plan - Share Options 10,607,005 13,118,656 2019 Equity Incentive Plan - RSUs 620,800 2,110,222 Conditional Share Capital Plan - RSUs 5,385,591 — Outstanding warrants 4,940,135 4,940,135 21,553,531 20,169,013

Description of Business and O_2

Description of Business and Organization - Narrative (Details)	3 Months Ended
	Mar. 31, 2024 subsidiary
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of subsidiaries	3

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accounting Policies [Abstract]
Cash and cash equivalents	$ 234,285	$ 278,598

Fair value measurements (Detail

Fair value measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deerfield warrant obligation	$ 3,364	$ 296
Total	3,364	296
Quoted prices in active markets for identical assets and liabilities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deerfield warrant obligation	0	0
Total	0	0
Other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deerfield warrant obligation	3,364	296
Total	3,364	296
Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deerfield warrant obligation	0	0
Total	$ 0	$ 0

Inventory - Schedule of Invento

Inventory - Schedule of Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Work in progress	$ 15,944	$ 16,095
Finished goods	53	82
Inventory	$ 15,997	$ 16,177

Inventory - Narrative (Details)

Inventory - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Inventory Disclosure [Abstract]
Write-downs of inventory	$ 748	$ 53

Property and equipment - Schedu

Property and equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Property and equipment	$ 10,365	$ 9,897
Less: accumulated depreciation	(4,580)	(4,275)
Property and equipment, net	5,785	5,622
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	3,940	3,953
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment	4,131	3,652
Office equipment
Property, Plant and Equipment [Line Items]
Property and equipment	1,122	1,119
Hardware and computer software
Property, Plant and Equipment [Line Items]
Property and equipment	$ 1,172	$ 1,173

Property and equipment - Narrat

Property and equipment - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Depreciation	$ 331	$ 263

Interest in joint ventures - Sc

Interest in joint ventures - Schedule of Joint Venture Investment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Equity Method Investments And Joint Ventures [Roll Forward]
Beginning balance	$ 1,647
Equity in net losses of joint venture	(687)	$ (1,363)
Ending balance	930
Overland ADCT BioPharma (CY) Limited
Equity Method Investments And Joint Ventures [Roll Forward]
Beginning balance	1,647	7,613
Equity in net losses of joint venture	(717)	$ (5,966)
Ending balance	$ 930

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Income tax expense	$ 163	$ 518
Loss before income taxes	$ 45,756	$ 57,493

Accrued expenses and other cu_3

Accrued expenses and other current liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued R&D costs	$ 20,709	$ 24,902
Accrued payroll and benefits	6,029	12,693
GTN sales adjustments	8,804	1,543
Operating lease liabilities, short-term	1,432	1,467
Other	11,696	11,496
Accrued expenses and other current liabilities	$ 48,670	$ 52,101

Senior secured term loan faci_3

Senior secured term loan facility - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Aug. 15, 2022	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Debt Instrument [Line Items]
Issuance of shares (in shares)	733,568
Senior secured term loans		$ 113,234		$ 112,730
Loan Agreement Warrants
Debt Instrument [Line Items]
Securities called by warrant (in shares)	527,295
Warrant exercise price (in dollars per share)	$ 8.30
Loan Agreement
Debt Instrument [Line Items]
Interest expense on debt		4,403	$ 4,540
Line of Credit | Loan Agreement | Secured Debt
Debt Instrument [Line Items]
Face amount	$ 175,000
Long-term debt	$ 120,000
Interest expense on debt		$ 4,403	$ 4,540
Debt effective interest rate		16.81%

Senior secured term loan faci_4

Senior secured term loan facility - Schedule of Interest Expense (Details) - Loan Agreement - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Debt Instrument [Line Items]
Total	$ 4,403	$ 4,540
Line of Credit | Secured Debt
Debt Instrument [Line Items]
Contractual interest expense	3,900	3,710
Amortization of debt discount	503	830
Total	$ 4,403	$ 4,540

Senior secured term loan faci_5

Senior secured term loan facility - Schedule of Maturities (Details) - Loan Agreement $ in Thousands	Mar. 31, 2024 USD ($)
Debt Instrument [Line Items]
2024 (remainder)	$ 0
2025	0
2026	3,090
2027	9,330
2028	12,480
Thereafter	99,840
Total	$ 124,740

Deerfield warrants - Narrative

Deerfield warrants - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Aug. 15, 2022	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Class of Warrant or Right [Line Items]
Deerfield warrant obligation, change in fair value (expense) income		$ (3,068)	$ 616
Deerfield warrant obligation		3,364		$ 296
Deerfield Warrants
Class of Warrant or Right [Line Items]
Debt conversion, warrants issued (in shares)	4,412,840
Deerfield warrant obligation, change in fair value (expense) income		(3,068)	$ 616
Deerfield warrant obligation		$ 296		$ 3,364
Warrants, Tranche One | Deerfield Warrants
Class of Warrant or Right [Line Items]
Debt conversion, warrants issued (in shares)	2,631,578
Warrant exercise price (in dollars per share)	$ 24.70
Warrants, Tranche Two | Deerfield Warrants
Class of Warrant or Right [Line Items]
Debt conversion, warrants issued (in shares)	1,781,262
Warrant exercise price (in dollars per share)	$ 28.07

Deerfield warrants - Schedule o

Deerfield warrants - Schedule of Fair Value Inputs (Details) - Deerfield Warrants	Dec. 31, 2024	Mar. 31, 2024 $ / shares	Dec. 31, 2023 $ / shares
Share price in $
Class of Warrant or Right [Line Items]
Warrants, measurement input		4.49	1.66
Risk-free interest rate
Class of Warrant or Right [Line Items]
Warrants, measurement input		0.050	0.046
Expected volatility
Class of Warrant or Right [Line Items]
Warrants, measurement input		1.362	1.160
Expected term (months)
Class of Warrant or Right [Line Items]
Warrants, term	16 months 22 days		28 months 22 days
Dividend yield
Class of Warrant or Right [Line Items]
Warrants, measurement input		0	0
Minimum | Exercise price in $
Class of Warrant or Right [Line Items]
Warrants, measurement input		24.70	24.70
Minimum | Black-Scholes value in $
Class of Warrant or Right [Line Items]
Warrants, measurement input		0.80	0.07
Maximum | Exercise price in $
Class of Warrant or Right [Line Items]
Warrants, measurement input		28.07	28.07
Maximum | Black-Scholes value in $
Class of Warrant or Right [Line Items]
Warrants, measurement input		0.71	0.06

Deferred royalty obligation - N

Deferred royalty obligation - Narrative (Details) - USD ($) $ in Millions		12 Months Ended
	Aug. 25, 2021	Dec. 31, 2023
Other Liabilities Disclosure [Abstract]
Royalty purchase agreement	$ 325
Proceeds from royalties	$ 225	$ 75

Deferred royalty obligation - S

Deferred royalty obligation - Schedule of Royalty Obligation (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Deferred Royalty Obligation [Roll Forward]
Beginning balance	$ 309,613	$ 222,277
Plus: Additional proceeds from the sale of future royalties		75,000
Less: Transaction costs		1,898
Less: royalty payments	1,229	8,709
Plus: interest expense	8,093	27,915
Less: cumulative catch-up adjustment, Other, net	263	4,972
Ending balance	$ 316,214	$ 309,613

Pension obligations - Narrative

Pension obligations - Narrative (Details)	3 Months Ended
	Mar. 31, 2024
Retirement Benefits [Abstract]
Capital and interest guarantee	100%

Pension obligations - Schedule

Pension obligations - Schedule of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Retirement Benefits [Abstract]
Service cost	$ 164	$ 172
Interest cost	38	74
Expected return on plan assets	(59)	(82)
Amortization of prior service cost	(41)	(39)
Net periodic benefit cost	$ 102	$ 125

Revenue - Schedule of Disaggreg

Revenue - Schedule of Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 18,053	$ 18,992
U.S.
Disaggregation of Revenue [Line Items]
Revenues	17,848	18,953
EMEA
Disaggregation of Revenue [Line Items]
Revenues	205	39
Product
Disaggregation of Revenue [Line Items]
Revenues	17,848	18,953
Royalties
Disaggregation of Revenue [Line Items]
Revenues	$ 205	$ 39

Revenue - Schedule of GTN Produ

Revenue - Schedule of GTN Product Revenue, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Gross To Net Sales Adjustment Rollforward [Roll Forward]
Balance as of January 1, 2023	$ 11,337	$ 3,746
GTN accruals for current period	6,504	5,616
Prior period adjustments	(273)	(648)
Credits, payments and reclassifications	(4,407)	(4,352)
Balance as of March 31, 2023	13,161	4,362
Gross To Net Sales Adjustment [Abstract]
Accounts receivable, net	2,310		$ 2,403
Other current and non-current liabilities	10,851		8,934
Gross to net sales adjustment	13,161	4,362	11,337
Discarded Drug Rebate
Gross To Net Sales Adjustment Rollforward [Roll Forward]
Balance as of January 1, 2023	7,391	0
GTN accruals for current period	2,046	1,316
Prior period adjustments	(44)	0
Credits, payments and reclassifications	0	0
Balance as of March 31, 2023	9,393	1,316
Gross To Net Sales Adjustment [Abstract]
Gross to net sales adjustment	9,393	1,316	7,391
Other Adjustments
Gross To Net Sales Adjustment Rollforward [Roll Forward]
Balance as of January 1, 2023	3,946	3,746
GTN accruals for current period	4,458	4,300
Prior period adjustments	(229)	(648)
Credits, payments and reclassifications	(4,407)	(4,352)
Balance as of March 31, 2023	3,768	3,046
Gross To Net Sales Adjustment [Abstract]
Gross to net sales adjustment	$ 3,768	$ 3,046	$ 3,946

Revenue - Schedule of Concentra

Revenue - Schedule of Concentration Risk by Customer (Details) - Revenue Benchmark - Customer Concentration Risk	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
McKesson
Disaggregation of Revenue [Line Items]
Concentration risk percentage	43%	39%
AmerisourceBergen Corporation
Disaggregation of Revenue [Line Items]
Concentration risk percentage	38%	36%
Cardinal Health
Disaggregation of Revenue [Line Items]
Concentration risk percentage	19%	25%

Other income (expense) - Narrat

Other income (expense) - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Other Income and Expenses [Abstract]
Interest income	$ 2.9	$ 2.2

Other income (expense) - Schedu

Other income (expense) - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Debt Instrument [Line Items]
Deferred royalty obligation interest expense	$ 8,093	$ 5,746
Other interest expense	0	5
Interest expense	12,496	10,291
Loan Agreement
Debt Instrument [Line Items]
Interest expense on debt	$ 4,403	$ 4,540

Other income (expense) - Sche_2

Other income (expense) - Schedule of Other, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Debt Instrument [Line Items]
Deerfield warrant obligation, change in fair value (expense) income	$ 3,068	$ (616)
Cumulative catch-up adjustment, deferred royalty obligation	(263)	(129)
Other	(37)	(52)
R&D tax credit	247	140
Other, net	(2,595)	833
Deerfield Warrants
Debt Instrument [Line Items]
Deerfield warrant obligation, change in fair value (expense) income	$ 3,068	$ (616)

Share-based compensation - Narr

Share-based compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended		12 Months Ended
	Jun. 30, 2022	Nov. 30, 2019	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			$ 158	$ 8,074
Awards vested and exercisable (in shares)			5,046,977
Outstanding (in shares)			10,607,005		10,744,406
Weighted average strike price (in dollars per share)			$ 18.64
Weighted average remaining life			6 years
Weighted average grant date fair value (in dollars per share)			$ 2.68
Nonvested (in shares)			5,560,028
Unrecognized compensation costs			$ 11,100
Share Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized			$ (1,434)	4,781
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25%
Vesting period		3 years
Unrecognized share-based compensation cost, period of recognition			1 year 6 months 18 days
Award life for options granted		10 years
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of shares vested			$ 1,300
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized				97
2019 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for future issuance		17,741,355
Share-based compensation expense			156,925		$ 157,906
Expense recognized			$ (981)	7,977
2019 Equity Incentive Plan | Share Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for future issuance			4,076,361
2019 Equity Incentive Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized			$ 1,516	$ 3,196
2019 Equity Incentive Plan | Restricted Stock Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		2 years
2019 Equity Incentive Plan | Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Conditional Share Capital Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for future issuance		8,000,000	2,614,409
Share-based compensation expense			$ 1,382
Expense recognized			1,063
Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum shares available for grant (in shares)					1,000,000
2022 ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized			$ 76
2022 ESPP | Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Offering period	6 months

Share-based compensation - Sche

Share-based compensation - Schedule of Option Activity (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Weighted average strike price per share (in $ per share)
Beginning balance	$ 11
Granted (in dollars per share)	3.41
Forfeited (in dollars per share)	12.67
Expired (in dollars per share)	15.01
Exercised (in dollars per share)	5
Ending balance	$ 11.21	$ 11
Number of awards
Beginning balance	10,744,406
Granted (in shares)	154,200
Forfeited (in shares)	(277,331)
Expired (in shares)	(7,886)
Exercised (in shares)	(6,384)
Ending balance	10,607,005	10,744,406
Additional Disclosures
Weighted average remaining life in years	7 years 3 months 29 days	8 years 1 month 20 days

Share-based compensation - Sc_2

Share-based compensation - Schedule of Stock Option Valuation Assumptions (Details) - $ / shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Strike price (in dollars per share)	$ 3.41
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award life, in years	6 years 29 days	6 years 29 days
Expected dividends	0%	0%
Risk-free interest rate, in %, minimum	3.75%	3.39%
Risk-free interest rate, in %, maximum	4.10%	4.13%
Employee Stock Option | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in dollars per share)	$ 1.69		$ 1.99
Strike price (in dollars per share)	$ 1.69	$ 1.99
Expected volatility, in %	95%	75%
Employee Stock Option | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in dollars per share)	$ 4.86		$ 5.45
Strike price (in dollars per share)	$ 4.86	$ 5.45
Expected volatility, in %		80%

Share-based compensation - Sc_3

Share-based compensation - Schedule of RSU Activity (Details) - Restricted Stock Units	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Beginning balance (in shares)	6,533,843
Vested (in shares)	(248,030)
Forfeited (in shares)	(279,422)
Ending balance (in shares)	6,006,391
Weighted-Average
Beginning balance (in dollars per share) | $ / shares	$ 2.03
Vested (in dollars per share) | $ / shares	12.06
Forfeited (in dollars per share) | $ / shares	3.31
Ending balance (in dollars per share) | $ / shares	$ 1.55
Conditional Share Capital Plan - RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Ending balance (in shares)	5,385,591

Loss per share (Details)

Loss per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share [Abstract]
Net loss	$ (46,606)	$ (59,374)
Weighted average shares outstanding, diluted (in shares)	82,552,322	80,805,770
Weighted average shares outstanding, basic (in shares)	82,552,322	80,805,770
Net loss per share, diluted (in dollars per share)	$ (0.56)	$ (0.73)
Net loss per share, basic (in dollars per share)	$ (0.56)	$ (0.73)

Loss per share - Schedule of Po

Loss per share - Schedule of Potentially Dilutive Securities Excluded from Earnings Per Share Calculation (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	21,553,531	20,169,013
2019 Equity Incentive Plan | Employee Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	10,607,005	13,118,656
2019 Equity Incentive Plan | Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	620,800	2,110,222
Conditional Share Capital Plan - RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	5,385,591	0
Outstanding warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	4,940,135	4,940,135