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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 10-Q
(Mark One)

☒ | QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
| For the quarterly period ended September 30, 2025
OR
☐ | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
| For the transition period from to

Commission File Number: 001-39071
ADC Therapeutics SA
(Exact name of registrant as specified in its charter)

Switzerland | Not Applicable
(State or other jurisdiction of incorporation or organization) | (I.R.S. Employer Identification No.)
Biopôle Route de la Corniche 3B 1066 Epalinges Switzerland (Address of principal executive offices) (Zip code) | +41 21 653 02 00 (Registrant’s telephone number)

N/A
(Former name or former address, if changed since last report)
Securities registered pursuant to Section 12(b) of the Act:

Title of each class |  | Trading symbol(s) |  | Name of each exchange on which registered
Common Shares, par value CHF 0.08 per share |  | ADCT |  | The New York Stock Exchange

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports) and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐
Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer |  | ☐ |  | Accelerated filer |  | ☐
Non-accelerated filer |  | ☒ |  | Smaller reporting company |  | ☒
|  |  |  | Emerging growth company |  | ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐
Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒
The number of common shares outstanding was 123,877,111 as of October 31, 2025.

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Table of Contents

PART I: FINANCIAL INFORMATION | 1
Condensed Consolidated Balance Sheets (Unaudited) - September 30, 2025 and December 31, 2024 | 1
Condensed Consolidated Statements of Operations (Unaudited) - Three and nine months ended September 30, 2025 and 2024 | 2
Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - Three and nine months ended September 30, 2025 and 2024 | 3
Condensed Consolidated Statements of Changes in Shareholders’ (Deficit) Equity (Unaudited) - Three and nine months ended September 30, 2025 and 2024 | 4
Condensed Consolidated Statements of Cash Flows (Unaudited) - Three and nine months ended September 30, 2025 and 2024 | 6
Notes to the Condensed Consolidated Financial Statements (Unaudited) | 7
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations | 24
Item 3. Quantitative and Qualitative Disclosures About Market Risk | 37
Item 4. Controls and Procedures | 37
PART II: OTHER INFORMATION | 37
Item 1. Legal Proceedings | 37
Item 1A. Risk Factors | 37
Item 2. Unregistered Sales of Equity Securities and Use of Proceeds | 37
Item 3. Defaults Upon Senior Securities | 38
Item 4. Mine Safety Disclosures | 38
Item 5. Other Information | 38
Item 6. Exhibits | 38
Signatures | 39

Unless otherwise indicated or the context otherwise requires, all references in this Annual Report to “ADC Therapeutics,” “ADCT,” the “Company,” “we,” “our,” “ours,” “us” or similar terms refer to ADC Therapeutics SA and its consolidated subsidiaries.

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FORWARD-LOOKING STATEMENTS
This Quarterly Report contains statements that constitute forward-looking statements. All statements other than statements of historical facts contained in this Quarterly Report, including statements regarding our future catalysts, results of operations and financial position, business and commercial strategy, market opportunities, products and product candidates, research pipeline, ongoing and planned preclinical studies and clinical trials, regulatory submissions and approvals, research and development costs, projected revenues and expenses and the timing of revenues and expenses, timing and likelihood of success, as well as plans and objectives of management for future operations are forward-looking statements. Many of the forward-looking statements contained in this Quarterly Report can be identified by the use of forward-looking words such as “anticipate,” “believe,” “could,” “expect,” “should,” “plan,” “intend,” “estimate,” “will” and “potential,” among others.
Forward-looking statements are based on our management’s beliefs and assumptions and on information available to our management at the time such statements are made. Such statements are subject to known and unknown risks and uncertainties, and actual results may differ materially from those expressed or implied in the forward-looking statements due to various factors, including, but not limited to:
•the substantial net losses that we have incurred since our inception, our expectation to continue to incur losses for the foreseeable future and our need to raise additional capital to fund our operations and execute our business plan;
•our ability to raise additional capital to fund our operations and execute our business plan, which will depend on financial, economic and market conditions, the number of authorized shares, and other factors, over which we may have no or limited control;
•our indebtedness under the loan agreement and guaranty (the “Loan Agreement”) with certain affiliates and/or funds managed by each of Oaktree Capital Management, L.P. and Owl Rock Capital Advisors LLC, as lenders, and Blue Owl Opportunistic Master Fund I, L.P., as administrative agent, and the associated restrictive covenants thereunder;
•the purchase and sale agreement (the “HCR Agreement”) with certain entities managed by HealthCare Royalty Management, LLC (“HCR”) and its negative effect on the amount of cash that we are able to generate from sales of, and licensing agreements involving, ZYNLONTA and on our attractiveness as an acquisition target;
•our ability to complete clinical trials on expected timelines, if at all;
•the timing, outcome and results of ongoing or planned clinical trials and the sufficiency of such results;
•undesirable side effects or adverse events of our products and product candidates;
•our and our partners’ ability to obtain and maintain regulatory approval for our product and product candidates;
•our and our partners’ ability to successfully commercialize our products;
•the availability and scope of coverage and reimbursement for our products;
•the complexity and difficulty of manufacturing our products and product candidates;
•the substantial competition in our industry, including new technologies and therapies;
•our ability to continue to fund, or enter into collaborative or partnership arrangements for our early research programs, and the timing, results and future clinical outcomes of such early research programs;
•our reliance on third parties for preclinical studies and clinical trials and for the manufacture, production, storage and distribution of our products and product candidates and certain commercialization activities for our products;
•our ability to obtain, maintain and protect our intellectual property rights and our ability to operate our business without infringing on the intellectual property rights of others;
•our estimates regarding future revenue, expenses, liquidity, capital resources and needs for additional financing;
•the size and growth potential of the markets for our products and product candidates;
•potential product liability lawsuits and product recalls for our products;
•the success of the Company's strategic restructuring plan; the estimated costs associated with the restructuring plan including the workforce reduction and planned closure of the UK facility, or any changes thereto;
•the uncertainties of international trade policies, including tariffs, sanctions and trade barriers and potential impact they may have on our business, financial condition, and results of operations;
•and those identified in the “Item 1A. Risk Factors” of this quarterly report on Form 10-Q and in our Annual Report on Form 10-K, and in our other reports filed with the U.S. Securities and Exchange Commission (the “SEC”), from time to time thereafter.
Because forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified and some of which are beyond our control, you should not rely on these forward-looking statements as predictions of future events. Moreover, we operate in an evolving environment. New risk factors and uncertainties may

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emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements, whether as a result of any new information, future events, changed circumstances or otherwise.
In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this Quarterly Report, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

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PART I: FINANCIAL INFORMATION
Item 1. Financial Statements
CONDENSED CONSOLIDATED BALANCE SHEETS
(Unaudited)
(in thousands, except share amounts)

| September 30, 2025 |  | December 31, 2024
ASSETS |  |  |
Current assets |  |  |
Cash and cash equivalents | $ | 234,738 |  |  | $ | 250,867 |
Accounts receivable, net | 22,918 |  |  | 20,316 |
Inventory | 18,042 |  |  | 18,387 |
Prepaid expenses | 5,928 |  |  | 8,370 |
Other current assets | 5,523 |  |  | 9,450 |
Total current assets | 287,149 |  |  | 307,390 |
Property and equipment, net | — |  |  | 5,075 |
Operating lease right-of-use assets | 1,393 |  |  | 8,354 |
Other long-term assets | 1,216 |  |  | 1,161 |
Total assets | $ | 289,758 |  |  | $ | 321,980 |
LIABILITIES AND SHAREHOLDERS’ (DEFICIT) EQUITY |  |  |
Current liabilities |  |  |
Accounts payable | $ | 8,119 |  |  | $ | 18,029 |
Accrued expenses and other current liabilities | 53,925 |  |  | 62,440 |
Total current liabilities | 62,044 |  |  | 80,469 |
Deferred royalty obligation, long-term | 340,170 |  |  | 320,093 |
Senior secured term loans | 115,206 |  |  | 113,632 |
Operating lease liabilities, long-term | 1,127 |  |  | 7,995 |
Other long-term liabilities | 9,394 |  |  | 2,433 |
Total liabilities | 527,941 |  |  | 524,622 |
Commitments and contingencies (See Note 12) |  |  |
Shareholders’ (deficit) equity |  |  |
Common shares, at CHF 0.08 par value | 9,763 |  |  | 8,425 |
Issued shares: 115,187,979 at September 30, 2025 and 101,606,376 December 31, 2024; outstanding shares: 112,626,731 at September 30, 2025 and 98,861,402 at December 31, 2024 |  |  |
Additional paid-in capital | 1,382,493 |  |  | 1,283,892 |
Treasury shares | (205) |  |  | (220) |
At September 30, 2025: 2,561,248 and December 31, 2024: 2,744,974 |  |  |
Accumulated other comprehensive loss | (702) |  |  | (1,421) |
Accumulated deficit | (1,629,532) |  |  | (1,493,318) |
Total shareholders’ (deficit) equity | (238,183) |  |  | (202,642) |
Total liabilities and shareholders’ (deficit) equity | $ | 289,758 |  |  | $ | 321,980 |

The accompanying notes are an integral part of these condensed consolidated financial statements.
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ADC Therapeutics SA

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
(Unaudited)
(in thousands, except share and per share amounts)

|  |  | Three Months Ended September 30, |  | Nine Months Ended September 30,
|  |  | 2025 |  | 2024 |  | 2025 |  | 2024
Revenue |  |  |  |  |  |  |  |  |
Product revenues, net |  |  | $ | 15,750 |  |  | $ | 18,016 |  |  | $ | 51,239 |  |  | $ | 52,894 |
License revenues and royalties |  |  | 677 |  |  | 448 |  |  | 7,060 |  |  | 1,033 |
Total revenue, net |  |  | 16,427 |  |  | 18,464 |  |  | 58,299 |  |  | 53,927 |
Operating expense |  |  |  |  |  |  |  |  |
Cost of product sales |  |  | (1,202) |  |  | (851) |  |  | (4,099) |  |  | (4,578) |
Research and development |  |  | (26,803) |  |  | (32,502) |  |  | (85,821) |  |  | (82,532) |
Selling and marketing |  |  | (10,688) |  |  | (10,673) |  |  | (31,388) |  |  | (32,764) |
General and administrative |  |  | (8,326) |  |  | (10,002) |  |  | (27,103) |  |  | (32,271) |
Restructuring, impairment and other related costs |  |  | (377) |  |  | — |  |  | (13,468) |  |  | — |
Total operating expense |  |  | (47,396) |  |  | (54,028) |  |  | (161,879) |  |  | (152,145) |
Loss from operations |  |  | (30,969) |  |  | (35,564) |  |  | (103,580) |  |  | (98,218) |
Other income (expense) |  |  |  |  |  |  |  |  |
Interest income |  |  | 2,470 |  |  | 3,438 |  |  | 6,458 |  |  | 9,639 |
Interest expense |  |  | (13,392) |  |  | (13,117) |  |  | (38,619) |  |  | (38,292) |
Other, net |  |  | 925 |  |  | 1,624 |  |  | 946 |  |  | 1,783 |
Total other expense, net |  |  | (9,997) |  |  | (8,055) |  |  | (31,215) |  |  | (26,870) |
Loss before income taxes |  |  | (40,966) |  |  | (43,619) |  |  | (134,795) |  |  | (125,088) |
Income tax expense |  |  | — |  |  | (90) |  |  | (1,419) |  |  | (487) |
Loss before equity in net losses of joint venture |  |  | (40,966) |  |  | (43,709) |  |  | (136,214) |  |  | (125,575) |
Equity in net losses of joint venture |  |  | — |  |  | (260) |  |  | — |  |  | (1,544) |
Net loss |  |  | $ | (40,966) |  |  | $ | (43,969) |  |  | $ | (136,214) |  |  | $ | (127,119) |
Net loss per share |  |  |  |  |  |  |  |  |
Net loss per share, basic and diluted |  |  | $ | (0.30) |  |  | $ | (0.42) |  |  | $ | (1.14) |  |  | $ | (1.35) |
Weighted average shares outstanding, basic and diluted |  |  | 136,446,534 |  | 104,824,877 |  | 119,237,877 |  | 94,394,355

The accompanying notes are an integral part of these condensed consolidated financial statements.
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CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
(Unaudited)
(in thousands)

|  |  | Three Months Ended September 30, |  | Nine Months Ended September 30, |  |
|  |  | 2025 |  | 2024 |  | 2025 |  | 2024 |  |
Net loss |  |  | $ | (40,966) |  |  | $ | (43,969) |  |  | $ | (136,214) |  |  | $ | (127,119) |  |  |
Other comprehensive (loss) income: |  |  |  |  |  |  |  |  |  |  |
Remeasurement of defined benefit pension liability |  |  | (47) |  |  | (44) |  |  | (136) |  |  | (125) |  |  |
Foreign currency translation adjustment |  |  | (267) |  |  | 585 |  |  | 855 |  |  | 524 |  |  |
Other comprehensive (loss) income before share of other comprehensive loss in joint venture |  |  | (314) |  |  | 541 |  |  | 719 |  |  | 399 |  |  |
Share of other comprehensive loss in joint venture |  |  | — |  |  | — |  |  | — |  |  | (103) |  |  |
Other comprehensive (loss) income |  |  | (314) |  |  | 541 |  |  | 719 |  |  | 296 |  |  |
Total comprehensive loss |  |  | $ | (41,280) |  |  | $ | (43,428) |  |  | $ | (135,495) |  |  | $ | (126,823) |  |  |

The accompanying notes are an integral part of these condensed consolidated financial statements.
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ADC Therapeutics SA

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS’ (DEFICIT) EQUITY
(Unaudited)
Three and Nine Months Ended September 30, 2025

(in thousands, except share amounts) |  |  | Number of shares |  | Common shares, par value |  | Additional paid-in capital |  | Number of shares (held or received)/delivered |  | Treasury shares |  | Accumulated other comprehensive (loss) income |  | Accumulated deficit |  | Total |
Balance as of June 30, 2025 |  |  | 115,080,481 |  |  | $ | 9,753 |  |  | $ | 1,380,224 |  |  | (2,581,398) |  |  | $ | (207) |  |  | $ | (388) |  |  | $ | (1,588,566) |  |  | $ | (199,184) |  |
Loss for the period |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | (40,966) |  |  | (40,966) |  |
Other comprehensive loss |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | (314) |  |  | — |  |  | (314) |  |
Exercise of stock options |  |  | 107,498 |  |  | 10 |  |  | 270 |  |  | 20,150 |  |  | 2 |  |  | — |  |  | — |  |  | 282 |  |
Share-based compensation expense |  |  | — |  |  | — |  |  | 1,999 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 1,999 |  |
Balance as of September 30, 2025 |  |  | 115,187,979 |  |  | $ | 9,763 |  |  | $ | 1,382,493 |  |  | (2,561,248) |  |  | $ | (205) |  |  | $ | (702) |  |  | $ | (1,629,532) |  |  | $ | (238,183) |  |

(in thousands, except share amounts) |  |  | Number of shares |  | Common shares, par value |  | Additional paid-in capital |  | Number of shares (held or received)/delivered |  | Treasury shares |  | Accumulated other comprehensive (loss) income |  | Accumulated deficit |  | Total |
Balance as of December 31, 2024 |  |  | 101,606,376 |  |  | $ | 8,425 |  |  | $ | 1,283,892 |  |  | (2,744,974) |  |  | $ | (220) |  |  | $ | (1,421) |  |  | $ | (1,493,318) |  |  | $ | (202,642) |  |
Loss for the period |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | (136,214) |  |  | (136,214) |  |
Other comprehensive income |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 719 |  |  | — |  |  | 719 |  |
Vestings of RSUs |  |  | 424,379 |  |  | 41 |  |  | (41) |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |
Exercise of stock options |  |  | 126,063 |  |  | 12 |  |  | 301 |  |  | 20,150 |  |  | 2 |  |  | — |  |  | — |  |  | 315 |  |
Issuance of shares, 2022 Employee Stock Purchase Plan |  |  | — |  |  | — |  |  | 258 |  |  | 163,576 |  |  | 13 |  |  | — |  |  | — |  |  | 271 |  |
Issuance of shares, June 2025 Private Placement, net of transaction costs |  |  | 13,031,161 |  |  | 1,285 |  |  | 41,091 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 42,376 |  |
Issuance of warrants, underwritten offering, net of transaction costs |  |  | — |  |  | — |  |  | 50,760 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 50,760 |  |
Share-based compensation expense |  |  | — |  |  | — |  |  | 6,232 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 6,232 |  |
Balance as of September 30, 2025 |  |  | 115,187,979 |  |  | $ | 9,763 |  |  | $ | 1,382,493 |  |  | (2,561,248) |  |  | $ | (205) |  |  | $ | (702) |  |  | $ | (1,629,532) |  |  | $ | (238,183) |  |

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ADC Therapeutics SA

Three and Nine Months Ended September 30, 2024

(in thousands, except share amounts) |  |  | Number of shares |  | Common shares, par value |  | Additional paid-in capital |  | Number of shares (held or received)/delivered |  | Treasury shares |  | Accumulated other comprehensive (loss) income |  | Accumulated deficit |  | Total |
Balance as of June 30, 2024 |  |  | 99,453,858 |  |  | $ | 8,233 |  |  | $ | 1,279,296 |  |  | (2,984,217) |  |  | $ | (239) |  |  | $ | (338) |  |  | $ | (1,418,622) |  |  | $ | (131,670) |  |
Loss for the period |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | (43,969) |  |  | (43,969) |  |
Other comprehensive income |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 541 |  |  | — |  |  | 541 |  |
Exercise of stock options |  |  | — |  |  | — |  |  | 108 |  |  | 55,834 |  |  | 3 |  |  | — |  |  | — |  |  | 111 |  |
Issuance of shares, 2022 Employee Stock Purchase Plan |  |  | — |  |  | — |  |  | 221 |  |  | 162,510 |  |  | 14 |  |  | — |  |  | — |  |  | 235 |  |
Share-based compensation expense |  |  | — |  |  | — |  |  | 2,806 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 2,806 |  |
Balance as of September 30, 2024 |  |  | 99,453,858 |  |  | $ | 8,233 |  |  | $ | 1,282,431 |  |  | (2,765,873) |  |  | $ | (222) |  |  | $ | 203 |  |  | $ | (1,462,591) |  |  | $ | (171,946) |  |

(in thousands, except share amounts) |  |  | Number of shares |  | Common shares, par value |  | Additional paid-in capital |  | Number of shares (held or received)/delivered |  | Treasury shares |  | Accumulated other comprehensive (loss) income |  | Accumulated deficit |  | Total |
Balance as of December 31, 2023 |  |  | 89,041,946 |  |  | $ | 7,312 |  |  | $ | 1,180,545 |  |  | (6,748,809) |  |  | $ | (541) |  |  | $ | (93) |  |  | $ | (1,335,472) |  |  | $ | (148,249) |  |
Loss for the period |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | (127,119) |  |  | (127,119) |  |
Other comprehensive income |  |  | — |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 296 |  |  | — |  |  | 296 |  |
Vestings of RSUs |  |  | — |  |  | — |  |  | (42) |  |  | 502,929 |  |  | 42 |  |  | — |  |  | — |  |  | — |  |
Exercise of stock options |  |  | — |  |  | — |  |  | 180 |  |  | 87,822 |  |  | 5 |  |  | — |  |  | — |  |  | 185 |  |
Issuance of shares, 2022 Employee Stock Purchase Plan |  |  | — |  |  | — |  |  | 526 |  |  | 392,185 |  |  | 32 |  |  | — |  |  | — |  |  | 558 |  |
Issuance of shares, underwritten offering, net of transaction costs |  |  | 10,411,912 |  |  | 921 |  |  | 59,345 |  |  | 3,000,000 |  |  | 240 |  |  | — |  |  | — |  |  | 60,506 |  |
Issuance of warrants, underwritten offering, net of transaction costs |  |  | — |  |  | — |  |  | 36,925 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 36,925 |  |
Share-based compensation expense |  |  | — |  |  | — |  |  | 4,952 |  |  | — |  |  | — |  |  | — |  |  | — |  |  | 4,952 |  |
Balance as of September 30, 2024 |  |  | 99,453,858 |  |  | $ | 8,233 |  |  | $ | 1,282,431 |  |  | (2,765,873) |  |  | $ | (222) |  |  | $ | 203 |  |  | $ | (1,462,591) |  |  | $ | (171,946) |  |

The accompanying notes are an integral part of these condensed consolidated financial statements.
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ADC Therapeutics SA

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
(Unaudited)
(in thousands)

| Nine Months Ended September 30,
| 2025 |  | 2024
Cash flows used in operating activities |  |  |
Net loss | $ | (136,214) |  |  | $ | (127,119) |
Adjustments to reconcile net loss to net cash used in operations: |  |  |
Share-based compensation expense | 6,232 |  |  | 4,952 |
Accretion expense of deferred royalty obligation | 21,348 |  |  | 20,964 |
Cumulative catch-up adjustment, deferred royalty obligation | (517) |  |  | (732) |
Impairment of long-lived assets and prepaid expenses, and other related costs | 7,240 |  |  | — |
Write-downs of inventory | 1,873 |  |  | 1,036 |
Depreciation | 705 |  |  | 993 |
Amortization of operating lease right-of-use assets | 1,058 |  |  | 1,490 |
Share of results in joint venture | — |  |  | 1,544 |
Amortization of debt discount, senior secured term loan | 1,574 |  |  | 1,459 |
Other | 426 |  |  | (369) |
Changes in operating assets and liabilities: |  |  |
Accounts receivable, net | (2,602) |  |  | 1,058 |
Inventory | (1,528) |  |  | (930) |
Prepaid expenses and other current assets | 5,448 |  |  | (2,055) |
Other long-term assets | (46) |  |  | (457) |
Accounts payable | (9,970) |  |  | (1,217) |
Accrued expenses and other current liabilities | (9,394) |  |  | (165) |
Operating lease liabilities | (1,994) |  |  | (1,499) |
Other long-term liabilities | 6,310 |  |  | (936) |
Net cash used in operating activities | (110,051) |  |  | (101,983) |
Cash flows used in investing activities |  |  |
Payment for purchases of property and equipment | (264) |  |  | (777) |
Net cash used in investing activities | (264) |  |  | (777) |
Cash flows provided by financing activities |  |  |
Proceeds from the sale of common shares, net of transaction costs | 42,760 |  |  | 60,506 |
Proceeds from Pre-Funded Warrants, net of transaction costs | 50,760 |  |  | 36,925 |
Proceeds from share issuance under stock purchase plan | 271 |  |  | 558 |
Proceeds from the exercise of stock options | 315 |  |  | 185 |
Taxes paid related to net settled equity awards | (250) |  |  | — |
Net cash provided by financing activities | 93,856 |  |  | 98,174 |
Net decrease in cash and cash equivalents | (16,459) |  |  | (4,586) |
Exchange gains on cash and cash equivalents | 330 |  |  | 260 |
Cash and cash equivalents at beginning of period | 250,867 |  |  | 278,598 |
Cash and cash equivalents at end of period | $ | 234,738 |  |  | $ | 274,272 |
Supplemental Cash Flow Information: |  |  |
Interest paid | $ | 10,882 |  |  | $ | 11,942 |
Interest received | 6,458 |  |  | 11,074 |
Payments made under royalty financing transaction | 4,816 |  |  | 3,927 |
Supplemental Non-Cash Investing and Financing Activities: |  |  |
Transaction costs recorded in Accounts payable and other current liabilities and Other long-term liabilities | 384 |  |  | — |
Capital expenditures recorded in Accounts payable and other current liabilities | — |  |  | 38 |

The accompanying notes are an integral part of these condensed consolidated financial statements.
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ADC Therapeutics SA
NOTES TO THE CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
(Unaudited)
(in thousands, except per share amounts)

1.Description of Business and Organization
ADC Therapeutics is a commercial-stage global leader and pioneer in the field of antibody drug conjugates (“ADCs”), transforming treatment for patients through our focused portfolio with ZYNLONTA ® (loncastuximab tesirine-lpyl) and an early stage prostate-specific membrane antigen targeting ADC (“PSMA-targeting ADC”).
The Company generates sales from its flagship product, ZYNLONTA, which was granted accelerated approval by the Food and Drug Administration (“FDA”) in the U.S. for the treatment of relapsed or refractory diffuse large B-cell lymphoma (“DLBCL”) in the 3L setting and has also been granted conditional approval from the European Commission, conditional approval from the China National Medical Products Administration and conditional approval by Health Canada. Beyond ZYNLONTA, ADC Therapeutics is leveraging its expertise to advance IND-enabling activities for a next-generation PSMA-targeting ADC which utilizes a differentiated exatecan-based payload with a novel hydrophilic linker.
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 two wholly-owned subsidiaries: ADC Therapeutics America, Inc. (“ADCT America”), which was incorporated in Delaware, USA on December 10, 2014 and ADC Therapeutics (UK) Ltd (“ADCT UK”), incorporated in England on December 12, 2014. The Company and its two 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 consolidated subsidiaries unless otherwise indicated.
2.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, 2024.
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 and nine months ended September 30, 2025 are not necessarily indicative of the results to be expected for the year ending December 31, 2025, 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, 2024.
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 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.
Restructuring Charges
On June 11, 2025, the Board of Directors approved a strategic reprioritization and restructuring plan (the “2025 Restructuring”), pursuant to which the Company is in the process of shutting down its UK facility, and has reduced its
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global workforce across functions by approximately 30%. Restructuring charges consist primarily of employee severance, contract termination costs and other costs. Liabilities for costs associated with a restructuring activity are recognized when the liability is incurred and are measured at fair value. For one-time employee terminations benefits, the Company recognizes the liability in full on the communication date when future services are not required or amortizes the liability ratably over the service period, if required. One-time termination benefits include severance, continuation of health insurance coverage for certain employees, and other company funded benefits. The Company evaluates and adjusts these costs as appropriate for changes in circumstances as additional information becomes available. See Note 15 for additional information regarding restructuring expenses.
Impairment of long-lived assets
The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. If such circumstances are determined to exist, an estimate of undiscounted future cash flows produced by the long-lived asset, including its eventual residual value, is compared to the carrying value to determine whether impairment exists. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written-down to their estimated fair values.
As a result of the 2025 Restructuring, the Company recognized $5.4 million of impairment losses on its long-lived asset group associated with the UK facility during the second quarter of 2025. See Note 15 for further information regarding the restructuring and associated impairment of long-lived assets.
Long-lived assets by geographic area are as follows:

(in thousands) |  |  |  |
Country |  | September 30, 2025 |  | December 31, 2024
Switzerland |  | $ | 1,527 |  |  | $ | 1,460 |
United Kingdom |  | — |  |  | 12,133 |
United States |  | 1,082 |  |  | 997 |
|  | $ | 2,609 |  |  | $ | 14,590 |

Income taxes
On July 4, 2025, the United States Congress passed budget reconciliation bill H.R. 1 referred to as the One Big Beautiful Bill (“OBBB”). The OBBB contains several changes to corporate taxation including modifications to capitalization of research and development expenses, limitations on deductions for interest expense and accelerated fixed asset depreciation. Under the OBBB, U.S. domestic R&D expenditures are now immediately deductible, while foreign R&D expenditures remain subject to capitalization and amortization. The Company has reflected the impact of these provisions in its estimated annual effective tax rate for the third quarter of 2025. Management does not expect the OBBB to have a material effect on the Company’s overall tax position for the current year.
Recent Accounting Pronouncements
Issued but not yet adopted
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. The Company does not anticipate that the adoption of this standard will have a material impact on our financial statements but may result in enhanced or expanded disclosures.
In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses Disclosure. The ASU requires disaggregation, in the notes to the financial statements, of certain cost and expense captions presented on the face of the Company’s interim and annual financial statements. ASU 2023-09 is effective for fiscal years beginning in January 2027 and interim periods beginning January 2028, with early adoption permitted. Adoption may be applied
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prospectively or retrospectively. The Company is currently evaluating the effect that adoption of ASU 2024-03 will have on its consolidated financial statements.
3.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 and deferred royalty financing obligation. The carrying value of our senior secured term loan approximates fair value as these borrowings are based on variable market rates. The carrying value of our deferred royalty obligation approximates fair value as the loan is recorded using the amortized cost method and considers our current estimates of future royalties expected to be paid over the estimated life of the royalty purchase agreement which are level 3 inputs, adjusted for accretion and royalty payments made by the Company during the nine months ended September 30, 2025. The carrying value of the liability is updated periodically for material changes to the expected payments to HCR based on its underlying revenue projection s.
The Deerfield warrants were measured at fair value on a recurring basis and were classified as Level 2. The warrants expired on May 19, 2025 in accordance with their terms and therefore, there were no warrants outstanding as of September 30, 2025. As of December 31, 2024 the value of the Deerfield warrants was $0. Fair values were 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 9, "Deerfield warrants." A Black-Scholes model was used to calculate the fair values.
There were no transfers between the respective levels during the period.
4.Inventory
As of September 30, 2025 and December 31, 2024 inventory consisted of the following:

(in thousands) |  | September 30, 2025 |  | December 31, 2024
Work in progress |  | $ | 17,783 |  |  | $ | 18,338 |
Finished goods |  | 259 |  |  | 49 |
Total inventory, net |  | $ | 18,042 |  |  | $ | 18,387 |

Inventory write-downs of $237 and $1,873 were recognized for the three and nine months ended September 30, 2025, respectively, and nil and $1,036 were recognized for the three and nine months ended September 30, 2024, respectively, and charged to cost of product sales in the Company’s unaudited condensed consolidated statements of operations.
5.Property and equipment
Property and equipment as of September 30, 2025 and December 31, 2024 consisted of the following:

(in thousands) |  | September 30, 2025 |  | December 31, 2024
Leasehold improvements |  | $ | 1,472 |  |  | $ | 3,873 |
Laboratory equipment |  | 2,949 |  |  | 4,415 |
Office equipment |  | 770 |  |  | 970 |
Hardware and computer software |  | 1,144 |  |  | 1,137 |
|  | 6,335 |  |  | 10,395 |
Less: accumulated depreciation |  | (6,335) |  |  | (5,320) |
Property and equipment, net |  | $ | — |  |  | $ | 5,075 |

Depreciation expense was nil and $705 for the three and nine months ended September 30, 2025, respectively, and $336 and $993 for the three and nine months ended September 30, 2024, respectively.
In connection with the 2025 Restructuring, the Company recorded impairment of property and equipment of $5.0 million during the second quarter of 2025,related to leasehold improvements, lab equipment and furniture and fixtures located at the UK facility. See Note 15 for further information regarding the restructuring and associated
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impairment of long-lived assets. There were no impairments of property and equipment recorded during the three and nine months ended September 30, 2024.
6.Leases
The Company leases space for its corporate offices and research and development facilities under non-cancellable operating leases.
As a result of the 2025 Restructuring, and in accordance with the UK facility lease agreement which allows for early termination upon notice and payment of breakage fees, the Company notified the landlord of its intention to terminate the lease. As a result, the associated lease liability and right-of-use asset were remeasured to $1.4 million and $0.4 million, respectively, reflecting the revised lease payments and term end date of January 28, 2026. The remeasurement resulted in a $6.8 million reduction to the lease liability and right-of-use asset as of September 30, 2025.
The remaining right-of-use asset associated with the UK facility was assessed for impairment as part of the overall asset group. See Note 15 for further information regarding the restructuring and associated impairment of long-lived assets.
On May 15, 2025, the Company modified the terms of its existing lease for its office in New Jersey, USA. The existing lease contract was scheduled to expire on June 30, 2025. The Company extended the term of the lease by eighteen months commencing on July 1, 2025 and expiring on December 31, 2026. Accordingly, the Company remeasured its lease liability and adjusted its right-of-use asset based on the revised lease term.
Maturities of lease liabilities are as follows:

Year ending December 31, 2025 |  | $ | 506 |
Year ending December 31, 2026 |  | 582 |
Year ending December 31, 2027 |  | 165 |
Year ending December 31, 2028 |  | 165 |
Year ending December 31, 2029 |  | 165 |
Thereafter |  | 640 |
Total lease payments |  | 2,223 |
Less: imputed interest |  | 163 |
Present value of lease liabilities |  | $ | 2,060 |

Other supplemental information related to leases is summarized below:

|  | September 30, 2025 |  | December 31, 2024 |  |
Weighted average remaining lease term (years) |  | 5.0 |  | 6.3 |  |
Weighted average discount rate |  | 3.7 | % |  | 4.6 | % |  |

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7.Accrued expenses and other current liabilities
Accrued expenses and other current liabilities consist of the following:

(in thousands) |  | September 30, 2025 |  | December 31, 2024
Accrued R&D costs |  | $ | 23,084 |  |  | $ | 20,523 |
Accrued payroll and benefits |  | 8,818 |  |  | 13,600 |
Accrued restructuring costs |  | 3,598 |  |  | — |
Gross-to-net sales adjustments, short-term |  | 7,748 |  |  | 15,697 |
Operating lease liabilities, short-term |  | 933 |  |  | 1,371 |
Other |  | 9,744 |  |  | 11,249 |
|  | $ | 53,925 |  |  | $ | 62,440 |

8.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 and nine months ended September 30, 2025, the Company recorded interest expense on the senior secured term loan in the amount of $4,396 and $12,455, respectively, and $4,585 and $13,401 for the three and nine months ended September 30, 2024, respectively, which was recorded in interest expense in the unaudited condensed consolidated statements of operations. The effective interest rate (“EIR”) at September 30, 2025 was 16.01%.
The following table provides a summary of the interest expense for the Company’s senior secured term loan for the three and nine months ended September 30, 2025 and 2024:

|  | Three Months Ended September 30, |  | Nine Months Ended September 30,
|  | 2025 |  | 2024 |  | 2025 |  | 2024
Contractual interest expense |  | $ | 3,663 |  |  | $ | 4,069 |  |  | $ | 10,881 |  |  | $ | 11,942 |
Amortization of debt discount |  | 733 |  |  | 516 |  |  | 1,574 |  |  | 1,459 |
Total |  | $ | 4,396 |  |  | $ | 4,585 |  |  | $ | 12,455 |  |  | $ | 13,401 |

The amount at which the senior secured term loan is presented as a liability in the unaudited condensed consolidated balance sheets 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 $115.2 million and $113.6 million as of September 30, 2025 and December 31, 2024, respectively.
Contractual payments due under our senior secured term loans, including exit fees are as follows (in thousands):
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2025 (remainder) |  | $ | — |
2026 (commencing third quarter) |  | 3,090 |
2027 |  | 9,330 |
2028 |  | 12,480 |
2029 |  | 99,840 |
Total |  | $ | 124,740 |

9.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 consisted 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 was 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, which was included in other long-term liabilities in the unaudited condensed consolidated balance sheets, was remeasured to fair value at the end of each reporting period. Changes in the fair value losses of the warrant obligation at the end of each period were recorded in the unaudited condensed consolidated statements of operations.
During the three and nine months ended September 30, 2025, the Company did not recognize any expense or income as a result of changes in the fair value of the warrant obligation. For the three and nine months ended September 30, 2024, the Company recognized income of $1.1 million and $0.3 million, respectively. This amount was recorded to Other, net in the unaudited condensed consolidated statements of operations. The warrants expired on May 19, 2025 in accordance with their terms and therefore, there were no warrants outstanding as of September 30, 2025. The fair value of the warrant obligation as of December 31, 2024 was $0. See Note 16, "Other income (expense)" for further information.
The Company valued the Deerfield warrant obligation using a Black-Scholes option-pricing model. Key inputs for the valuation of the warrant obligation as of December 31, 2024 were as follows:

|  |  | As of
|  |  | December 31, 2024
Exercise price in $ |  |  | 24.70 and 28.07
Share price in $ |  |  | 1.99 |
Risk-free interest rate |  |  | 4.3 | %
Expected volatility |  |  | 83.0 | %
Expected term (years) |  |  | 0.4 years
Dividend yield |  |  | — |
Black-Scholes value in $ |  |  | nil and nil

10.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”).
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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, 2024 |  | $ | 309,613 |
Less: royalty payments |  | 5,384 |
Plus: interest expense |  | 33,608 |
Less: cumulative catch-up adjustment, Other, net |  | 11,178 |
Liability balance at December 31, 2024 |  | 326,659 |
Less: royalty payments |  | 4,816 |
Plus: interest expense |  | 26,164 |
Less: cumulative catch-up adjustment, Other, net |  | 517 |
Liability balance at September 30, 2025 |  | $ | 347,490 |

11.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 and nine months ended September 30, 2025 and 2024 is as follows:

|  | Three Months Ended September 30, |  | Nine Months Ended September 30,
(in thousands) |  | 2025 |  | 2024 |  | 2025 |  | 2024
Net periodic benefit cost: |  |  |  |  |  |  |  |
Service cost |  | $ | 208 |  |  | $ | 185 |  |  | $ | 605 |  |  | $ | 532 |
Interest cost |  | 28 |  |  | 40 |  |  | 81 |  |  | 115 |
Expected return on plan assets |  | (72) |  |  | (63) |  |  | (209) |  |  | (181) |
Amortization of prior service cost |  | (47) |  |  | (44) |  |  | (136) |  |  | (125) |
Amortization of actuarial losses |  | 5 |  |  | — |  |  | 15 |  |  | — |
Net periodic benefit cost |  | $ | 122 |  |  | $ | 118 |  |  | $ | 356 |  |  | $ | 341 |

The components of net periodic benefit cost are included in operating expense on the unaudited condensed consolidated statements of operations.
12.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, 2024.
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Contingent liabilities
As a result of the 2025 Restructuring, and in accordance with the UK lease agreement, the Company notified the landlord of its intention to terminate the lease. In accordance with the lease terms, t he landlord may require the Company to return the leased space to its original condition upon termination of the lease agreement, including the removal of the Company’s leasehold improvements. The Company continues to monitor negotiations with the landlord to determine the specific works to be removed, if any, and as of September 30, 2025, amounts are reasonably estimable and a liability of $0.8 million was recorded. See Note 15 for additional information regarding restructuring expenses.
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 of any matters for which the likelihood of a loss is probable and reasonably estimable and which could have a material impact on our consolidated financial condition, liquidity, or results of operations.
13.Shareholders’ equity
June 2025 Private Placement
On June 11, 2025, the Company entered into securities purchase agreements for the sale of its equity securities to certain institutional investors. In the private placement, the Company sold 13,031,161 common shares at $3.53 per share, which was the last reported sale price of the common shares on the New York Stock Exchange on June 11, 2025, and pre-funded warrants (the “June 2025 Pre-Funded Warrants”) to purchase 15,734,267 common shares at $3.43 per pre-funded warrant, which is the price per common share in the private placement minus the exercise price of CHF 0.08 per pre-funded warrant (collectively, the “June 2025 Private Placement”). The private placement closed on June 16, 2025. Gross proceeds from the June 2025 Private Placement were $100.0 million, and, after giving effect to $6.9 million of transaction costs related to the private placement, net proceeds were $93.1 million.
The June 2025 Pre-Funded Warrants are exercisable, on a cash or cashless basis, at the option of the holder after the date of issuance until the tenth anniversary of their original issuance. At any time during the last 90 days of the term, the holder may exchange the June 2025 Pre-Funded Warrant for, and we will issue, a new pre-funded warrant for the number of common shares then remaining under the June 2025 Pre-Funded Warrant. The June 2025 Pre-Funded Warrants have certain limitations on exercise, including (i) any exercise must be for at least 50,000 common shares (or, if less, the remaining common shares available for purchase under the June 2025 Pre-Funded Warrants), (ii) a holder cannot exercise for any amount that would cause such holder’s beneficial ownership of our common shares to exceed 9.99% (or 19.99% with 61-days’ notice to us), and (iii) cashless exercise is not available in certain circumstances as specified in the June 2025 Pre-Funded Warrants. The warrants contain customary anti-dilution adjustments and will entitle holders to receive any dividends or other distributions paid on the underlying common shares prior to their expiration on an as-exercised basis.
Accounting for the June 2025 Private Placement and Pre-funded Warrants
The Company has accounted for the common shares and June 2025 Pre-funded Warrants described above each as freestanding financial instruments.
The common shares for the private placement were issued from the Company’s capital range. The common shares were recorded as $42.4 million to equity for the issuance of the common shares, net of transaction costs accrued and paid, and an increase in cash and cash equivalents.
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, including the warrant holders cannot require “net cash settlement” in a circumstance outside of the Company’s control, and there is sufficient authorized and unissued shares to settle the warrants. Accordingly, these warrants are recognized as $50.8 million in equity and accounted for as a component of additional paid-in capital at the time of issuance, net of transaction costs accrued and paid, and an increase in cash and cash equivalents.
Transaction costs have been allocated to the warrants and the common shares based on the relative fair value method. Transaction costs associated to the warrants and common shares have been deducted from the respective instrument in equity.
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14.Revenue
The table below provides a disaggregation of revenues by type and customer location for the three and nine months ended September 30, 2025 and 2024:

|  | Three Months Ended September 30, |  | Nine Months Ended September 30,
(in thousands) |  | 2025 |  | 2024 |  | 2025 |  | 2024
Types of goods and services |  |  |  |  |  |  |  |
Product revenues, net |  | $ | 15,750 |  |  | $ | 18,016 |  |  | $ | 51,239 |  |  | $ | 52,894 |
License revenues |  | — |  |  | — |  |  | 5,000 |  |  | — |
Royalties |  | 677 |  |  | 448 |  |  | 2,060 |  |  | 1,033 |
Total revenue |  | $ | 16,427 |  |  | $ | 18,464 |  |  | $ | 58,299 |  |  | $ | 53,927 |
Customer Location |  |  |  |  |  |  |  |
U.S. |  | $ | 15,750 |  |  | $ | 18,016 |  |  | $ | 51,239 |  |  | $ | 52,894 |
EMEA(1) |  | 677 |  |  | 448 |  |  | 7,060 |  |  | 1,033 |
Total revenue |  | $ | 16,427 |  |  | $ | 18,464 |  |  | $ | 58,299 |  |  | $ | 53,927 |

(1) Europe, the Middle East and Africa
Product revenues, net
The table below provides a rollforward of the Company’s accruals related to the gross-to-net (“GTN”) sales adjustments for the three and nine months ended September 30, 2025:

(in thousands) |  | Discarded Drug Rebate |  | Other Adjustments |  | Total
Balance as of June 30, 2025 |  | $ | 11,692 |  |  | $ | 2,490 |  |  | $ | 14,182 |
GTN accruals for current period |  | 1,547 |  |  | 3,641 |  |  | 5,188 |
Prior period adjustments |  | (545) |  |  | (235) |  |  | (780) |
Credits, payments and reclassifications |  | — |  |  | (3,810) |  |  | (3,810) |
Balance as of September 30, 2025 |  | $ | 12,694 |  |  | $ | 2,086 |  |  | $ | 14,780 |
Balance as of December 31, 2024 |  | $ | 15,103 |  |  | $ | 2,386 |  |  | $ | 17,489 |
GTN accruals for current period |  | 5,516 |  |  | 11,651 |  |  | 17,167 |
Prior period adjustments |  | (745) |  |  | (808) |  |  | (1,553) |
Credits, payments and reclassifications |  | (7,180) |  |  | (11,143) |  |  | (18,323) |
Balance as of September 30, 2025 |  | $ | 12,694 |  |  | $ | 2,086 |  |  | $ | 14,780 |

The table below provides a rollforward of the Company’s accruals related to the gross-to-net (“GTN”) sales adjustments for the three and nine months ended September 30, 2024:
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(in thousands) |  | Discarded Drug Rebate |  | Other Adjustments |  | Total
Balance as of June 30, 2024 |  | $ | 11,251 |  |  | $ | 3,257 |  |  | $ | 14,508 |
GTN accruals for current period |  | 2,051 |  |  | 4,436 |  |  | 6,487 |
Prior period adjustments |  | — |  |  | (378) |  |  | (378) |
Credits, payments and reclassifications |  | — |  |  | (4,224) |  |  | (4,224) |
Balance as of September 30, 2024 |  | $ | 13,302 |  |  | $ | 3,091 |  |  | $ | 16,393 |
Balance as of December 31, 2023 |  | $ | 7,391 |  |  | $ | 3,946 |  |  | $ | 11,337 |
GTN accruals for current period |  | 5,955 |  |  | 12,653 |  |  | 18,608 |
Prior period adjustments |  | (44) |  |  | (1,398) |  |  | (1,442) |
Credits, payments and reclassifications |  | — |  |  | (12,110) |  |  | (12,110) |
Balance as of September 30, 2024 |  | $ | 13,302 |  |  | $ | 3,091 |  |  | $ | 16,393 |

The table below provides the classification of the accruals related to the GTN sales adjustment included in the Company’s unaudited condensed consolidated balance sheets as of September 30, 2025 and December 31, 2024.

(in thousands) |  | September 30, 2025 |  | December 31, 2024
Accounts receivable, net |  | $ | 1,516 |  |  | $ | 1,792 |
Other current and non-current liabilities |  | 13,264 |  |  | 15,697 |
|  | $ | 14,780 |  |  | $ | 17,489 |

Customers from which we derive more than 10% of our total product revenues for the three and nine months ended September 30, 2025 and 2024 are as follows:

|  | Three Months Ended September 30, |  | Nine Months Ended September 30,
|  | 2025 |  | 2024 |  | 2025 |  | 2024
McKesson |  | 45 | % |  | 39 | % |  | 40 | % |  | 40 | %
AmerisourceBergen Corporation(1) |  | 36 | % |  | 35 | % |  | 39 | % |  | 36 | %
Cardinal Health |  | 19 | % |  | 26 | % |  | 21 | % |  | 24 | %

(1) AmerisourceBergen also operates under the name Cencora.
License revenues
The Company is party to an exclusive license agreement with Sobi for the development and commercialization of ZYNLONTA for all hematologic and solid tumor indications outside of the U.S., greater China, Singapore and Japan. Under the terms of the agreement, the Company is eligible to receive regulatory and net sales-based milestones. In March 2025, the Company recognized $5.0 million in license revenue upon ZYNLONTA’s conditional approval by Health Canada for the treatment of relapsed or refractory DLBCL after two or more lines of systemic therapy. The payment was received in the second quarter of 2025.
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15.Restructuring, impairment and other related costs
On June 11, 2025, the Board of Directors approved a strategic reprioritization and restructuring plan (the “2025 Restructuring”) to focus resources on ZYNLONTA® (loncastuximab tesirine-lpyl) expansion opportunities and the advancement of its PSMA-targeting ADC. The Company is discontinuing early development efforts for the remaining preclinical programs in solid tumors. In connection with the 2025 Restructuring, the Company is in the process of shutting down its UK research and development facility, and has reduced its global workforce across functions by approximately 30%.
In connection with the 2025 Restructuring, the Company reported the following costs in restructuring, impairment and other related costs:

(in thousands) | Three Months Ended September 30, 2025 |  | Nine Months Ended September 30, 2025
Severance and benefit expense (reversal) | $ | (450) |  |  | $ | 6,228 |
Impairment of long-lived assets and prepaid expenses, and other related costs | 827 |  |  | 7,240 |
Total restructuring, impairment and other related costs | $ | 377 |  |  | $ | 13,468 |

Severance and benefit expense
Employees affected by the reduction in force under the 2025 Restructuring are entitled to receive severance payments, continuing healthcare benefits and other employee-related costs. Costs associated with one-time termination benefits were recorded pursuant to ASC 420, while costs associated with ongoing benefit arrangements were recorded pursuant to ASC 712. As a result, the Company recorded $6.2 million to Restructuring, impairment and other related costs in the Company’s unaudited condensed consolidated statements of operations during the nine months ended September 30, 2025, of which $3.4 million was paid as of September 30, 2025. The remaining $2.8 million not paid as of September 30, 2025 was accrued in Accrued expenses and other current liabilities in the Company’s unaudited condensed consolidated balance sheet and the Company expects to pay the remainder of the restructuring costs by the first quarter of 2026.
Impairment of long-lived assets and prepaid expenses and other related costs
As a result of the 2025 Restructuring, the Company recognized impairment losses of $6.4 million during the second quarter of 2025, which included $5.4 million recorded to the long-lived asset group associated with the UK facility and $1.0 million recorded to prepaid expenses in the UK. The long-lived asset group associated with the UK facility lease, included the right-of-use asset, leasehold improvements, lab equipment and furniture and fixtures. The $5.4 million recognized as impairment losses on the long-lived asset group were allocated to the various assets within the long-lived asset group based on their relative carrying values and consisted of $0.4 million recorded to right-of-use asset, $2.7 million recorded to leasehold improvements, $2.1 million recorded to lab equipment and $0.2 million recorded to furniture and fixtures.
Furthermore, as a result of the 2025 Restructuring, and in accordance with the UK facility lease agreement, the Company notified the landlord of its intention to terminate the lease. In accordance with the lease terms, the landlord may require the Company to return the leased space to its original condition upon termination of the lease agreement, including the removal of the Company’s leasehold improvements. The Company is in negotiations with the landlord to determine the specific works to be removed or restored, if any, and for the three and nine months ended September 30, 2025, amounts are reasonably estimable and a liability of $0.8 million was recorded.
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16.Other income (expense)
Interest Expense
The components of Interest expense for the three and nine months ended September 30, 2025 and 2024 are as follows:

|  |  |  |  |  |  |  | Three Months Ended September 30, |  | Nine Months Ended September 30,
(in thousands) |  |  |  |  |  |  |  | 2025 |  | 2024 |  | 2025 |  | 2024
Deferred royalty obligation interest expense |  |  |  |  |  |  |  | $ | 8,996 |  |  | $ | 8,532 |  |  | $ | 26,164 |  |  | $ | 24,891 |
Effective interest expense on senior secured term loan facility |  |  |  |  |  |  |  | 4,396 |  |  | 4,585 |  |  | 12,455 |  |  | 13,401 |
Interest expense |  |  |  |  |  |  |  | $ | 13,392 |  |  | $ | 13,117 |  |  | $ | 38,619 |  |  | $ | 38,292 |

Other, net
The components of Other, net for the three and nine months ended September 30, 2025 and 2024 are as follows:

|  |  |  | Three Months Ended September 30, |  | Nine Months Ended September 30,
(in thousands) |  |  |  | 2025 |  | 2024 |  | 2025 |  | 2024
Deerfield warrant obligation, change in fair value income |  |  |  | $ | — |  |  | $ | 1,130 |  |  | $ | — |  |  | $ | 292 |
Cumulative catch-up adjustment, deferred royalty obligation |  |  |  | 321 |  |  | 206 |  |  | 517 |  |  | 732 |
Exchange differences gain (loss) |  |  |  | 338 |  |  | 21 |  |  | (599) |  |  | (75) |
R&D tax credit gain |  |  |  | 266 |  |  | 267 |  |  | 1,028 |  |  | 834 |
Other, net |  |  |  | $ | 925 |  |  | $ | 1,624 |  |  | $ | 946 |  |  | $ | 1,783 |

17.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 22,591,355 common shares for future issuance under the 2019 Equity Incentive Plan (including share-based equity awards granted to date less awards forfeited). As of September 30, 2025, the Company has 6,975,464 common shares available for the future issuance of share-based equity awards.
As of September 30, 2025 and December 31, 2024, the cumulative amount recorded as a net increase to additional paid-in capital within equity on the unaudited condensed consolidated balance sheets in respect of the 2019 Equity Incentive Plan was $164,690 and $160,945, respectively. The amounts of expense recognized for all awards for services received during the three and nine months ended September 30, 2025 were $1,116 and $3,996, respectively, and $1,541 and $1,408 during the three and nine months ended September 30, 2024, respectively.
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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. On February 13, 2025 the Company issued its 2025 annual equity award under the Conditional Share Capital Plan, which was approved by the Compensation Committee of the Board of Directors and by the Board of Directors for the senior management team, consisted of 5,015,765 RSUs. No share options were issued in connection with this award. As of September 30, 2025, the Company has 1,684,004 common shares available for the future issuance of share-based equity awards.
As of September 30, 2025 and December 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 $4,893 and $2,964. The amounts of expense for all awards recognized for services received during the three and nine months ended September 30, 2025 were $699 and $1,929, respectively, and $970 and $3,008 during the three and nine months ended September 30, 2024, respectively.
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 2,000,000 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. As of September 30, 2025, the Company has 1,087,943 common shares available for the future issuance of share-based equity awards under this plan.
As of September 30, 2025 and December 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 Inducement Plan was $1,111 and $554. The amounts of expense for all awards recognized for services received during the three and nine months ended September 30, 2025 were $184 and $557, respectively, and $232 and $327 during the three and nine months ended September 30, 2024.
Share Options
Pursuant to the 2019 Equity Incentive Plan, the Conditional Share Capital Plan and Inducement Plan (the “Share-based Compensation Plans”), 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 and Inducement 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 statements of operations and a corresponding increase to additional paid-in capital within equity on the unaudited condensed consolidated balance sheets.
The expense recognized for services received during the three and nine months ended September 30, 2025 were $531 and $2,114, respectively, and $1,386 and $641 during the three and nine months ended September 30, 2024, respectively.
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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, 2024 |  | $8.69 |  | 10,697,288 |  |  | 7.56 |  | $ | — |
Granted |  | 2.61 |  | 536,650 |  |  |  |  |
Forfeited |  | 3.53 |  | (422,773) |  |  |  |  |
Expired |  | 17.41 |  | (302,625) |  |  |  |  |
Exercised |  | 2.18 |  | (146,213) |  |  |  |  |
Outstanding as of September 30, 2025 |  | $8.43 |  | 10,362,327 |  |  | 6.88 |  | $ | — |

As of September 30, 2025, 7,003,807 awards are vested and exercisable out of the total outstanding awards of 10,362,327 common shares. As of September 30, 2025, the weighted average strike price and weighted average remaining life for vested and exercisable awards is $10.83 and 6.27 years, respectively. Awards outstanding as of September 30, 2025 have expiration dates through 2035. The weighted average grant date fair value of the awards granted during the nine months ended September 30, 2025 was $2.21. The aggregate intrinsic value of vested and exercisable options was zero. As of September 30, 2025, the unrecognized compensation cost related to 3,358,520 unvested share options expected to vest was $4.3 million. This unrecognized cost will be recognized over an estimated weighted-average amortization period of 1.59 years.
The exercise price of stock options granted is equal to the closing price of the common stock on the date of grant. The fair values of the options granted under the 2019 Equity Incentive Plan and the Inducement Plan were estimated on the date of the grant using the Black-Scholes option-pricing model. Expected volatility is historical volatility of our common stock. 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. The assumptions used were as follows:

|  | Three Months Ended September 30, |  | Nine Months Ended September 30,
|  | 2025 |  | 2024 |  | 2025 |  | 2024
Expected volatility |  | 100% |  | 95% |  | 100 | % |  | 95 | %
Expected life, (years) |  | 6.08 |  | 6.08 |  | 6.08 |  | 6.08
Expected dividend yield |  | — |  |  | — |  |  | — |  |  | — |
Risk-free interest rate |  | 3.87-3.94% |  | 3.63-4.35% |  | 3.87-4.43% |  | 3.63-4.54%

RSUs
Pursuant to the Share-based Compensation Plans, 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 to three years commencing on the first anniversary of the date of grant. The RSUs may be settled only in common shares of the Company. Therefore, the grant of RSUs under both the 2019 Equity Incentive Plan and Conditional Share Capital 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 statements of operations and a corresponding increase to additional paid-in capital within equity on the unaudited condensed consolidated balance sheets. The expense recognized for services received during the three and nine months ended September 30, 2025 is $1,468 and $4,368, respectively, and $1,357 and $4,102 during the three and nine months ended September 30, 2024, respectively. An amount of $250 was withheld for tax withholding obligations during the nine months ended September 30, 2025.
The following table summarizes the RSU awards outstanding as of September 30, 2025:
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| Number of awards |  | Weighted average grant date fair value (in $ per share)
December 31, 2024 | 3,106,310 |  |  | $1.81
Granted | 5,295,765 |  |  | 1.71
Vested (1) | (511,433) |  |  | 5.38
Forfeited | (873,880) |  |  | 1.44
September 30, 2025 | 7,016,762 |  |  | $1.52

(1) Includes 87,054 shares withheld to cover tax withholding obligations in connection with the vesting of RSUs previously granted.
The total fair value of RSU awards vested (as measured on the date of vesting) during the nine months ended September 30, 2025 was $1,364.
18.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:

|  | Three Months Ended September 30, |  | Nine Months Ended September 30, |  |
(in thousands, except share and per share amounts) |  | 2025 |  | 2024 |  | 2025 |  | 2024 |  |
Net loss |  | $ | (40,966) |  |  | $ | (43,969) |  |  | $ | (136,214) |  |  | $ | (127,119) |  |  |
Weighted average number of shares outstanding |  | 136,446,534 |  |  | 104,824,877 |  |  | 119,237,877 |  |  | 94,394,355 |  |  |
Basic and diluted loss per share |  | $ | (0.30) |  |  | $ | (0.42) |  |  | $ | (1.14) |  |  | $ | (1.35) |  |  |

For the three and nine months ended September 30, 2025 and 2024, basic and diluted loss per share are calculated on the weighted average number of shares issued and outstanding and also include the June 2025 Pre-funded warrants issued in connection with the 2024 Equity Offering and the June 2025 Private Placement. The calculation excludes shares to be issued under the Share-based Compensation Plans, the Company’s Deerfield warrants and shares to be issued under the 2022 ESPP as the effect of including those shares would be anti-dilutive. See Note 8, “Senior secured term loan facility,” Note 9, “Deerfield warrants”, and Note 17, “Share-based compensation,” 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:

|  | Nine Months Ended September 30,
|  | 2025 |  | 2024
2019 Equity Incentive Plan - Share Options |  | 9,470,420 |  |  | 9,710,737 |
Inducement Plan - Share Options |  | 891,907 |  |  | 529,700 |
2019 Equity Incentive Plan - RSUs |  | 2,847,534 |  |  | 616,740 |
Conditional Share Capital Plan - RSUs |  | 4,169,228 |  |  | 5,055,191 |
Outstanding warrants |  | 527,295 |  |  | 4,940,135 |
|  | 17,906,384 |  |  | 20,852,503 |

19.Segment reporting
The Company is managed and operated as one reportable segment, which includes all global activities related to the development and commercialization of targeted ADC cancer therapies. The determination of a single reportable segment is consistent with the consolidated financial information regularly provided to the Company’s CODM, which is its chief executive officer. The CODM uses loss from operations and consolidated net loss for purposes of assessing performance, making operating decisions, allocating resources and planning and forecasting for future periods. The CODM allocates resources and plans for the long-term growth of the Company based on the Company's available cash resources, forecasted cash flow, and expenditures on a consolidated basis, as well as an assessment of the probability of success of its research and development activities. Resource allocation and long-term growth decisions are informed
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by budgeted and forecasted expense information, along with actual expenses incurred to date. The measure of segment assets is reported on the consolidated balance sheets as total assets.
The following table is the summary of the segment profit or loss information, including the significant expense categories for the three and nine months ended September 30, 2025 and 2024, respectively:

|  | Three Months Ended September 30, |  | Nine Months Ended September 30,
|  | 2025 |  | 2024 |  | 2025 |  | 2024
Total revenues, net |  | $ | 16,427 |  |  | $ | 18,464 |  |  | $ | 58,299 |  |  | $ | 53,927 |
Significant operating expenses: |  |  |  |  |  |  |  |
Cost of product sales |  | (1,202) |  |  | (851) |  |  | (4,099) |  |  | (4,578) |
Research and development(1) |  | (26,293) |  |  | (31,511) |  |  | (83,833) |  |  | (81,683) |
Selling and marketing(1) |  | (10,345) |  |  | (10,318) |  |  | (30,422) |  |  | (32,852) |
General and administrative(1) |  | (7,180) |  |  | (8,542) |  |  | (23,575) |  |  | (28,080) |
Restructuring and impairment expenses |  | (377) |  |  | — |  |  | (13,468) |  |  | — |
Share-based compensation |  | (1,999) |  |  | (2,806) |  |  | (6,482) |  |  | (4,952) |
Total operating expenses |  | (47,396) |  |  | (54,028) |  |  | (161,879) |  |  | (152,145) |
Loss from operations |  | (30,969) |  |  | (35,564) |  |  | (103,580) |  |  | (98,218) |
Other segment items(2) |  | (9,997) |  |  | (8,405) |  |  | (32,634) |  |  | (28,901) |
Net loss |  | $ | (40,966) |  |  | $ | (43,969) |  |  | $ | (136,214) |  |  | $ | (127,119) |

(1)Excludes share-based compensation.
(2)Includes Other expense, net, Income tax expense and Equity in net losses of joint venture.
20.Subsequent events
October 2025 Private Placement
On October 12, 2025, the Company entered into securities purchase agreements for the sale of its equity securities to certain institutional investors. In the private placement, the Company sold 11,250,000 common shares at $4.00 per share, and pre-funded warrants (the “October 2025 Pre-Funded Warrants”) to purchase 3,846,153 common shares at $3.90 per pre-funded warrant, which is the price per common share in the private placement minus the exercise price of CHF 0.08 per pre-funded warrant (collectively, the “October 2025 Private Placement”). The private placement closed on October 27, 2025. Gross proceeds from the October 2025 Private Placement were $60.0 million, and, after giving effect to $2.4 million of transaction costs related to the private placement, net proceeds were $57.6 million.
The October 2025 Pre-Funded Warrants are exercisable, on a cash or cashless basis, at the option of the holder after the date of issuance until the tenth anniversary of their original issuance. At any time during the last 90 days of the term, the holder may exchange the October 2025 Pre-Funded Warrant for, and we will issue, a new pre-funded warrant for the number of common shares then remaining under the October 2025 Pre-Funded Warrant. The October 2025 Pre-Funded Warrants have certain limitations on exercise, including (i) any exercise must be for at least 50,000 common shares (or, if less, the remaining common shares available for purchase under the October 2025 Pre-Funded Warrants), (ii) a holder cannot exercise for any amount that would cause such holder’s beneficial ownership of our common shares to exceed 9.99% (or 19.99% with 61-days’ notice to us), and (iii) cashless exercise is not available in certain circumstances as specified in the October 2025 Pre-Funded Warrants. The warrants contain customary anti-dilution
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adjustments and will entitle holders to receive any dividends or other distributions paid on the underlying common shares prior to their expiration on an as-exercised basis.
Accounting for the October 2025 Private Placement and Pre-funded Warrants
The Company will account for the common shares and October 2025 Pre-funded Warrants described above each as freestanding financial instruments.
The common shares for the private placement were issued from the Company’s capital range. The common shares will be recorded as $43.0 million to equity for the issuance of the common shares, net of transaction costs accrued and paid, and an increase in cash and cash equivalents.
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, including the warrant holders cannot require “net cash settlement” in a circumstance outside of the Company’s control, and there is sufficient authorized and unissued shares to settle the warrants. Accordingly, these warrants will be recognized as $14.6 million in equity and accounted for as a component of additional paid-in capital at the time of issuance, net of transaction costs accrued and paid, and an increase in cash and cash equivalents.
Transaction costs will be allocated to the warrants and the common shares based on the relative fair value method. Transaction costs associated to the warrants and common shares will be deducted from the respective instrument in equity.
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Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations
You should read the following discussion and analysis of our financial condition and results of operations together with our unaudited condensed consolidated financial statements, including the notes thereto, included in this Quarterly Report, as well as our audited consolidated financial statements, including the notes thereto, included in our Annual Report on Form 10-K. The following discussion includes forward-looking statements that involve risks, uncertainties and assumptions. Our actual results may differ materially from those anticipated in these forward-looking statements. See “Forward-Looking Statements.”
Business Overview
ADC Therapeutics is a commercial-stage global leader and pioneer in the field of antibody drug conjugates (“ADCs”), transforming treatment for patients through our focused portfolio with ZYNLONTA ® (loncastuximab tesirine-lpyl) and an early stage prostate-specific membrane antigen targeting ADC (“PSMA-targeting ADC”). Headquartered in Lausanne (Biopôle), Switzerland, with operations in London and New Jersey, ADC Therapeutics is focused on driving innovation in ADC development with specialized capabilities from clinical to manufacturing and commercialization.
Our flagship product, ZYNLONTA, a CD19-directed ADC, received accelerated approval from the U.S. FDA, conditional approval from the European Commission, conditional approval from the China National Medical Products Administration (“NMPA”) and conditional approval by Health Canada for the treatment of relapsed or refractory DLBCL after two or more lines of systemic therapy. We are seeking to continue expanding ZYNLONTA internationally, and into earlier lines of DLBCL as a single agent and in combination through our LOTIS-5 confirmatory Phase 3 clinical trial and LOTIS-7 Phase 1b clinical trial as well as into indolent lymphomas, including marginal zone lymphoma (“MZL”) and follicular lymphoma (”FL”), through investigator-initiated trials (“IITs”) at leading institutions. In the second quarter of 2025, the company discontinued the Phase 1/2 ADCT 602 clinical trial, sponsored by The University of Texas MD Anderson Cancer Center.
Beyond ZYNLONTA, ADC Therapeutics is leveraging its expertise to advance IND-enabling activities for a next-generation PSMA-targeting ADC which utilizes a differentiated exatecan-based payload with a novel hydrophilic linker.
On June 11, 2025, the Board of Directors approved a strategic reprioritization and restructuring plan (the “2025 Restructuring”) to focus resources on ZYNLONTA expansion opportunities and the advancement of its preclinical exatecan-based PSMA-targeting ADC. The Company is discontinuing early development efforts for the remaining preclinical programs in solid tumors. In connection with the Restructuring, the Company is in the process of shutting down its UK research and development facility, and has reduced its global workforce across functions by approximately 30%.
On June 11, 2025, the Company also entered into securities purchase agreements for the sale of its equity securities to certain institutional investors. In the private placement, the Company sold 13,031,161 common shares at $3.53 per share, which was the last reported sale price of the common shares on the New York Stock Exchange on June 11, 2025, and pre-funded warrants (the “June 2025 Pre-Funded Warrants”) to purchase 15,734,267 common shares at $3.43 per pre-funded warrant, which is the price per common share in the private placement minus the exercise price of CHF 0.08 per pre-funded warrant (collectively, the “June 2025 Private Placement”). The private placement closed on June 16, 2025. Gross proceeds from the June 2025 Private Placement were $100.0 million, and, after giving effect to $6.9 million of transaction costs related to the private placement, net proceeds were $93.1 million.
On October 12, 2025, the Company entered into securities purchase agreements for the sale of its equity securities to certain institutional investors. In the private placement, the Company sold 11,250,000 common shares at $4.00 per share, and pre-funded warrants (the “October 2025 Pre-Funded Warrants”) to purchase 3,846,153 common shares at $3.90 per pre-funded warrant, which is the price per common share in the private placement minus the exercise price of CHF 0.08 per pre-funded warrant (collectively, the “October 2025 Private Placement”). The private placement closed on October 27, 2025. Gross proceeds from the October 2025 Private Placement were $60.0 million, and, after giving effect to $2.4 million of transaction costs related to the private placement, net proceeds were approximately $57.6 million.
Clinical Trial Updates
In July 2025 we provided an update on the progress of the LOTIS-5 Phase 3 confirmatory trial of ZYNLONTA in combination with rituximab in patients with 2L+ DLBCL. In June 2025, we provided an update on the progress of LOTIS-7, the ongoing Phase 1b global multicenter, multi-arm trial studying ZYNLONTA plus the bispecific antibody glofitamab in patients with relapsed or refractory B-NHL that includes Part 1 (dose escalation) and Part 2 (dose expansion). In addition, in June 2025 and September 2025, IIT data was presented on ZYNLONTA in MZL patients and ZYNLONTA in combination with rituximab in FL patients, respectively.
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LOTIS-5
In July 2025 we presented updated safety run-in results from our LOTIS-5 confirmatory Phase 3 clinical trial. The 20 patients in the safety run-in were a median age of 74.5 years and had a median of 1 prior therapy ( range of 1-7) . Patients received a median of five cycles of ZYNLONTA in combination with rituximab and one previous therapy. As of the October 4, 2024, data cutoff with a median follow-up of 37.2 months:
•The ORR by central review was 16/20 (80%). A total of 10/20 (50%) patients received a complete response
•The median DoR was 8.0 months and the median PFS was 8.3 months
•Median DOCR was not reached with 4 patients with CR >28.5 months beyond end of therapy.
•Of 7 patients with ctDNA available, all 7 had a decrease in ctDNA by cycle 3 with all 3 CR patients MRD negative at C3
•A total of 11 (55%) patients had Grade ≥3 TEAEs. The most common Grade ≥3 TEAEs were increased gamma-glutamyltransferase (five patients (25%) and neutropenia (three patients (15%))
We expect to provide topline data in the first half of 2026 once the pre-specified number of progression-free survival (“PFS”) events is reached and data are available. A supplemental Biologics License Application (“sBLA”) submission to regulatory authorities will follow, with pote ntial confirmatory approval in 2L+ DLBCL as well as publication and compendia inclusion in the first half of 2027.
LOTIS-7
On June 12, 2025 we announced updated data from our LOTIS-7 clinical trial. As of April 14, 2025, r/r LBCL patients received dose levels of 120 µg/kg or 150 µg/kg of ZYNLONTA plus the bispecific antibody glofitamab, with 41 patients evaluable for safety and 30 patients evaluable for efficacy.
Key highlights of the LOTIS-7 data presentation are as follows:
•Best overall response data among the 30 efficacy evaluable patients shows overall response rate (ORR) of 93.3% (28/30 pts) as assessed by Lugano Criteria
•Complete response (CR) rate of 86.7% (26/30 pts)
◦Of these, 25/26 patients achieving CR remain in CR as of the data cut-off
▪Median time to CR in 120 µg/kg = 80 days
▪Median time to CR in 150 µg/kg = 42 days
•12 patients converted from stable disease (SD) or partial response (PR) to CR over time (1 and 11 pts respectively)
•Of the 6 patients previously treated with CAR-T and undergoing response assessment, 5 achieved a CR
•Among the 41 safety evaluable patients, the combination was generally well tolerated with a manageable safety profile and no DLTs across dose levels
•Grade 3 or higher treatment emergent adverse events (TEAEs) observed in > 5% of patients included neutropenia (24.4%), anemia (9.8%), AST increased (7.3%), GGT increased (7.3%), and thrombocytopenia (7.3%)
•In the 150 µg/kg dose, cytokine release syndrome (CRS) (23.8%), all of which were Grade 1, and immune effector cell-associated neurotoxicity syndrome (ICANS) (4.8%), with one case of Grade 2, were observed
•In the 120 µg/kg dose, CRS all grades (55%), all of which were Grade 1/2 except one case of Grade 3, and ICANS (10%), with one case of Grade 1 and one case of Grade 2, were observed
•TEAEs leading to discontinuation included 3 each for ZYNLONTA and glofitamab
•There were no Grade 5 TEAEs observed
We expanded enrollment for LOTIS-7 to 100 patients at 150 µg/kg dose with enrollment focused on a DLBCL population.
We expect to share more mature data from the LOTIS-7 trial through a corporate update by the end of the year. Once sufficient data with longer follow-up is available, the Company plans to engage with the U.S. Food and Drug Administration (“FDA”). In addition, the Company plans to pursue publication and compendia inclusion in the first half of 2027.
Phase 2 Investor Initiated Trials (IITs)
Marginal Zone Lymphoma
Updated data from the Phase 2 multicenter IIT of ZYNLONTA to treat relapsed/refractory marginal zone lymphoma (r/r MZL) was presented during a poster session at the 18th International Conference on Malignant Lymphoma (“ICML”) in
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Lugano, Switzerland in June 2025. As of February 10, 2025, a total of 27 adult patients with r/r MZL and previously treated with ≥1 line of systemic therapy were enrolled with 26 patients evaluable for response. Patient had a median of 2 prior line of treatment. Highlights of the data include:
•Overall response rate (ORR) of 84.6% (22/26); complete response (CR) rate of 69.2% (18/26)
•Among POD24 patients assessed for response, a CR rate of 61.5% (8/13) was observed
•CR was maintained in 17 of 18 CR patients who achieved CR, with longest duration of CR of 27 months from start of treatment
•Progression-free survival (PFS) was 92.9% at 12 months
•27 enrolled patients experienced adverse events (AE), consistent with the known safety profile of ZYNLONTA and most commonly grade 1 or 2. Grade 3 and 4 AEs were observed in 16 and 2 patients, respectively and included neutropenia, RSV lung infection and hyponatremia (with 2 AEs occurring in the same patient). Three patients needed dose reduction and one patient discontinued treatment after cycle 4 due to cholestatic hepatitis that fully recovered
The trial has been expanded to enroll 50 patients, and we plan to assess regulatory and updated compendia pathways as soon as sufficient data are available.
Follicular Lymphoma
Juan Pablo Alderuccio, MD, Clinical Site Disease Group Leader, Lymphoma Section, at Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine, presented updated data at iWNHL in September 2025 from the Phase 2 IIT evaluating ZYNLONTA in combination with rituximab in r/r FL. Data from the 55 evaluable patients to date in this trial had an overall response rate (ORR) of 98.2%, a complete response rate (CR) of 83.6%. After median follow-up of 28 months, median PFS was not reached and the 12-month PFS was 93.9%. Safety was consistent with the known profile of ZYNLONTA. The trial has been expanded to enroll 100 patients, and we plan to assess regulatory and updated compendia pathways as soon as sufficient data are available.
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Results of Operations
Three Months Ended September 30, 2025 Compared to Three Months Ended September 30, 2024
The following table summarizes our results of operations for the three months ended September 30, 2025 and 2024:

| Three Months Ended September 30,
(in thousands, except percentages and per share) | 2025 |  | 2024 |  | Change |  | % Change
Revenue |  |  |  |  |  |  |
Product revenues, net | $ | 15,750 |  |  | $ | 18,016 |  |  | $ | (2,266) |  |  | (12.6) | %
License revenues and royalties | 677 |  |  | 448 |  |  | 229 |  |  | 51.1 | %
Total revenue, net | 16,427 |  |  | 18,464 |  |  | (2,037) |  |  | (11.0) | %
Operating expense |  |  |  |  |  |  |
Cost of product sales | (1,202) |  |  | (851) |  |  | (351) |  |  | 41.2 | %
Research and development | (26,803) |  |  | (32,502) |  |  | 5,699 |  |  | (17.5) | %
Selling and marketing | (10,688) |  |  | (10,673) |  |  | (15) |  |  | 0.1 | %
General and administrative | (8,326) |  |  | (10,002) |  |  | 1,676 |  |  | (16.8) | %
Restructuring, impairment and other related costs | (377) |  |  | — |  |  | (377) |  |  | 100.0 | %
Total operating expense | (47,396) |  |  | (54,028) |  |  | 6,632 |  |  | (12.3) | %
Loss from operations | (30,969) |  |  | (35,564) |  |  | 4,595 |  |  | (12.9) | %
Other income (expense) |  |  |  |  |  |  |
Interest income | 2,470 |  |  | 3,438 |  |  | (968) |  |  | (28.2) | %
Interest expense | (13,392) |  |  | (13,117) |  |  | (275) |  |  | 2.1 | %
Other, net | 925 |  |  | 1,624 |  |  | (699) |  |  | (43.0) | %
Total other expense, net | (9,997) |  |  | (8,055) |  |  | (1,942) |  |  | 24.1 | %
Loss before income taxes | (40,966) |  |  | (43,619) |  |  | 2,653 |  |  | (6.1) | %
Income tax expense | — |  |  | (90) |  |  | 90 |  |  | (100.0) | %
Loss before equity in net losses of joint venture | (40,966) |  |  | (43,709) |  |  | 2,743 |  |  | (6.3) | %
Equity in net losses of joint venture | — |  |  | (260) |  |  | 260 |  |  | (100.0) | %
Net loss | $ | (40,966) |  |  | $ | (43,969) |  |  | $ | 3,003 |  |  | (6.8) | %
Net loss per share, basic and diluted | $ | (0.30) |  |  | $ | (0.42) |  |  | $ | 0.12 |  |  | (28.6) | %

Revenue
Product Revenues, net
We generate product revenue through the sale of ZYNLONTA in the United States. Revenue is recognized when control is transferred to the customer at the net selling price, which includes reductions for gross-to-net (“GTN”) sales adjustments such as government rebates, chargebacks, distributor service fees, other rebates and administrative fees, sales returns and allowances and sales discounts. Our product revenue may fluctuate from period to period based on a number of factors, including patient demand, as well as the timing, dose and duration of patient therapy and customers’ ordering patterns and GTN deductions. We expect a relatively consistent level of GTN sales adjustments as a percentage of gross sales, but may also experience variability in GTN sales adjustments due to additional information and actual experience such as actual rebate and return rates.
Product revenues, net, were $15.8 million for the three months ended September 30, 2025 as compared to $18.0 million for the three months ended September 30, 2024, a decrease of $2.3 million, or 12.6%. The decrease is primarily attributable to lower sales volume, partially offset by a higher price and favorability in GTN sales adjustments.
License Revenues and Royalties
We generate license revenue and royalties from our strategic agreements for the development and commercialization of ZYNLONTA and other product candidates outside of the United States. Under these agreements, we receive upfront payments and are eligible for certain milestone payments and royalties. We are unable to predict the timing and amounts of
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license revenue and royalties as meeting milestones is subject to many factors outside of our control and we have limited control over our partners’ commercialization efforts.
License revenues and royalties were $0.7 million for the three months ended September 30, 2025 as compared to $0.4 million for the three months ended September 30, 2024, an increase of $0.2 million. The increase was attributable to increased royalty revenue from our exclusive license agreement with SOBI to develop and commercialize ZYNLONTA in all territories other than the United States, greater China, Singapore and Japan.
Operating Expenses
Cost of Product Sales
Cost of product sales primarily includes direct and indirect costs relating to the third-party manufacture and distribution of ZYNLONTA, royalties payable to a collaboration partner based on net product sales of ZYNLONTA and inventory write-downs. We expect that cost of product sales will increase over time as we sell through pre-approval inventory that was previously expensed prior to commercialization under U.S. GAAP. Factors such as inflation, tariffs and other external factors may also increase our cost of product sales as a percentage of product revenue if we are not able to increase the price at which we sell ZYNLONTA to offset such increases in our cost of product sales.
Cost of product sales were $1.2 million for the three months ended September 30, 2025 as compared to cost of product sales of $0.9 million for the three months ended September 30, 2024, an increase of $0.4 million, or 41.2%. The increase in cost of product sales was primarily attributable to inventory write-downs for the three months ended September 30, 2025.
Research and Development Expenses
The following table summarizes our research and development expenses for the three months ended September 30, 2025 and 2024:

| Three Months Ended September 30,
(in thousands) | 2025 |  | 2024 |  | Change
External costs and overhead | $ | 15,023 |  |  | $ | 20,248 |  |  | $ | (5,225) |
Employee expenses(1) | 11,270 |  |  | 11,263 |  |  | 7 |
Share-based compensation expense | 510 |  |  | 991 |  |  | (481) |
Research and development expenses | $ | 26,803 |  |  | $ | 32,502 |  |  | $ | (5,699) |

(1) Excludes share-based compensation expense.
Research and development expense consists primarily of employee related expenses, including share-based compensation expense; costs for production of preclinical and clinical-stage product candidates by CMOs; fees and other costs paid to contract research organizations in connection with the performance of preclinical studies and clinical trials; costs of related facilities, materials and equipment; external costs associated with obtaining intellectual property; depreciation; and upfront fees and achieved milestone payments associated with R&D collaboration arrangements.
Our research and development expense may fluctuate from period to period based on a number of factors, including the timing, progress and stage of clinical trials, costs associated with regulatory approval processes and manufacturing costs associated with commercialization activities prior to the receipt of regulatory approval.
Our R&D expenses were $26.8 million for the three months ended September 30, 2025 as compared to $32.5 million for the three months ended September 30, 2024, a decrease of $5.7 million, or 17.5%. The decrease in external costs and overhead of $5.2 million was primarily driven by a reduction in spending on discontinued programs including ADCT-601 that was discontinued in November 2024 for which we continue to incur close-out costs, and our preclinical product candidates and research pipeline as a result of the strategic re-prioritization announced in the second quarter of 2025. The decrease was also attributable to the timing and enrollment of our ZYNLONTA clinical trials, including a decrease in clinical supply costs associated with the LOTIS-5 clinical trial. These decreases were partially offset by increased costs associated with the timing of IND-enabling activities for the PSMA-targeting ADC program. We expect to continue to incur research and development costs in connection with the ongoing ZYNLONTA clinical trials, and that costs associated with IND-enabling activities for the PSMA-targeting ADC asset will wind down by the end of 2025.
Employee expenses were relatively consistent at $11.3 million for the three months ended September 30, 2025 and September 30, 2024 and driven by an increase in temporary project help of $1.1 million, offset by lower wages and benefits of $1.1 million. The decrease in share-based compensation expense was primarily due to the timing of forfeitures of awards in connection with employee terminations.
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Selling and Marketing Expenses
The following table summarizes our selling and marketing expenses for the three months ended September 30, 2025 and 2024:

| Three Months Ended September 30,
(in thousands) | 2025 |  | 2024 |  | Change
External costs and overhead | $ | 4,999 |  |  | $ | 5,056 |  |  | $ | (57) |
Employee expenses(1) | 5,346 |  |  | 5,262 |  |  | 84 |
Share-based compensation expense | 343 |  |  | 355 |  |  | (12) |
Selling and marketing expenses | $ | 10,688 |  |  | $ | 10,673 |  |  | $ | 15 |

(1) Excludes share-based compensation expense.
Selling and marketing costs (“S&M”) are expensed as incurred and are primarily attributable to commercialization of ZYNLONTA in the United States. S&M includes employee costs and share-based compensation expense for commercial employees and external costs related to commercialization (including professional fees, communication costs and IT costs, travel expenses and depreciation of property and equipment).
Selling and marketing expenses were relatively consistent at $10.7 million for the three months ended September 30, 2024 and September 30, 2025.
General and Administrative Expenses
The following table summarizes our general and administrative expenses for the three months ended September 30, 2025 and 2024:

| Three Months Ended September 30,
(in thousands) | 2025 |  | 2024 |  | Change
External costs and overhead | $ | 3,112 |  |  | $ | 3,901 |  |  | $ | (789) |
Employee expenses(1) | 4,067 |  |  | 4,641 |  |  | (574) |
Share-based compensation expense | 1,147 |  |  | 1,460 |  |  | (313) |
General and administrative expenses | $ | 8,326 |  |  | $ | 10,002 |  |  | $ | (1,676) |

(1) Excludes share-based compensation expense.
General and administrative expense includes employee related costs (including wages, benefits and share-based compensation expense) for general and administrative employees, external costs (including, in particular, professional fees, legal fees and costs associated with maintaining patents and other intellectual property, communications costs and IT costs, facility expenses and travel expenses) and depreciation of property and equipment and right-of-use assets.
General and administrative expenses were $8.3 million million for the three months ended September 30, 2025 as compared to $10.0 million for the three months ended September 30, 2024, an overall decrease of $1.7 million, or 16.8%. The decrease in external costs and overhead of $0.8 million was primarily related to lower professional fees of $0.6 million as a result of lower legal expenses. The decrease in employee expenses of $0.6 million was primarily due to lower wages and benefits. The decrease in share-based compensation expense of $0.3 million was primarily due to the timing of forfeitures of awards in connection with employee terminations.
Restructuring, Impairment and Other Related Costs
In connection with the 2025 Restructuring we incurred restructuring, impairment and other related costs, which included severance and related benefit costs, charges related to impairment of long-lived assets and prepaid expenses, and charges for the estimated fair value of retirement costs associated with the U.K. lease agreement.
Restructuring, impairment, and other related costs were $0.4 million for the three months ended September 30, 2025 and consisted of $0.8 million for the estimated fair value of retirement costs associated with the U.K. lease agreements, partially offset by $0.5 million in adjustments related to severance and related benefit costs. We did not incur restructuring, impairment and other related costs during the three months ended September 30, 2024.
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Other Income (Expense)
Interest Income
Interest income includes interest received from banks on our cash balances. Our policy is to invest funds in a variety of capital preservation instruments, which may include all or a combination of cash and cash equivalents, short-term and long-term interest-bearing instruments, investment-grade securities, and direct or guaranteed obligations of the U.S. government.
Interest income was $2.5 million for the three months ended September 30, 2025 as compared to $3.4 million for the three months ended September 30, 2024, a decrease of $1.0 million, or 28.2%. The decrease was primarily due to lower yields received on our cash deposits and lower average cash balances.
Interest Expense
Interest expense is primarily related to the accretion of our deferred royalty obligation with HCR and the senior secured term loan facility. Interest expense was $13.4 million for the three months ended September 30, 2025 as compared to $13.1 million for the three months ended September 30, 2024, an increase of $0.3 million, or 2.1%. The increase was primarily related to higher accretion of our deferred royalty obligation with HCR of $0.5 million as a result of higher total revenue, net, partially offset by lower interest on our senior secured term loan facility of $0.2 million as a result of a lower effective interest rate.
Income Tax Expense
We are subject to corporate taxation in Switzerland. We are also subject to taxation in other jurisdictions in which we operate, in particular, the United States and the United Kingdom, where our two wholly-owned subsidiaries are incorporated. We recorded an income tax expense of nil for the three months ended September 30, 2025 as compared to $0.1 million for the three months ended June 30, 2024.
On July 4, 2025, the United States Congress passed budget reconciliation bill H.R. 1 referred to as the One Big Beautiful Bill (“OBBB”). The OBBB contains several changes to corporate taxation including modifications to capitalization of research and development expenses, limitations on deductions for interest expense and accelerated fixed asset depreciation. U nder the OBBB, U.S. domestic R&D expenditures are now immediately deductible, while foreign R&D expenditures remain subject to capitalization and amortization. The Company has reflected the impact of these provisions in its estimated annual effective tax rate for the third quarter of 2025. Management does not expect the OBBB to have a material effect on the Company’s overall tax position for the current year.
Equity in Net Losses of Joint Venture

| Three Months Ended September 30,
(in thousands) | 2025 |  | 2024 |  | Change
Share of Overland ADCT BioPharma net loss | $ | — |  |  | $ | (260) |  |  | $ | 260 |

We recorded our proportionate share of Overland ADCT BioPharma’s net loss of $0.3 million for the three months ended September 30, 2024. We recorded our share of Overland ADCT Biopharma’s net loss up until the point at which our share of losses exceeded our interest in Overland ADCT BioPharma. Losses were not recognized in excess of our total investment, as we have not incurred legal or constructive obligations or committed to additional funding on behalf of the joint venture.
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Nine Months Ended September 30, 2025 Compared to Nine Months Ended September 30, 2024
The following table summarizes our results of operations for the nine months ended September 30, 2025 and 2024:

| Nine Months Ended September 30,
(in thousands, except percentages and per share) | 2025 |  | 2024 |  | Change |  | % Change
Revenue |  |  |  |  |  |  |
Product revenues, net | $ | 51,239 |  |  | $ | 52,894 |  |  | $ | (1,655) |  |  | (3.1) | %
License revenues and royalties | 7,060 |  |  | 1,033 |  |  | 6,027 |  |  | 583.4 | %
Total revenue, net | 58,299 |  |  | 53,927 |  |  | 4,372 |  |  | 8.1 | %
Operating expense |  |  |  |  |  |  |
Cost of product sales | (4,099) |  |  | (4,578) |  |  | 479 |  |  | (10.5) | %
Research and development | (85,821) |  |  | (82,532) |  |  | (3,289) |  |  | 4.0 | %
Selling and marketing | (31,388) |  |  | (32,764) |  |  | 1,376 |  |  | (4.2) | %
General and administrative | (27,103) |  |  | (32,271) |  |  | 5,168 |  |  | (16.0) | %
Restructuring, impairment and other related costs | (13,468) |  |  | — |  |  | (13,468) |  |  | 100.0 | %
Total operating expense | (161,879) |  |  | (152,145) |  |  | (9,734) |  |  | 6.4 | %
Loss from operations | (103,580) |  |  | (98,218) |  |  | (5,362) |  |  | 5.5 | %
Other income (expense) |  |  |  |  |  |  |
Interest income | 6,458 |  |  | 9,639 |  |  | (3,181) |  |  | (33.0) | %
Interest expense | (38,619) |  |  | (38,292) |  |  | (327) |  |  | 0.9 | %
Other, net | 946 |  |  | 1,783 |  |  | (837) |  |  | (46.9) | %
Total other expense, net | (31,215) |  |  | (26,870) |  |  | (4,345) |  |  | 16.2 | %
Loss before income taxes | (134,795) |  |  | (125,088) |  |  | (9,707) |  |  | 7.8 | %
Income tax expense | (1,419) |  |  | (487) |  |  | (932) |  |  | 191.4 | %
Loss before equity in net losses of joint venture | (136,214) |  |  | (125,575) |  |  | (10,639) |  |  | 8.5 | %
Equity in net losses of joint venture | — |  |  | (1,544) |  |  | 1,544 |  |  | (100.0) | %
Net loss | $ | (136,214) |  |  | $ | (127,119) |  |  | $ | (9,095) |  |  | 7.2 | %
Net loss per share, basic and diluted | $ | (1.14) |  |  | $ | (1.35) |  |  | $ | 0.21 |  |  | (15.6) | %

Revenue
Product Revenues, net
We generate product revenue through the sale of ZYNLONTA in the United States. Revenue is recognized when control is transferred to the customer at the net selling price, which includes reductions for gross-to-net (“GTN”) sales adjustments such as government rebates, chargebacks, distributor service fees, other rebates and administrative fees, sales returns and allowances and sales discounts. Our product revenue may fluctuate from period to period based on a number of factors, including patient demand, as well as the timing, dose and duration of patient therapy and customers’ ordering patterns and GTN deductions. We expect a relatively consistent level of GTN sales adjustments as a percentage of gross sales, but may also experience variability in GTN sales adjustments due to additional information and actual experience such as actual rebate and return rates.
Product revenues, net, were $51.2 million for the nine months ended September 30, 2025 as compared to $52.9 million for the nine months ended September 30, 2024, a decrease of $1.7 million, or 3.1%. The decrease is primarily attributable to lower sales volume, partially offset by a higher price and favorability in GTN sales adjustments.
License Revenues and Royalties
We generate license revenue and royalties from our strategic agreements for the development and commercialization of ZYNLONTA and other product candidates outside of the United States. Under these agreements, we receive upfront payments and are eligible for certain milestone payments and royalties. We are unable to predict the timing and amounts of
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license revenue and royalties as meeting milestones is subject to many factors outside of our control and we have limited control over our partners’ commercialization efforts.
License revenues and royalties were $7.1 million for the nine months ended September 30, 2025 as compared to $1.0 million for the nine months ended September 30, 2024, an increase of $6.0 million. We have an exclusive license agreement with SOBI to develop and commercialize ZYNLONTA in all territories other than the United States, greater China, Singapore and Japan. In March 2025, the Company recognized $5.0 million in license revenue in connection with a milestone due upon ZYNLONTA’s conditional approval by Health Canada for the treatment of relapsed or refractory DLBCL after two or more lines of systemic therapy, which was paid to us by SOBI in the second quarter of 2025. The increase was also attributable to increased royalty revenue from SOBI.
Operating Expenses
Cost of Product Sales
Cost of product sales primarily includes direct and indirect costs relating to the third-party manufacture and distribution of ZYNLONTA, royalties payable to a collaboration partner based on net product sales of ZYNLONTA and inventory write-downs. We expect that cost of product sales will increase over time as we sell through pre-approval inventory that was previously expensed prior to commercialization under U.S. GAAP. Factors such as inflation, tariffs and other external factors may also increase our cost of product sales as a percentage of product revenue if we are not able to increase the price at which we sell ZYNLONTA to offset such increases in our cost of product sales.
Cost of product sales were $4.1 million for the nine months ended September 30, 2025 as compared to cost of product sales of $4.6 million for the nine months ended September 30, 2024, a decrease of $0.5 million, or 10.5%. The decrease in cost of product sales was primarily driven by a $1.1 million batch cancellation fee recognized during the nine months ended September 30, 2024 and $0.3 million attributable to lower shipping and storage charges for the nine months ended September 30, 2025. This decrease was partially offset by higher inventory write-downs of $0.8 million during the nine months ended September 30, 2025.
Research and Development Expenses
The following table summarizes our research and development expenses for the nine months ended September 30, 2025 and 2024:

| Nine Months Ended September 30,
(in thousands) | 2025 |  | 2024 |  | Change
External costs and overhead | $ | 48,073 |  |  | $ | 47,036 |  |  | $ | 1,037 |
Employee expenses(1) | 35,760 |  |  | 34,647 |  |  | 1,113 |
Share-based compensation expense | 1,988 |  |  | 849 |  |  | 1,139 |
Research and development expenses | $ | 85,821 |  |  | $ | 82,532 |  |  | $ | 3,289 |

(1) Excludes share-based compensation expense.
Research and development expense consists primarily of employee related expenses, including share-based compensation expense; costs for production of preclinical and clinical-stage product candidates by CMOs; fees and other costs paid to contract research organizations in connection with the performance of preclinical studies and clinical trials; costs of related facilities, materials and equipment; external costs associated with obtaining intellectual property; depreciation; and upfront fees and achieved milestone payments associated with R&D collaboration arrangements.
Our research and development expense may fluctuate from period to period based on a number of factors, including the timing, progress and stage of clinical trials, costs associated with regulatory approval processes and manufacturing costs associated with commercialization activities prior to the receipt of regulatory approval.
Our R&D expenses were $85.8 million for the nine months ended September 30, 2025 as compared to $82.5 million for the nine months ended September 30, 2024, an increase of $3.3 million, or 4.0%. The increase in external costs and overhead of $1.0 million was primarily driven by timing of costs incurred in connection with IND-enabling activities for the PSMA-targeting ADC program and the timing and enrollment of our ZYNLONTA clinical trials and related costs incurred in connection with the LOTIS 5 trials. These increases were partially offset by a reduction in spending on discontinued programs, including ADCT-601 that was discontinued in November 2024 for which we continue to incur close-out costs, and our preclinical product candidates and research pipeline as a result of the strategic re-prioritization announced in the second quarter of 2025. We expect to continue to incur research and development costs in connection with the ongoing
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ZYNLONTA clinical trials, and that costs associated with IND-enabling activities for the PSMA-targeting ADC asset will wind down by the end of 2025.
The increase in employee expenses of $1.1 million was primarily driven by higher temporary project help of $3.4 million, partially offset by lower wages and benefits of $2.3 million. The increase in share-based compensation expense was primarily driven by the forfeitures of awards in connection with employee terminations in the prior year.
Selling and Marketing Expenses
The following table summarizes our selling and marketing expenses for the nine months ended September 30, 2025 and 2024:

| Nine Months Ended September 30,
(in thousands) | 2025 |  | 2024 |  | Change
External costs and overhead | $ | 13,631 |  |  | $ | 15,718 |  |  | $ | (2,087) |
Employee expenses(1) | 16,791 |  |  | 17,134 |  |  | (343) |
Share-based compensation expense (reversal) | 966 |  |  | (88) |  |  | 1,054 |
Selling and marketing expenses | $ | 31,388 |  |  | $ | 32,764 |  |  | $ | (1,376) |

(1) Excludes share-based compensation expense (reversal).
Selling and marketing costs (“S&M”) are expensed as incurred and are primarily attributable to commercialization of ZYNLONTA in the United States. S&M includes employee costs and share-based compensation expense for commercial employees and external costs related to commercialization (including professional fees, communication costs and IT costs, travel expenses and depreciation of property and equipment).
Selling and marketing expenses were $31.4 million for the nine months ended September 30, 2025 as compared to $32.8 million for the nine months ended September 30, 2024, a decrease of $1.4 million or 4.2%. The decrease in external costs and overhead was primarily attributable to $2.1 million in lower spend on marketing and advertising expenses as a result of reduced spending initiatives within the U.S. The decrease in employee expenses was primarily due to lower wages and benefits of $0.3 million. The increase in share-based compensation expense of $1.1 million was primarily driven by the forfeitures of awards in connection with employee terminations in the prior year.
General and Administrative Expenses
The following table summarizes our general and administrative expenses for the nine months ended September 30, 2025 and 2024:

| Nine Months Ended September 30,
(in thousands) | 2025 |  | 2024 |  | Change
External costs and overhead | $ | 9,943 |  |  | $ | 13,675 |  |  | $ | (3,732) |
Employee expenses(1) | 13,632 |  |  | 14,405 |  |  | (773) |
Share-based compensation expense | 3,528 |  |  | 4,191 |  |  | (663) |
General and administrative expenses | $ | 27,103 |  |  | $ | 32,271 |  |  | $ | (5,168) |

(1) Excludes share-based compensation expense.
General and administrative expense includes employee related costs (including wages, benefits and share-based compensation expense) for general and administrative employees, external costs (including, in particular, professional fees, legal fees and costs associated with maintaining patents and other intellectual property, communications costs and IT costs, facility expenses and travel expenses) and depreciation of property and equipment and right-of-use assets.
General and administrative expenses were $27.1 million for the nine months ended September 30, 2025 as compared to $32.3 million for the nine months ended September 30, 2024, a decrease of $5.2 million, or 16.0%. The decrease in external costs and overhead was primarily related to lower professional fees of $2.3 million primarily as a result of lower legal and accounting expenses, VAT recoveries of $0.5 million, lower insurance costs of $0.4 million and lower travel and IT costs of $0.5 million. The decrease in employee expenses of $0.8 million was primarily due to lower wages and benefits of $0.4 million and lower recruitment costs of $0.4 million. The decrease in share-based compensation expense of $0.7 million was primarily due to the timing of forfeitures of awards in connection with employee terminations.
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Restructuring, Impairment and Other Related Costs
In connection with the 2025 Restructuring we incurred restructuring, impairment and other related costs, which included severance and related benefit costs, charges related to impairment of long-lived assets and prepaid expenses, and charges for the estimated fair value of retirement costs associated with the U.K. lease agreement.
Restructuring, impairment, and other related costs were $13.5 million for the nine months ended September 30, 2025 and consisted of $6.2 million in severance and related benefit costs, the majority of which will be paid by the end of 2025, $6.4 million in impairment of long-lived assets and prepaid expenses, and $0.8 million for the estimated fair value of retirement costs associated with the U.K. lease agreement. We did not incur restructuring, impairment and other related costs during the nine months ended September 30, 2024.
Other Income (Expense)
Interest Income
Interest income includes interest received from banks on our cash balances. Our policy is to invest funds in a variety of capital preservation instruments, which may include all or a combination of cash and cash equivalents, short-term and long-term interest-bearing instruments, investment-grade securities, and direct or guaranteed obligations of the U.S. government.
Interest income was $6.5 million for the nine months ended September 30, 2025 as compared to $9.6 million for the nine months ended September 30, 2024, a decrease of $3.2 million or 33.0%. The decrease was primarily due to lower yields received on our cash deposits and lower average cash balances.
Interest Expense
Interest expense is primarily related to the accretion of our deferred royalty obligation with HCR and the senior secured term loan facility. Interest expense was $38.6 million for the nine months ended September 30, 2025 as compared to $38.3 million for the nine months ended September 30, 2024, an increase of $0.3 million, or 0.9%. This was due to higher accretion of our deferred royalty obligation with HCR of $1.2 million as a result of higher total revenue, net, partially offset by lower interest on our senior secured term loan facility of $0.9 million as a result of a lower effective interest rate.
Income Tax Expense
We are subject to corporate taxation in Switzerland. We are also subject to taxation in other jurisdictions in which we operate, in particular, the United States and the United Kingdom, where our two wholly-owned subsidiaries are incorporated. We recorded an income tax expense of $1.4 million for the nine months ended September 30, 2025 as compared to $0.5 million for the nine months ended September 30, 2024, primarily driven by a tax adjustment recorded in our UK operations as a result of the 2025 restructuring.
On July 4, 2025, the United States Congress passed budget reconciliation bill H.R. 1 referred to as the One Big Beautiful Bill (“OBBB”). The OBBB contains several changes to corporate taxation including modifications to capitalization of research and development expenses, limitations on deductions for interest expense and accelerated fixed asset depreciation. U nder the OBBB, domestic R&D expenditures are now immediately deductible, while foreign R&D expenditures remain subject to capitalization and amortization. The Company has reflected the impact of these provisions in its estimated annual effective tax rate for the third quarter of 2025. Management does not expect the OBBB to have a material effect on the Company’s overall tax position for the current year.
Equity in Net Losses of Joint Venture

| Nine Months Ended September 30, |  |
(in thousands) | 2025 |  | 2024 |  | Change |  |
Share of Overland ADCT BioPharma net loss | $ | — |  |  | $ | (1,544) |  |  | $ | 1,544 |  |  |

We recorded our proportionate share of Overland ADCT BioPharma’s net loss of $1.5 million for the nine months ended September 30, 2024. We recorded our share of Overland ADCT Biopharma’s net loss up until the point at which our share of losses exceeded our interest in Overland ADCT BioPharma. Losses were not recognized in excess of our total investment, as we have not incurred legal or constructive obligations or committed to additional funding on behalf of the joint venture.
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Liquidity and Capital Resources
As of September 30, 2025, we had cash and cash equivalents of $234.7 million and believe that our current cash position and capital resources are sufficient to fund our operation and meet capital requirements for at least the next twelve months from the date of this report. After September 30, 2025, we completed the October 2025 Private Placement, which generated net proceeds of approximately $57.6 million to support expansion of ZYNLONTA in anticipation of 2L+DLBCL launch.
We plan to continue to fund our operating needs through our existing cash and cash equivalents, revenues from sales of ZYNLONTA, milestone and royalty payments under our licensing agreements and additional equity financings, debt financings and/or other forms of financing, as well as potential funds provided by collaborations. We are continuously exploring strategic collaborations, business combinations, licensing opportunities or similar strategies for clinical development and commercialization of ZYNLONTA and/or our PSMA-targeting ADC. However, we may be unable to obtain such future financing, licensing and collaboration arrangements on favorable terms, if at all.
Sources of Liquidity and Capital Resources
To date, we have financed our operations primarily through equity financings, convertible debt and senior secured term loan financings, and additional funds provided by collaborations and royalty financings and sales of ZYNLONTA in the United States. For a description of the Loan Agreement, HCR Agreement and other license and collaboration agreements, see “Item 1. Business - Material Contracts” in our Annual Report.
On October 12, 2025, we entered into securities purchase agreements for the sale of our equity securities to certain institutional investors in a $60 million private placement. In the private placement, we sold 11,250,00 common shares at $4.00 per share and pre-funded warrants (the “October 2025 Pre-Funded Warrants”) to purchase 3,846,153 common shares at $3.90 per pre-funded warrant, which is the price per common share in the private placement minus the exercise price per pre-funded warrant. The private placement closed on October 27, 2025 and resulted in net proceeds of approximately $57.6 million. The October 2025 Pre-Funded Warrants are exercisable, on a cash or cashless basis, at the option of the holder after the date of issuance until the tenth anniversary of their original issuance. At any time during the last 90 days of the term, the holder may exchange the October 2025 Pre-Funded Warrant for, and we will issue, a new pre-funded warrant for the number of common shares then remaining under the October 2025 Pre-Funded Warrant. The October 2025 Pre-Funded Warrants have certain limitations on exercise, including (i) any exercise must be for at least 50,000 common shares (or, if less, the remaining common shares available for purchase under the October 2025 Pre-Funded Warrants), (ii) a holder cannot exercise for any amount that would cause such holder’s beneficial ownership of our common shares to exceed 9.99% (or 19.99% with 61-days’ notice to us), and (iii) cashless exercise is not available in certain circumstances as specified in the October 2025 Pre-Funded Warrants. The warrants contain customary anti-dilution adjustments and will entitle holders to receive any dividends or other distributions paid on the underlying common shares prior to their expiration on an as-exercised basis.
On June 16, 2025, the Company completed a $100.0 million private placement which resulted in net proceeds of $93.1 million and included the sale of common shares and June 2025 Pre-Funded Warrants. The June 2025 Pre-Funded Warrants are exercisable, on a cash or cashless basis, at the option of the holder after the date of issuance until the tenth anniversary of their original issuance. At any time during the last 90 days of the term, the holder may exchange the June 2025 Pre-Funded Warrant for, and we will issue, a new pre-funded warrant for the number of common shares then remaining under the June 2025 Pre-Funded Warrant. The June 2025 Pre-Funded Warrants have certain limitations on exercise, including (i) any exercise must be for at least 50,000 common shares (or, if less, the remaining common shares available for purchase under the June 2025 Pre-Funded Warrants), (ii) a holder cannot exercise for any amount that would cause such holder’s beneficial ownership of our common shares to exceed 9.99% (or 19.99% with 61-days’ notice to us), and (iii) cashless exercise is not available in certain circumstances as specified in the June 2025 Pre-Funded Warrants. The warrants contain customary anti-dilution adjustments and will entitle holders to receive any dividends or other distributions paid on the underlying common shares prior to their expiration on an as-exercised basis.
Uses of Capital Resources
Our primary uses of capital are, and we expect will continue to be, research and development expenses, selling and marketing expenses, compensation and related expenses, interest and principal payments on debt obligations and other operating expenses. We expect to incur substantial expenses as we continue to devote substantial resources to research and development and marketing and commercialization efforts, in particular to grow ZYNLONTA in the 3L+ DLBCL setting, continue to study and advance ZYNLONTA in earlier lines of therapy and in combinations to potentially expand our market opportunity and further develop our PSMA-targeting ADC. Cash used to fund operating expenses is impacted by the timing of when we pay expenses, as reflected in the change in our outstanding accounts payable and accrued expenses, as well as the timing of collecting receivables from the sale of ZYNLONTA and paying royalties related to our deferred royalty obligation.
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Cash Flows
The following table summarizes our cash flows for the nine months ended September 30, 2025 and 2024:

| Nine Months Ended September 30,
(in thousands) | 2025 |  | 2024 |  | Change
Net cash (used in) provided by: |  |  |  |  |
Operating activities | $ | (110,051) |  |  | $ | (101,983) |  |  | $ | (8,068) |
Investing activities | (264) |  |  | (777) |  |  | 513 |
Financing activities | 93,856 |  |  | 98,174 |  |  | (4,318) |
Net change in cash and cash equivalents | $ | (16,459) |  |  | $ | (4,586) |  |  | $ | (11,873) |

Net Cash Used in Operating Activities
Net cash used in operating activities was $110.1 million for the nine months ended September 30, 2025 as compared to $102.0 million for the nine months ended September 30, 2024, an increase of $8.1 million. The increase was primarily due to the payment of the 2023 discarded drug rebate of $7.2 million paid in the first quarter of 2025, a $4.0 million period over period increase in annual bonus and retention payments, $3.9 million period over period decrease in interest income, $3.4 million in severance payments as a result of the 2025 restructuring, partially offset by a $2.1 million period over period increase in partner collections and the timing of other operating cash payments and receipts.
Net Cash Used in Investing Activities
Net cash used in investing activities was $0.3 million for the nine months ended September 30, 2025 as compared to $0.8 million for the nine months ended September 30, 2024, a decrease of $0.5 million. The decrease in net cash used in investing activities relates to timing of purchases of property and equipment.
Net Cash Provided by Financing Activities
Net cash provided by financing activities was $93.9 million for the nine months ended September 30, 2025 and primarily related to the net proceeds received from the completion of the Company’s June 2025 Private Placement. Net cash provided by financing activities was $98.2 million for the nine months ended September 30, 2024 and primarily related to the net proceeds received from the completion of the Company’s 2024 Equity Offering in May 2024.
Off-Balance Sheet Arrangements
During the periods presented, we did not have, and we do not currently have, any off-balance sheet arrangements.
Contractual Obligations and Commitments
As a result of the 2025 Restructuring, and in accordance with the UK facility lease agreement, the Company notified the landlord of its intention to terminate the lease. In accordance with the lease terms, the landlord may require the Company to return the leased space to its original condition upon termination of the lease agreement, including the removal of the Company’s leasehold improvements. The Company is in negotiations with the landlord to determine the specific works to be removed or restored, if any, and as of September 30, 2025, amounts are reasonably estimable and a liability of $0.8 million was recorded. There have been no further changes from the contractual obligations and commitments previously disclosed in our Annual Report.
Critical Accounting Estimates
The preparation of our unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in our unaudited condensed consolidated financial statements. There have been no material changes to the significant accounting estimates previously disclosed in our Annual Report.
Recently Issued and Adopted Accounting Pronouncements
Refer to Note 2 to our unaudited condensed consolidated financial statements for recently issued accounting pronouncements not yet adopted as of the date of this Quarterly Report.
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Item 3. Quantitative and Qualitative Disclosures About Market Risk
We are not required to provide the information required by this Item 3 as we are a smaller reporting company.
Item 4. Controls and Procedures
Disclosure Controls and Procedures
Our management, under the supervision and with the participation of our Chief Executive Officer and Chief Financial Officer, has performed an evaluation of our disclosure controls and procedures (as defined in Rule 13a-15(e) under the Exchange Act) as of the end of the period covered by this report, as required by Rule 13a-15(b) under the Exchange Act. Based upon this evaluation, our Chief Executive Officer and Chief Financial Officer, has concluded that, as of the end of the period covered by this Quarterly Report, our disclosure controls and procedures were effective in ensuring that the information required to be disclosed by us in the reports that we file or submit under the Exchange Act is recorded, processed, summarized and reported within the time periods specified by the SEC’s rules and forms, and that the information required to be disclosed by us in the reports that we file or submit under the Exchange Act is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate, to allow timely decisions regarding required disclosure.
Changes in Internal Control Over Financial Reporting
There were no changes to internal control over financial reporting during the quarter ended September 30, 2025, that would have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.
PART II: OTHER INFORMATION
Item 1. Legal Proceedings
From time to time, we may be subject to various legal proceedings and claims that arise in the ordinary course of our business activities. The results of litigation and claims cannot be predicted with certainty. As of the date of this Quarterly Report, we do not believe that we are party to any claim or litigation, the outcome of which would, individually or in the aggregate, be reasonably expected to have a material adverse effect on our business.
Item 1A. Risk Factors
Below we are providing, in supplemental form, additions to our risk factors as previously disclosed in our Annual Report on Form 10-K for the year ended December 31, 2024.
Changes in tariffs could increase our cost of sales and our operating expenses.
The U.S. government has recently announced, and is expected to continue to announce, significant changes to its trade policy, including the imposition of tariffs. Negotiations between the United States and other countries are ongoing, and the outcome of those negotiations and the scope of any tariff exemptions remain uncertain. We operate internationally and our products are manufactured outside of the United States, primarily in Europe. As a result, we may experience higher costs of sales and increased operating expenses in the future due to tariffs that may be imposed on U.S imports of our product for commercial sale in the U.S. These tariffs could adversely affect our financial condition and results of operations.
Changes in drug pricing policies of the current U.S. administration may negatively impact our product sales revenue.
The current administration has indicated that it plans to pursue additional policies aimed at lowering prescription drug costs. For example, in May 2025, the administration published an executive order regarding most favored nation (“MFN”) drug pricing, which is sometimes referred to as international reference pricing. This executive order directs the Secretary of Health and Human Services to communicate MFN price targets to pharmaceutical manufacturers, and if significant progress towards MFN pricing is not delivered, to propose a rule making plan to impose MFN pricing. The scope, timing, and potential impact of current and future policy initiatives remain uncertain, and accordingly, we cannot predict how such legal and regulatory changes may affect our business, operations, or financial condition. However, if MFN drug pricing is implemented, the U.S. list price of ZYNLONTA that is also being commercialized outside of the United States could be substantially reduced, which could negatively impact our U.S. product sale revenues and the overall U.S. market opportunity.
Item 2. Unregistered Sales of Equity Securities and Use of Proceeds
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Recent Sales of Unregistered Securities
The information required to be reported under this item has been disclosed on Form 8-K filed on October 14, 2025 and is incorporated herein by reference.
Issuer Purchases of Equity Securities
There were no purchases of our equity securities by or on behalf of us or any affiliated purchaser during the period covered by this report.
Item 3. Defaults Upon Senior Securities
None.
Item 4. Mine Safety Disclosure
Not applicable.
Item 5. Other Information
Insider Trading Arrangements
None of our directors or officers adopted or terminated a Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement during the period covered by this report.
Item 6. Exhibits
Exhibits
The exhibits listed below are filed with or incorporated by reference into this Quarterly Report.

|  |  | Incorporation by Reference
Exhibit No. | Description |  | Form | File No. | Exhibit No. | Filing Date
3.1 | Articles of Association of ADC Therapeutics SA |  | 8-K | 001-39071 | 3.1 | June 5, 2025
10.1 | Form of securities purchase agreement |  | 8-K | 001-39071 | 10.1 | October 14, 2025
10.2 | Form of Pre-Funded Warrant |  | 8-K | 001-39071 | 10.2 | October 14, 2025
31.1* | Certification of Principal Executive Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 |  |  |  |  |
31.2* | Certification of Principal Financial Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 |  |  |  |  |
32.1* | Certification of Principal Executive Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 |  |  |  |  |
32.2* | Certification of Principal Financial Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 |  |  |  |  |
101.INS | XBRL Taxonomy Instance Document |  |  |  |  |
101.SCH | XBRL Taxonomy Extension Schema Document |  |  |  |  |
101.CAL | XBRL Taxonomy Extension Calculation Linkbase Document |  |  |  |  |
101.DEF | XBRL Taxonomy Extension Definition Linkbase Document |  |  |  |  |
101.LAB | XBRL Taxonomy Extension Label Linkbase Document |  |  |  |  |
101.PRE | XBRL Taxonomy Extension Presentation Linkbase Document |  |  |  |  |
104 | Cover Page Interactive Data File (embedded with the Inline XBRL document and contained in Exhibit 101) |  |  |  |  |

* Filed herewith.
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SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

|  | ADC Therapeutics SA
|  |  | /s/ Ameet Mallik
Date: November 10, 2025 |  | By: | Ameet Mallik
|  |  | Chief Executive Officer
|  |  | (Principal Executive Officer)

|  |  | /s/ Jose Carmona
Date: November 10, 2025 |  | By: | Jose Carmona
|  |  | Chief Financial Officer
|  |  | (Principal Financial Officer)

|  |  | /s/ Lisa Kallebo
Date: November 10, 2025 |  | By: | Lisa Kallebo
|  |  | Corporate Controller and Chief Accounting Officer
|  |  | (Principal Accounting Officer)

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