ADC Therapeutics Receives NYSE Notice of Non-Compliance With Continued Listing Standards Lausanne, Switzerland

ADC Therapeutics Receives NYSE Notice of Non-Compliance

With Continued Listing Standards

Lausanne, Switzerland, November 7, 2023

- ADC Therapeutics SA (NYSE: ADCT) today announced that on October 10, 2023, it received a notice from the New York Stock Exchange

(NYSE) that the Company is not in compliance with the continued listing minimum price criteria set forth in Section 802.01C of the NYSE

Listed Company Manual, which requires listed companies to maintain an average closing share price of at least $1.00 over a consecutive

30 trading-day period.

In accordance with Section 802.01C of the NYSE

Listed Company Manual, the Company has a cure period of six months from receipt of the notice to regain compliance with the continued

listing minimum price criteria. The notice has no immediate impact on the listing of the Company's common shares, which will remain

listed and traded on the NYSE during this period, subject to the Company's compliance with the other continued listing requirements.

The Company can regain compliance if on the last

trading day of any calendar month during the cure period the Company's common shares have a closing share price of at least $1.00

and an average closing share price of at least $1.00 over the 30 trading-day period ending on the last trading day of that month. The

Company has notified the NYSE of its intent to cure the deficiency, which may include, if necessary, effecting a reverse share split,

subject to board and shareholder approval.

About ADC Therapeutics

ADC Therapeutics (NYSE: ADCT) is a commercial-stage

global leader and pioneer in the field of antibody drug conjugates (ADCs). The Company is advancing its proprietary ADC technology to

transform the treatment paradigm for patients with hematologic malignancies and solid tumors.

ADC Therapeutics' CD19-directed ADC ZYNLONTA

(loncastuximab tesirine-lpyl) received accelerated approval by the FDA and conditional approval from the European Commission for the treatment

of relapsed or refractory diffuse large B-cell lymphoma after two or more lines of systemic therapy. ZYNLONTA is also in development in

combination with other agents and in earlier lines of therapy. In addition to ZYNLONTA, ADC Therapeutics has multiple ADCs in ongoing

clinical and preclinical development.

ADC Therapeutics is based in Lausanne (Biop le),

Switzerland and has operations in London, the San Francisco Bay Area and New Jersey. For more information, please visit https://www.adctherapeutics.com/

and follow the Company on LinkedIn.

ZYNLONTA is a registered trademark of ADC

Forward-Looking Statements

This press release contains

forward-looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. In

some cases you can identify forward-looking statements by terminology such as "may", "will", "should",

"would", "expect", "intend", "plan", "anticipate", "believe",

"estimate", "predict", "potential", "seem", "seek", "future",

"continue", or "appear" or the negative of these terms or similar expressions, although not all forward-looking

statements contain these identifying words. Forward-looking statements are subject to certain risks and uncertainties that can cause actual

results to differ materially from those described. Factors that may cause such differences include, but are not limited to: the ability

of the Company to cure the deficiency and regain compliance with NYSE listing standards and for the Company's common shares to remain

listed on the NYSE; the success of the Company's updated corporate strategy including operating efficiencies, capital deployment

and portfolio prioritization; the Company's ability to achieve the decrease in total operating expenses for 2023 and 2024, the expected

cash runway into the middle of 2025, the effectiveness of the new commercial go-to-market strategy, competition from new technologies,

the Company's ability to continue to commercialize ZYNLONTA in the United States and future revenue from the same; Swedish

Orphan Biovitrum AB (Sobi ) ability to successfully commercialize ZYNLONTA in the European Economic Area and market acceptance,

adequate reimbursement coverage, and future revenue from the same; approval by the NMPA of the BLA for ZYNLONTA in China submitted by

Overland ADCT BioPharma and future revenue from the same, our strategic partners', including Mitsubishi Tanabe Pharma Corporation,

ability to obtain regulatory approval for ZYNLONTA in foreign jurisdictions, and the timing and amount of future revenue and payments

to us from such partnerships; the Company's ability to market its products in compliance with applicable laws and regulations; the

Company's expectations regarding the impact of the Infrastructure Investment and Jobs Act; the timing and results of the Company's

or its partners' research projects or clinical trials including LOTIS 5 and 7, ADCT 901, 601 and 602, the impact, if any, from discontinuation

of the LOTIS-9 study, actions by the FDA or foreign regulatory authorities with respect to the Company's products or product candidates,

the timing and outcome of regulatory submissions for the Company's products or product candidates; the ability to complete clinical

trials on expected timelines, if at all; projected revenue and expenses; the Company's indebtedness, including Healthcare Royalty

Management and Blue Owl and Oaktree facilities, and the restrictions imposed on the Company's activities by such indebtedness, the

ability to repay such indebtedness and the significant cash required to service such indebtedness; and the Company's ability to

obtain financial and other resources for its research, development, clinical, and commercial activities. Additional information concerning

these and other factors that may cause actual results to differ materially from those anticipated in the forward-looking statements is

contained in the "Risk Factors" section of the Company's Annual Report on Form 20-F and in the Company's other periodic reports

and filings with the Securities and Exchange Commission. These statements involve known and unknown risks, uncertainties and other factors

that may cause actual results, performance, achievements or prospects to be materially different from any future results, performance,

achievements or prospects expressed in or implied by such forward-looking statements. The Company cautions investors not to place undue

reliance on the forward-looking statements contained in this document. The Company undertakes no obligation to revise or update these

forward-looking statements to reflect events or circumstances after the date of this press release, except as required by law.