ADC Therapeutics Provides Business Updates ZYNLONTA 1 4Q 2023 net sales expected to be ~$16.5 million, a double-digit percentage increase as compared to 3Q 2023 LOTIS-7: Study of ZYNLONTA in combination with bispecifics

ADC Therapeutics Provides Business Updates

ZYNLONTA 1 4Q 2023 net sales expected

to be ~$16.5 million, a double-digit percentage increase as compared to 3Q 2023

LOTIS-7: Study of ZYNLONTA in combination with

bispecifics cleared first dosing cohort with no DLT and with early signs of efficacy

ADCT-601 (targeting AXL): Reached MTD and currently

in dose optimization; Early signs of antitumor activity in both monotherapy and in combination

Multiple data catalysts expected in 2024 and

with a cash runway now expected into 4Q 2025

Lausanne, Switzerland,

January 4, 2024 - ADC Therapeutics SA (NYSE: ADCT) today provided business updates.

we took a number of decisive actions to help position the Company for success in 2024 and beyond. We prioritized our pipeline, strengthened

our organization and implemented a disciplined capital allocation model to generate cost efficiencies," said Ameet Mallik, Chief

Executive Officer of ADC Therapeutics. "We believe we are starting to see signs of the commercial turnaround. We are also encouraged

to see positive initial signals in the LOTIS-7 trial of ZYNLONTA in combination with bispecifics as well as early signs of antitumor

activity in the Phase 1b trial of ADCT-601. We now expect our cash runway to extend into the fourth quarter of 2025 and believe we are

on a path to unlock the substantial value in the Company."

(loncastuximab tesirine-lpyl)

survival (PFS) was not reached, and the 12-month PFS was 92.3% . The majority of AEs were grade 1. Grade 3 AEs included neutropenia

(n=2; 6.2%), and one case each (3.1%) of hyperglycemia, increased ALT, fatigue, dyspnea and skin infection. Neutropenia was the only

grade 4 AE (n=1; 3.1%).

the fourth quarter of 2023 with cash and cash equivalents of ~$278.5 million.

the following based on its current business plan:

the Company's Form 8-K and accompanying presentation filed with the Securities and Exchange Commission today for additional information.

(loncastuximab tesirine-lpyl)

is a CD19-directed antibody drug conjugate (ADC). Once bound to a CD19-expressing cell, ZYNLONTA is internalized by the cell, where

enzymes release a pyrrolobenzodiazepine (PBD) payload. The potent payload binds to DNA minor groove with little distortion, remaining

less visible to DNA repair mechanisms. This ultimately results in cell cycle arrest and tumor cell death.

Drug Administration (FDA) and the European Medicines Agency (EMA) have approved ZYNLONTA (loncastuximab tesirine-lpyl) for the treatment

of adult patients with relapsed or refractory (r/r) large B-cell lymphoma after two or more lines of systemic therapy, including diffuse

large B-cell lymphoma (DLBCL) not otherwise specified (NOS), DLBCL arising from low-grade lymphoma and also high-grade B-cell lymphoma.

The trial included a broad spectrum of heavily pre-treated patients (median three prior lines of therapy) with difficult-to-treat disease,

including patients who did not respond to first-line therapy, patients refractory to all prior lines of therapy, patients with double/triple

hit genetics and patients who had stem cell transplant and CAR-T therapy prior to their treatment with ZYNLONTA. This indication is approved

by the FDA under accelerated approval and in the European Union under conditional approval based on overall response rate and continued

approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial. Please

see full prescribing information including important safety information about ZYNLONTA at www.ZYNLONTA.com.

being evaluated as a therapeutic option in combination studies in other B-cell malignancies and earlier lines of therapy.

About 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.

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.

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://adctherapeutics.com/ and follow the Company on LinkedIn.

ZYNLONTA is a registered

trademark of ADC Therapeutics SA.

Forward-Looking Statements

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", "assumes",

"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 actual Zynlonta revenue for 4Q 2023, 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 4Q 2025, the effectiveness of the new commercial go-to-market strategy, competition

from new technologies, and the Company's ability to grow ZYNLONTA revenue in the United States; 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 impact, if any, from data reported by the University of Miami

for their IIT in FL; the timing and results of the Company's or its partners' clinical trials including LOTIS 5 and 7, ADCT

601 and 602 as well as the Company's early-stage pipeline research projects, actions by the FDA or foreign regulatory authorities

with respect to the Company's products or product candidates; projected revenue and expenses; the Company's indebtedness,

including Healthcare Royalty Management and Oaktree and Blue Owl 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

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