6-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K****

REPORTOF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of January 2023.

Commission FileNumber: 001-39071

ADC Therapeutics SA

(Exact name ofregistrant as specified in its charter)

Biopôle

Route de la Corniche3B

1066 Epalinges

Switzerland

(Address of principalexecutive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ☐

INFORMATION CONTAINEDIN THIS REPORT ON FORM 6-K

On January 3, 2023, ADC Therapeutics SA (the “Company”) announced that Mohamed Zaki, M.D., Ph.D., has been appointed as the Company’s Chief Medical Officer. Joseph Camardo is stepping down from full-time work to pursue other avenues to engage with the pharmaceutical industry and patient community. Below are the biographical and other information required by Item 6.A. of Form 20-F with respect to Dr. Zaki:

Dr. Zaki was appointed as our Chief Medical Officer in January 2023. From September 2018 to December 2022, Dr. Zaki served in senior clinical development roles at AbbVie Inc., including as Vice President & Global Head of Oncology Clinical Development and Vice President & Global Head of Hematology Clinical Development. From February 2010 to September 2018, Dr. Zaki served in various senior clinical development roles at Celgene Corporation. Prior to that, Dr. Zaki worked at Sanofi-Aventis and Centocor, Inc., a subsidiary of Johnson & Johnson. Dr. Zaki holds an M.D. and an M.S. from Ain Shams University School of Medicine and a Ph.D. jointly from the University of Pennsylvania and Ain Shams University School of Medicine. Dr. Zaki also served on the faculty of both institutions and was a practicing physician earlier in his career. There are no family relationships between Dr. Zaki or any of our directors or executive officers.

The Company issued a press release in connection with Dr. Zaki’s appointment as Chief Medical Officer, which is attached hereto as Exhibit 99.1.

INCORPORATIONBY REFERENCE

This Report on Form 6-K (other than Exhibit 99.1 hereto) shall be deemed to be incorporated by reference into the registration statements on Form F-3 (Registration Nos. 333-256807, 333-267293 and 333-267295) of ADC Therapeutics SA and to be a part thereof from the date on which this report is filed, to the extent not superseded by documents or reports subsequently filed or furnished.

SIGNATURE

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.

EXHIBIT INDEX

ADC Therapeutics Appoints Mohamed Zaki as ChiefMedical OfficerLAUSANNE, Switzerland,January 3, 2023 – ADC Therapeutics SA (NYSE: ADCT) today announced the appointment of industry veteran Mohamed Zaki, MD, PhD,as Chief Medical Officer (CMO), effective January 3, 2023. He will serve on the Company’sexecutive leadership team. Dr. Zaki succeeds Joseph Camardo, MD, who is stepping down from full-time work to pursue other avenues toengage with the pharmaceutical industry and patient community.“We are excitedto welcome Dr. Zaki to ADC Therapeutics and look forward to his leadership of the development of our deep pipeline of antibody drug conjugates,”said Ameet Mallik, Chief Executive Officer of ADC Therapeutics. “We sincerely thank Dr. Camardo for his tireless commitment toADC Therapeutics and people living with cancer around the world.”Dr. Zaki has spentover 20 years in oncology and hematology drug development. Most recently, he served as Vice President & Global Head of Oncology Developmentat AbbVie. Prior to AbbVie he spent 9 years at Celgene. Previously, Dr. Zaki worked at Sanofi-Aventis and Centocor, Inc., a subsidiaryof Johnson & Johnson. He earned his MD and MS at Ain Shams University School of Medicine in Cairo, Egypt and his PhD from the Universityof Pennsylvania and Ain Shams University School of Medicine in a joint degree program. Dr. Zaki also served on the faculty of both institutionsand was a practicing physician earlier in his career.“ADCTherapeutics is a pioneer and leader in the evolving field of antibody drug conjugates,” said Dr.Zaki. “I look forward to working with the Company’s experienced team of researchers to expand on their innovative scienceand bring more therapeutic options to those impacted by cancer worldwide.”About ADC TherapeuticsADC Therapeutics(NYSE: ADCT) is a commercial-stage biotechnology company helping to improve the lives of those affected by cancer with its next-generation,targeted antibody drug conjugates (ADCs). The Company is advancing its proprietary PBD-based ADC technology to transform the treatmentparadigm for patients with hematologic malignancies and solid tumors.ADC Therapeutics’CD19-directed ADC ZYNLONTA (loncastuximab tesirine-lpyl) is approved by the FDA for the treatment of relapsed or refractory diffuse largeB-cell lymphoma after two or more lines of systemic therapy. ZYNLONTA is also in development in combination with other agents. In additionto ZYNLONTA, ADC Therapeutics has multiple ADCs in ongoing clinical and preclinical development.ADC Therapeuticsis based in Lausanne (Biopôle), 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 Twitterand LinkedIn.Forward-Looking Statements Thispress release contains forward-looking statements within the meaning of the safe harbor provisions of the Private Securities LitigationReform Act of 1995. Forward-looking statements are subject to certain risks and uncertainties that can cause actual results to differmaterially from those described. Factors that may cause such differences include, but are not limited to: the Company’s abilityto 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; our strategic partners’, including Mitsubishi Tanabe Pharma Corporation and Overland Pharmaceuticals,ability to obtain regulatory approval for ZYNLONTA® in foreign jurisdictions, and the timing and amount of future revenue and paymentsto us from such partnerships; the Company’s ability to market its products in compliance with applicable laws and regulations;the timing and results of the Company’s or its partners’ research projects or clinical trials including LOTIS 2, 5 and 9,ADCT 901, 601 and 212, the timing and outcome of regulatory submissions and actions by the FDA or other regulatory agencies with respectto the Company’s products or product candidates; projected revenue and expenses, the Company’s indebtedness including HealthcareRoyalty Management and Oak Tree facilities and the restrictions imposed on the Company’s activities by such indebtedness, the abilityto repay such indebtedness and the significant cash required to service such indebtedness; the Company’s ability to obtain financialand other resources for its research, development, clinical, and commercial activities and other statements regarding matters that arenot historical facts, and involve predictions. These statements involve known and unknown risks, uncertainties and other factors thatmay cause actual results, performance, achievements or prospects to be materially different from any future results, performance, achievementsor prospects expressed in or implied by such forward-looking statements. In some cases you can identify forward-looking statements byterminology 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. Additional information concerning these and other factorsthat may cause actual results to differ materially from those anticipated in the forward-looking statements is contained in the "RiskFactors" section of the Company's Annual Report on Form 20-F and in the Company's other periodic reports and filings with the Securitiesand Exchange Commission. The Company cautions investors not to place undue reliance on the forward-looking statements containedin this press release. All forward-looking statements are based on information currently available to the Company on the date hereof,and the Company undertakes no obligation to revise or update these forward-looking statements to reflect events or circumstances afterthe date of this press release, except as required by law.InvestorsEugeniaLitzADCTherapeuticsEugenia.Litz@adctherapeutics.com+447879 627205 Amanda LoshbaughADC TherapeuticsAmanda.Loshbaugh@adctherapeutics.com+1 917-288-7023MediaMary Ann OndishADC TherapeuticsMaryann.Ondish@adctherapeutics.com+1 914-552-4625