Report of Foreign Issuer Pursuant to Rule 13a-16 or 15d-16 (6-k)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

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

For the month of September 2021.

____________________

Commission File Number: 001-39071

ADC Therapeutics SA

(Exact name of registrant as specified in its charter)

Biopôle

Route de la Corniche 3B

1066 Epalinges

Switzerland

(Address of principal executive office)

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

Form 20-F

☒

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): ☐

ADC Therapeutics Doses First Patient in Phase 1 Clinical Trial of ADCT-901 in Advanced Solid Tumors

ADCT-901 targets KAAG1, a novel tumor target for ADC development

LAUSANNE, Switzerland, September 27, 2021 – ADC Therapeutics SA (NYSE: ADCT), a commercial-stage biotechnology company improving the lives of those affected by cancer with its next-generation, targeted antibody drug conjugates (ADCs) for patients with hematologic malignancies and solid tumors, today announced the first patient has been dosed in the Phase 1 clinical trial evaluating ADCT-901, targeting kidney associated antigen 1 (KAAG1), in patients with selected advanced solid tumors with high unmet medical needs.

ADCT-901 is composed of a humanized monoclonal antibody (3A4) directed against human KAAG1 conjugated through a cathepsin-cleavable linker to the PBD dimer SG3199, the same cytotoxin used in ADCT’s lead product, ZYNLONTA®. KAAG1 is an attractive, novel tumor target for ADCs expressed on the membrane of tumor cells, while its expression on healthy tissue is very limited.

The open-label, dose-escalation and dose-expansion clinical trial will evaluate the safety, tolerability, pharmacokinetics, and antitumor activity of ADCT-901 as monotherapy in patients with selected advanced solid tumors. For more information about the Phase 1 trial, please visit www.clinicaltrials.gov (identifier NCT04972981).

About ADC Therapeutics

ADC Therapeutics (NYSE: ADCT) is a commercial-stage biotechnology company improving 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 treatment paradigm 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 large b-cell lymphoma after two or more lines of systemic therapy. ZYNLONTA is also in development in combination with other agents. Cami (camidanlumab tesirine) is being evaluated in a late-stage clinical trial for relapsed or refractory Hodgkin lymphoma and in a Phase 1b clinical trial for various advanced solid tumors. In addition to ZYNLONTA and Cami, ADC Therapeutics has multiple ADCs in ongoing clinical and preclinical development.

ADC Therapeutics is based in Lausanne (Biopôle), Switzerland and has operations in London, the San Francisco Bay Area and New Jersey.

ZYNLONTA® is a registered trademark of ADC Therapeutics SA.

INCORPORATION BY REFERENCE

This Report on Form 6-K shall be deemed to be incorporated by reference into the registration statements on Form F-3 (Registration Nos. 333-256686 and 333-256807) 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.