ADC Therapeutics SA

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, 2023.

We do not control the conduct of current or any potential future investigator-initiated clinical trials, and the data from such trials is not subject to our review or quality control.

We have provided clinical data from an investigator-initiated Phase 2 clinical trial of ZYNLONTA for the treatment of relapsed/refractory marginal zone lymphoma. In the future, we may provide clinical data from this and other investigator-initiated clinical trials. We do not control the design or administration of such trials, nor the submission, approval or maintenance of any regulatory and institutional filings required to conduct such trials. Furthermore, we have limited or no rights to audit, review or apply quality control procedures to the clinical data generated from such trials. As a result, we have no control over the conduct of such trials and the timing of any data releases from such trials and we cannot be certain that such trials are or will be conducted in accordance with applicable regulatory requirements or that the clinical data provided to us by the investigators of such trials are accurate, reliable or complete. There can be no assurance regarding the outcome or timing of any IITs, including whether such trials will meet their respective endpoint and whether severe adverse events will occur during the trials. In addition, positive preliminary results in any ongoing IIT may not be predictive of results in the completed trial.

Our articles of association provide that the competent court with jurisdiction over our registered office in Switzerland will be the exclusive forum for shareholder suits against us, members of our board of directors or members of our executive committee.

Our articles of association provide that the competent court with jurisdiction over our registered office in Switzerland will be the exclusive forum for shareholder suits against us, members of our board of directors or members of our executive committee; provided that the foregoing provision does not apply to claims brought to enforce a duty or liability created by the Securities Act or the Exchange Act or any claim for which the courts in the United States have exclusive jurisdiction. This forum selection provision may impose additional litigation costs on shareholders in pursuing any such claims, particularly if the shareholders do not reside in or near Switzerland and limit a shareholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us, members of our board of directors or members of our executive committee, which may discourage lawsuits against us, members of our board of directors and members of our executive committee, although our shareholders will not be deemed to have waived our compliance with federal securities laws and the rules and regulations thereunder.