ADC Therapeutics Announces U.S. Food and Drug Administration Has Lifted Partial Clinical Hold on Pivotal Phase 2 Clinical Trial of Camidanlumab Tesirine Lausanne, Switzerland

ADC Therapeutics Announces U.S. Food and

Drug Administration Has Lifted Partial Clinical Hold on Pivotal Phase 2 Clinical Trial of Camidanlumab Tesirine

Lausanne, Switzerland -

July 6, 2020 - ADC Therapeutics SA (NYSE:ADCT), a clinical-stage oncology-focused biotechnology company leading

the development and commercialization of next-generation antibody drug conjugates (ADCs) with highly potent and targeted pyrrolobenzodiazepine

(PBD) dimer technology, today announced that the U.S. Food and Drug Administration (FDA) has lifted the partial clinical hold

on the pivotal Phase 2 clinical trial of camidanlumab tesirine (Cami, formerly ADCT-301) in patients with relapsed or refractory

Hodgkin lymphoma (HL).

"The ADC Therapeutics team

worked diligently to provide a thorough and prompt response to the FDA following its request for information about our pivotal

Phase 2 clinical trial of Cami," said Jay Feingold, MD, PhD, Senior Vice President and Chief Medical Officer of ADC Therapeutics.

"During the partial clinical hold we continued to treat patients benefiting from Cami, and now look forward to resuming

the enrollment of new patients in the trial as soon as possible."

The 100-patient Phase 2, multi-center,

open-label, single-arm clinical trial is evaluating the safety and efficacy of Cami in patients with relapsed or refractory HL.

Patients with pathologically confirmed relapsed or refractory HL who have failed three prior lines of therapy, including brentuximab

vedotin and a checkpoint inhibitor approved for HL such as nivolumab or pembrolizumab, are eligible for enrollment in the clinical

trial. The trial is intended to support the submission of a Biologics License Application to the FDA.

About Camidanlumab Tesirine

Camidanlumab tesirine (Cami, formerly

ADCT-301) is an antibody drug conjugate (ADC) comprised of a monoclonal antibody that binds to CD25 (HuMax -TAC, licensed

from Genmab A/S), conjugated to the pyrrolobenzodiazepine (PBD) dimer payload, tesirine. Once bound to a CD25-expressing cell,

ADCT-301 is internalized into the cell where enzymes release the PBD-based warhead killing the cell with an immunogenic cell death.

The intra-tumoral release of its PBD warhead may also cause bystander killing of neighboring tumor cells. The ADC also depletes

CD25-positive regulatory T cells in the tumor environment. All of these properties of Cami may enhance immune-mediated anti-tumor

activity. Cami is being evaluated in a pivotal Phase 2 clinical trial in patients with relapsed or refractory Hodgkin lymphoma

(HL), as well as in a Phase 1a/1b clinical trial in patients with relapsed or refractory HL and non-Hodgkin lymphoma and a Phase

1b clinical trial in solid tumors.

ADC Therapeutics SA (NYSE:ADCT)

is a late clinical-stage oncology-focused biotechnology company pioneering the development and commercialization of highly potent

and targeted antibody drug conjugates (ADCs) for patients with hematological malignancies and solid tumors. The Company develops

ADCs by applying its decades of experience in this field and using next-generation pyrrolobenzodiazepine (PBD) technology to which

ADC Therapeutics has proprietary rights for its targets. Strategic target selection for PBD-based ADCs and substantial investment

development have enabled ADC Therapeutics to build a deep clinical and research pipeline of therapies for the

treatment of hematological and solid tumor cancers. The Company has multiple PBD-based ADCs in ongoing clinical trials, ranging

from first in human to pivotal Phase 2 clinical trials, in the USA and Europe, and numerous preclinical ADCs in development.

Loncastuximab tesirine (Lonca,

formerly ADCT-402), the Company's lead product candidate, has been evaluated in a 145-patient pivotal Phase 2 clinical trial

for the treatment of relapsed or refractory diffuse large B-cell lymphoma (DLBCL) that showed a 48.3% interim overall response

rate (ORR), which exceeded the target primary endpoint. Camidanlumab tesirine (Cami, formerly ADCT-301), the Company's second

lead product candidate, is being evaluated in a 100-patient pivotal Phase 2 clinical trial for the treatment of relapsed or refractory

Hodgkin lymphoma (HL) after having shown an 86.5% ORR in HL patients in a Phase 1 clinical trial. The Company is also evaluating

Cami as a novel immuno-oncology approach for the treatment of various advanced solid tumors.

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

Forward-Looking Statements

This press release includes forward-looking

statements, beliefs or opinions, including statements with respect to our business strategies and plans, competitive position

and our objectives for future operations and our financial performance. These forward-looking statements involve known and unknown

risks and uncertainties, including those described in our filings with the U.S. Securities and Exchange Commission, many of which

are beyond our control and all of which are based on our management's current beliefs and expectations about future events. These

forward-looking statements include all matters that are not historical facts. Forward-looking statements may and often do differ

materially from actual results. No assurance can be given that such future results will be achieved. Such forward-looking statements

contained in this document speak only as of the date of this document. We expressly disclaim any obligation or undertaking to

update these forward-looking statements contained in this document to reflect any change in our expectations or any change in

events, conditions, or circumstances on which such statements are based unless required to do so by applicable law. No representations

or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements.

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About ADC Therapeutics

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on a regular basis. This list of channels may be updated from time to time on ADC Therapeutics' investor relations website and

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under the Securities Act of 1933, as amended.

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