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Exhibit 99.1 ADC THERAPEUTICS ADC Therapeutics Announces FDA Approval of ZYNLONTA ™ ( loncastuximab tesirine - lpyl ) in Relapsed or Refractory Diffuse Large B - Cell Lymphoma First and only CD19 - targeted antibody drug conjugate ( ADC ) as a single - agent treatment for adult patients with relapsed or refractory ( r / r ) diffuse large B - cell lymphoma ( DLBCL ) ZYNLONTA addresses an unmet need across a broad population of third - line ( 3L ) + r / r patients , including patients with DLBCL not otherwise specified , DLBCL arising from low grade lymphoma and high - grade B - cell lymphoma ZYNLONTA demonstrated 48.3 % overall response rate , 24.1 % complete response rate and durable responses in heavily pretreated patients in pivotal LOTIS - 2 trial Investor conference call and webcast to be held Friday , April 23rd at 4 p.m. ET LAUSANNE , Switzerland , April 23 , 2021 - ADC Therapeutics SA ( NYSE : ADCT ) today announced that the U.S. Food and Drug Administration ( FDA ) has approved ZYNLONTA TM ( 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 high - grade B - cell lymphoma . 1 ZYNLONTA , a CD19 - targeted antibody drug conjugate ( ADC ) , has been granted accelerated approval by the FDA based on overall response rate . Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial . " There is a significant unmet need for treatment options for patients with r / r DLBCL , including those who have been heavily pretreated and have difficult - to - treat disease , " said Paolo F. Caimi , MD , University Hospitals Cleveland Medical Center and Case Comprehensive Cancer Center , Case Western Reserve University . " Single - agent ZYNLONTA demonstrated clinically important outcomes in the pivotal LOTIS - 2 study across several disease subtypes . Notably , this included transplant eligible and ineligible patients and patients who previously received stem cell transplant or CAR- T cell therapy . " The FDA approval was based on data from LOTIS - 2 , a large ( n = 145 ) Phase 2 multinational , single - arm clinical trial of ZYNLONTA for the treatment of adult patients with r / r DLBCL following two or more prior lines of systemic therapy . Results from the trial demonstrated an overall response rate ( ORR ) of 48.3 % ( 70/145 patients ) , which included a complete response ( CR ) rate of 24.1 % ( 35/145 patients ) and a partial response ( PR ) rate of 24.1 % ( 35/145 patients ) . Patients had a median time to response of 1.3 months and the median duration of response ( mDoR ) for the 70 responders was 10.3 months ( inclusive of patients who were censored ) . In a pooled safety population the most common adverse reactions ( ≥20 % ) were thrombocytopenia , gamma - glutamyltransferase increased , neutropenia , anemia , hyperglycemia , transaminase elevation , fatigue , hypoalbuminemia , rash , edema , nausea and musculoskeletal pain . In LOTIS - 2 , the most common ( ≥10 % ) grade ≥3 treatment - emergent adverse events were neutropenia ( 26.2 % ) , thrombocytopenia ( 17.9 % ) , gamma - glutamyltransferase increased ( 17.2 % ) and anemia ( 10.3 % ) . " The FDA approval of ZYNLONTA is an exciting advancement for patients with r / r DLBCL and a transformational event for ADC Therapeutics , " said Chris Martin , Chief Executive Officer of ADC