Overland ADCT BioPharma Announces Pivotal Phase 2 Clinical Trial in China Evaluating ZYNLONTA® for DLBCL Achieves Primary Objective

Shanghai, April 12, 2023 — Overland ADCT BioPharma, a joint venture created by Overland Pharmaceuticals and ADC Therapeutics SA (NYSE:ADCT), announced today that the pivotal Phase 2 clinical trial (OL-ADCT-402-001) evaluating the efficacy and safety of ZYNLONTA® (loncastuximab tesirine) as a single-agent treatment for Chinese patients with relapsed or refractory diffuse large B-cell lymphoma (r/r DLBCL) has achieved the primary objective. Based on the positive results, the marketing authorization application seeking approval for ZYNLONTA for the treatment of r/r DLBCL is planned to be submitted to the China National Medical Products Administration (NMPA).

Overland ADCT BioPharma is also conducting a confirmatory Phase 3 clinical trial (ADCT-402-311) in China to evaluate the efficacy and safety of ZYNLONTA in combination with rituximab (Lonca-R) versus rituximab plus gemcitabine and oxaliplatin (R-GemOx) for the treatment of patients with r/r DLBCL. The trial is expected to provide scientific evidence to support a marketing authorization application for the complete approval of ZYNLONTA as a single-agent treatment for r/r DLBCL patients assuming conditional approval is previously granted by the China National Medical Products Administration (NMPA) and seeking approval of ZYNLONTA in combination with rituximab as a second-line treatment for r/r DLBCL patients in China in the future.

“We are thrilled that the first registered clinical trial for ZYNLONTA in China has achieved the primary objective after we successfully completed patient enrollment ahead of schedule during the challenging year of COVID-19 pandemic,” said Dr. Feng Roger Luo, Chief Development Officer and Head of Clinical and Preclinical Development of Overland Pharmaceuticals. “We are grateful for the strong support from all clinical research centers and collaborators. We will continue to advance the clinical development of ZYNLONTA in China, and are committed to bring effective and safe treatment options to Chinese DLBCL patients.”

On April 23, 2021, ADC Therapeutics was granted accelerated approval for ZYNLONTA by the U.S. Food and Drug Administration (FDA) as the first and only CD19-targeted ADC as a single-agent treatment for adult patients with r/r DLBCL after two or more lines of systemic therapy. In December 2022, ADCT Therapeutics was also granted conditional marketing authorization for Zynlonta by the European Commission for the treatment of r/r DLBCL.

About the Pivotal Phase 2 Clinical Trial (OL-ADCT-402-001)
OL-ADCT-402-001 is an open-label, single-arm study designed to evaluate the efficacy and safety of ZYNLONTA (loncastuximab tesirine) as a single-agent treatment for Chinese patients with relapsed or refractory (r/r) diffuse large B-cell lymphoma (DLBCL). The primary endpoint of this study is the overall response rate (ORR), and the secondary endpoints include duration of response (DOR), complete response (CR), and progression-free survival (PFS). The first China pivotal study OL-ADCT-402-001 had achieved its primary objective, and had demonstrated the efficacy and safety data which are consistent with the results of the global pivotal study ADCT-402-201.

About ZYNLONTA® (loncastuximab tesirine)
ZYNLONTA® is a CD19-directed antibody drug conjugate (ADC). Once bound to a CD19-expressing cell, ZYNLONTA® is internalized by the cell, where enzymes release a pyrrolobenzodiazepine (PBD) payload. The potent payload binds to DNA minor groove with little distortion, remaining less visible to DNA repair mechanisms. This ultimately results in cell cycle arrest and tumor cell death.
The U.S. Food and Drug Administration (FDA) has approved ZYNLONTA (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 also high-grade B-cell lymphoma. The trial included a broad spectrum of heavily pre-treated patients (median three prior lines of therapy) with difficult-to-treat disease, including patients who did not respond to first-line therapy, patients refractory to all prior lines of therapy, patients with double/triple hit genetics and patients who had stem cell transplant and CAR-T therapy prior to their treatment with ZYNLONTA. This indication is approved by the FDA under accelerated approval based on overall response rate and continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial. Please see full prescribing information including important safety information about ZYNLONTA at www.ZYNLONTA.com.
ZYNLONTA is also being evaluated as a therapeutic option in combination studies in other B-cell malignancies and earlier lines of therapy.
ZYNLONTA® is a registered trademark of ADC Therapeutics SA.

About ADC Therapeutics
ADC 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 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. In addition to ZYNLONTA, 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. For more information, please visit https://adctherapeutics.com/ and follow the Company on Twitter and LinkedIn.
ZYNLONTA® is a registered trademark of ADC Therapeutics SA.

About Overland Pharmaceuticals
Overland Pharmaceuticals is building a fully integrated biopharma company with a mission to bring innovative medicines to underserved patients in Asia and around the world. By leveraging our resources, global network, and local expertise across the biopharma ecosystem in Asia, Overland is establishing a portfolio of differentiated therapeutic candidates in a few carefully selected therapeutic areas. Through formative partnerships, Overland will move forward the development and commercialization of the most promising advances in medicine.

ADC Therapeutics Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements are subject to certain risks and uncertainties that can cause actual results to differ materially from those described. Factors that may cause such differences include, but are not limited to: Overland ADCT Biopharma’s ability to obtain marketing authorization approval for ZYNLONTA in China and future revenue from the same, the Company’s ability to achieve the 2023 net product sales guidance for ZYNLONTA® and the decrease in total operating expenses for 2023 and 2024, the expected cash runway into the middle of 2025, the Company’s ability to 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 payments to us from such partnerships; the Company’s ability to market its products in compliance with applicable laws and regulations; the Company’s expectations regarding the impact of the Infrastructure Investment and Jobs Act; 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 respect to the Company’s products or product candidates; projected revenue and expenses; the Company’s indebtedness, including Healthcare Royalty Management and Blue Owl and Oaktree facilities, and the restrictions imposed on the Company’s activities by such indebtedness, the ability to repay such indebtedness and the significant cash required to service such indebtedness; the Company’s ability to obtain financial and other resources for its research, development, clinical, and commercial activities and other statements regarding matters that are not historical facts, and involve predictions. These statements involve known and unknown risks, uncertainties and other factors that may cause actual results, performance, achievements or prospects to be materially different from any future results, performance, achievements or prospects expressed in or implied by such forward-looking statements. In some cases you can identify forward-looking statements by terminology 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 factors that may cause actual results to differ materially from those anticipated in the forward-looking statements is contained in the “Risk Factors” section of the Company’s Annual Report on Form 20-F and in the Company’s other periodic reports and filings with the Securities and Exchange Commission. The Company cautions investors not to place undue reliance on the forward-looking statements contained in this document. The Company undertakes no obligation to revise or update these forward-looking statements to reflect events or circumstances after the date of this press release, except as required by law.