Heidelberg Pharma AG / DE000A11QVV0

PRESS RELEASE Ladenburg, Germany, 24 November 2025 – Heidelberg Pharma AG (FSE: HPHA), a clinical stage biotech company developing innovative Antibody Drug Conjugates (ADCs), today announced that the Supervisory Board has revoked the appointment of Professor Andreas Pahl as member of the Executive Management Board and Chief Executive Officer, and has instead appointed Dr Dongzhou Jeffery Liu as Chairman of the Executive Management Board and new Chief Executive Officer, with immediate effect. Today, Dr Liu has stepped down from his position as a member of the Supervisory Board of Heidelberg Pharma, with effect as of 23 December 2025. His permanent appointment as Chairman of the Executive Management Board and Chief Executive Officer will become effective as of 24 December 2025. For the transition period from today until 23 December 2025 he will be seconded as a deputy member to the Executive Management Board pursuant to section 105 (2) of the German Stock Corporation Act (Aktiengesetz). Dr. Karl Benedikt Biesinger, Chairman of the Supervisory Board of Heidelberg Pharma AG, commented: "On behalf of the Supervisory Board, I would like to thank Professor Pahl for his many years of service on the Executive Management Board of Heidelberg Pharma. With his scientific expertise, he shaped our unique Amanitin-based ADC technology to the lead clinical stage ADC project HDP-101. We heartly welcome Dr Liu as new Chief Executive Officer of the Company, we are convinced that he will further strengthen Heidelberg Pharma’s profile with great dedication.” Dr Liu is Chief Scientific Officer (CSO) and President of Huadong Global Development at Huadong Medicine in Hangzhou, China. Prior to that he held various leading positions in the pharma industry in the US, including GlaxoSmithKline, Wyeth (now Pfizer) and Forest Labs (now Abbvie). His more than 25 years of industry experience include clinical and preclinical research & development of medicinal products, including ADC products. Dr Jeffery Liu, Chief Executive Officer of Heidelberg Pharma, added: “I am very pleased to join the company as CEO. I am confident that Heidelberg Pharma’s ATAC technology has great potential for the effective treatment of cancer patients as shown by the latest clinical data with HDP-101. I am looking forward to leading the Company on its journey towards a new generation of ADC products.” About Heidelberg Pharma Heidelberg Pharma is a biopharmaceutical company working on a new treatment approach in oncology and developing novel drugs based on its ADC technologies for the targeted and highly effective treatment of cancer. ADCs are antibody-drug conjugates that combine the specificity of antibodies with the efficacy of toxins to fight cancer. Selected antibodies are loaded with cytotoxic compounds, the so-called payloads, that are transported into diseased cells. Inside the cells, the toxins then unleash their effect and kill the diseased cells. Heidelberg Pharma is the first company to use the compound Amanitin from the green death cap mushroom in cancer therapy. The biological mechanism of action of the toxin represents a new therapeutic modality and is used as a compound in the Amanitin-based ADC technology, the so-called ATAC technology. The lead candidate HDP-101 (INN: pamlectabart tismanitin) is a BCMA ATAC in clinical development for multiple myeloma. The candidate has been granted Orphan Drug Designation and Fast Track Designation from the FDA. A second ATAC candidate, HDP-102 is in clinical development stage in Non-Hodgkin Lymphoma. HDP-103 against metastatic castration-resistant prostate cancer and HDP-104 targeting gastrointestinal tumors such as colorectal cancer have completed preclinical development. Heidelberg Pharma is open for partnering. The company is based in Ladenburg, Germany, and is listed on the Frankfurt Stock Exchange: ISIN DE000A11QVV0 / WKN A11QVV / Symbol HPHA. More information is available at www.heidelberg-pharma.com ATAC® is a registered trademark of Heidelberg Pharma Research GmbH.

Contact Heidelberg Pharma AG Sylvia Wimmer Director Corporate Communications Tel.: +49 89 41 31 38-29 E-Mail: investors@hdpharma.com Gregor-Mendel-Str. 22, 68526 Ladenburg

IR/PR-Support MC Services AG Katja Arnold (CIRO) Managing Director & Partner Tel.: +49 89 210 228-40 E-Mail: katja.arnold@mc-services.eu

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