PRESS RELEASE

Heidelberg Pharma Announces Change in Executive Board

• CFO Walter Miller is leaving Heidelberg Pharma at the end of April
• Supervisory Board appoints Peter Willinger as a new Chief Financial Officer, effective 1 May 2026

Ladenburg, Germany, 17 April 2026 – Heidelberg Pharma AG (FSE: HPHA), a clinical-stage biotech company developing innovative Antibody Drug Conjugates (ADCs), announces the change of its Chief Financial Officer. The current Chief Financial Officer of Heidelberg Pharma AG, Mr. Walter Miller, is leaving Heidelberg Pharma AG at his own request upon the expiration of his employment contract to pursue new professional challenges. Mr. Peter Willinger will assume the role of Chief Financial Officer effective 1 May 2026.

Mr. Willinger has more than 20 years of experience as Chief Financial Officer of private and publicly listed companies, such as Apogenix AG, SYGNIS Pharma AG and LION bioscience AG. During this time, he managed numerous transactions such as IPO, M&A and fundraising, and directed several departments, such as Human Resources, Legal/IP, Quality Assurance, Investor & Public Relations and Corporate Development.

Dr. Dongzhou Jeffery Liu, Chief Executive Officer and Chairman of the Executive Management Board of Heidelberg Pharma, commented: “I would like to thank Mr. Miller for his dedicated contributions to Heidelberg Pharma. During his tenure, he demonstrated a high level of commitment and led the company’s finance division in a focused and solution-oriented manner. At the same time, I warmly welcome Peter Willinger as member of our Executive Management Board and new colleague. We are on the verge of launching the second part of our Phase I/IIa trial with our lead ADC candidate HDP-101 and are entering a groundbreaking phase. He is taking on this position during a challenging period, and his experience will play a crucial role in strengthening and securing the company’s long-term financial foundation.”

“We would like to express our sincere gratitude to Mr. Walter Miller. His professional leadership during the recent challenging times and his strong support for the recent successful financings has been very valuable and we wish him all the very best for his future endeavours”, added Dr. Karl Benedikt Biesinger, Chairman of the Supervisory Board of Heidelberg Pharma AG. “Furthermore, we are very pleased to have recruited Mr. Willinger as the new Chief Financial Officer for Heidelberg Pharma. He is a profound expert of the biotech industry and has extensive experience in leading finance departments.”

Mr. Peter Willinger, designated Chief Financial Officer, said: “I have known Heidelberg Pharma for many years and am very excited to join at this important stage in the company’s development where strong clinical progress and disciplined financial management can create significant value. Together with the motivated team I look forward to continuing on the chosen path and to accelerate Heidelberg Pharma’s sustainable and profitable growth.”

About Heidelberg Pharma

Heidelberg Pharma is the first company to develop cancer therapies using Amanitin, a compound derived from the green death cap mushroom. 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. These programs are available 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.

This communication contains certain forward-looking statements relating to the Company's business, which can be identified by the use of forward-looking terminology such as "estimates", "believes", "expects", "may", "will" "should" "future", "potential" or similar expressions or by a general discussion of the Company's strategy, plans or intentions. Such forward-looking statements involve known and unknown risks, uncertainties and other factors, which may cause our actual results of operations, financial condition, performance, or achievements, or industry results, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Given these uncertainties, prospective investors and partners are cautioned not to place undue reliance on such forward-looking statements. We disclaim any obligation to update any such forward-looking statements to reflect future events or developments.