PRESS RELEASE

Heidelberg Pharma’s Partner Takeda Reached Development Milestone

Ladenburg, Germany, 8 August 2023 – Heidelberg Pharma AG (FSE: HPHA) announced today that its partner Takeda reached a development milestone for starting a GLP (Good Laboratory Practice) toxicology study for an Antibody Targeted Amanitin Conjugate. Upon achievement of the milestone, Heidelberg Pharma received a milestone payment. The payment was already budgeted for in Heidelberg Pharma's financial forecast for financial year 2023.

Prof. Andreas Pahl, CSO of Heidelberg Pharma AG, commented: "We are happy that the development of Takeda’s ATAC candidate, an Amanitin-based ADC, is progressing successfully and that the important GLP study was started. We are looking forward to the next development steps."

In 2022, Takeda exclusively licensed the worldwide development and commercialization rights from Heidelberg Pharma for the use of the ATAC technology with an antibody directed to a defined target and the resulting product candidates.

About Heidelberg Pharma's proprietary ATAC technology

Antibody drug conjugates (ADCs) combine the high affinity and specificity of antibodies with the potency of cytotoxic small molecules for the treatment of cancer. Heidelberg Pharma works with ADCs based on its proprietary ATAC technology using Amanitin as the active ingredient. Amanitin belongs to the amatoxin molecules, bicyclic peptides that occur naturally in the green deathcap mushroom. Amanitin inhibits mRNA transcription by binding to RNA polymerase II, a mechanism that is crucial for the survival of eukaryotic cells. Inhibition of RNA polymerase II is a new mode of action for cancer therapy. In preclinical testing, ATACs have been shown to be highly efficacious, overcoming frequently encountered resistance mechanisms and combating even quiescent tumor cells.

About Heidelberg Pharma

Heidelberg Pharma is an oncology specialist and the first company to develop the toxin Amanitin into cancer therapies using its proprietary ATAC technology and to advance the biological mode of action of the toxin as a novel therapeutic principle. The proprietary technology platform is being applied to develop the Company’s own therapeutic ATACs as well as in third-party collaborations. The proprietary lead candidate HDP-101 is a BCMA ATAC in clinical development for multiple myeloma. Further ATAC candidates are being developed against different targets such as CD37, PSMA or GCC each in the indications non-Hodgkin's lymphoma, metastatic castration-resistant prostate cancer or gastrointestinal tumors such as colorectal cancer.

Heidelberg Pharma AG is based in Ladenburg, Germany, and is listed on the Frankfurt Stock Exchange: ISIN DE000A11QVV0 / WKN A11QVV / Symbol HPHA. More information is available at http://www.heidelberg-pharma.com/.

ATAC^® is a registered trademark of Heidelberg Pharma Research GmbH in the EU and the USA.

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