PRESS RELEASE

Heidelberg Pharma to Present New Data on its Proprietary ATAC Technology Platform at the AACR Annual Meeting 2021

Ladenburg, Germany, 31 March 2021 - Heidelberg Pharma AG (FSE: HPHA) announced today that it will present preclinical data on its novel ATAC candidates HDP-102 and HDP-103 as well as data on synergistic effects of ATACs with checkpoint inhibitors at the American Association for Cancer Research (AACR) 2021 Annual Meeting. The meeting will be held in a virtual format from April 10 - 15, 2021.

Details of the poster presentation - PSMA ATACs:
Amanitin-based ADCs targeting PSMA as novel therapeutic modality for prostate cancer therapy
Abstract number: 910
Date and time: 10 April 2021, 8:30 AM - 12:00 PM EDT
Link for the abstract: https://www.abstractsonline.com/pp8/#!/9325/presentation/1947

The poster presentation will cover preclinical data on ATACs targeting PSMA (prostate-specific membrane antigen). This surface protein is overexpressed on prostate tumor cells and can therefore also be used as a biomarker. We show that ATACs targeting PSMA possess high antitumor activity and inhibit tumor growth in animal models even at low concentrations. The favorable safety profile due to the good tolerability of these ATACs confirms that they may represent a promising new therapeutic option against prostate cancer.

Details of the poster presentation - CD37 ATACs:
Preclinical evaluation of anti-CD37 Antibody-Targeted Amanitin Conjugates (ATAC) in B-cell malignancies
Abstract number: 915
Date and time: 10 April 2021, 8:30 AM - 12:00 PM EDT
Link to the abstract: https://www.abstractsonline.com/pp8/#!/9325/presentation/1952

The poster shows preclinical data on CD37 ATACs. CD37 is a protein that is overexpressed on B-cell lymphoma cells. The data presented show that CD37-ATACs have high antitumor activity and inhibit the growth of hematologic tumors even at low concentrations. The good tolerability of the different ATACs is a further confirmation that CD37 ATACs may represent a promising therapeutic option against certain B-cell lymphomas.

Details of the poster presentation - immuno-oncology:
Combination of Antibody-Targeted Amanitin Conjugates (ATAC) with Immune checkpoint inhibitors shows synergistic therapeutic effect in vitro and in vivo
Abstract number: 921
Date and time: 10 April 2021, 8:30 AM - 12:00 PM EDT
Link to the abstract: https://www.abstractsonline.com/pp8/#!/9325/presentation/1959

The poster shows preclinical data on the use of ATACs together with immune checkpoint inhibitors. Treatment of cancer cells with ATACs triggers their immunogenic cell death, leading to activation of the immune system. Combining this immunostimulatory property of ATACs with immune checkpoint inhibitors may represent a promising approach for further oncological therapies.

Online poster presentations will be available on the AACR website (https://www.aacr.org/meeting/aacr-annual-meeting-2021/) beginning Saturday, 10 April 2021, 2:30 PM CEST (8:30 AM US EDT).

On the company website, the posters will be available under "Press & Investors > Calendar and Presentations > Scientific Posters" from 16 April 2021.

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. Antibody Targeted Amanitin Conjugates (ATACs) are ADCs whose active ingredient is made up of amatoxin molecules. Amatoxins are small bicyclic peptides naturally occurring in the death cap mushroom. They inhibit mRNA transcription by binding to RNA polymerase II, a mechanism that is crucial for the survival of eukaryotic cells. 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 AG is an oncology company and the first company to develop the toxin Amanitin into cancer therapies using its proprietary Antibody Targeted Amanitin Conjugate (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 for multiple myeloma.

Heidelberg Pharma AG is listed on the Frankfurt Stock Exchange: ISIN DE000A11QVV0/ WKN A11QVV / Symbol HPHA. The More information is available at www.heidelberg-pharma.com.

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.