DGAP-News: Heidelberg Pharma Announces Several Presentations of Research Results on ATAC Technology at the ASH Annual Meeting 2020

PRESS RELEASE

Heidelberg Pharma Announces Several Presentations of Research Results on ATAC Technology at the ASH Annual Meeting 2020

- Heidelberg Pharma presents the design for the planned clinical study with HDP-101

- Partner MD Anderson Cancer Center presents in an oral presentation preclinical data with HDP-101 on the induction of an immune response against multiple myeloma by HDP-101

- Licensing partner Magenta presents further preclinical data on the ATAC candidate MGTA-117

Ladenburg, Germany, 5 November 2020 - Heidelberg Pharma AG (FSE: HPHA) today announced that it will present the design for the planned clinical trial with HDP-101 at the 62^nd Annual Meeting of the American Society of Hematology (ASH). In addition, partners MD Anderson Cancer Center, Houston, TX, USA, (MD Anderson) and Magenta Therapeutics, Cambridge, MA, USA, (Magenta) (NASDAQ: MGTA) will present data on the ATAC technology. The conference will take place from 5^th to 8^th December 2020 in a virtual format.

Prof. Andreas Pahl, CSO of Heidelberg Pharma AG, commented: "We are very pleased to present the design of our first clinical study with an Antibody Targeted Amanitin Conjugate (ATAC) at this important conference. The study will be conducted with the BCMA-ATAC HDP-101 in the indication of multiple myeloma. The design has already been discussed in a Pre-IND meeting with the U.S. Food and Drug Administration (FDA), and the submission of the study application to the FDA is expected to follow shortly. Developing a candidate to first in human is a complex process and the IND is an important milestone for us."

Poster title: A First in Human Study Planned to Evaluate HDP-101, an Anti-BCMA Amanitin Antibody-Drug Conjugate with a New Payload and a New Mode of Action, in Multiple Myeloma

Presentation details
Abstract #3230
Session Name: 653. Myeloma: Therapy, excluding Transplantation: Poster III
Session Date: Monday, 7^th December 2020
Poster hall: On 7^th December 2020 the poster will be available in the virtual poster hall from 7:00 am - 03:00 pm PST (04:00 pm - 10:00 pm CET)

Dr. András Strassz, Senior Medical Officer of Heidelberg Pharma AG, will present the study design of the planned clinical Phase I trial with HDP-101 in a recorded presentation and will then be available to answer questions virtually.

HDP-101, an Antibody Targeted Amanitin Conjugate, consists of a BCMA antibody, a specific linker and the toxin Amanitin. Heidelberg Pharma is working towards developing a novel approach to cancer treatment that focuses on the unique biological mode of action of Amanitin, a mushroom toxin. Amanitin works by inhibiting RNA polymerase II, which results in programmed cell death, or apoptosis. RNA polymerase inhibition is a novel principle in cancer therapy and offers the possibility of breaking through drug resistance and destroying dormant tumor cells, which could produce major clinical advances.

Oral presentation of MD Anderson

Previous studies with myeloma cell lines and primary patient samples showed that Amanitin has the potential to be particularly effective on tumors with aggressive progression associated with 17p deletion. Here, the section on a chromosome 17 is missing that contains the tumor suppressor gene TP53, which gives tumor cells a survival advantage. In addition, the gene for RNA polymerase II is also affected by the deletion, which means that less RNA polymerase II is produced by these tumor cells and they are particularly sensitive to Amanitin. In their presentation, MD Anderson will present new preclinical data confirming the earlier results as well as new findings on the induction of a specific immune response against multiple myeloma cells by HDP-101.

Title: The Anti-B-Cell Maturation Antigen (BCMA) Antibody-α-Amanitin Conjugate HDP-101 Induces Immunogenic Cell Death and Immunologic Memory in Models of Multiple Myeloma

Abstract #668
Session Name: 652. Myeloma: Pathophysiology and Pre-Clinical Studies, excluding Therapy
Presenter: Dr. Ram Kumar Singh, Department of Lymphoma/Myeloma, MD Anderson Cancer Center
Date: Monday, 7^th December 2020
Session time: 11:30 am - 01:00 pm PST (08:30 pm - 10:00 pm CET)
Presentation time: 12:15 pm PST (09:15 pm CET)

Poster presentations from our licensing partner Magenta

Poster title: A Single Dose of a Novel Anti-Human CD117-Amanitin ADC Engineered for a Short Half-life Provides Dual Conditioning and Anti-Leukemia Activity and Extends Survival Compared to Standard of Care in Multiple Pre-Clinical Models of Acute Myeloid Leukemia (AML)

Presentation details

Abstract #1044
Session Name: 616. Acute Myeloid Leukemia: Novel Therapy, excluding Transplantation: Poster I
Session Date: Saturday, 5^th December 2020
Poster hall: On 5^th December 2020 the poster will be available in the virtual poster hall from 7:00 am - 03:30 pm PST (04:00 pm - 10:30 pm CET)

All abstracts and further information will be available online on the ASH conference website from 5^th November and will be published online in the November 2020 supplement of the journal "Blood".

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 a biopharmaceutical company based in Ladenburg, Germany. Heidelberg Pharma is an oncology specialist 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. This proprietary technology platform is being applied to develop the Company's proprietary therapeutic ATACs, as well as in third-party collaborations, to create a variety of ATAC candidates. The proprietary lead candidate is HDP-101, a BCMA ATAC for multiple myeloma.

The Company has entered into partnerships to further develop and commercialize its clinical assets upamostat (formerly MESUPRON^(R)) and TLX250-CDx (formerly REDECTANE^(R)). Heidelberg Pharma AG is listed on the Frankfurt Stock Exchange: ISIN DE000A11QVV0 / WKN A11QVV / Symbol HPHA. More information is available at www.heidelberg-pharma.com.

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