PR: Heidelberg Pharma Presents New Preclinical Data from its Proprietary ATAC Technology Platform at AACR Annual Meeting 2023

Ladenburg, Germany, 4^th April 2023 – Heidelberg Pharma AG (FSE: HPHA) will present data from preclinical studies at this year's American Association for Cancer Research (AACR) annual meeting that provide positive evidence of the efficacy and tolerability of the company's proprietary ATAC technology. Heidelberg Pharma is active in cancer research and works with antibody drug conjugates (ADCs) that use the toxin Amanitin as payload. The meeting will be held in Orlando, Florida, USA, from 14^th to 19^th April 2023.

Details of the poster presentation:

Subcutaneous dosing increases the therapeutic index of Amatoxin-based ADCs

The study investigated how the pharmacokinetics, tolerability and efficacy of different ATACs are affected by the route of administration (subcutaneous versus intravenous). While intravenous dosing is the common administration method for marketed ADCs, subcutaneous dosing in general has pharmacokinetic advantages and is preferable for patients. Subcutaneous (s.c.) dosing of ATACs was shown to result in prolonged half-life and lower maximal serum levels in preclinical models compared with intravenous (i.v.) administration. Both factors resulted in improved tolerability of the ATACs. At the same time, antitumor efficacy in a xenograft model using human cancer cell lines was comparable after s.c. or i.v. administration.

The improved tolerability combined with consistent efficacy resulted in an improved therapeutic index of the candidate HDP-103. The present study demonstrates that s.c. dosing not only refines the pharmacokinetic distribution of ATACs but also can improve the therapeutic index. Thus, s.c. dosing may represent a promising route of administration for ATACs in humans as well.

Details of the poster presentation:

Amanitin-based ADCs targeting Guanylyl cyclase C (GCC) as novel therapeutic modality for treatment of colorectal cancer

The poster presentation will cover preclinical data on ATACs targeting GCC (guanylyl cyclase C). This surface protein is overexpressed in many gastrointestinal tumors, and most notably in colorectal cancer. Due to its specific expression profile, GCC represents an exceptionally tumor-specific target. ATACs directed against GCC possess high antitumor activity and inhibit tumor growth in preclinical models even at low concentrations after single or multiple dose treatment. The favorable safety profile due to the good tolerability of these ATACs confirms that they may represent a promising new therapeutic option against colorectal cancer.

Poster presentations can be found from 18^th April 2023, on the company website in the "Research & Development > Scientific Posters" section.