US-patent office granted patent for amatoxin conjugates for tumour therapy

The WILEX AG (ISIN DE000A11QVV0 / WL6 / FSE) today announced that an important patent for its own ADC technology for the manufacture of Antibody Amanitin Conjugates was granted in the USA. The patent is named “Amatoxin armed therapeutic cell surface binding components designed for tumor therapy” and was submitted by Prof Dr Heinz Faulstich and employees of the German Cancer Research Centre (DKFZ). Heidelberg Pharma exclusively in-licensed the patent in December 2009.

The subject matter of the patent is the chemical reaction to crosslink certain carrier molecules, e.g. antibodies, to amatoxins. Amatoxins are natural poisons occurring in, for example, the death cap mushroom (Amanita phalloides). Heidelberg Pharma is the first company worldwide to work with the corresponding toxin Amanitin to develop Antibody Targeted Amanitin Conjugates (ATACs) for the use in cancer therapy.

Amanitin is known in oncology for its unique mode of action: the inhibition of RNA polymerase II, which leads the cells to programmed cell death (apoptosis) independent from cell division. This offers the opportunity to treat therapy-resistant tumours and kill quiescent tumour cells, which could result in significant clinical progress.

The chemical linkage to natural Amanitin is only possible at certain positions without loss of efficacy of the molecule. The granted US-patent protects the use of positions for the ATAC technology which are chemically easy to access and which produce the biologic function of the Amanitin.

Dr Jan Schmidt-Brand, Spokesman of the Executive Management Board of WILEX AG, comments: “This patent strengthens our position and, along with other patents and patent applications, is an important component in protecting our outstanding ATAC technology. Our goal is to develop highly effective and innovative cancer therapies with this interesting toxin Amanitin, both with pharma partners as well as developing our own ATAC candidates.”

About Heidelberg Pharma’s proprietary ATAC technology
Antibody-drug conjugates (ADCs) combine the high affinity and specificity of antibodies with the potential of small cytotoxic molecules for the treatment of cancer and inflammatory diseases. ATACs are ADCs based on highly potent amatoxin payloads. Amatoxins are small bicyclic peptides naturally occurring in the Green Death Cap mushroom. Mode of action of amatoxins is the inhibition of mRNA transcription by binding to RNA polymerase II, a mechanism that is crucial for the survival of eukaryotic cells. Accordingly, ATACs exhibit comparable activity against proliferating and resting tumor cells. This proliferation independent activity differentiates ATACs from other ADCs, which preferentially target proliferating tumor cells. As an additional advantage ATACs could offer a substantial capability to overcome the resistance mechanisms that might limit the efficacy of other antibody drug conjugates.

About WILEX and Heidelberg Pharma
WILEX AG is a biopharmaceutical company which has a ready for partnering portfolio of antibody-based diagnostic and therapeutic Phase III product candidates for the detection and targeted treatment of clear cell renal cell carcinoma. Research and development focus on the operations of its subsidiary Heidelberg Pharma GmbH in Ladenburg, which primarily advances the development of the innovative platform technology for antibody drug conjugates (ADC technology) and provides pre-clinical drug discovery and development services. WILEX is listed at the Frankfurt Stock Exchange: ISIN DE000A11QVV0 / WKN A11QVV / Symbol WL6. More information is available at

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02.02.2016 - 08:00