Wilex’s Germany-based subsidiary Heidelberg Pharma and Roche have extended an existing 2013 license agreement to apply the antibody drug conjugate (ADC) technology for the further development of Roche antibodies. The aim is to identify and develop novel Antibody Targeted Amanitin Conjugates (ATACs) based on Heidelberg Pharma's patented technology to couple α-Amanitin to antibodies.

Heidelberg Pharma will receive an upfront payment and further regular payments for granting access to its technology and providing research services to Roche, which has the opportunity to exercise options for licenses to develop and market selected ATACs. Heidelberg Pharma will manufacture these substances for clinical research and receive undisclosed milestone payments and royalties for each development candidate selected.

Furthermore, exclusive rights to one additional undisclosed tumor target will be granted to Roche. For this target, Heidelberg Pharma could potentially receive up to $66.4 million in upfront and milestone payments for successful clinical development and regulatory approval plus royalties.

α-Amanitin is a bicyclic peptide naturally occurring in the green Death Cap mushroom. It potently inhibits the biosynthesis of RNA, a mechanism that is critical for the survival of 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. The ATACs tested so far have shown strong anti-tumor activity in several preclinical tumor models.