Positive Safety and Activity Results from DRIIV-1 Led to Initiation of Ongoing DRIIV-1b Phase 1b Study of AsiDNA™ in Combination with Chemotherapy

Paris (France), October 15, 2019 – 6:00 pm CEST – Onxeo S.A. (Euronext Paris, NASDAQ Copenhagen: ONXEO), (“Onxeo” or “the Company”), a clinical-stage biotechnology company specializing in the development of innovative drugs targeting tumor DNA Damage Response (DDR) in oncology, in particular against rare or resistant cancers, today announced that the Company will present the final results of its DRIIV-1 Phase 1 study of AsiDNA™, the Company’s first-in-class DDR inhibitor, in a poster session on October 27, 2019, during the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics in Boston.

Olivier de Beaumont, Medical Director of Onxeo, commented“DRIIV-1 demonstrated AsiDNA’s favorable safety profile and validated its mechanism of action in patients’ tumor cells through the activation of its biological targets. Most importantly, the optimal active dose of AsiDNA™ of 600 mg was determined and is currently being utilized in our ongoing DRIIV-1b study, which is evaluating AsiDNA™ in combination with chemotherapy. DRIIV-1 was the foundation of our clinical development strategy for AsiDNA™ via intravenous administration and we look forward to presenting and discussing the compelling results of this important study, as well as reviewing our anticipated next steps, with the international oncology community.”

The poster, titled “Phase I dose escalation study evaluating the safety, pharmacokinetics (PK) and pharmacodynamics (PD) of AsiDNA, a first-in-class DNA Repair Inhibitor, administered intravenously (IV) in patients with advanced solid tumors,” will be presented by Professor Christophe Le Tourneau, principal investigator of the study and Head of the Department of Drug Development and Innovation at the Curie Institute (Paris, France).