Paris (France), August 27, 2020 – 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 particular against rare or resistant cancers, today reported the publication in the British Journal of Cancer of the final results of its DRIIV Phase 1 dose escalation study of AsiDNA™, the Company’s first-in-class DDR inhibitor, administered intravenously (IV). DRIIV was instrumental in demonstrating the good safety profile and activity of AsiDNA™ via the IV route. The active dose of 600 mg was determined to be the optimal dose for use in combination and is currently being used in the evaluation of AsiDNA™ in combination with chemotherapies (DRIIV-1b study) and a PARP inhibitor (REVOCAN study).

This open-label, dose-escalation study was conducted at 4 centers in France and Belgium (Institut Curie —Paris, Institut Claudius Régaud IUCT—Oncopôle Toulouse, Centre Léon Bérard—Lyon and Institut Jules Bordet—Brussels).

“I would like to warmly thank the teams at Onxeo and at these four renowned oncology centers who have provided the fastest access to AsiDNA™ to patients in this clinical study that represented a key milestone for Onxeo,” commented Olivier de Beaumont, Chief Medical Officer of Onxeo. “DRIIV demonstrated AsiDNA™’s favorable safety profile and validated its activity in patients’ tumor cells through a robust activation of its biological targets. Most importantly, the optimal active dose of 600 mg was determined and is currently being utilized in our ongoing combination studies. With a unique mechanism of action as decoy agonist, AsiDNA™ has the potential to both synergize with a variety of DNA-damaging agents and to abrogate resistance to targeted therapies such as PARP inhibitors. We now eagerly look forward to reporting in the coming months the topline results from DRIIV-1b, an extension study of DRIIV assessing the clinical interest of AsiDNA™ in combination with carboplatin and paclitaxel, and in early 2021, the initial data from REVOCAN, a phase 1b/2 study designed to show that the addition of AsiDNA™ to niraparib reverse the tumor resistance to this PARP inhibitor in relapsed ovarian cancer.”