2 OCT., 2017

• PlatON™ will generate new best-in-class DNA-targeting drug candidates starting in 2018
• In parallel, the Company advances its robust development programs for AsiDNA™ and belinostat, supported by recent promising combination data and preliminary clinical data expected in 2018
• Company is well-financed into early 2020, with the resources to support the current clinical development plan

Paris (France), October 2, 2017 – 07:00 am CEST– Onxeo S.A. (Euronext Paris, NASDAQ Copenhagen: ONXEO), (“Onxeo” or the “Company”), a French biotechnology company specializing in the development of innovative drugs in oncology, in particular orphan cancers, today introduced its proprietary chemistry platform of decoy oligonucleotides, platON™.

PlatON™ is a proprietary chemistry platform of decoy oligonucleotides based on three components, a sequence of double strand oligonucleotides, a linker and a cellular uptake facilitator. This platform and its potential applications are fully protected by a patent family encompassing notably US patent # 9,687,557 granted in June 2017.

Each of these three components is modifiable to generate various compounds expressing different properties and/or activities, with the common feature of targeting tumor DNA repair pathways through a decoy mechanism.

AsiDNA™, Onxeo’s first-in-class DNA break repair inhibitor, represents the first drug candidate generated from platON™. It has already undergone a convincing phase I clinical trial via intratumoral administration and demonstrated a very promising in-vivo efficacy profile via systemic administration.

The Company intends to leverage platON™ to expand its pipeline with additional innovative DNA-targeting drug candidates and expects to initiate the preclinical evaluation of a new drug candidate as soon as the first half of 2018.

“We are very excited about the potential of platON™, a truly unique platform of decoy oligonucleotides,” said Françoise Bono, Chief Scientific Officer of Onxeo. “As we continue to advance our two lead candidates, AsiDNA™ and oral belinostat, towards clinical development, platON™ will be generating new and unique compounds which will expand our pipeline in the highly sought-after field of DNA-targeting. We will apply our deep translational expertise, particularly in the field of oligonucleotides, to lead the preclinical and clinical development of these new compounds in the best possible way and demonstrate their potential in cancer treatment.”

Onxeo’s strategy is to advance the development of drug candidates to proof of concept in man (phase I/phase II), the most relevant inflection points in terms of value creation for Onxeo before licensing them out.

Onxeo’s current pipeline includes two lead products, AsiDNA™, and belinostat, a potent histone deacetylase inhibitor (HDACi). Their underlying mechanisms of action, DNA-targeting and epigenetics, are among the most attractive today for pharmaceutical companies, garnering significant deal values for the past three years^[1].

 “Our two drugs in development are based on the emerging areas of DNA-targeting and epigenetics, which are among the most promising approaches in cancer treatment research for both the pharmaceutical industry and academia today,” said Judith Greciet, Chief Executive Officer of Onxeo. “This strategic focus should enable Onxeo to create significant shareholder value in the short-term, and well into the future. In the coming quarters, we will be focused on building the most compelling data packages, including proof of concept in man, for AsiDNA™ and belinostat, alone or in combination with other anti-cancer agents, thereby creating multiple partnering opportunities. We have a sound financial visibility sufficient to cover clinical operations until early 2020, far beyond the next planned clinical milestones.”