• OX425 is a novel DDR Decoy Agonist which also mediates multiple immunostimulatory effects, making it a promising candidate for combination with immunotherapy, especially in “cold” tumors
• Late-stage preclinical development confirms high antitumor activity with activation of the STING pathway in multiple tumor models
• Ongoing toxicology studies with OX425 demonstrate favourable safety profile making it a promising candidate for monotherapy and potential combination-based therapy

Paris (France), November 30, 2022 – 6:00 p.m. CET – Onxeo S.A. (Euronext Growth Paris: ALONX), hereafter “Onxeo” or the “Company”, a clinical-stage biotechnology company specializing in the development of innovative drugs targeting tumor DNA Damage Response (DDR), today announces the expansion of its pipeline of drug candidates with OX425, the optimized new compound of OX400 series sourced from its proprietary PlatON™ platform.

OX425 is a new-generation decoy oligonucleotide (ODN) with a well differentiated mechanism of action from PARP inhibitors as it drives PARP-1 hyperactivation and leads to exhaustion of the DNA damage response, ultimately killing cancer cells. In addition, it also leads to activation of the STING pathway. In preclinical proof-of-concept studies performed to date, OX425 demonstrated high antitumor activity while sparing healthy cells. It also showed the ability to mediate multiple immunostimulatory effects, standing out as promising option for potential combination with immunotherapy, especially in tumors that are not attackable by the immune system (“cold” tumors).

Like the other drug candidates sourced from platON™, such as AsiDNA™, OX425’s benefits from decoy agonist mechanism of action and does not induce tumor resistance to treatment. This profile represents a clear differentiation from other targeted therapies such as PARP inhibitors. Moreover, OX425 shows no activity on healthy cells, which should yield a favorable safety profile in the clinical setting.

Based on these promising results, Onxeo will complete the preclinical development with the objective to file an Investigational New Drug (IND) with the FDA in mid of 2023.

Dr. Shefali Agarwal, President and CEO of Onxeo, stated: “With the selection of OX425, we demonstrate once again our ability to source new drug candidates with distinctive properties based on the unique decoy mechanism of action which is the technological engine of our PlatON™ platform. OX425 showed robust antitumor activity during our preclinical studies in multiple solid tumor models from different indications. OX425 is thus positioned as an innovative monotherapy and an ideal candidate for partnering, particularly in combination with immunotherapies, and specifically in cold tumors.”

• OX425 is a novel DDR Decoy Agonist which also mediates multiple immunostimulatory effects, making it a promising candidate for combination with immunotherapy, especially in “cold” tumors
• Late-stage preclinical development confirms high antitumor activity with activation of the STING pathway in multiple tumor models
• Ongoing toxicology studies with OX425 demonstrate favourable safety profile making it a promising candidate for monotherapy and potential combination-based therapy

Paris (France), November 30, 2022 – 6:00 p.m. CET – Onxeo S.A. (Euronext Growth Paris: ALONX), hereafter “Onxeo” or the “Company”, a clinical-stage biotechnology company specializing in the development of innovative drugs targeting tumor DNA Damage Response (DDR), today announces the expansion of its pipeline of drug candidates with OX425, the optimized new compound of OX400 series sourced from its proprietary PlatON™ platform.

OX425 is a new-generation decoy oligonucleotide (ODN) with a well differentiated mechanism of action from PARP inhibitors as it drives PARP-1 hyperactivation and leads to exhaustion of the DNA damage response, ultimately killing cancer cells. In addition, it also leads to activation of the STING pathway. In preclinical proof-of-concept studies performed to date, OX425 demonstrated high antitumor activity while sparing healthy cells. It also showed the ability to mediate multiple immunostimulatory effects, standing out as promising option for potential combination with immunotherapy, especially in tumors that are not attackable by the immune system (“cold” tumors).

Like the other drug candidates sourced from platON™, such as AsiDNA™, OX425’s benefits from decoy agonist mechanism of action and does not induce tumor resistance to treatment. This profile represents a clear differentiation from other targeted therapies such as PARP inhibitors. Moreover, OX425 shows no activity on healthy cells, which should yield a favorable safety profile in the clinical setting.

Based on these promising results, Onxeo will complete the preclinical development with the objective to file an Investigational New Drug (IND) with the FDA in mid of 2023.

Dr. Shefali Agarwal, President and CEO of Onxeo, stated: “With the selection of OX425, we demonstrate once again our ability to source new drug candidates with distinctive properties based on the unique decoy mechanism of action which is the technological engine of our PlatON™ platform. OX425 showed robust antitumor activity during our preclinical studies in multiple solid tumor models from different indications. OX425 is thus positioned as an innovative monotherapy and an ideal candidate for partnering, particularly in combination with immunotherapies, and specifically in cold tumors.”