Onxeo to Present New Preclinical Data at AACR 2021

  • Confirming the effect of AsiDNA™ on resistance to KRAS inhibitors
  • Introducing OX400, a new generation of PARP interfering cancer drug candidates


Paris (France), April 8, 2021 – 6:00 pm CEST - Onxeo S.A. (Euronext Growth Paris: ALONX, First North Copenhagen: ONXEO), (“Onxeo” or “the Company”), a clinical-stage biotechnology company specializing in the development of innovative drugs targeting tumor DNA Damage response (DDR), today announced the presentation of preclinical data confirming the differentiated antitumoral properties of the drug candidates generated by platON™, its patent-protected platform of decoy-agonists of the DNA Damage Response, in e-poster sessions during the American Association for Cancer Research (AACR 2021) virtual annual meeting on April 10, 2021.

The first e-poster supports the ability of AsiDNA™, the Company’s first-in-class DNA Damage Response (DDR) inhibitor, to prevent resistance to KRAS inhibitors (KRASi) emerging from drug-tolerant persister cells (DTC). Novel therapies targeting the inhibition of KRAS, an oncogenic protein present in a third of cancers, have shown very promising clinical results especially in non-small cell lung cancer. However, acquired resistance hinders their efficacy. Combining AsiDNA™ to KRASi could be an additional development opportunity for AsiDNA™, in the context of its use to prevent acquired resistance to targeted therapies.

The second e-poster describes the mechanism of action of the molecules of the new OX400 family, specifically designed to interfere with PARP signaling and display immunomodulatory properties and metabolic effects.

Judith Greciet, Chief Executive Officer of Onxeo, commented: “Pharmaco-tolerant cells are a well-established cause of resistance to TKIs, and, as we already demonstrated last year, to PARP inhibitors. We have generated new data demonstrating that these cells are also involved in resistance to KRAS inhibitors and confirmed the efficacy of AsiDNA™ on these cells thus preventing or even reversing tumor regrowth. These results open the door for another potential combination with these innovative compounds which show high efficiency but struggle with resistance issues. In parallel, we continue to optimize the efficacy profile of the next candidates from the OX400 family, while keeping the established benefits shared by all our platON™-sourced compounds in terms of safety and absence of resistance. Our new results confirm that, by trapping and exhausting specifically PARP, OX400 compounds have the potential to modulate the immune response and wear out the tumor cell metabolism. We will continue to explore these original properties.”


Session:                PO.ET03.05 - Reversal of Drug Resistance                                                                E-poster:           1433

Date/ Time:        April 10, 2021 – 8:30 AM - 11:59 PM (U.S. Eastern Daylight Time -EDT)

To read the abstract: Acquired resistance to KRASG12C inhibitors evolves from drug-tolerant persister cells vulnerable to AsiDNA™.

Recent progress has been made in the development of therapeutics against KRASG12C mutated tumors, which represent approximately 15% of lung adenocarcinoma. However, therapeutic resistance to KRASG12C inhibition is still a clinical hurdle. As we have previously shown with PARP inhibitors, we describe in these new data that resistance to KRASG12C inhibitors could also emerge, at least in part, from drug-tolerant persister cells, a specific cell population that undergo “dormancy” during treatment and accumulate mutations enabling the development of resistance to KRASG12C inhibitors. AsiDNA™ can target specifically this source of resistance and therefore prevents the emergence of acquired resistance to KRASG12C inhibitors, pointing to the therapeutic opportunity of combining AsiDNA and KRASG12C to overcome tumor progression or relapse.

Session:                PO.CL06.07 - Immunomodulatory Agents and Interventions                             E-poster:           527

Date/ Time:        April 10, 2021 - 8:30 AM – 11:59 PM (U.S. Eastern Daylight Time -EDT)

To read the abstract:  A new generation of PARP interfering drug candidates for cancer treatment.

Onxeo pioneered a new approach of anti-cancer treatment to tackle acquired drug resistance: the decoy agonist mechanism of action. Drugs based on this mechanism hijack and hyperactivate therapeutic targets leading to an impairment of their physiological function. Our first compound using this breakthrough decoy agonist action, AsiDNA™, has already shown target engagement, excellent safety profile in humans and importantly, lack of acquired resistance. We now describe the mechanism of action of our OX400 molecules, designed to trap PARP proteins. We show that these molecules, by interfering with PARP signaling, display immunomodulatory properties and metabolic effects. Our results provide a preclinical rationale for using OX400 molecules as immunomodulatory and “metabolic exhauster” agents, especially in appropriately molecularly selected patients with tumors showing metabolic deficiencies.