Paris (France), September 1^st, 2022 – 8 pm CEST – Onxeo S.A. (Euronext Growth: ALONX, Nasdaq First North[1]: ONXEO), a clinical-stage biotechnology company specializing in the development of innovative drugs targeting tumor DNA Damage Response (DDR)n in particular against rare or resistant forms of cancer, today announced that the first patient has been enrolled and treated in the phase 1b/2 clinical study that aims to evaluate the efficacy and tolerability of AsiDNA[2], Onxeo’s first-in-class DDR inhibitor, combined with radiotherapy in children, adolescents or young adults with relapsed High-Grade Glioma (HGG). The clinical validation of this innovative therapy offers the hope of providing better care and treatment for these high-risk pediatric cancers.

High Grade Gliomas (HGG), which represents approximately 20% of tumors of the central nervous system (CNS) in children, continue to have a very poor prognosis with a 5-year survival rate of less than 20%. Surgery combined with radiotherapy or chemotherapy often allows the disease to be controlled. However, this disease control is not durable due to the development of treatment-resistant tumor cells. Studies conducted in preclinical models as well as initial clinical trials conducted in adults[3] have highlighted AsiDNA’s synergetic effect when combined with treatments that target and destroy the DNA, such as radiotherapy.

This phase 1b/2 trial, sponsored by Institut Curie, is being conducted within the framework of the European ITCC[4] consortium, in order to evaluate AsiDNA’s efficacy and tolerability by enrolling a maximum of 32 patients (children, adolescents or young adults) with relapsed HGG. A first patient has been enrolled in the study at the Institut Curie’s SIREDO (Soins, Innovation, Recherche en cancérologie de l’Enfant, l’aDOlescent et l’adulte jeune, i.e. care, innovation, research in cancer in children, adolescents and young adults) Center. Additionally, other French centers as well as European countries are planned to be initiated in the coming months. The study’s first interim results are projected in the first quarter of 2024.

Shefali Agarwal, Onxeo’s President and Chief Executive Officer, stated: “Onxeo is proud of its clinical collaboration with Institut Curie, and would like to thank Professor François Doz – the study’s lead investigator – for his involvement in this project. We hope that the combination of AsiDNA and radiotherapy in this type of cancer will provide a real benefit to patients suffering from a recurrent form of high-grade glioma”.

“The enrollment of the first patient is a major step in this proof-of-concept study whose goal is to evaluate the efficacy and good tolerability of the systemic administration of AsiDNA in combination with a new radiotherapy.  We hope that this study will provide encouraging evidence enabling an improvement in the prognostic outcome of a disease that is a key unmet need”, added Prof. François Doz, pediatric oncologist, deputy head of clinical research, innovation and teaching at Institut Curie’s SIREDO Center and this study’s lead investigator.

This phase 1b/2 study is supported by a grant from the European Fight Kids Cancer^[5] program.

[1] The company reminds shareholders that the delisting of Onxeo shares from the First North Growth market in Copenhagen has been approved and the last day of trading on this market will be November 8, 2022. The company will keep its primary listing on Euronext Growth Paris.

[2] In 2016, Onxeo acquired DNA Therapeutics, a spin-off of Institut Curie building on the innovative work of Marie Dutreix, CNRS research director research at Institut Curie, which led to the development of AsiDNA.

[3] “First-in-human phase I study of the DNA repair inhibitor DT01 in combination with radiotherapy in patients with skin metastases from melanoma.” Le Tourneau C et al. Br J Cancer. 2016 May 24;114(11):1199-205.

[4] The Innovative Therapies for Children with Cancer (ITCC) consortium is a non-profit organization incorporating 63 European pediatric oncology departments with expertise in conducting early-stage trials in children and adolescents and 25 European research laboratories.

[5] Fight Kids Cancer is a European call for projects, a joint initiative of France’s Imagine for Margo association, Belgium’s KickCancer foundation and Luxembourg’s Kriibskrank Kanner foundation.