Onxeo S.A (CPH:ONXEO) (Paris:ONXEO), a clinical-stage biotechnology company, announced on Monday a new milestone in the clinical development of AsiDNA with the treatment of the first patient in DRIIV-1b.

The company said DRIIV-1b is a phase 1b clinical study of AsiDNA, a first-in-class tumour DNA repair inhibitor, in combination with carboplatin and with carboplatin plus paclitaxel, in patients with solid tumours eligible to such treatments.

DRIIV-1b is an extension of the DRIIV-1 (DNA Repair Inhibitor administered I ntraVenously) phase 1 study currently being completed, in which AsiDNA, administered intravenously (IV) demonstrated its intratumoral activity by inducing a significant increase in its activity biomarkers in the tumour cells of patients, with a favourable safety profile at various active doses.

Reportedly, at the active dose of 600 mg, among the three patients included in the cohort, two patients with relapsed, multi-treated metastatic colorectal cancer were controlled with medical imaging, which showed no further disease progression after the second treatment cycle and continued their treatment with AsiDNA for three months. The 600 mg active dose was considered to be optimal for further development of AsiDNA in combination with chemotherapy.

According to Onxeo, DRIIV-1b aims at showing the safety and efficacy of a 600 mg dose of AsiDNA in combination with carboplatin and carboplatin plus paclitaxel, in up to 18 patients with solid tumours eligible for such treatments (lung, breast, ovarian or head and neck cancers). The efficacy of the combinations will be evaluated every six to eight weeks by medical imaging in accordance with RECIST criteria (Response evaluation criteria in solid tumours). This study will take place in Belgium, and initial results are expected in the second half of 2019.

Onxeo added that this first combination trial represents a major milestone in the clinical development of AsiDNA. As a result of the highly differentiated mechanism of action, confirmed by exhaustive preclinical studies, the combination of AsiDNA with various anti-cancer treatments appears especially relevant to increase their efficacy and avoid the occurrence of resistance from tumours.

Onxeo developing innovative oncology drugs targeting tumour DNA-binding functions through unique mechanisms of action in the sought-after field of DNA Damage Response (DDR), in particular against rare or resistant cancers.