NOX66, a novel investigational product containing the active ingredient idronoxil, is under investigation as a chemo- and radio-sensitizing agent across multiple therapy combinations and tumour types. It is hypothesised, with pre-clinical evidence supporting the hypothesis, that NOX66 can prevent DNA repair within tumour cells following administration of radiotherapy. As such, dosing of NOX66 in combination with palliative dose radiotherapy may provide therapeutic response whilst minimising the adverse events associated with higher doses of radiotherapy. This phase 1 dose escalation study will investigate the safety of multiple dose levels of NOX66 and establish the appropriate dose level for future research.
Patients with end stage metastatic prostate cancer will be allocated to ascending dose cohorts of NOX66 in combination with palliative dose radiotherapy (20Gy across 5 fractions). NOX66 dosing commences on Day 1, with radiotherapy administered on 5 consecutive working days from Day 2. NOX66 treatment continues daily until 7 days following the final dose of radiotherapy. Dose escalation will be determined upon safety review following the two-week treatment period of all patients within a cohort. Three dose escalation cohorts (400mg, 800mg, 1200mg) are planned, with four patients per cohort with assessment of response using PMSA-PET/CT scans and PSA levels performed at week 6, week 12 and week 24. Data collected at week 6 for the dose escalation cohorts, in combination with safety assessments, will determine the dose for the remaining patients in the study. Recruitment is due to commence in September 2017 at centres across Australia and New Zealand. Preliminary safety data for the first dose escalation cohorts will be presented at this conference.