Safety and Tolerability of NOX66 in Combination With Palliative Radiotherapy in Patients With Late-Stage Prostate Cancer

This study will investigate three escalating doses of NOX66 in combination with palliative dose of radiation therapy to establish safety profile and / or obtain efficacy signals and to determine the optimal dose for future radiation therapy combination studies. The key hypotheses to be tested in this study are: 1. That NOX66 can be safely added to palliative dose radiation therapy. 2. That NOX66 may sensitise tumours to palliative doses of radiation therapy 3. That NOX66 in combination with radiation therapy may trigger or augment an abscopal effect Participants will have a minimum of 1 symptomatic lesion amenable to radiation therapy. Radiation therapy will be delivered at a 20Gy dosage over 5 fractions. NOX66 will be taken on 13 consecutive days starting 1 day prior to radiotherapy. The response of irradiated and non-irradiated target tumour lesions will be measured by CT/MRI scan and RECIST1.1 criteria at three time points post treatment. Pain response will be evaluated using the Brief Pain Inventory-Short Form (BPI-SF) instrument at five time points post treatment. Patients will be suitable for the study as they become indicated for palliative radiation therapy for management of their cancer. This study will enrol up to 24 patients in 3 NOX66 dose level cohorts of 4 patients (n=12) and an expansion cohort of 12 patients. Dose escalation decisions will be based on patients who experience adverse events directly related to NOX66 treatment. Following the review of accumulated safety data, disease status and treatment efficacy signals at WEEK 6 for the first 12 patients, the Study Steering Committee will determine the dose at which to continue treatment for the expansion patient Cohort 4 in the study. A further 12 patients will be recruited at this dose level.